scholarly journals Suboptimal SARS-CoV-2−specific CD8+ T cell response associated with the prominent HLA-A*02:01 phenotype

2020 ◽  
Vol 117 (39) ◽  
pp. 24384-24391 ◽  
Author(s):  
Jennifer R. Habel ◽  
Thi H. O. Nguyen ◽  
Carolien E. van de Sandt ◽  
Jennifer A. Juno ◽  
Priyanka Chaurasia ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Ex Vivo ◽  
T Cell Response ◽  
Clinical Severity ◽  
Effector Memory ◽  
Cell Mediated Immunity ◽  
Cell Memory ◽  
Activation Markers

An improved understanding of human T cell-mediated immunity in COVID-19 is important for optimizing therapeutic and vaccine strategies. Experience with influenza shows that infection primes CD8+ T cell memory to peptides presented by common HLA types like HLA-A2, which enhances recovery and diminishes clinical severity upon reinfection. Stimulating peripheral blood mononuclear cells from COVID-19 convalescent patients with overlapping peptides from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to the clonal expansion of SARS-CoV-2−specific CD8+ and CD4+ T cells in vitro, with CD4+ T cells being robust. We identified two HLA-A*02:01-restricted SARS-CoV-2-specfic CD8+ T cell epitopes, A2/S269–277 and A2/Orf1ab3183–3191. Using peptide−HLA tetramer enrichment, direct ex vivo assessment of A2/S269+CD8+ and A2/Orf1ab3183+CD8+ populations indicated that A2/S269+CD8+ T cells were detected at comparable frequencies (∼1.3 × 10−5) in acute and convalescent HLA-A*02:01+ patients. These frequencies were higher than those found in uninfected HLA-A*02:01+ donors (∼2.5 × 10−6), but low when compared to frequencies for influenza-specific (A2/M158) and Epstein–Barr virus (EBV)-specific (A2/BMLF1280) (∼1.38 × 10−4) populations. Phenotyping A2/S269+CD8+ T cells from COVID-19 convalescents ex vivo showed that A2/S269+CD8+ T cells were predominantly negative for CD38, HLA-DR, PD-1, and CD71 activation markers, although the majority of total CD8+ T cells expressed granzymes and/or perforin. Furthermore, the bias toward naïve, stem cell memory and central memory A2/S269+CD8+ T cells rather than effector memory populations suggests that SARS-CoV-2 infection may be compromising CD8+ T cell activation. Priming with appropriate vaccines may thus be beneficial for optimizing CD8+ T cell immunity in COVID-19.

scholarly journals Suboptimal SARS-CoV-2-specific CD8+ T-cell response associated with the prominent HLA-A*02:01 phenotype

2020 ◽  
Author(s):  
Jennifer R Habel ◽  
Thi H O Nguyen ◽  
Carolien E van de Sandt ◽  
Jennifer A Juno ◽  
Priyanka Chaurasia ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Ex Vivo ◽  
Cd8 T Cell ◽  
Clinical Severity ◽  
Effector Memory ◽  
Cell Mediated Immunity ◽  
Cell Memory ◽  
Activation Markers

An improved understanding of human T-cell-mediated immunity in COVID-19 is important if we are to optimize therapeutic and vaccine strategies. Experience with influenza shows that infection primes CD8+ T-cell memory to shared peptides presented by common HLA types like HLA-A2. Following re-infection, cross-reactive CD8+ T-cells enhance recovery and diminish clinical severity. Stimulating peripheral blood mononuclear cells from COVID-19 convalescent patients with overlapping peptides from SARS-CoV-2 Spike, Nucleocapsid and Membrane proteins led to the clonal expansion of SARS-CoV-2-specific CD8+ and CD4+ T-cells in vitro, with CD4+ sets being typically robust. For CD8+ T-cells taken directly ex vivo, we identified two HLA-A*02:01-restricted SARS-CoV-2 epitopes, A2/S269-277 and A2/Orf1ab3183-3191. Using peptide-HLA tetramer enrichment, direct ex vivo assessment of the A2/S269+CD8+ and A2/Orf1ab3183+CD8+ populations indicated that the more prominent A2/S269+CD8+ set was detected at comparable frequency (1.3x10-5) in acute and convalescent HLA-A*02:01+ patients. But, while the numbers were higher than those found in uninfected HLA-A*02:01+ donors (2.5x10-6), they were low when compared with frequencies for influenza-specific (A2/M158) and EBV-specific (A2/BMLF1280) (1.38x10-4) populations. Phenotypic analysis ex vivo of A2/S269+CD8+ T-cells from COVID-19 convalescents showed that A2/S269+CD8+ T-cells were predominantly negative for the CD38, HLA-DR, PD-1 and CD71 activation markers, although the majority of total CD8+ T-cells were granzyme and/or perforin-positive. Furthermore, the bias towards naive, stem cell memory and central memory A2/S269+CD8+ T-cells rather than effector memory populations suggests that SARS-CoV2 infection may be compromising CD8+ T-cell activation. Priming with an appropriate vaccine may thus have great value for optimizing protective CD8+ T-cell immunity in COVID-19.

