IMMU-36. B CELL-VACCINE ELICITS LONG TERM IMMUNITY AGAINST GLIOBLASTOMA VIA ACTIVATION AND DIFFERENTIATION OF TUMOR-SPECIFIC CD8+ MEMORY T CELLS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi100-vi100
Author(s):  
David Hou ◽  
Brandyn Castro ◽  
Mark Dapash ◽  
Aida Rashidi ◽  
Peng Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Tumor Bearing

Abstract While immunotherapy is used clinically to treat many cancers, its translation into brain tumors remains elusive. The importance of B cells in cancer immunity has become increasingly clear, and we previously developed a B cell-based cellular vaccine (BVax) against glioblastoma (GBM) by further activating 4-1BBL+ B cells with CD40 agonism and IFNγ. BVax were characterized as professional antigen-presenting cells (APCs) that promote CD8+ T cell migration and persistence in murine tumor-bearing brains. This study seeks to understand the mechanisms underlying BVax-induced CD8+ T cell fitness in the tumor microenvironment. Initial transcriptomic analysis highlighted that Bvax express high levels of IL15Rα, indicating their potential ability to trans-present IL15. Considering IL15 trans-presentation is fundamental in T-cell memory differentiation, we used BVax to induce T cell activation in the presence of exogenous IL15. BVax were better capable of activating antigen-specific CD8+ T cells and promoting a memory phenotype when compared to other professional APCs such as dendritic cells (DCs). T cell receptor (TCR) CDR3β sequencing showed that BVax expanded a number of TCR clones in-vitro that were found in brains of CT2A tumor-bearing mice in-vivo. These BVax-activated CD8+ T cells displayed a stronger antigen recall response and unique metabolic profile compared to DC-activated CD8+ T cells as shown by metabolomic analysis of tumor-infiltrating CD8+ T cells. When comparing the anti-tumor effects of CD8+ T cells activated by various APCs, BVax with exogenous IL15 promoted CD8+ T cells that displayed the most potent cytotoxicity against GBM cells in-vitro. Collectively, this study suggests that the IL15/IL15Rα axis and interactions with CD8+ T cell are key factors of BVax therapy in promoting a robust survival benefit and long-term immunologic memory against GBM in preclinical models. Additionally, the development of T cell therapies based on B cell licensing can be a promising future approach for glioblastoma therapy.

scholarly journals IL4I1 Accelerates the Expansion of Effector CD8+ T Cells at the Expense of Memory Precursors by Increasing the Threshold of T-Cell Activation

2020 ◽  
Vol 11 ◽  
Author(s):  
Marie-Line Puiffe ◽  
Aurélie Dupont ◽  
Nouhoum Sako ◽  
Jérôme Gatineau ◽  
José L. Cohen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Cell Clone ◽  
Cd8 T Cell ◽  
Lymphocytic Choriomeningitis ◽  
T Cell Clone

IL4I1 is an immunoregulatory enzyme that inhibits CD8 T-cell proliferation in vitro and in the tumoral context. Here, we dissected the effect of IL4I1 on CD8 T-cell priming by studying the differentiation of a transgenic CD8 T-cell clone and the endogenous repertoire in a mouse model of acute lymphocytic choriomeningitis virus (LCMV) infection. Unexpectedly, we show that IL4I1 accelerates the expansion of functional effector CD8 T cells during the first several days after infection and increases the average affinity of the elicited repertoire, supporting more efficient LCMV clearance in WT mice than IL4I1-deficient mice. Conversely, IL4I1 restrains the differentiation of CD8 T-cells into long-lived memory precursors and favors the memory response to the most immunodominant peptides. IL4I1 expression does not affect the phenotype or antigen-presenting functions of dendritic cells (DCs), but directly reduces the stability of T-DC immune synapses in vitro, thus dampening T-cell activation. Overall, our results support a model in which IL4I1 increases the threshold of T-cell activation, indirectly promoting the priming of high-affinity clones while limiting memory T-cell differentiation.

