---
_id: '14697'
acknowledged_ssus:
- _id: LifeSc
- _id: Bio
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Julian A
  full_name: Stopp, Julian A
  id: 489E3F00-F248-11E8-B48F-1D18A9856A87
  last_name: Stopp
citation:
  ama: 'Stopp JA. Neutrophils on the hunt: Migratory strategies employed by neutrophils
    to fulfill their effector function. 2023. doi:<a href="https://doi.org/10.15479/at:ista:14697">10.15479/at:ista:14697</a>'
  apa: 'Stopp, J. A. (2023). <i>Neutrophils on the hunt: Migratory strategies employed
    by neutrophils to fulfill their effector function</i>. Institute of Science and
    Technology Austria. <a href="https://doi.org/10.15479/at:ista:14697">https://doi.org/10.15479/at:ista:14697</a>'
  chicago: 'Stopp, Julian A. “Neutrophils on the Hunt: Migratory Strategies Employed
    by Neutrophils to Fulfill Their Effector Function.” Institute of Science and Technology
    Austria, 2023. <a href="https://doi.org/10.15479/at:ista:14697">https://doi.org/10.15479/at:ista:14697</a>.'
  ieee: 'J. A. Stopp, “Neutrophils on the hunt: Migratory strategies employed by neutrophils
    to fulfill their effector function,” Institute of Science and Technology Austria,
    2023.'
  ista: 'Stopp JA. 2023. Neutrophils on the hunt: Migratory strategies employed by
    neutrophils to fulfill their effector function. Institute of Science and Technology
    Austria.'
  mla: 'Stopp, Julian A. <i>Neutrophils on the Hunt: Migratory Strategies Employed
    by Neutrophils to Fulfill Their Effector Function</i>. Institute of Science and
    Technology Austria, 2023, doi:<a href="https://doi.org/10.15479/at:ista:14697">10.15479/at:ista:14697</a>.'
  short: 'J.A. Stopp, Neutrophils on the Hunt: Migratory Strategies Employed by Neutrophils
    to Fulfill Their Effector Function, Institute of Science and Technology Austria,
    2023.'
date_created: 2023-12-18T19:14:28Z
date_published: 2023-12-20T00:00:00Z
date_updated: 2023-12-21T14:30:02Z
day: '20'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: GradSch
- _id: MiSi
doi: 10.15479/at:ista:14697
ec_funded: 1
file:
- access_level: closed
  checksum: 457927165d5d556305d3086f6b83e5c7
  content_type: application/pdf
  creator: jstopp
  date_created: 2023-12-20T09:35:34Z
  date_updated: 2023-12-20T09:35:34Z
  embargo: 2024-12-20
  embargo_to: open_access
  file_id: '14699'
  file_name: Thesis.pdf
  file_size: 51585778
  relation: main_file
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  checksum: e8d26449ac461f5e8478a62c9507506f
  content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
  creator: jstopp
  date_created: 2023-12-20T09:35:35Z
  date_updated: 2023-12-20T10:41:42Z
  file_id: '14700'
  file_name: Thesis.docx
  file_size: 69625950
  relation: source_file
file_date_updated: 2023-12-20T10:41:42Z
has_accepted_license: '1'
language:
- iso: eng
month: '12'
oa_version: Published Version
page: '226'
project:
- _id: 2564DBCA-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '665385'
  name: International IST Doctoral Program
publication_identifier:
  isbn:
  - 978-3-99078-038-1
  issn:
  - 2663 - 337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
  record:
  - id: '6328'
    relation: part_of_dissertation
    status: public
  - id: '7885'
    relation: part_of_dissertation
    status: public
  - id: '12272'
    relation: part_of_dissertation
    status: public
  - id: '14274'
    relation: part_of_dissertation
    status: public
  - id: '14360'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Michael K
  full_name: Sixt, Michael K
  id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
  last_name: Sixt
  orcid: 0000-0002-6620-9179
title: 'Neutrophils on the hunt: Migratory strategies employed by neutrophils to fulfill
  their effector function'
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2023'
...
---
_id: '12401'
abstract:
- lang: eng
  text: "Detachment of the cancer cells from the bulk of the tumor is the first step
    of metastasis, which\r\nis the primary cause of cancer related deaths. It is unclear,
    which factors contribute to this step.\r\nRecent studies indicate a crucial role
    of the tumor microenvironment in malignant\r\ntransformation and metastasis. Studying
    cancer cell invasion and detachments quantitatively in\r\nthe context of its physiological
    microenvironment is technically challenging. Especially, precise\r\ncontrol of
    microenvironmental properties in vivo is currently not possible. Here, I studied
    the\r\nrole of microenvironment geometry in the invasion and detachment of cancer
    cells from the\r\nbulk with a simplistic and reductionist approach. In this approach,
    I engineered microfluidic\r\ndevices to mimic a pseudo 3D extracellular matrix
    environment, where I was able to\r\nquantitatively tune the geometrical configuration
    of the microenvironment and follow tumor\r\ncells with fluorescence live imaging.
    To aid quantitative analysis I developed a widely applicable\r\nsoftware application
    to automatically analyze and visualize particle tracking data.\r\nQuantitative
    analysis of tumor cell invasion in isotropic and anisotropic microenvironments\r\nshowed
    that heterogeneity in the microenvironment promotes faster invasion and more\r\nfrequent
    detachment of cells. These observations correlated with overall higher speed of
    cells at\r\nthe edge of the bulk of the cells. In heterogeneous microenvironments
    cells preferentially\r\npassed through larger pores, thus invading areas of least
    resistance and generating finger-like\r\ninvasive structures. The detachments
    occurred mostly at the tips of these structures.\r\nTo investigate the potential
    mechanism, we established a two dimensional model to simulate\r\nactive Brownian
    particles representing the cell nuclei dynamics. These simulations backed our
    in\r\nvitro observations without the need of precise fitting the simulation parameters.
    Our model\r\nsuggests the importance of the pore heterogeneity in the direction
    perpendicular to the\r\norientation of bias field (lateral heterogeneity), which
    causes the interface roughening."
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Saren
  full_name: Tasciyan, Saren
  id: 4323B49C-F248-11E8-B48F-1D18A9856A87
  last_name: Tasciyan
  orcid: 0000-0003-1671-393X
citation:
  ama: Tasciyan S. Role of microenvironment heterogeneity in cancer cell invasion.