Evaluation Of CD33 Expression and Functional Analysis Of The CD33/CD3 Bispecific BiTE® Antibody AMG 330 In Primary AML Samples

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 239-239 ◽  
Author(s):  
Christina Krupka ◽  
Peter Kufer ◽  
Roman Kischel ◽  
Gerhard Zugmaier ◽  
Jan Boegeholz ◽  
...  
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Ex Vivo ◽  
Natural Setting ◽  
Single Chain ◽  
Activation Markers ◽  
Expression Levels ◽  
Equity Ownership

Abstract Antibody-based immunotherapy represents a promising strategy to specifically target and eliminate chemoresistant leukemic cells in acute myeloid leukemia (AML). We evaluated a single-chain bispecific CD33/CD3 BiTE® antibody (AMG 330) for its suitability as immunotherapy in AML. A prerequisite for successful immunotherapeutic approaches using this molecule is the expression of CD33 on AML blasts including leukemic stem cells (LSCs). Therefore, we quantified CD33 expression on AML blasts and LSCs by flow cytometry (mean fluorescence intensity, MFI) and correlated expression intensity with cytogenetic and molecular disease characteristics in order to identify patient cohorts possibly most suited for CD33-targeted therapies. CD33 expression was detected in >99% of patient samples (n=621, MFI ratio ≥ 1.5) although highly variable. A strong correlation between high CD33 expression levels and NPM1 mutations (p<0.001) was found. In contrast, low CD33 expression levels were significantly associated with complex karyotypes and t(8,21) translocations (p<0.001). Furthermore, LSCs within the CD34+/CD38- compartment displayed CD33 at higher levels than healthy donor stem cells (p=0.047). Importantly, colony formation of CD34+/Lin-cells from healthy donors was not affected after pre-incubation with AMG 330 and T-cells. A major hurdle for measuring cytotoxic effects on AML blasts has long been that primary AML patient samples show progressive cell death within a few days ex-vivo. To simulate the natural setting of target and T-cells in AML patients, we developed a long-term culture system for AML blasts that allowed us to observe these co-cultures for up to 5 weeks. Thus, we were able to show effective elimination of AML blasts within primary samples by AMG 330-activated and expanded residual CD3+/CD45RA-/CCR7+ memory T-lymphocytes. While the functional relevance of CD33 expression levels was shown by faster lysis kinetics of CD33BRIGHT vs. CD33DIM AML cell lines in an in-vitro cytotoxicity assay potent anti-leukemic activity on primary AML blasts was observed irrespective of CD33 expression level. At low effector to target ratios (up to 1:79), the recruited T-cells lysed autologous blasts completely in the majority of samples. Further T-cell analysis showed that naive T-cells (CD45RA+/CCR7+) were not expanded by AMG 330; neither were terminally differentiated T-cells (CD45RA+/CCR7-), probably due to their poor proliferative capacity. We did not observe an increase in percentage of CD3+/CD4+/CD25+/FoxP3+regulatory T-cells in the presence of AMG 330, suggesting that these cells may not have impacted AMG 330-mediated T-cell activity in our experiments. Compared to control cultures, T-cells were shown to up-regulate the activation markers CD25, PD-1, TIM3 and LAG3 upon response to AMG 330, which was partially reversible after complete target cell elimination. However, PD-1 up-regulation did not correlate with an up-regulation of PD-L1 on AML blasts despite substantial INFγ secretion by activated T-cells. This study provides the first correlation of CD33 expression levels to a comprehensive genotype analysis in adult AML patients. While CD33 expression may vary by AML biologic subgroup, AMG 330 exposure led to lysis of AML blasts even in samples with low levels of expression. Targeting CD33 using AMG 330 in primary AML samples led to efficient T-cell activation and expansion as expected from the mechanism of action of BiTE® antibodies. The remarkable ex-vivo activity of AMG 330 supports further development of AMG 330 as an immunotherapy for patients with AML. Disclosures: Kufer: AMGEN Research (Munich) GmbH: Employment; AMGEN Inc.: Equity Ownership. Kischel:AMGEN Research (Munich) GmbH: Employment; AMGEN Inc.: Equity Ownership. Zugmaier:Amgen Research (Munich) GmbH: Employment; Amgen Inc.: Equity Ownership. Baeuerle:AMGEN Research (Munich) GmbH: Employment; AMGEN Inc.: Equity Ownership. Riethmüller:AMGEN Inc.: Equity Ownership.