Leukemia-associated monoclonal and oligoclonal TCR-BV use in patients with B-cell chronic lymphocytic leukemia

Blood ◽  
2003 ◽  
Vol 101 (3) ◽  
pp. 1063-1070 ◽  
Author(s):  
Mohammad-Reza Rezvany ◽  
Mahmood Jeddi-Tehrani ◽  
Hans Wigzell ◽  
Anders Österborg ◽  
Håkan Mellstedt
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Cd8 T Cells ◽  
Leukemia Cell ◽  
Lymphocytic Leukemia ◽  
Cell Chronic Lymphocytic Leukemia

Abstract T-cell receptor–B-variable (TCR-BV) gene usage and the CDR3 size distribution pattern were analyzed by reverse transcription–polymerase chain reaction (RT-PCR) in patients with B-cell chronic lymphocytic leukemia (B-CLL) to assess the T-cell repertoire. The use of TCR-BV families in CD4 and CD8 T cells stimulated with autologous activated leukemic cells was compared with that of freshly obtained blood T cells. Overexpression of individual TCR-BV families was found in freshly isolated CD4 and CD8 T cells. Polyclonal, oligoclonal, and monoclonal TCR-CDR3 patterns were seen within such overexpressed native CD4 and CD8 TCR-BV families. In nonoverexpressed TCR-BV families, monoclonal and oligoclonal populations were noted only within the CD8 subset. After in vitro stimulation of T cells with autologous leukemic B cells, analyses of the CDR3 length patterns showed that in expanded TCR-BV populations, polyclonal patterns frequently shifted toward a monoclonal/oligoclonal profile, whereas largely monoclonal patterns in native overexpressed TCR-BV subsets remained monoclonal. Seventy-five percent of CD8 expansions found in freshly obtained CD8 T cells further expanded on in vitro stimulation with autologous leukemic B cells. This suggests a memory status of such cells. In contrast, the unusually high frequency of CD4 T-cell expansions found in freshly isolated peripheral blood cells did not correlate positively to in vitro stimulation as only 1 of 9 expansions continued to expand. Our data suggest that leukemia cell–specific memory CD4 and CD8 T cells are present in vivo of patients with CLL and that several leukemia cell–associated antigens/epitopes are recognized by the patients' immune system, indicating that whole leukemia cells might be of preference for vaccine development.

scholarly journals Obligatory Requirement for Antibody in Recovery from a Primary Poxvirus Infection

2006 ◽  
Vol 80 (13) ◽  
pp. 6339-6344 ◽  
Author(s):  
Geeta Chaudhri ◽  
Vijay Panchanathan ◽  
Horst Bluethmann ◽  
Gunasegaran Karupiah
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd8 T Cells ◽  
Cell Function ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Ectromelia Virus ◽  
B Cell Function

ABSTRACT To understand the correlates of protective immunity against primary variola virus infection in humans, we have used the well-characterized mousepox model. This is an excellent surrogate small-animal model for smallpox in which the disease is caused by infection with the closely related orthopoxvirus, ectromelia virus. Similarities between the two infections include virus replication and transmission, aspects of pathology, and development of pock lesions. Previous studies using ectromelia virus have established critical roles for cytokines and effector functions of CD8 T cells in the control of acute stages of poxvirus infection. Here, we have used mice deficient in B cells to demonstrate that B-cell function is also obligatory for complete virus clearance and recovery of the host. In the absence of B cells, virus persists and the host succumbs to infection, despite the generation of CD8 T-cell responses. Intriguingly, transfer of naive B cells or ectromelia virus-immune serum to B-cell-deficient mice with established infection allowed these animals to clear virus and fully recover. In contrast, transfer of ectromelia virus-immune CD8 T cells was ineffective. Our data show that mice deficient in CD8 T-cell function die early in infection, whereas those deficient in B cells or antibody production die much later, indicating that B-cell function becomes critical after the effector phase of the CD8 T-cell response to infection subsides. Strikingly, our results show that antibody prevents virus from seeding the skin and forming pock lesions, which are important for virus transmission between hosts.

scholarly journals CD8 Effector T Cells Function Synergistically With Broadly Neutralizing Antibodies to Enhance Suppression of HIV Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Rebecca T. Veenhuis ◽  
Caroline C. Garliss ◽  
Justin R. Bailey ◽  
Joel N. Blankson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Viral Replication ◽  
Cd8 T Cells ◽  
Neutralizing Antibodies ◽  
Cd8 T Cell ◽  
Combinatorial Approach ◽  
Broadly Neutralizing Antibodies