    2022. doi:<a href="https://doi.org/10.15479/at:ista:12401">10.15479/at:ista:12401</a>
  apa: Tasciyan, S. (2022). <i>Role of microenvironment heterogeneity in cancer cell
    invasion</i>. Institute of Science and Technology Austria. <a href="https://doi.org/10.15479/at:ista:12401">https://doi.org/10.15479/at:ista:12401</a>
  chicago: Tasciyan, Saren. “Role of Microenvironment Heterogeneity in Cancer Cell
    Invasion.” Institute of Science and Technology Austria, 2022. <a href="https://doi.org/10.15479/at:ista:12401">https://doi.org/10.15479/at:ista:12401</a>.
  ieee: S. Tasciyan, “Role of microenvironment heterogeneity in cancer cell invasion,”
    Institute of Science and Technology Austria, 2022.
  ista: Tasciyan S. 2022. Role of microenvironment heterogeneity in cancer cell invasion.
    Institute of Science and Technology Austria.
  mla: Tasciyan, Saren. <i>Role of Microenvironment Heterogeneity in Cancer Cell Invasion</i>.
    Institute of Science and Technology Austria, 2022, doi:<a href="https://doi.org/10.15479/at:ista:12401">10.15479/at:ista:12401</a>.
  short: S. Tasciyan, Role of Microenvironment Heterogeneity in Cancer Cell Invasion,
    Institute of Science and Technology Austria, 2022.
date_created: 2023-01-26T11:55:16Z
date_published: 2022-12-22T00:00:00Z
date_updated: 2024-09-10T12:04:26Z
day: '22'
ddc:
- '610'
degree_awarded: PhD
department:
- _id: GradSch
- _id: MiSi
doi: 10.15479/at:ista:12401
file:
- access_level: open_access
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  date_created: 2023-01-26T11:58:14Z
  date_updated: 2023-12-21T23:30:03Z
  embargo: 2023-12-20
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  content_type: application/x-zip-compressed
  creator: cchlebak
  date_created: 2023-01-26T12:00:10Z
  date_updated: 2023-12-21T23:30:03Z
  embargo_to: open_access
  file_id: '12403'
  file_name: Source Files - Saren Tasciyan - PhD Thesis.zip
  file_size: 261256696
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file_date_updated: 2023-12-21T23:30:03Z
has_accepted_license: '1'
language:
- iso: eng
month: '12'
oa: 1
oa_version: Published Version
page: '105'
publication_identifier:
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
  record:
  - id: '679'
    relation: part_of_dissertation
    status: public
  - id: '10703'
    relation: part_of_dissertation
    status: public
  - id: '7885'
    relation: part_of_dissertation
    status: public
  - id: '9429'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Michael K
  full_name: Sixt, Michael K
  id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
  last_name: Sixt
  orcid: 0000-0002-6620-9179
title: Role of microenvironment heterogeneity in cancer cell invasion
type: dissertation
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
year: '2022'
...
---
_id: '10307'
abstract:
- lang: eng
  text: Bacteria-host interactions represent a continuous trade-off between benefit
    and risk. Thus, the host immune response is faced with a non-trivial problem –
    accommodate beneficial commensals and remove harmful pathogens. This is especially
    difficult as molecular patterns, such as lipopolysaccharide or specific surface
    organelles such as pili, are conserved in both, commensal and pathogenic bacteria.
    Type 1 pili, tightly regulated by phase variation, are considered an important
    virulence factor of pathogenic bacteria as they facilitate invasion into host
    cells. While invasion represents a de facto passive mechanism for pathogens to
    escape the host immune response, we demonstrate a fundamental role of type 1 pili
    as active modulators of the innate and adaptive immune response.
acknowledged_ssus:
- _id: LifeSc
- _id: Bio
- _id: PreCl
- _id: EM-Fac
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Kathrin
  full_name: Tomasek, Kathrin
  id: 3AEC8556-F248-11E8-B48F-1D18A9856A87
  last_name: Tomasek
  orcid: 0000-0003-3768-877X
citation:
  ama: Tomasek K. Pathogenic Escherichia coli hijack the host immune response. 2021.
    doi:<a href="https://doi.org/10.15479/at:ista:10307">10.15479/at:ista:10307</a>
  apa: Tomasek, K. (2021). <i>Pathogenic Escherichia coli hijack the host immune response</i>.
    Institute of Science and Technology Austria. <a href="https://doi.org/10.15479/at:ista:10307">https://doi.org/10.15479/at:ista:10307</a>
  chicago: Tomasek, Kathrin. “Pathogenic Escherichia Coli Hijack the Host Immune Response.”
    Institute of Science and Technology Austria, 2021. <a href="https://doi.org/10.15479/at:ista:10307">https://doi.org/10.15479/at:ista:10307</a>.
  ieee: K. Tomasek, “Pathogenic Escherichia coli hijack the host immune response,”
    Institute of Science and Technology Austria, 2021.
  ista: Tomasek K. 2021. Pathogenic Escherichia coli hijack the host immune response.
    Institute of Science and Technology Austria.
  mla: Tomasek, Kathrin. <i>Pathogenic Escherichia Coli Hijack the Host Immune Response</i>.
    Institute of Science and Technology Austria, 2021, doi:<a href="https://doi.org/10.15479/at:ista:10307">10.15479/at:ista:10307</a>.
  short: K. Tomasek, Pathogenic Escherichia Coli Hijack the Host Immune Response,
    Institute of Science and Technology Austria, 2021.
date_created: 2021-11-18T15:05:06Z
date_published: 2021-11-18T00:00:00Z
date_updated: 2023-09-07T13:34:38Z
day: '18'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: MiSi
- _id: CaGu
- _id: GradSch
doi: 10.15479/at:ista:10307
file:
- access_level: open_access
  checksum: b39c9e0ef18d0484d537a67551effd02
  content_type: application/pdf
  creator: ktomasek
  date_created: 2021-11-18T15:07:31Z
  date_updated: 2022-12-20T23:30:05Z
  embargo: 2022-11-18
  file_id: '10308'
  file_name: ThesisTomasekKathrin.pdf
  file_size: 13266088
  relation: main_file
- access_level: closed
  checksum: c0c440ee9e5ef1102a518a4f9f023e7c
  content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
  creator: ktomasek
  date_created: 2021-11-18T15:07:46Z
  date_updated: 2022-12-20T23:30:05Z
  embargo_to: open_access
  file_id: '10309'
  file_name: ThesisTomasekKathrin.docx
  file_size: 7539509
  relation: source_file
file_date_updated: 2022-12-20T23:30:05Z
has_accepted_license: '1'
language:
- iso: eng
month: '11'
oa: 1
oa_version: Published Version
page: '73'
publication_identifier:
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
  record:
  - id: '10316'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Michael K
  full_name: Sixt, Michael K
  id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
  last_name: Sixt
  orcid: 0000-0002-4561-241X
- first_name: Calin C
  full_name: Guet, Calin C
  id: 47F8433E-F248-11E8-B48F-1D18A9856A87
  last_name: Guet
  orcid: 0000-0001-6220-2052
title: Pathogenic Escherichia coli hijack the host immune response
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2021'
...
