scholarly journals Rab27a Is Required for Regulated Secretion in Cytotoxic T Lymphocytes

2001 ◽  
Vol 152 (4) ◽  
pp. 825-834 ◽  
Author(s):  
Jane C. Stinchcombe ◽  
Duarte C. Barral ◽  
Emilie H. Mules ◽  
Sarah Booth ◽  
Alistair N. Hume ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Immunological Synapse ◽  
Target Cells ◽  
Rab Proteins ◽  
Loss Of Function ◽  
Α Subunit ◽  
Lytic Granules ◽  
Granzyme A ◽  
Geranylgeranyl Transferase

Rab27a activity is affected in several mouse models of human disease including Griscelli (ashen mice) and Hermansky-Pudlak (gunmetal mice) syndromes. A loss of function mutation occurs in the Rab27a gene in ashen (ash), whereas in gunmetal (gm) Rab27a dysfunction is secondary to a mutation in the α subunit of Rab geranylgeranyl transferase, an enzyme required for prenylation and activation of Rabs. We show here that Rab27a is normally expressed in cytotoxic T lymphocytes (CTLs), but absent in ashen homozygotes (ash/ash). Cytotoxicity and secretion assays show that ash/ash CTLs are unable to kill target cells or to secrete granzyme A and hexosaminidase. By immunofluorescence and electron microscopy, we show polarization but no membrane docking of ash/ash lytic granules at the immunological synapse. In gunmetal CTLs, we show underprenylation and redistribution of Rab27a to the cytosol, implying reduced activity. Gunmetal CTLs show a reduced ability to kill target cells but retain the ability to secrete hexosaminidase and granzyme A. However, only some of the granules polarize to the immunological synapse, and many remain dispersed around the periphery of the CTLs. These results demonstrate that Rab27a is required in a final secretory step and that other Rab proteins also affected in gunmetal are likely to be involved in polarization of the granules to the immunological synapse.

scholarly journals Behavior and Properties of Mature Lytic Granules at the Immunological Synapse of Human Cytotoxic T Lymphocytes

PLoS ONE ◽  
2015 ◽  
Vol 10 (8) ◽  
pp. e0135994 ◽  
Author(s):  
Min Ming ◽  
Claudia Schirra ◽  
Ute Becherer ◽  
David R. Stevens ◽  
Jens Rettig
Keyword(s):  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Immunological Synapse ◽  
Lytic Granules

scholarly journals Cortical actin recovery at the immunological synapse leads to termination of lytic granule secretion in cytotoxic T lymphocytes

2017 ◽  
Vol 114 (32) ◽  
pp. E6585-E6594 ◽  
Author(s):  
Alex T. Ritter ◽  
Senta M. Kapnick ◽  
Sricharan Murugesan ◽  
Pamela L. Schwartzberg ◽  
Gillian M. Griffiths ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Immunological Synapse ◽  
Cortical Actin ◽  
Immune Synapse ◽  
Superresolution Microscopy ◽  
Lytic Granules ◽  
Infected Cells ◽  
Granule Secretion ◽  
Lytic Granule

CD8+ cytotoxic T lymphocytes (CTLs) eliminate virally infected cells through directed secretion of specialized lytic granules. Because a single CTL can kill multiple targets, degranulation must be tightly regulated. However, how CTLs regulate the termination of granule secretion remains unclear. Previous work demonstrated that centralized actin reduction at the immune synapse precedes degranulation. Using a combination of live confocal, total internal reflection fluorescence, and superresolution microscopy, we now show that, after granule fusion, actin recovers at the synapse and no further secretion is observed. Depolymerization of actin led to resumed granule secretion, suggesting that recovered actin acts as a barrier preventing sustained degranulation. Furthermore, RAB27a-deficient CTLs, which do not secrete cytotoxic granules, failed to recover actin at the synapse, suggesting that RAB27a-mediated granule secretion is required for actin recovery. Finally, we show that both actin clearance and recovery correlated with synaptic phosphatidylinositol 4,5-bisphosphate (PIP2) and that alterations in PIP2 at the immunological synapse regulate cortical actin in CTLs, providing a potential mechanism through which CTLs control cortical actin density. Our work provides insight into actin-related mechanisms regulating CTL secretion that may facilitate serial killing during immune responses.

