Cell surface markers of T-cell activation

1991 ◽  
Vol 5 (1) ◽  
pp. 9-30 ◽  
Author(s):  
Gregorio G. Aversa ◽  
Bruce M. Hall
Keyword(s):  
T Cell ◽  
Cell Surface ◽  
T Cell Activation ◽  
Cell Activation ◽  
Surface Markers ◽  
Cell Surface Markers

scholarly journals Bifidobacterial Species Differentially Affect Expression of Cell Surface Markers and Cytokines of Dendritic Cells Harvested from Cord Blood

2004 ◽  
Vol 11 (4) ◽  
pp. 686-690 ◽  
Author(s):  
Sarah L. Young ◽  
Mary A. Simon ◽  
Margaret A. Baird ◽  
Gerald W. Tannock ◽  
Rodrigo Bibiloni ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Cell Surface ◽  
Cord Blood ◽  
Cell Activation ◽  
Bifidobacterium Longum ◽  
Surface Markers ◽  
Cell Surface Markers ◽  
Atopic Diseases ◽  
Dendritic Cell Activation

ABSTRACT The gut microbiota may be important in the postnatal development of the immune system and hence may influence the prevalence of atopic diseases. Bifidobacteria are the most numerous bacteria in the guts of infants, and the presence or absence of certain species could be important in determining the geographic incidence of atopic diseases. We compared the fecal populations of bifidobacteria from children aged 25 to 35 days in Ghana (which has a low prevalence of atopy), New Zealand, and the United Kingdom (high-prevalence countries). Natal origin influenced the detection of bifidobacterial species in that fecal samples from Ghana almost all contained Bifidobacterium infantis whereas those of the other children did not. Choosing species on the basis of our bacteriological results, we tested bifidobacterial preparations for their effects on cell surface markers and cytokine production by dendritic cells harvested from cord blood. Species-specific effects on the expression of the dendritic-cell activation marker CD83 and the production of interleukin-10 (IL-10) were observed. Whereas CD83 expression was increased and IL-10 production was induced by Bifidobacterium bifidum, Bifidobacterium longum, and Bifidobacterium pseudocatenulatum, B. infantis failed to produce these effects. We concluded that B. infantis does not trigger the activation of dendritic cells to the degree necessary to initiate an immune response but that B. bifidum, B. longum, and B. pseudocatenulatum induce a Th2-driven immune response. A hypothesis is presented to link our observations to the prevalence of atopic diseases in different countries.

scholarly journals Specific interaction of lymphocyte function-associated antigen 3 with CD2 can inhibit T cell responses.

1993 ◽  
Vol 178 (1) ◽  
pp. 211-222 ◽  
Author(s):  
G T Miller ◽  
P S Hochman ◽  
W Meier ◽  
R Tizard ◽  
S A Bixler ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Surface ◽  
T Cell Activation ◽  
Cell Activation ◽  
Hepatitis B Surface Antigen ◽  
Specific Interaction ◽  
T Cell Responses ◽  
Accessory Cell ◽  
Lymphocyte Function ◽  
Cell Responses

Accessory cell surface molecules, such as T cell antigen CD2 and its ligand lymphocyte function-associated antigen 3 (LFA-3; CD58), are critical costimulatory pathways for optimal T cell activation in response to antigens. Interaction of CD2 with cell surface LFA-3 not only increases T cell/accessory cell adhesion, but also induces signal transduction events involved in the regulation of T cell responses. In this report, we show that specific interactions of LFA-3 with CD2 can result in T cell unresponsiveness to antigenic or mitogenic stimuli in vitro. By deletion of certain regions of the extracellular domain of LFA-3, we localized the CD2 binding site to the first domain of LFA-3. We then demonstrated that a soluble, purified first domain-LFA-3/IgG1 fusion protein (LFA3TIP) interacts with CD2 and binds to the same CD2 epitope as purified multimeric or cell surface-expressed LFA-3. LFA3TIP inhibits tetanus toxoid, hepatitis B surface antigen, anti-CD3 mAb, Con A, and phytohemagglutinin P-induced T cell proliferation, as well as xenogeneic and allogeneic mixed lymphocyte reactions (MLR). Unlike anti-LFA-3 or anti-CD2 monoclonal antibodies (mAbs) which inhibit T cell responses by blocking LFA-3/CD2 binding, LFA3TIP is capable of rendering T cells unresponsive to antigenic stimuli in situations where T cell activation is independent of CD2/LFA-3 interactions. Furthermore, LFA3TIP, but not blocking anti-CD2 mAbs, is capable of inducing T cell unresponsiveness to secondary stimulation in allogeneic MLR. This inhibition of T cell responses by LFA3TIP occurs through a different mechanism from that of mAbs to LFA-3 or CD2.