---
_id: '6947'
abstract:
- lang: eng
  text: Lymph nodes  are es s ential organs  of the immune  s ys tem where adaptive
    immune responses originate, and consist of various leukocyte populations and a
    stromal backbone. Fibroblastic reticular  cells (FRCs) are  the  main  stromal  cells
    and  form  a sponge-like extracellular matrix network,   called  conduits ,  which  they   thems
    elves   enwrap   and  contract.  Lymph,  containing  s oluble  antigens ,  arrive
    in  lymph  nodes  via afferent lymphatic  vessels that  connect  to  the  s ubcaps
    ular  s inus   and  conduit  network.  According  to  the  current  paradigm,  the  conduit  network   dis
    tributes   afferent  lymph  through   lymph  nodes   and  thus   provides   acces
    s   for  immune  cells to lymph-borne  antigens. An  elas tic  caps ule  s urrounds   the  organ  and  confines   the
    immune  cells and  FRC  network.   Lymph   nodes   are  completely  packed  with  lymphocytes   and  lymphocyte  numbers  directly  dictates  the
    size  of  the  organ.  Although  lymphocytes   cons tantly  enter  and  leave  the  lymph  node,  its   s
    ize  remains   remarkedly   s table  under  homeostatic conditions. It is only
    partly known  how the cellularity and s ize of the lymph node is regulated and  how  the  lymph  node  is
    able to swell in inflammation.  The role of the FRC network   in  lymph  node   s
    welling  and  trans fer  of  fluids   are  inves tigated in  this   thes is.  Furthermore,   we  s
    tudied  what  trafficking  routes   are  us ed  by  cancer  cells   in  lymph  nodes   to  form  distal
    metastases.We examined the role of a mechanical feedback in regulation of lymph  node
    swelling. Using parallel plate compression  and UV-las er  cutting  experiments   we  dis
    s ected  the  mechanical  force dynamics  of the whole lymph  node, and individually
    for FRCs  and the  caps ule. Physical forces   generated  by  packed  lymphocytes   directly  affect  the  tens
    ion  on  the  FRC  network  and  capsule,  which  increases  its  resistance  to   swelling.  This  implies  a  feedback  mechanism  between   tis
    s ue   pres s ure   and   ability   of   lymphocytes    to   enter   the   organ.   Following   inflammation,  the  lymph  node  swells
    ∼10 fold in two weeks . Yet, what  is  the role  for tens ion on  the  FRC  network   and  caps
    ule,  and  how  are  lymphocytes   able  to  enter  in  conditions  that resist
    swelling remain open ques tions . We s how that tens ion on the FRC network is  important
    to  limit  the  swelling  rate  of  the  organ  so  that  the  FRC  network  can  grow  in  a  coordinated  fashion.
    This is illustrated by interfering with FRC contractility, which leads to faster
    swelling rates  and a dis organized FRC network  in the inflamed lymph  node.
    Growth  of the FRC network  in  turn  is   expected  to  releas e  tens ion  on  thes
    e  s tructures   and  lowers   the  res is tance  to  swelling, thereby allowing
    more lymphocytes to enter the organ and drive more swelling. Halt of  swelling
    coincides   with  a  thickening  of  the  caps ule,  which  forms   a  thick  res
    is tant  band  around  the organ and lowers  tens ion on the FRC network  to form
    a new force equilibrium.The  FRC  and  conduit   network   are  further   believed  to  be  a  privileged  s
    ite  of  s oluble  information  within  the  lymph  node,  although  many  details   remain  uns
    olved.  We  s how  by  3D  ultra-recons truction   that  FRCs   and  antigen  pres
    enting  cells   cover  the  s urface  of  conduit  s ys tem for more  than 99%
    and we dis cus s  the implications  for s oluble information  exchangeat the conduit
    level.Finally, there  is an ongoing debate in the cancer field whether and how
    cancer cells  in lymph nodes   s eed  dis tal  metas tas es .  We  s how  that  cancer  cells   infus
    ed  into  the  lymph  node  can  utilize trafficking routes of immune  cells and  rapidly  migrate  to  blood  vessels.
    Once  in  the  blood circulation,  these cells are able to form  metastases in
    distal tissues.
acknowledged_ssus:
- _id: Bio
- _id: PreCl
- _id: EM-Fac
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Frank P
  full_name: Assen, Frank P
  id: 3A8E7F24-F248-11E8-B48F-1D18A9856A87
  last_name: Assen
  orcid: 0000-0003-3470-6119
citation:
  ama: 'Assen FP. Lymph node mechanics: Deciphering the interplay between stroma contractility,
    morphology and lymphocyte trafficking. 2019. doi:<a href="https://doi.org/10.15479/AT:ISTA:6947">10.15479/AT:ISTA:6947</a>'
  apa: 'Assen, F. P. (2019). <i>Lymph node mechanics: Deciphering the interplay between
    stroma contractility, morphology and lymphocyte trafficking</i>. Institute of
    Science and Technology Austria. <a href="https://doi.org/10.15479/AT:ISTA:6947">https://doi.org/10.15479/AT:ISTA:6947</a>'
  chicago: 'Assen, Frank P. “Lymph Node Mechanics: Deciphering the Interplay between
    Stroma Contractility, Morphology and Lymphocyte Trafficking.” Institute of Science
    and Technology Austria, 2019. <a href="https://doi.org/10.15479/AT:ISTA:6947">https://doi.org/10.15479/AT:ISTA:6947</a>.'
  ieee: 'F. P. Assen, “Lymph node mechanics: Deciphering the interplay between stroma
    contractility, morphology and lymphocyte trafficking,” Institute of Science and
    Technology Austria, 2019.'
  ista: 'Assen FP. 2019. Lymph node mechanics: Deciphering the interplay between stroma
    contractility, morphology and lymphocyte trafficking. Institute of Science and
    Technology Austria.'