scholarly journals Ex VivoRestimulation of Human PBMC Expands aCD3+CD4-CD8-γδ+T Cell Population That Can Confound the Evaluation of CD4 and CD8 T Cell Responses to Vaccination

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
B. J. Sedgmen ◽  
L. Papalia ◽  
L. Wang ◽  
A. R. Dyson ◽  
H. A. McCallum ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Cell Population ◽  
Large Scale ◽  
Ex Vivo ◽  
Vaccine Trial ◽  
T Cell Response ◽  
Study Cohort ◽  
Cell Mediated Immunity

The measurement of vaccine-induced humoral andCD4+andCD8+cellular immune responses represents an important correlate of vaccine efficacy. Accurate and reliable assays evaluating such responses are therefore critical during the clinical development phase of vaccines. T cells play a pivotal role both in coordinating the adaptive and innate immune responses and as effectors. During the assessment of cell-mediated immunity (CMI) in subjects participating in a large-scale influenza vaccine trial, we identified the expansion of an IFN-γ-producingCD3+CD4-CD8-γδ+T cell population in the peripheral blood of 90/610 (15%) healthy subjects. The appearance ofCD3+CD4-CD8-γδ+T cells in the blood of subjects was transient and found to be independent of the study cohort, vaccine group, subject gender and ethnicity, andex vivorestimulation conditions. Although the function of this population and relevance to vaccination are unclear, their inclusion in the total vaccine-specific T-cell response has the potential to confound data interpretation. It is thus recommended that when evaluating the induction of IFN-γ-producingCD4+andCD8+immune responses following vaccination, theCD3+CD4-CD8-γδ+T cells are either excluded or separately enumerated from the overall frequency determination.

scholarly journals Human Memory CD4+T Cell Immune Responses against Giardia lamblia

2015 ◽  
Vol 23 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Christina Skår Saghaug ◽  
Steinar Sørnes ◽  
Dimitra Peirasmaki ◽  
Staffan Svärd ◽  
Nina Langeland ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Giardia Lamblia ◽  
Mononuclear Cells ◽  
T Cell Response ◽  
Effector Memory ◽  
Content Type ◽  
Tnf Α

ABSTRACTThe intestinal protozoan parasiteGiardia lambliamay cause severe prolonged diarrheal disease or pass unnoticed as an asymptomatic infection. T cells seem to play an important role in the immune response toGiardiainfection, and memory responses may last years. Recently, TH17 responses have been found in three animal studies ofGiardiainfection. The aim of this study was to characterize the human CD4+T cell responses toGiardia. Peripheral blood mononuclear cells (PBMCs) were obtained from 21 returning travelers with recent or ongoing giardiasis and 12 low-risk healthy controls and stimulatedin vitrowithGiardia lambliaproteins. Production of tumor necrosis factor alpha (TNF-α), gamma interferon, interleukin-17A (IL-17A), IL-10, and IL-4 was measured in CD4+effector memory (EM) T cells after 24 h by flow cytometry. After 6 days of culture, activation and proliferation were measured by flow cytometry, while an array of inflammatory cytokine levels in supernatants were measured with multiplex assays. We found the number of IL-17A-producing CD4+EM T cells, as well as that of cells simultaneously producing both IL-17A and TNF-α, to be significantly elevated in theGiardia-exposed individuals after 24 h of antigen stimulation. In supernatants of PBMCs stimulated withGiardiaantigens for 6 days, we found inflammation-associated cytokines, including 1L-17A, as well as CD4+T cell activation and proliferation, to be significantly elevated in theGiardia-exposed individuals. We conclude that symptomaticGiardiainfection in humans induces a CD4+EM T cell response of which IL-17A production seems to be an important component.