scholarly journals Centrosome docking at the immunological synapse is controlled by Lck signaling

2011 ◽  
Vol 192 (4) ◽  
pp. 663-674 ◽  
Author(s):  
Andy Tsun ◽  
Ihjaaz Qureshi ◽  
Jane C. Stinchcombe ◽  
Misty R. Jenkins ◽  
Maike de la Roche ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
T Cell ◽  
Tyrosine Kinase ◽  
T Cell Receptor ◽  
Cytotoxic T Lymphocytes ◽  
Immunological Synapse ◽  
Cell Receptor ◽  
Target Cells ◽  
Lytic Granules ◽  
Distal Side

Docking of the centrosome at the plasma membrane directs lytic granules to the immunological synapse. To identify signals controlling centrosome docking at the synapse, we have studied cytotoxic T lymphocytes (CTLs) in which expression of the T cell receptor–activated tyrosine kinase Lck is ablated. In the absence of Lck, the centrosome is able to translocate around the nucleus toward the immunological synapse but is unable to dock at the plasma membrane. Lytic granules fail to polarize and release their contents, and target cells are not killed. In CTLs deficient in both Lck and the related tyrosine kinase Fyn, centrosome translocation is impaired, and the centrosome remains on the distal side of the nucleus relative to the synapse. These results show that repositioning of the centrosome in CTLs involves at least two distinct steps, with Lck signaling required for the centrosome to dock at the plasma membrane.

scholarly journals Terminal transport of lytic granules to the immune synapse is mediated by the kinesin-1/Slp3/Rab27a complex

Blood ◽  
2012 ◽  
Vol 119 (17) ◽  
pp. 3879-3889 ◽  
Author(s):  
Mathieu Kurowska ◽  
Nicolas Goudin ◽  
Nadine T. Nehme ◽  
Magali Court ◽  
Jérôme Garin ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Target Cells ◽  
Microtubule Organizing Center ◽  
Immune Synapse ◽  
Lytic Granules ◽  
Polarized Secretion ◽  
Organizing Center ◽  
Dependent Transport ◽  
Lytic Granule

Abstract Cytotoxic T lymphocytes kill target cells via the polarized secretion of cytotoxic granules at the immune synapse. The lytic granules are initially recruited around the polarized microtubule-organizing center. In a dynein-dependent transport process, the granules move along microtubules toward the microtubule-organizing center in the minus-end direction. Here, we found that a kinesin-1–dependent process is required for terminal transport and secretion of polarized lytic granule to the immune synapse. We show that synaptotagmin-like protein 3 (Slp3) is an effector of Rab27a in cytotoxic T lymphocytes and interacts with kinesin-1 through the tetratricopeptide repeat of the kinesin-1 light chain. Inhibition of the Rab27a/Slp3/kinesin-1 transport complex impairs lytic granule secretion. Our data provide further molecular insights into the key functional and regulatory mechanisms underlying the terminal transport of cytotoxic granules and the latter's secretion at the immune synapse.

scholarly journals Interfacial actin protrusions mechanically potentiate killing by cytotoxic T cells

2018 ◽  
Author(s):  
Fella Tamzalit ◽  
Mitchell S. Wang ◽  
Weiyang Jin ◽  
Vitaly Boyko ◽  
John M. Heddleston ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Target Cell ◽  
Immune Cell ◽  
Immunological Synapse ◽  
Cytotoxic T Cells ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Target Cells ◽  
Immunological Synapses