HIV-specific CD8 T cells and broadly neutralizing antibodies (bNAbs) both contribute to the control of viremia, but in most cases, neither can completely suppress viral replication. To date, therapeutic vaccines have not been successful in eliciting HIV-specific CD8 T cell or bNAb responses that are capable of preventing long-term viral rebound upon ART cessation. These challenges suggest that a combinatorial approach that harnesses both bNAbs and CD8 T cell responses may be necessary for long term control of viral replication. In this study we demonstrate a synergistic interaction between CD8 T cells and bNAbs using an in vitro model. Our data suggest that this combinatorial approach is very effective at suppressing viral replication in vitro and should be considered in future therapeutic studies.

T Cell Pathway Deficiencies in Chronic Lymphocityc Leukemia: Partial Restoration with OKT3/IL-2 Activation.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4692-4692
Author(s):  
Mauro Di Ianni ◽  
Lorenzo Moretti ◽  
Beatrice Del Papa ◽  
Maria De Ioanni ◽  
Adelmo Terenzi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Activated T Cells ◽  
Mutational Status ◽  
The Impact

Abstract As Chronic Lymphocytic Leukemia (CLL) is associated with several defects in the T cell compartment, the impact of tumour burden on the autologous immune system was studied. Gene expression profiles (using Applied Biosystem Human Genome Microarray) identified 237 genes with significantly increased expression and 221 genes with significantly decreased expression (p<0.05) in CD3+ cells from CLL patients compared with healthy donors. Panther software analysis identified 34/237 upregulated genes and 26/221 downregulated genes that were involved in specific pathways, mainly cell differentiation and proliferation, survival, apoptosis, cytoskeleton formation, vesicle trafficking and T cell activation. The 26 dowregulated genes included Zap70, a member of the syk family protein tyrosine kinase, which is involved in T-cell activation. Zap-70 results were validated by mRNA quantification by RT-PCR (−1.77 fold in comparison with healthy controls) and by flow-cytometric analysis (Mean Intensity Fluorescence=33±12 vs 80±23.62 in controls, p<0.05). To test the hypothesis that activation with OKT3 /IL-2 could bypass these T cell deficiencies, activated T cells from 20 patients with CLL were tested in vitro for cytotoxicity (using the 51chromium release assay) against mutated and unmutated (according to IgVH mutational status) autologous B cells, DAUDI, K562 and P815 cell lines. After 10 days’ culture, the T cell count remained unchanged; CD8 cells expanded more than CD4; TCR spectratyping analysis indicated no differences in TCR repertoires. Activation restored the ZAP-70 mRNA (+1.67 fold). The 51chromium release cytotoxicity assay showed an index > 30% in 5/20 patients. The other 15 were partially cytotoxic against P815, K562 and Daudi. Cell line analysis in all 20 confirmed prevalently T cell-mediated cytotoxicity and poor NK/LAK activity. Cytotoxicity did not correlate with B cell mutational status. We tested the cytotoxic activity of autologous activated T cells in NOD/SCID mice co-transplanted with leukaemic B cells. Only activated T cells exerting cytotoxicity vs autologous B-cell CLL prevent CLL in human-mouse chimera, as confirmed by PCR and FACS analysis which visualised only CD3+ cells. In conclusion, in patients with CLL, activating autologous T cells with OKT3 /IL-2 bypasses, at least in part, the T cell immunological deficiencies. These in vitro and in vivo findings might serve to throw light on new mechanisms that could be exploited in immunotherapy designed to exert disease control.

scholarly journals Lack of B Lymphocytes Enhances CD8 T Cell-Mediated Resistance against Respiratory Viral Infection but Compromises Memory Cell Formation

2019 ◽  
Vol 94 (3) ◽  
Author(s):  
Pritesh Desai ◽  
Jessica Stanfield ◽  
Vikas Tahiliani ◽  
Georges Abboud ◽  
Shahram Salek-Ardakani
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Viral Infection ◽  
B Cell ◽  
Cd8 T Cells ◽  
Host Resistance ◽  
Memory Cell ◽  
Cd8 T Cell ◽  
Respiratory Viral Infection