scholarly journals CTLA-4–B7 Interaction Is Sufficient to Costimulate T Cell Clonal Expansion

1997 ◽  
Vol 185 (7) ◽  
pp. 1327-1336 ◽  
Author(s):  
Yan Wu ◽  
Yong Guo ◽  
Andy Huang ◽  
Pan Zheng ◽  
Yang Liu
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Response ◽  
Cell Activation ◽  
Critical Role ◽  
Clonal Expansion ◽  
T Cell Response ◽  
Cell Mediated Immunity ◽  
Cell Clonal Expansion

T cell costimulation, particularly by the B7 family members B7-1 and B7-2, plays a critical role in regulating T cell–mediated immunity. Two molecules on T cells, CD28 and CTLA-4, are known to bind to B7. It has been suggested that CD28–B7 interaction promotes T cell response, whereas B7–CTLA-4 interaction downregulates T cell clonal expansion. However, the proposed responses of individual receptors to B7 have not been verified directly. Here, we report that B7-1 promotes clonal expansion of CD28-deficient T cells, and that the CD28-independent costimulatory activity is mediated by CTLA-4, as it is completely blocked by intact and Fab of anti–CTLA-4 mAb. In addition, a mutant B7-1 molecule, B7W88 &gt;A, which has lost binding to CD28 but retained significant CTLA-4 binding activity, promotes T cell clonal expansion. Furthermore, while presence of CD28 enhances T cell response to B7-1, such response is also completely blocked by anti–CTLA-4 mAb. Taken together, our results demonstrate that B7–CTLA-4 interaction promotes T cell clonal expansion, and that optimal T cell response to B7 is achieved when both CD28 and CTLA-4 interact with B7. These results establish an important function of CTLA-4 in promoting T cell activation, and suggest an alternative interpretation of the function of CTLA-4 in T cell activation.

scholarly journals Biomarkers for Comorbidities Modulate the Activity of T-Cells in COPD

2021 ◽  
Vol 22 (13) ◽  
pp. 7187
Author(s):  
Kaschin Jamal Jameel ◽  
Willem-Jakob Gallert ◽  
Sarah D. Yanik ◽  
Susanne Panek ◽  
Juliane Kronsbein ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Systemic Inflammation ◽  
T Cell Activation ◽  
Cell Activation ◽  
Ex Vivo ◽  
Enzyme Linked Immunosorbent Assay ◽  
Activation Markers ◽  
Gm Csf

In smoking-induced chronic obstructive pulmonary disease (COPD), various comorbidities are linked to systemic inflammation and infection-induced exacerbations. The underlying mechanisms are unclear but might provide therapeutic targets. T-cell activity is central in systemic inflammation and for infection-defense mechanisms and might be influenced by comorbidities. Hypothesis: Circulating biomarkers of comorbidities modulate the activity of T-cells of the T-helper type 1 (Th1) and/or T-cytotoxic type 1 (Tc1). T-cells in peripheral blood mononuclear cells (PBMCs) from non-smokers (NS), current smokers without COPD (S), and COPD subjects (total n = 34) were ex vivo activated towards Th1/Tc1 and were then stimulated with biomarkers for metabolic and/or cardiovascular comorbidities (Brain Natriuretic Peptide, BNP; chemokine (C-C motif) ligand 18, CCL18; C-X3-C motif chemokine ligand 1, CX3CL1; interleukin-18, IL-18) or for asthma- and/or cancer-related comorbidities (CCL22; epidermal growth factor, EGF; IL-17; periostin) each at 10 or 50 ng/mL. The Th1/Tc1 activation markers interferon-γ (IFNγ), tumor necrosis factor-α (TNFα), and granulocyte-macrophage colony-stimulating factor (GM-CSF) were analyzed in culture supernatants by Enzyme-Linked Immunosorbent Assay (ELISA). Ex-vivo activation induced IFNγ and TNFα without differences between the groups but GM-CSF more in S vs. NS. At 10 ng/mL, the different biomarkers increased or reduced the T-cell activation markers without a clear trend for one direction in the different categories of comorbidities or for the different T-cell activation markers. At 50 ng/mL, there was a clear shift towards suppressive effects, particularly for the asthma— and cancer-related biomarkers and in cells of S and COPD. Comorbidities might suppress T-cell immunity in COPD. This could explain the association of comorbidities with frequent exacerbations.