  mla: 'Assen, Frank P. <i>Lymph Node Mechanics: Deciphering the Interplay between
    Stroma Contractility, Morphology and Lymphocyte Trafficking</i>. Institute of
    Science and Technology Austria, 2019, doi:<a href="https://doi.org/10.15479/AT:ISTA:6947">10.15479/AT:ISTA:6947</a>.'
  short: 'F.P. Assen, Lymph Node Mechanics: Deciphering the Interplay between Stroma
    Contractility, Morphology and Lymphocyte Trafficking, Institute of Science and
    Technology Austria, 2019.'
date_created: 2019-10-14T16:54:52Z
date_published: 2019-10-09T00:00:00Z
date_updated: 2023-09-13T08:50:57Z
day: '9'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: MiSi
doi: 10.15479/AT:ISTA:6947
file:
- access_level: closed
  checksum: 53a739752a500f84d0f8ec953cbbd0b6
  content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
  creator: fassen
  date_created: 2019-11-06T12:30:02Z
  date_updated: 2020-11-07T23:30:03Z
  embargo_to: open_access
  file_id: '6990'
  file_name: PhDthesis_FrankAssen_revised2.docx
  file_size: 214172667
  relation: source_file
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  checksum: 8c156b65d9347bb599623a4b09f15d15
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  creator: fassen
  date_created: 2019-11-06T12:30:57Z
  date_updated: 2020-11-07T23:30:03Z
  embargo: 2020-11-06
  file_id: '6991'
  file_name: PhDthesis_FrankAssen_revised2.pdf
  file_size: 83637532
  relation: main_file
file_date_updated: 2020-11-07T23:30:03Z
has_accepted_license: '1'
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
page: '142'
publication_identifier:
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
  record:
  - id: '664'
    relation: part_of_dissertation
    status: public
  - id: '402'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Michael K
  full_name: Sixt, Michael K
  id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
  last_name: Sixt
  orcid: 0000-0002-6620-9179
title: 'Lymph node mechanics: Deciphering the interplay between stroma contractility,
  morphology and lymphocyte trafficking'
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '6891'
abstract:
- lang: eng
  text: "While cells of mesenchymal or epithelial origin perform their effector functions
    in a purely anchorage dependent manner, cells derived from the hematopoietic lineage
    are not committed to operate only within a specific niche. Instead, these cells
    are able to function autonomously of the molecular composition in a broad range
    of tissue compartments. By this means, cells of the hematopoietic lineage retain
    the capacity to disseminate into connective tissue and recirculate between organs,
    building the foundation for essential processes such as tissue regeneration or
    immune surveillance. \r\nCells of the immune system, specifically leukocytes,
    are extraordinarily good at performing this task. These cells are able to flexibly
    shift their mode of migration between an adhesion-mediated and an adhesion-independent
    manner, instantaneously accommodating for any changes in molecular composition
    of the external scaffold. The key component driving directed leukocyte migration
    is the chemokine receptor 7, which guides the cell along gradients of chemokine
    ligand. Therefore, the physical destination of migrating leukocytes is purely
    deterministic, i.e. given by global directional cues such as chemokine gradients.
    \r\nNevertheless, these cells typically reside in three-dimensional scaffolds
    of inhomogeneous complexity, raising the question whether cells are able to locally
    discriminate between multiple optional migration routes. Current literature provides
    evidence that leukocytes, specifically dendritic cells, do indeed probe their
    surrounding by virtue of multiple explorative protrusions. However, it remains
    enigmatic how these cells decide which one is the more favorable route to follow
    and what are the key players involved in performing this task. Due to the heterogeneous
    environment of most tissues, and the vast adaptability of migrating leukocytes,
    at this time it is not clear to what extent leukocytes are able to optimize their
    migratory strategy by adapting their level of adhesiveness. And, given the fact
    that leukocyte migration is characterized by branched cell shapes in combination
    with high migration velocities, it is reasonable to assume that these cells require
    fine tuned shape maintenance mechanisms that tightly coordinate protrusion and
    adhesion dynamics in a spatiotemporal manner. \r\nTherefore, this study aimed
    to elucidate how rapidly migrating leukocytes opt for an ideal migratory path
    while maintaining a continuous cell shape and balancing adhesive forces to efficiently
    navigate through complex microenvironments. \r\nThe results of this study unraveled
    a role for the microtubule cytoskeleton in promoting the decision making process
    during path finding and for the first time point towards a microtubule-mediated
    function in cell shape maintenance of highly ramified cells such as dendritic
    cells. Furthermore, we found that migrating low-adhesive leukocytes are able to
    instantaneously adapt to increased tensile load by engaging adhesion receptors.
    This response was only occurring tangential to the substrate while adhesive properties
    in the vertical direction were not increased. As leukocytes are primed for rapid
    migration velocities, these results demonstrate that leukocyte integrins are able
    to confer a high level of traction forces parallel to the cell membrane along
    the direction of migration without wasting energy in gluing the cell to the substrate.
    \r\nThus, the data in the here presented thesis provide new insights into the
    pivotal role of cytoskeletal dynamics and the mechanisms of force transduction
    during leukocyte migration. \r\nThereby the here presented results help to further
    define fundamental principles underlying leukocyte migration and open up potential
    therapeutic avenues of clinical relevance.\r\n"
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Aglaja
  full_name: Kopf, Aglaja
  id: 31DAC7B6-F248-11E8-B48F-1D18A9856A87
  last_name: Kopf
  orcid: 0000-0002-2187-6656
citation:
  ama: Kopf A. The implication of cytoskeletal dynamics on leukocyte migration. 2019.
    doi:<a href="https://doi.org/10.15479/AT:ISTA:6891">10.15479/AT:ISTA:6891</a>
  apa: Kopf, A. (2019). <i>The implication of cytoskeletal dynamics on leukocyte migration</i>.
    Institute of Science and Technology Austria. <a href="https://doi.org/10.15479/AT:ISTA:6891">https://doi.org/10.15479/AT:ISTA:6891</a>
  chicago: Kopf, Aglaja. “The Implication of Cytoskeletal Dynamics on Leukocyte Migration.”
    Institute of Science and Technology Austria, 2019. <a href="https://doi.org/10.15479/AT:ISTA:6891">https://doi.org/10.15479/AT:ISTA:6891</a>.
  ieee: A. Kopf, “The implication of cytoskeletal dynamics on leukocyte migration,”
    Institute of Science and Technology Austria, 2019.
  ista: Kopf A. 2019. The implication of cytoskeletal dynamics on leukocyte migration.
    Institute of Science and Technology Austria.
  mla: Kopf, Aglaja. <i>The Implication of Cytoskeletal Dynamics on Leukocyte Migration</i>.