ABSTRACTCytotoxic T lymphocytes (CTLs) kill by forming immunological synapses with target cells and secreting toxic proteases and the pore forming protein perforin into the intercellular space. Immunological synapses are highly dynamic structures that potentiate perforin activity by applying mechanical force against the target cell. Here, we employed high-resolution imaging and microfabrication to investigate how CTLs exert synaptic forces and coordinate their mechanical output with perforin secretion. Using micropatterned stimulatory substrates that enable synapse growth in three dimensions, we found that perforin release occurs at the base of actin-rich protrusions that extend from central and intermediate locations within the synapse. These protrusions, which depended on the cytoskeletal regulator WASP and the Arp2/3 actin nucleation complex, were required for synaptic force exertion and efficient killing. They also mediated physical distortion of the target cell surface during CTL-target cell interactions. Our results reveal the mechanical basis of cellular cytotoxicity and highlight the functional importance of dynamic, three-dimensional architecture in immune cell-cell interfaces.One sentence summaryCytotoxic T lymphocytes use F-actin-rich protrusions at the immunological synapse to potentiate perforin-and granzyme-mediated target cell killing.

scholarly journals HLA restriction of human cytotoxic T lymphocytes specific for influenza virus. Poor recognition of virus associated with HLA A2.

1978 ◽  
Vol 148 (6) ◽  
pp. 1458-1467 ◽  
Author(s):  
A McMichael
Keyword(s):  
Influenza Virus ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Influenza A ◽  
Human Peripheral Blood ◽  
Peripheral Blood Lymphocytes ◽  
The Other ◽  
Target Cells ◽  
Surface Molecules ◽  
Human Peripheral Blood Lymphocytes

Cytotoxic T lymphocytes (CTL), specific for influenza A/X31 virus, were generated from human peripheral blood lymphocytes. These CTL lysed target cells that were infected with the same virus and that shared HLA A or B locus antigens. Minimal lysis was observed when HLA-D antigens were shared. Not all HLA A and B antigens were equally effective. Efficient lysis of target cells was seen when HLA A1, A3, B7, B8, B27 and BW21 were shared with the CTL, but when HLA A2 was the only shared antigen lysis was usually minimal. This deficiency in CTL function associated with HLA A2 was not absolute. It is suggested that the function of this antigen might be influenced by other surface molecules on the cell and in particular the other HLA products.

N-linked oligosaccharides can protect target cells from the lysis mediated by NK cells but not by cytotoxic T lymphocytes: role of NKG2-A

1999 ◽  
Vol 54 (2) ◽  
pp. 113-121 ◽  
Author(s):  
M.-A. Sol ◽  
N. Vacaresse ◽  
J. Lule ◽  
C. Davrinche ◽  
B. Gabriel ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Nk Cells ◽  
Cytotoxic T Lymphocytes ◽  
Target Cells

scholarly journals Extracellular Cystatin F Is Internalised by Cytotoxic T Lymphocytes and Decreases Their Cytotoxicity

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3660
Author(s):  
Mateja Prunk ◽  
Milica Perišić Nanut ◽  
Tanja Jakoš ◽  
Jerica Sabotič ◽  
Urban Švajger ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Cathepsin L ◽  
Killer Cell ◽  
Full Length ◽  
Cytotoxic T Cell ◽  
Target Cells ◽  
Natural Killer Cell Cytotoxicity ◽  
Cathepsin C ◽  
Cysteine Cathepsins

Cystatin F is a protein inhibitor of cysteine cathepsins, peptidases involved in the activation of the effector molecules of the perforin/granzyme pathway. Cystatin F was previously shown to regulate natural killer cell cytotoxicity. Here, we show that extracellular cystatin F has a role in regulating the killing efficiency of cytotoxic T lymphocytes (CTLs). Extracellular cystatin F was internalised into TALL-104 cells, a cytotoxic T cell line, and decreased their cathepsin C and H activity. Correspondingly, granzyme A and B activity was also decreased and, most importantly, the killing efficiency of TALL-104 cells as well as primary human CTLs was reduced. The N-terminally truncated form of cystatin F, which can directly inhibit cathepsin C (unlike the full-length form), was more effective than the full-length inhibitor. Furthermore, cystatin F decreased cathepsin L activity, which, however, did not affect perforin processing. Cystatin F derived from K-562 target cells could also decrease the cytotoxicity of TALL-104 cells. These results clearly show that, by inhibiting cysteine cathepsin proteolytic activity, extracellular cystatin F can decrease the cytotoxicity of CTLs and thus compromise their function.

Sign in / Sign up

Export Citation Format

Share Document