scholarly journals Blockade of β-adrenergic receptor signaling improves cancer vaccine efficacy through its effect on naive CD8+ T-cell priming

2018 ◽  
Author(s):  
Clara Daher ◽  
Lene Vimeux ◽  
Ralitsa Stoeva ◽  
Elisa Peranzoni ◽  
Georges Bismuth ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Adrenergic Receptor ◽  
Cell Activation ◽  
Ex Vivo ◽  
T Cell Response ◽  
Differential Sensitivity ◽  
Priming Phase

Abstractβ-adrenergic receptor (β-AR) signaling, by acting directly on tumor cells and angiogenesis, has been showed to exert pro-tumoral effects. Growing evidence also suggests that β-AR expressed by immune cells affect the associated anti-tumor immune response. However, how and where β-AR signaling impinges the anti-tumor immune response is still unclear. Using a mouse model of vaccine-based immunotherapy, we show here that propranolol, a non-selective β-blocker, strongly improved the efficacy of the vaccine by enhancing the frequency of CD8+ T lymphocytes infiltrating the tumor (TILs). However, propranolol had no obvious effect on the reactivity of CD8+ TILs, a result further strengthened by ex-vivo experiments showing that these cells are insensitive to AR signaling triggered by adrenaline or noradrenaline. In contrast, we show that naive CD8+ T cell activation was strongly inhibited by β-AR signaling and that the beneficial effect of propranolol mainly occurred during their initial priming phase. We also demonstrate that the differential sensitivity of CD8+ TILs and naive CD8+ T cells is related to their activation status since in vitro-activated CD8+ T cells behaved similarly to CD8+ TILs, both exhibiting a down-regulation of the β2-AR expression. These results reveal that the initial priming phase of the anti-tumor response in the tumor-draining lymph node is a decisive part of the suppressive effect of β-AR signaling on the CD8+ T-cell response against cancer. These findings provide a rationale for the strategic use of clinically available β-blockers in patients to improve cancer immunotherapies such as anti-cancer vaccination strategies.

scholarly journals Analysis of tumor-infiltrating NK and T cells highlights IL-15 stimulation and TIGIT blockade as a combination immunotherapy strategy for soft tissue sarcomas

2020 ◽  
Vol 8 (2) ◽  
pp. e001355
Author(s):  
Sean J Judge ◽  
Morgan A Darrow ◽  
Steve W Thorpe ◽  
Alicia A Gingrich ◽  
Edmond F O'Donnell ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Soft Tissue ◽  
T Cell Activation ◽  
Ex Vivo ◽  
Unmet Need ◽  
Soft Tissue Sarcomas ◽  
Cell Phenotype ◽  
Activation Markers ◽  
And Function

PurposeGiven the unmet need for novel immunotherapy in soft tissue sarcoma (STS), we sought to characterize the phenotype and function of intratumoral natural killer (NK) and T cells to identify novel strategies to augment tumor-infiltrating lymphocyte (TIL) function.Experimental designUsing prospectively collected specimens from dogs and humans with sarcomas, archived specimens, and The Cancer Genome Atlas (TCGA) data, we evaluated blood and tumor NK and T cell phenotype and function and correlated those with outcome. We then assessed the effects of interleukin 15 (IL-15) stimulation on both NK and T cell activation and TIGIT upregulation. Finally, we evaluated cytotoxic effects of IL-15 combined with TIGIT blockade using a novel anti-TIGIT antibody.ResultsTILs were strongly associated with survival outcome in both archived tissue and TCGA, but higher TIL content was also associated with higher TIGIT expression. Compared with blood, intratumoral NK and T cells showed significantly higher expression of both activation and exhaustion markers, in particular TIGIT. Ex vivo stimulation of blood and tumor NK and T cells from patients with STS with IL-15 further increased both activation and exhaustion markers, including TIGIT. Dogs with metastatic osteosarcoma receiving inhaled IL-15 also exhibited upregulation of activation markers and TIGIT. Ex vivo, combined IL-15 and TIGIT blockade using STS blood and tumor specimens significantly increased cytotoxicity against STS targets.ConclusionIntratumoral NK and T cells are prognostic in STS, but their activation is marked by significant upregulation of TIGIT. Our data suggest that combined IL-15 and TIGIT blockade may be a promising clinical strategy in STS.