ABSTRACT Following a respiratory virus infection, CXCR3hi CX3CR1lo and CXCR3lo CX3CR1hi CD8 T cells localize to different compartments within the lung and play an important role in host resistance, but mechanisms governing their optimal generation are poorly defined. We serendipitously found that B cell-deficient (μMT−/−) mice were highly resistant to lethal infection with a virulent poxvirus strain and that depletion of CD8 T cells rendered these mice susceptible to infection. B cells were not required for the expansion of virus-specific CD8 T cells, but a greater proportion of activated CD8 T cells acquired an effector-like CXCR3lo CX3CR1hi phenotype in the absence of B cells. After recovery from infection, CD8 T cells in μMT−/− mice contracted normally but failed to survive and seed the memory cell pool in both the lungs and spleen. These findings reveal a previously unappreciated role for B cells in regulating the balance between CD8 T cell-mediated resistance against respiratory viral infection and memory cell development. IMPORTANCE B cells play critical role in host resistance against many respiratory viral infections. However, the role of B cells beyond antibody-producing cells is less well defined. In this study, we made a surprising observation that mice lacking B cells were more resistant to respiratory infection with vaccinia virus than wild-type mice. This enhanced resistance was mediated by CD8 T cells because when we depleted CD8 T cells in B cell-deficient mice, these mice were unable to survive the infection. Interestingly, CD8 T cells in B cell-deficient mice were skewed more toward effector phenotype and less toward memory phenotype, which resulted in severely compromised memory CD8 T cell development. Thus, our study shows a novel role of B cells as regulators of CD8 T cell-mediated host resistance and memory CD8 T cell formation during respiratory viral infection.

scholarly journals The CD8 T Cell-Epstein-Barr Virus-B Cell Trialogue: A Central Issue in Multiple Sclerosis Pathogenesis

2021 ◽  
Vol 12 ◽  
Author(s):  
Caterina Veroni ◽  
Francesca Aloisi
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd8 T Cells ◽  
Epstein Barr Virus ◽  
Cd8 T Cell ◽  
Barr Virus ◽  
Epstein Barr

The cause and the pathogenic mechanisms leading to multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system (CNS), are still under scrutiny. During the last decade, awareness has increased that multiple genetic and environmental factors act in concert to modulate MS risk. Likewise, the landscape of cells of the adaptive immune system that are believed to play a role in MS immunopathogenesis has expanded by including not only CD4 T helper cells but also cytotoxic CD8 T cells and B cells. Once the key cellular players are identified, the main challenge is to define precisely how they act and interact to induce neuroinflammation and the neurodegenerative cascade in MS. CD8 T cells have been implicated in MS pathogenesis since the 80’s when it was shown that CD8 T cells predominate in MS brain lesions. Interest in the role of CD8 T cells in MS was revived in 2000 and the years thereafter by studies showing that CNS-recruited CD8 T cells are clonally expanded and have a memory effector phenotype indicating in situ antigen-driven reactivation. The association of certain MHC class I alleles with MS genetic risk implicates CD8 T cells in disease pathogenesis. Moreover, experimental studies have highlighted the detrimental effects of CD8 T cell activation on neural cells. While the antigens responsible for T cell recruitment and activation in the CNS remain elusive, the high efficacy of B-cell depleting drugs in MS and a growing number of studies implicate B cells and Epstein-Barr virus (EBV), a B-lymphotropic herpesvirus that is strongly associated with MS, in the activation of pathogenic T cells. This article reviews the results of human studies that have contributed to elucidate the role of CD8 T cells in MS immunopathogenesis, and discusses them in light of current understanding of autoreactivity, B-cell and EBV involvement in MS, and mechanism of action of different MS treatments. Based on the available evidences, an immunopathological model of MS is proposed that entails a persistent EBV infection of CNS-infiltrating B cells as the target of a dysregulated cytotoxic CD8 T cell response causing CNS tissue damage.