    Institute of Science and Technology Austria, 2019, doi:<a href="https://doi.org/10.15479/AT:ISTA:6891">10.15479/AT:ISTA:6891</a>.
  short: A. Kopf, The Implication of Cytoskeletal Dynamics on Leukocyte Migration,
    Institute of Science and Technology Austria, 2019.
date_created: 2019-09-19T08:19:44Z
date_published: 2019-07-24T00:00:00Z
date_updated: 2023-10-18T08:49:17Z
day: '24'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: MiSi
doi: 10.15479/AT:ISTA:6891
file:
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  relation: main_file
file_date_updated: 2020-10-17T22:30:03Z
has_accepted_license: '1'
keyword:
- cell biology
- immunology
- leukocyte
- migration
- microfluidics
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
page: '171'
project:
- _id: 265E2996-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: W01250-B20
  name: Nano-Analytics of Cellular Systems
publication_identifier:
  eissn:
  - 2663-337X
  isbn:
  - 978-3-99078-002-2
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
  link:
  - relation: press_release
    url: https://ist.ac.at/en/news/feeling-like-a-cell/
  record:
  - id: '6328'
    relation: part_of_dissertation
    status: public
  - id: '15'
    relation: part_of_dissertation
    status: public
  - id: '6877'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Michael K
  full_name: Sixt, Michael K
  id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
  last_name: Sixt
  orcid: 0000-0002-6620-9179
title: The implication of cytoskeletal dynamics on leukocyte migration
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '323'
abstract:
- lang: eng
  text: 'In the here presented thesis, we explore the role of branched actin networks
    in cell migration and antigen presentation, the two most relevant processes in
    dendritic cell biology. Branched actin networks construct lamellipodial protrusions
    at the leading edge of migrating cells. These are typically seen as adhesive structures,
    which mediate force transduction to the extracellular matrix that leads to forward
    locomotion. We ablated Arp2/3 nucleation promoting factor WAVE in DCs and found
    that the resulting cells lack lamellipodial protrusions. Instead, depending on
    the maturation state, one or multiple filopodia were formed. By challenging these
    cells in a variety of migration assays we found that lamellipodial protrusions
    are dispensable for the locomotion of leukocytes and actually dampen the speed
    of migration. However, lamellipodia are critically required to negotiate complex
    environments that DCs experience while they travel to the next draining lymph
    node. Taken together our results suggest that leukocyte lamellipodia have rather
    a sensory- than a force transducing function. Furthermore, we show for the first
    time structure and dynamics of dendritic cell F-actin at the immunological synapse
    with naïve T cells. Dendritic cell F-actin appears as dynamic foci that are nucleated
    by the Arp2/3 complex. WAVE ablated dendritic cells show increased membrane tension,
    leading to an altered ultrastructure of the immunological synapse and severe T
    cell priming defects. These results point towards a previously unappreciated role
    of the cellular mechanics of dendritic cells in T cell activation. Additionally,
    we present a novel cell culture based system for the differentiation of dendritic
    cells from conditionally immortalized hematopoietic precursors. These precursor
    cells are genetically tractable via the CRISPR/Cas9 system while they retain their
    ability to differentiate into highly migratory dendritic cells and other immune
    cells. This will foster the study of all aspects of dendritic cell biology and
    beyond. '
acknowledged_ssus:
- _id: NanoFab
- _id: Bio
- _id: PreCl
- _id: EM-Fac
acknowledgement: "First of all I would like to thank Michael Sixt for giving me the
  opportunity to work in \r\nhis group and for his support throughout the years. He
  is a truly inspiring person and \r\nthe  best  boss  one  can  imagine.  I  would
  \ also  like  to  thank  all  current  and  past \r\nmembers of the Sixt group for
  their help and the great working atmosphere in the lab. \r\nIt is a true privilege
  to work with such a bright, funny and friendly group of people and \r\nI’m  proud
  \ that  I  could  be  part  of  it.  Furthermore,  I  would  like  to  say  ‘thank
  \ you’  to Daria Siekhaus for all the meetings and discussion we had throughout
  the years \r\nand to  Federica  Benvenuti  for  being  part  of  my  committee.
  \ I  am  also  grateful  to  Jack \r\nMerrin  in  the  nanofabrication  facility
  \ and  all  the  people  working  in  the  bioimaging-\r\n, the electron microscopy-
  and the preclinical facilities."
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Alexander F
  full_name: Leithner, Alexander F
  id: 3B1B77E4-F248-11E8-B48F-1D18A9856A87
  last_name: Leithner
  orcid: 0000-0002-1073-744X
citation:
  ama: Leithner AF. Branched actin networks in dendritic cell biology. 2018. doi:<a
    href="https://doi.org/10.15479/AT:ISTA:th_998">10.15479/AT:ISTA:th_998</a>
  apa: Leithner, A. F. (2018). <i>Branched actin networks in dendritic cell biology</i>.
    Institute of Science and Technology Austria. <a href="https://doi.org/10.15479/AT:ISTA:th_998">https://doi.org/10.15479/AT:ISTA:th_998</a>
  chicago: Leithner, Alexander F. “Branched Actin Networks in Dendritic Cell Biology.”
    Institute of Science and Technology Austria, 2018. <a href="https://doi.org/10.15479/AT:ISTA:th_998">https://doi.org/10.15479/AT:ISTA:th_998</a>.
  ieee: A. F. Leithner, “Branched actin networks in dendritic cell biology,” Institute
    of Science and Technology Austria, 2018.
  ista: Leithner AF. 2018. Branched actin networks in dendritic cell biology. Institute
    of Science and Technology Austria.
  mla: Leithner, Alexander F. <i>Branched Actin Networks in Dendritic Cell Biology</i>.
    Institute of Science and Technology Austria, 2018, doi:<a href="https://doi.org/10.15479/AT:ISTA:th_998">10.15479/AT:ISTA:th_998</a>.
  short: A.F. Leithner, Branched Actin Networks in Dendritic Cell Biology, Institute
    of Science and Technology Austria, 2018.
date_created: 2018-12-11T11:45:49Z
date_published: 2018-04-12T00:00:00Z
date_updated: 2023-09-07T12:39:44Z
day: '12'
ddc:
- '571'
- '599'
- '610'
degree_awarded: PhD
department:
- _id: MiSi
doi: 10.15479/AT:ISTA:th_998
file:
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  checksum: d5e3edbac548c26c1fa43a4b37a54a4c
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  date_created: 2019-04-05T09:23:11Z
  date_updated: 2021-02-11T23:30:17Z
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  date_created: 2019-04-05T09:23:11Z
  date_updated: 2021-02-11T11:17:16Z
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file_date_updated: 2021-02-11T23:30:17Z
has_accepted_license: '1'
language:
- iso: eng
month: '04'
oa: 1
oa_version: Published Version
page: '99'
publication_identifier:
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '7542'
pubrep_id: '998'
related_material:
  record:
  - id: '1321'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Michael K
  full_name: Sixt, Michael K
  id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
  last_name: Sixt
  orcid: 0000-0002-6620-9179
title: Branched actin networks in dendritic cell biology
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2018'
...