Adjuavnt tyrosinase peptide vaccination in patients with resected stage III/IV melanoma

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 2570-2570
Author(s):  
A. Letsch ◽  
C. Scheibenbogen ◽  
M. Fluck ◽  
A. Asemissen ◽  
D. Nagorsen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Disease Progression ◽  
Clinical Efficacy ◽  
Ex Vivo ◽  
T Cell Response ◽  
Stage Iii ◽  
Effector Memory ◽  
Rapid Progression ◽  
Melanoma Patients

2570 Background: This phase II study was undertaken to evaluate the immunogenicity and clinical efficacy of vaccination with tyrosinase peptides as adjuvant treatment in melanoma patients after multiple relapses. Methods: Stage III/IV melanoma patients after complete resection of relapses were vaccinated with tyrosinase peptides together with GM-CSF and KLH. Vaccination was given bi-weekly times 4, followed by monthly times 8 in absence of relevant disease progression. Tyrosinase-specific T cells were quantitated and characterized ex vivo by intracellular cytokine flow cytometry. Results: 44 patients were accrued with a median of 5.8 (range 2–25) previous relapses at cutaneous /s.c. only (n = 11), ln (n = 30) and/or visceral sites (n = 7). 11 patients received less than 6 vaccinations due to rapid progression. Of 32 patients evaluable for immunological response 16 (50%) displayed pre-vaccine spontaneous tyrosinase-specific T cells (median 0.32%). In 7 of the 15 patients without pre-existing T cells tyrosinase-specific T cells were induced after 6 vaccinations (median 0.08% CD3+CD8+ T cells) and in 10 of 12 patients after 12 vaccinations (median 0.36%, p = 0.03 compared to 6 vaccinations). Similarly, in 9 of the 16 patients with pre-existing T cell responses the frequency of tyrosinase-specific T cells did increase after 6 cycles (median 0.43 %), but in none of 10 patients with pre-existing T cells an increase was observed after 12 vaccinations (median 0.20%). Both, the spontaneous and the vaccine-induced T cells were predominantly of effector and effector-memory phenotype. With respect to clinical efficacy vaccination was terminated after 3 to 9 cycles due to disease progression in 19 of 44 patients. Of the remaining 25 patients receiving all 12 vaccinations 7 (16% of all 44 enrolled) had a favourable clinical course with cessation of recurrences. Conclusions: Taken together, this study shows high immunogenicity of the vaccine in patients with limited tumor burden associated with clinical efficacy. In case of a spontaneous pre-existing T cell response to the vaccine peptides, however, this could not, or only transiently be augmented. No significant financial relationships to disclose.

scholarly journals Regulation of T cell receptor signaling by protein acyltransferase DHHC21

2020 ◽  
Author(s):  
Ying Fan ◽  
Bieerkehazhi Shayahati ◽  
Ritika Tewari ◽  
Darren Boehning ◽  
Askar M. Akimzhanov
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Signaling ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
Cell Receptor ◽  
Cell Mediated Immunity ◽  
T Cell Signaling ◽  
Activation Markers ◽  
Dhhc Protein

ABSTRACTS-acylation – reversible post-translational lipidation of cysteine residues – is emerging as an important regulatory mechanism in T cell signaling. Dynamic S-acylation is critical for protein recruitment into the T cell receptor complex and initiation of the subsequent signaling cascade. However, the enzymatic control of protein S-acylation in T cells remains poorly understood. Here, we report a previously uncharacterized role of DHHC21, a member of the mammalian family of DHHC protein acyltransferases, in regulation of the T cell receptor pathway. We found that loss of DHHC21 prevented S-acylation of key T cell signaling proteins, resulting in disruption of the early signaling events and suppressed expression of T cell activation markers. Furthermore, downregulation of DHHC21 prevented activation and differentiation of naïve T cells into effector subtypes. Together, our study provides the first direct evidence that DHHC protein acyltransferases can play an essential role in regulation of T cell-mediated immunity.

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