Low Incidence of Post-Transplant EBV-Related Disease After Alemtuzumab-Mediated T Cell Depletion Is Explained by the Differential Susceptibility to Alemtuzumab of B Cells and Protective CD8 and CD4 T Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2330-2330
Author(s):  
Constantijn J.M. Halkes ◽  
Inge Jedema ◽  
Judith Olde Wolbers ◽  
Esther M van Egmond ◽  
Peter A. Von Dem Borne ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Cell Depletion ◽  
T Cell Depletion

Abstract Abstract 2330 In vivo T cell depletion with anti-thymocyte globulin (ATG) or alemtuzumab (anti-CD52) before reduced intensity allogeneic stem cell transplantation (alloSCT) in combination with in vitro T cell depletion with alemtuzumab reduces the risk of GVHD. Detectable levels of circulating antibodies are present up to several months after the alloSCT, leading to a delayed immune reconstitution which is associated with an increased incidence of opportunistic infections and early relapses. Prior to 2007, combined in vitro (Alemtuzumab 20 mg added “to the bag”) and in vivo T cell depletion with horse-derived ATG (h-ATG) resulted in good engraftment without GVHD in the absence of GVHD prophylaxis after reduced intensity alloSCT using conditioning with fludarabine and busulphan. Due to the unavailability of h-ATG, rabbit-derived ATG (r-ATG) 10–14 mg/kg was introduced in the conditioning regimen in 2007. Strikingly, in this cohort of patients, early EBV reactivation and EBV-associated post-transplantation lymphoproliferative disease (PTLD) was observed in 10 out of 18 patients at a median time of 6 weeks after alloSCT (range 5 to 11 weeks) in the absence of GVHD or immunosuppressive treatment. Analysis of T and B cell recovery early after transplantation revealed preferential depletion of T cells as compared to B cells, thereby allowing unrestricted proliferation of EBV infected B cells. Due to this unacceptable high incidence of EBV-related complications, in the conditioning regimen r-ATG was replaced by low dose alemtuzumab (15 mg i.v. day -4 and -3) in 2008. In this cohort of 60 patients, only 2 patients experienced transient EBV reactivation during the first 3 months after alloSCT and one patient developed an EBV-associated lymphoma 4 weeks after alloSCT. To investigate the mechanisms underlying the low incidence of EBV reactivation using alemtuzumab for T cell depletion, we studied the in vivo and in vitro effects of alemtuzumab on different lymphocyte subsets. First, lineage-specific reconstitution was studied in 20 patients from the alemtuzumab cohort with known CD52 negative diseases (11 AML and 9 multiple myeloma) to exclude the confounding effect of antibody absorption by malignant cells. Whereas at 3 weeks after alloSCT detectable numbers of circulating NK cells and T cells were observed (medians 71 (range 6–378), and 12 (range 1–1164)E6/L, respectively), no circulating B cells could be detected (median 0, range 0–1 E6/L). At 6 weeks after alloSCT, NK and T cell numbers further increased (medians 212 (52-813), and 130 (range 25–1509)E6/L, respectively), whereas B cell numbers still remained low in the majority of patients (median 15, range 0–813E6/L). In all patients, T cells were detectable before the appearance of circulating B cells. Furthermore, the expression of CD52 and the sensitivity to alemtuzumab-mediated complement-dependent cell lysis (CDC) of B cells, T cells and NK cells was measured in vitro. The highest CD52 expression was observed on B cells (mean fluorescence intensity (MFI) 120), resulting in 95% lysis after incubation with 10ug/mL alemtuzumab and rabbit complement. NK cells showed a significantly lower CD52 expression (MFI 41), which was also reflected by a lower susceptibility to alemtuzumab-mediated CDC (62% lysis). Interestingly, differential expression of CD52 was observed on CD4 and CD8 T cells (MFI 120 and 101, respectively). Cytotoxicity analysis revealed relative protection of CD8 compared to CD4 T cells against alemtuzumab-mediated CDC, resulting in 52% and 90% lysis, respectively. Based on these results, we investigated in detail the presence and phenotype of the CD4 and CD8 subsets and EBV-specific CD8 T cells using tetramer staining at 6 weeks after alloSCT. In accordance with the in-vitro expression and susceptibility data, circulating CD52+ CD8 T cells including EBV-specific T cells were detectable. Interestingly, the majority of circulating CD4 T cells (64-93%, n=4) lacked CD52 expression, explaining their capacity to persist in the presence of alemtuzumab. We conclude that in vivo and in vitro T cell depletion with alemtuzumab is associated with a relatively low risk of EBV-associated PTLD because of efficient B cell depletion and persistent EBV immunity allowed by the relative insusceptibility for alemtuzumab of CD8 T cells and the development of CD52 negative escape variants of CD4 T cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals An Optimized CD4 T-Cell Response Can Control Productive and Latent Gammaherpesvirus Infection