---
_id: '1129'
abstract:
- lang: eng
  text: "Directed cell migration is a hallmark feature, present in almost all multi-cellular\r\norganisms.
    Despite its importance, basic questions regarding force transduction\r\nor directional
    sensing are still heavily investigated. Directed migration of cells\r\nguided
    by immobilized guidance cues - haptotaxis - occurs in key-processes,\r\nsuch as
    embryonic development and immunity (Middleton et al., 1997; Nguyen\r\net al.,
    2000; Thiery, 1984; Weber et al., 2013). Immobilized guidance cues\r\ncomprise
    adhesive ligands, such as collagen and fibronectin (Barczyk et al.,\r\n2009),
    or chemokines - the main guidance cues for migratory leukocytes\r\n(Middleton
    et al., 1997; Weber et al., 2013). While adhesive ligands serve as\r\nattachment
    sites guiding cell migration (Carter, 1965), chemokines instruct\r\nhaptotactic
    migration by inducing adhesion to adhesive ligands and directional\r\nguidance
    (Rot and Andrian, 2004; Schumann et al., 2010). Quantitative analysis\r\nof the
    cellular response to immobilized guidance cues requires in vitro assays\r\nthat
    foster cell migration, offer accurate control of the immobilized cues on a\r\nsubcellular
    scale and in the ideal case closely reproduce in vivo conditions. The\r\nexploration
    of haptotactic cell migration through design and employment of such\r\nassays
    represents the main focus of this work.\r\nDendritic cells (DCs) are leukocytes,
    which after encountering danger\r\nsignals such as pathogens in peripheral organs
    instruct naïve T-cells and\r\nconsequently the adaptive immune response in the
    lymph node (Mellman and\r\nSteinman, 2001). To reach the lymph node from the periphery,
    DCs follow\r\nhaptotactic gradients of the chemokine CCL21 towards lymphatic vessels\r\n(Weber
    et al., 2013). Questions about how DCs interpret haptotactic CCL21\r\ngradients
    have not yet been addressed. The main reason for this is the lack of\r\nan assay
    that offers diverse haptotactic environments, hence allowing the study\r\nof DC
    migration as a response to different signals of immobilized guidance cue.\r\nIn
    this work, we developed an in vitro assay that enables us to\r\nquantitatively
    assess DC haptotaxis, by combining precisely controllable\r\nchemokine photo-patterning
    with physically confining migration conditions. With this tool at hand, we studied
    the influence of CCL21 gradient properties and\r\nconcentration on DC haptotaxis.
    We found that haptotactic gradient sensing\r\ndepends on the absolute CCL21 concentration
    in combination with the local\r\nsteepness of the gradient. Our analysis suggests
    that the directionality of\r\nmigrating DCs is governed by the signal-to-noise
    ratio of CCL21 binding to its\r\nreceptor CCR7. Moreover, the haptotactic CCL21
    gradient formed in vivo\r\nprovides an optimal shape for DCs to recognize haptotactic
    guidance cue.\r\nBy reconstitution of the CCL21 gradient in vitro we were also
    able to\r\nstudy the influence of CCR7 signal termination on DC haptotaxis. To
    this end,\r\nwe used DCs lacking the G-protein coupled receptor kinase GRK6, which
    is\r\nresponsible for CCL21 induced CCR7 receptor phosphorylation and\r\ndesensitization
    (Zidar et al., 2009). We found that CCR7 desensitization by\r\nGRK6 is crucial
    for maintenance of haptotactic CCL21 gradient sensing in vitro\r\nand confirm
    those observations in vivo.\r\nIn the context of the organism, immobilized haptotactic
    guidance cues\r\noften coincide and compete with soluble chemotactic guidance
    cues. During\r\nwound healing, fibroblasts are exposed and influenced by adhesive
    cues and\r\nsoluble factors at the same time (Wu et al., 2012; Wynn, 2008). Similarly,\r\nmigrating
    DCs are exposed to both, soluble chemokines (CCL19 and truncated\r\nCCL21) inducing
    chemotactic behavior as well as the immobilized CCL21. To\r\nquantitatively assess
    these complex coinciding immobilized and soluble\r\nguidance cues, we implemented
    our chemokine photo-patterning technique in a\r\nmicrofluidic system allowing
    for chemotactic gradient generation. To validate\r\nthe assay, we observed DC
    migration in competing CCL19/CCL21\r\nenvironments.\r\nAdhesiveness guided haptotaxis
    has been studied intensively over the\r\nlast century. However, quantitative studies
    leading to conceptual models are\r\nlargely missing, again due to the lack of
    a precisely controllable in vitro assay. A\r\nrequirement for such an in vitro
    assay is that it must prevent any uncontrolled\r\ncell adhesion. This can be accomplished
    by stable passivation of the surface. In\r\naddition, controlled adhesion must
    be sustainable, quantifiable and dose\r\ndependent in order to create homogenous
    gradients. Therefore, we developed a novel covalent photo-patterning technique
    satisfying all these needs. In\r\ncombination with a sustainable poly-vinyl alcohol
    (PVA) surface coating we\r\nwere able to generate gradients of adhesive cue to
    direct cell migration. This\r\napproach allowed us to characterize the haptotactic
    migratory behavior of\r\nzebrafish keratocytes in vitro. Furthermore, defined
    patterns of adhesive cue\r\nallowed us to control for cell shape and growth on
    a subcellular scale."
acknowledged_ssus:
- _id: Bio
- _id: PreCl
- _id: LifeSc
acknowledgement: "First, I would like to thank Michael Sixt for being a great supervisor,
  mentor and\r\nscientist. I highly appreciate his guidance and continued support.