scholarly journals Downregulation of the T-Cell Receptor Complex and Impairment of T-Cell Activation by Human Herpesvirus 6 U24 Protein

2007 ◽  
Vol 82 (2) ◽  
pp. 602-608 ◽  
Author(s):  
Brian M. Sullivan ◽  
Laurent Coscoy
Keyword(s):  
T Cell ◽  
Cell Surface ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Cell Activation ◽  
Human Herpesvirus ◽  
Cell Receptor ◽  
Immune Recognition ◽  
Human Herpesvirus 6 ◽  
Herpesvirus 6

ABSTRACT We have performed a screen aimed at identifying human herpesvirus 6 (HHV-6)-encoded proteins that modulate immune recognition. Here we show that the U24 protein encoded by HHV-6 variant A downregulates cell surface expression of the T-cell receptor (TCR)/CD3 complex, a complex essential to T-cell activation and the generation of an immune adaptive response. In the presence of U24, the TCR/CD3 complex is endocytosed but is not recycled back to the plasma membrane. Instead, it accumulates in early and late endosomes. Interestingly, whereas CD3 downregulation from the cell surface is normally associated with T-cell activation, U24 downregulates CD3 independently of T-cell activation. Moreover, we found that U24-expressing T cells are resistant to activation by antigen-presenting cells. HHV-6 has evolved a unique mechanism of inhibition of T-cell activation that may impair the establishment of an adaptive immune response. Furthermore, lymphocyte activation creates an environment favorable to the reactivation and replication of lymphotropic herpesviruses. Thus, by inhibiting T-cell activation, HHV-6 might limit its reactivation and thus minimize immune recognition.

scholarly journals TMEM16F activation by Ca2+triggers plasmalemma expansion and directs PD-1 trafficking

2018 ◽  
Author(s):  
Christopher Bricogne ◽  
Michael Fine ◽  
Pedro M. Pereira ◽  
Julia Sung ◽  
Maha Tijani ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Surface ◽  
T Cell Activation ◽  
Membrane Trafficking ◽  
Large Scale ◽  
Cell Activation ◽  
Transmembrane Domain ◽  
Surface Membrane ◽  
Hek293 Cells

AbstractTMEM16F, an ion channel gated by high cytoplasmic Ca2+, is required for cell surface phosphatidylserine exposure during platelet aggregation and T cell activation. Here we demonstrate in Jurkat T cells and HEK293 cells that TMEM16F activation triggers large-scale surface membrane expansion in parallel with lipid scrambling. Following TMEM16F mediated scrambling and surface expansion, cells undergo extensive membrane shedding. The membrane compartment that expands the cell surface does not involve endoplasmic reticulum or acidified lysosomes. Surprisingly, T cells lacking TMEM16F expression not only fail to expand surface membrane, but instead rapidly internalize membrane via massive endocytosis (MEND). The T cell co-receptor PD-1 is selectively shed when TMEM16F triggers membrane expansion, while it is selectively internalized in the absence of TMEM16F. Its participation in this trafficking is determined by its single transmembrane domain. Thus, we establish a fundamental role for TMEM16F as a regulator of Ca2+-activated membrane trafficking.

scholarly journals Empty conformers of HLA-B preferentially bind CD8 and regulate CD8+ T cell function

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Jie Geng ◽  
John D Altman ◽  
Sujatha Krishnakumar ◽  
Malini Raghavan
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Surface ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Cell Function ◽  
Cd8 T Cell ◽  
Cell Surface Expression ◽  
Antigenic Peptides

When complexed with antigenic peptides, human leukocyte antigen (HLA) class I (HLA-I) molecules initiate CD8+ T cell responses via interaction with the T cell receptor (TCR) and co-receptor CD8. Peptides are generally critical for the stable cell surface expression of HLA-I molecules. However, for HLA-I alleles such as HLA-B*35:01, peptide-deficient (empty) heterodimers are thermostable and detectable on the cell surface. Additionally, peptide-deficient HLA-B*35:01 tetramers preferentially bind CD8 and to a majority of blood-derived CD8+ T cells via a CD8-dependent binding mode. Further functional studies reveal that peptide-deficient conformers of HLA-B*35:01 do not directly activate CD8+ T cells, but accumulate at the immunological synapse in antigen-induced responses, and enhance cognate peptide-induced cell adhesion and CD8+ T cell activation. Together, these findings indicate that HLA-I peptide occupancy influences CD8 binding affinity, and reveal a new set of regulators of CD8+ T cell activation, mediated by the binding of empty HLA-I to CD8.