2004 ◽  
Vol 78 (13) ◽  
pp. 6827-6835 ◽  
Author(s):  
Rebecca L. Sparks-Thissen ◽  
Douglas C. Braaten ◽  
Scott Kreher ◽  
Samuel H. Speck ◽  
Herbert W. Virgin
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
B Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Acute Infection ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Cd4 T Cell

ABSTRACT CD4 T cells are important for control of infection with murine gammaherpesvirus 68 (γHV68), but it is not known whether CD4 T cells function via provision of help to other lymphocyte subsets, such as B cells and CD8 T cells, or have an independent antiviral function. Moreover, under conditions of natural infection, the CD4 T-cell response is not sufficient to eliminate infection. To determine the functional capacities of CD4 T cells under optimal or near-optimal conditions and to determine whether CD4 T cells can control γHV68 infection in the absence of CD8 T cells or B cells, we studied the effect of ovalbumin (OVA)-specific CD4 T cells on infection with a recombinant γHV68 that expresses OVA. OVA-specific CD4 T cells limited acute γHV68 replication and prolonged the life of infected T-cell receptor-transgenic RAG (DO.11.10/RAG) mice, demonstrating CD4 T-cell antiviral activity, independent of CD8 T cells and B cells. Despite CD4 T-cell-mediated control of acute infection, latent infection was established in DO.11.10/RAG mice. However, OVA-specific CD4 T cells reduced the frequency of latently infected cells both early (16 days postinfection) and late (42 days postinfection) after infection of mice containing CD8 T cells and B cells (DO.11.10 mice). These results show that OVA-specific CD4 T cells have B-cell and CD8 T-cell-independent antiviral functions in the control of acute infection and can, in the absence of preexisting CD8 T-cell or B-cell immunity, inhibit the establishment of gammaherpesvirus latency.

scholarly journals CD8+ T Cell Metabolic Rewiring Defined by Single-Cell RNA-Sequencing Identifies a Critical Role of ASNS Expression Dynamics in T Cell Differentiation

2021 ◽  
Author(s):  
Juan Fernandez-Garcia ◽  
Fabien Franco ◽  
Sweta Parik ◽  
Antonino A Pane ◽  
Dorien Broekaert ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
T Cell Differentiation

Cytotoxic T cells dynamically rewire their metabolism during the course of an immune response. While T cell metabolism has been extensively studied at phenotypic endpoints of activation and differentiation, the underlying dynamics remain largely elusive. Here, we leverage on single-cell RNA-sequencing (scRNA-seq) measurements of in vitro activated and differentiated CD8+ T cells cultured in physiological media to resolve these metabolic dynamics. We find that our scRNA-seq analysis identifies most metabolic changes previously defined in in vivo experiments, such as a rewiring from an oxidative to an anabolism-promoting metabolic program during activation to an effector state, which is later reverted upon memory polarization. Importantly, our scRNA-seq data further provide a dynamic description of these changes. In this sense, our data predict a differential time-dependent reliance of CD8+ T cells on the synthesis versus uptake of various non-essential amino acids during T cell activation, which we corroborate with additional functional in vitro experiments. We further exploit our scRNA-seq data to identify metabolic genes that could potentially dictate the outcome of T cell differentiation, by ranking them based on their expression dynamics. Among the highest-ranked hits, we find asparagine synthetase (Asns), whose expression sharply peaks for effector CD8+ T cells and further decays towards memory polarization. We then confirm that these in vitro Asns expression dynamics are representative of an in vivo situation in a mouse model of viral infection. Moreover, we find that disrupting these expression dynamics in vitro, by depleting asparagine from the culture media, delays central-memory polarization. Accordingly, we find that preventing the decay of ASNS by stable overexpression at the protein level in vivo leads to a significant increase in effector CD8+ T cell expansion, and a concomitant decrease in central-memory formation, in a mouse model of viral infection. This shows that ASNS expression dynamics dictate the fate of CD8+ T cell differentiation. In conclusion, we provide a resource of dynamic expression changes during CD8+ T cell activation and differentiation that is expected to increase our understanding of the dynamic metabolic requirements of T cells progressing along the immune response cascade.

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