  Furthermore, I\r\nam very grateful that he gave me the exceptional opportunity to
  pursue many\r\nideas of which some managed to be included in this thesis.\r\nI owe
  sincere thanks to the members of my PhD thesis committee, Daria\r\nSiekhaus, Daniel
  Legler and Harald Janovjak. Especially I would like to thank\r\nDaria for her advice
  and encouragement during our regular progress meetings.\r\nI also want to thank
  the team and fellows of the Boehringer Ingelheim Fond\r\n(BIF) PhD Fellowship for
  amazing and inspiring meetings and the BIF for\r\nfinancial support.\r\nImportant
  factors for the success of this thesis were the warm, creative\r\nand helpful atmosphere
  as well as the team spirit of the whole Sixt Lab.\r\nTherefore I would like to thank
  my current and former colleagues Frank Assen,\r\nMarkus Brown, Ingrid de Vries,
  Michelle Duggan, Alexander Eichner, Miroslav\r\nHons, Eva Kiermaier, Aglaja Kopf,
  Alexander Leithner, Christine Moussion, Jan\r\nMüller, Maria Nemethova, Jörg Renkawitz,
  Anne Reversat, Kari Vaahtomeri,\r\nMichele Weber and Stefan Wieser. We had an amazing
  time with many\r\nlegendary evenings and events. Along these lines I want to thank
  the in vitro\r\ncrew of the lab, Jörg, Anne and Alex, for lots of ideas and productive\r\ndiscussions.
  I am sure, some day we will reveal the secret of the ‘splodge’.\r\nI want to thank
  the members of the Heisenberg Lab for a great time and\r\nthrilling kicker matches.
  In this regard I especially want to thank Maurizio\r\n‘Gnocci’ Monti, Gabriel Krens,
  Alex Eichner, Martin Behrndt, Vanessa Barone,Philipp Schmalhorst, Michael Smutny,
  Daniel Capek, Anne Reversat, Eva\r\nKiermaier, Frank Assen and Jan Müller for wonderful
  after-lunch matches.\r\nI would not have been able to analyze the thousands of cell
  trajectories\r\nand probably hundreds of thousands of mouse clicks without the productive\r\ncollaboration
  with Veronika Bierbaum and Tobias Bollenbach. Thanks Vroni for\r\ncountless meetings,
  discussions and graphs and of course for proofreading and\r\nadvice for this thesis.
  For proofreading I also want to thank Evi, Jörg, Jack and\r\nAnne.\r\nI would like
  to acknowledge Matthias Mehling for a very productive\r\ncollaboration and for introducing
  me into the wild world of microfluidics. Jack\r\nMerrin, for countless wafers, PDMS
  coated coverslips and help with anything\r\nmicro-fabrication related. And Maria
  Nemethova for establishing the ‘click’\r\npatterning approach with me. Without her
  it still would be just one of the ideas…\r\nMany thanks to Ekaterina Papusheva,
  Robert Hauschild, Doreen Milius\r\nand Nasser Darwish from the Bioimaging Facility
  as well as the Preclinical and\r\nthe Life Science facilities of IST Austria for
  excellent technical support. At this\r\npoint I especially want to thank Robert
  for countless image analyses and\r\ntechnical ideas. Always interested and creative
  he played an essential role in all\r\nof my projects.\r\nAdditionally I want to
  thank Ingrid and Gabby for welcoming me warmly\r\nwhen I first started at IST, for
  scientific and especially mental support in all\r\nthose years, countless coffee
  sessions and Heurigen evenings. #BioimagingFacility #LifeScienceFacility #PreClinicalFacility"
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Jan
  full_name: Schwarz, Jan
  id: 346C1EC6-F248-11E8-B48F-1D18A9856A87
  last_name: Schwarz
citation:
  ama: Schwarz J. Quantitative analysis of haptotactic cell migration. 2016.
  apa: Schwarz, J. (2016). <i>Quantitative analysis of haptotactic cell migration</i>.
    Institute of Science and Technology Austria.
  chicago: Schwarz, Jan. “Quantitative Analysis of Haptotactic Cell Migration.” Institute
    of Science and Technology Austria, 2016.
  ieee: J. Schwarz, “Quantitative analysis of haptotactic cell migration,” Institute
    of Science and Technology Austria, 2016.
  ista: Schwarz J. 2016. Quantitative analysis of haptotactic cell migration. Institute
    of Science and Technology Austria.
  mla: Schwarz, Jan. <i>Quantitative Analysis of Haptotactic Cell Migration</i>. Institute
    of Science and Technology Austria, 2016.
  short: J. Schwarz, Quantitative Analysis of Haptotactic Cell Migration, Institute
    of Science and Technology Austria, 2016.
date_created: 2018-12-11T11:50:18Z
date_published: 2016-07-01T00:00:00Z
date_updated: 2023-09-07T11:54:33Z
day: '01'
ddc:
- '570'
degree_awarded: PhD
department:
- _id: MiSi
file:
- access_level: closed
  checksum: e3cd6b28f9c5cccb8891855565a2dade
  content_type: application/pdf
  creator: dernst
  date_created: 2019-08-13T10:55:35Z
  date_updated: 2019-08-13T10:55:35Z
  file_id: '6813'
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  date_created: 2021-02-22T11:43:14Z
  date_updated: 2021-02-22T11:43:14Z
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  file_size: 8396717
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  success: 1
file_date_updated: 2021-02-22T11:43:14Z
has_accepted_license: '1'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
page: '178'
publication_identifier:
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '6231'
status: public
supervisor:
- first_name: Michael K
  full_name: Sixt, Michael K
  id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
  last_name: Sixt
  orcid: 0000-0002-6620-9179
title: Quantitative analysis of haptotactic cell migration
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2016'
...