scholarly journals Hypoxia is a dominant remodeler of the CD8+ T cell surface proteome relative to activation and regulatory T cell-mediated suppression

2021 ◽  
Author(s):  
James Robert Byrnes ◽  
Amy M Weeks ◽  
Julia Carnevale ◽  
Eric Shifrut ◽  
Lisa Kirkemo ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Surface ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Function ◽  
Metabolic Reprogramming ◽  
T Cell Function ◽  
Human T Cells ◽  
Surface Proteome

Immunosuppressive factors in the tumor microenvironment (TME) impair T cell function and limit the anti-tumor immune response. T cell surface receptors that influence interactions and function in the TME are already proven targets for cancer immunotherapy. However, surface proteome remodeling of primary human T cells in response to suppressive forces in the TME has never been characterized systematically. Using a reductionist cell culture approach with primary human T cells and SILAC-based quantitative cell surface capture glycoproteomics, we examined how two immunosuppressive TME factors, regulatory T cells (Tregs) and hypoxia, globally affect the activated CD8+ surface proteome (surfaceome). Surprisingly, the CD8+/Treg co-culture only modestly affected the CD8+ surfaceome, but did reverse several activation-induced surfaceomic changes. In contrast, hypoxia dramatically altered the CD8+ surfaceome in a manner consistent with both metabolic reprogramming and induction of an immunosuppressed state. The CD4+ T cell surfaceome similarly responded to hypoxia, revealing a novel hypoxia-induced surface receptor program. Our findings are consistent with the premise that hypoxic environments create a metabolic challenge for T cell activation, which may underlie the difficulty encountered in treating solid tumors with immunotherapies. Together, the data presented here provide insight into how suppressive TME factors remodel the T cell surfaceome and represent a valuable resource to inform future therapeutic efforts to enhance T cell function in the TME.

scholarly journals IL-2 receptors preassemble and signal in the ER/Golgi causing resistance to antiproliferative anti–IL-2Rα therapies

2019 ◽  
Vol 116 (42) ◽  
pp. 21120-21130 ◽  
Author(s):  
Julianna Volkó ◽  
Ádám Kenesei ◽  
Meili Zhang ◽  
Péter Várnai ◽  
Gábor Mocsár ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Surface ◽  
T Cell Activation ◽  
Cell Activation ◽  
Secretory Pathway ◽  
Interleukin 2 ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Correlation Spectroscopy ◽  
Autocrine Signaling

Interleukin-2 (IL-2) and IL-15 play pivotal roles in T cell activation, apoptosis, and survival, and are implicated in leukemias and autoimmune diseases. Their heterotrimeric receptors share their β- and γc-chains, but have distinct α-chains. Anti–IL-2Rα (daclizumab) therapy targeting cell surface-expressed receptor subunits to inhibit T cell proliferation has only brought limited success in adult T cell leukemia/lymphoma (ATL) and in multiple sclerosis. We asked whether IL-2R subunits could already preassemble and signal efficiently in the endoplasmic reticulum (ER) and the Golgi. A combination of daclizumab and anti–IL-2 efficiently blocked IL-2–induced proliferation of IL-2–dependent wild-type (WT) ATL cells but not cells transfected with IL-2, suggesting that in IL-2–producing cells signaling may already take place before receptors reach the cell surface. In the Golgi fraction isolated from IL-2–producing ATL cells, we detected by Western blot phosphorylated Jak1, Jak3, and a phosphotyrosine signal attributed to the γc-chain, which occurred at much lower levels in the Golgi of WT ATL cells. We expressed EGFP- and mCherry-tagged receptor chains in HeLa cells to study their assembly along the secretory pathway. Confocal microscopy, Förster resonance energy transfer, and imaging fluorescence cross-correlation spectroscopy analysis revealed partial colocalization and molecular association of IL-2 (and IL-15) receptor chains in the ER/Golgi, which became more complete in the plasma membrane, further confirming our hypothesis. Our results define a paradigm of intracellular autocrine signaling and may explain resistance to antagonistic antibody therapies targeting receptors at the cell surface.

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