---
_id: '3275'
abstract:
- lang: eng
  text: 'Chemokines organize immune cell trafficking by inducing either directed (tactic)
    or random (kinetic) migration and by activating integrins in order to support
    surface adhesion (haptic). Beyond that the same chemokines can establish clearly
    defined functional areas in secondary lymphoid organs. Until now it is unclear
    how chemokines can fulfill such diverse functions. One decisive prerequisite to
    explain these capacities is to know how chemokines are presented in tissue. In
    theory chemokines could occur either soluble or immobilized, and could be distributed
    either homogenously or as a concentration gradient. To dissect if and how the
    presenting mode of chemokines influences immune cells, I tested the response of
    dendritic cells (DCs) to differentially displayed chemokines. DCs are antigen
    presenting cells that reside in the periphery and migrate into draining lymph
    nodes (LNs) once exposed to inflammatory stimuli to activate naïve T cells. DCs
    are guided to and within the LN by the chemokine receptor CCR7, which has two
    ligands, the chemokines CCL19 and CCL21. Both CCR7 ligands are expressed by fibroblastic
    reticular cells in the LN, but differ in their ability to bind to heparan sulfate
    residues. CCL21 has a highly charged C-terminal extension, which mediates binding
    to anionic surfaces, whereas CCL19 is lacking such residues and likely distributes
    as a soluble molecule. This study shows that surface-bound CCL21 causes random,
    haptokinetic DC motility, which is confined to the chemokine coated area by insideout
    activation of β2 integrins that mediate cell binding to the surface. CCL19 on
    the other hand forms concentration gradients which trigger directional, chemotactic
    movement, but no surface adhesion. In addition DCs can actively manipulate this
    system by recruiting and activating serine proteases on their surfaces, which
    create - by proteolytically removing the adhesive C-terminus - a solubilized variant
    of CCL21 that functionally resembles CCL19. By generating a CCL21 concentration
    gradient DCs establish a positive feedback loop to recruit further DCs from the
    periphery to the CCL21 coated region. In addition DCs can sense chemotactic gradients
    as well as immobilized haptokinetic fields at the same time and integrate these
    signals. The result is chemotactically biased haptokinesis - directional migration
    confined to a chemokine coated track or area - which could explain the dynamic
    but spatially tightly controlled swarming leukocyte locomotion patterns that have
    been observed in lymphatic organs by intravital microscopists. The finding that
    DCs can approach soluble cues in a non-adhesive manner while they attach to surfaces
    coated with immobilized cues raises the question how these cells transmit intracellular
    forces to the environment, especially in the non-adherent migration mode. In order
    to migrate, cells have to generate and transmit force to the extracellular substrate.
    Force transmission is the prerequisite to procure an expansion of the leading
    edge and a forward motion of the whole cell body. In the current conceptions actin
    polymerization at the leading edge is coupled to extracellular ligands via the
    integrin family of transmembrane receptors, which allows the transmission of intracellular
    force. Against the paradigm of force transmission during migration, leukocytes,
    like DCs, are able to migrate in threedimensional environments without using integrin
    transmembrane receptors (Lämmermann et al., 2008). This reflects the biological
    function of leukocytes, as they can invade almost all tissues, whereby their migration
    has to be independent from the extracellular environment. How the cells can achieve
    this is unclear. For this study I examined DC migration in a defined threedimensional
    environment and highlighted actin-dynamics with the probe Lifeact-GFP. The result
    was that chemotactic DCs can switch between integrin-dependent and integrin- independent
    locomotion and can thereby adapt to the adhesive properties of their environment.
    If the cells are able to couple their actin cytoskeleton to the substrate, actin
    polymerization is entirely converted into protrusion. Without coupling the actin
    cortex undergoes slippage and retrograde actin flow can be observed. But retrograde
    actin flow can be completely compensated by higher actin polymerization rate keeping
    the migration velocity and the shape of the cells unaltered. Mesenchymal cells
    like fibroblast cannot balance the loss of adhesive interaction, cannot protrude
    into open space and, therefore, strictly depend on integrinmediated force coupling.
    This leukocyte specific phenomenon of “adaptive force transmission” endows these
    cells with the unique ability to transit and invade almost every type of tissue. '
acknowledgement: "I would like to express my sincere gratitude to the following people
  who made with their continuous support and encouragement this thesis possible: First,
  I want to thank Prof. Dr. Michael Sixt for his excellent supervision and mentoring,
  especially for the nice, relaxed working atmosphere, a lot of brilliant ideas and
  the freedom to work in my own way.\r\n\r\nProf. Dr. Reinhard Fässler for his constant
  support of the Sixt lab and for providing excellent working conditions. \r\n\r\nProf.
  Dr. Sanjiv Luther and Prof. Dr. Tobias Bollenbach for agreeing to be member of my
  thesis committee and to evaluate my work.\r\n\r\nDr. Walther Göhring, Carmen Schmitz,
  the Recombinant Protein Production core facility and the animal care takers for
  providing the “infrastructure” for this thesis. \r\n\r\nProf. Dr. Daniel Legler,
  Markus Bruckner and Dr. Julien Polleux for very fruitful collaborations and discussions.\r\n\r\nMy
  labmates for their help, a lot of discussions and to make the Sixt lab to a convenient
  place to work : Karin Hirsch, Tim Lämmeramnn, Holger Pflicke, Jörg Renkawitz, Michele
  Weber and Alexander Eichner All members of the Department of Molecular Medicine
  for their help. Especially I want to thank Sarah Schmidt, Karin Hirsch and Raphael
  Ruppert for their friendship, nice chats and their uncensored point of view. "
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Kathrin
  full_name: Schumann, Kathrin
  id: F44D762E-4F9D-11E9-B64C-9EB26CEFFB5F
  last_name: Schumann
citation:
  ama: Schumann K. The role of chemotactic gradients in dendritic cell migration.
    2011.
  apa: Schumann, K. (2011). <i>The role of chemotactic gradients in dendritic cell
    migration</i>. Institute of Science and Technology Austria.
  chicago: Schumann, Kathrin. “The Role of Chemotactic Gradients in Dendritic Cell
    Migration.” Institute of Science and Technology Austria, 2011.
  ieee: K. Schumann, “The role of chemotactic gradients in dendritic cell migration,”
    Institute of Science and Technology Austria, 2011.
  ista: Schumann K. 2011. The role of chemotactic gradients in dendritic cell migration.
    Institute of Science and Technology Austria.
  mla: Schumann, Kathrin. <i>The Role of Chemotactic Gradients in Dendritic Cell Migration</i>.
    Institute of Science and Technology Austria, 2011.
  short: K. Schumann, The Role of Chemotactic Gradients in Dendritic Cell Migration,
    Institute of Science and Technology Austria, 2011.
date_created: 2018-12-11T12:02:24Z
date_published: 2011-03-01T00:00:00Z
date_updated: 2023-09-07T11:31:48Z
day: '01'
ddc:
- '570'
- '579'
degree_awarded: PhD
department:
- _id: MiSi
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language:
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month: '03'
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oa_version: Published Version
page: '141'
publication_identifier:
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '3371'
pubrep_id: '11'
status: public
supervisor:
- first_name: Michael K
  full_name: Sixt, Michael K
  id: 41E9FBEA-F248-11E8-B48F-1D18A9856A87
  last_name: Sixt
  orcid: 0000-0002-6620-9179
title: The role of chemotactic gradients in dendritic cell migration
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2011'
...
