scholarly journals Bone Marrow GZMK +IL7R + Progenitor-Exhausted CD8 + T Cells Correlate with Sustained Clinical Remission in Patients with Acute Myeloid Leukemia (AML) Undergoing Chemotherapy

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 521-521
Author(s):  
Francesco Mazziotta ◽  
Luca Biavati ◽  
Rupkatha Mukhopadhyay ◽  
Hanna A. Knaus ◽  
Ivan M. Borrello ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Myeloid Leukemia ◽  
Cd8 T Cell ◽  
T Cell Subsets ◽  
Spectral Flow

Abstract Introduction The role of T cells in chemotherapy response and maintenance of remission in acute myeloid leukemia (AML) patients is not fully understood. In solid tumors and chronic infections, exhaustion is a multistep process ranging from less differentiated progenitor exhausted (Tpex) to intermediate and terminally exhausted T cells (Beltra et al. 2020). High frequencies of Tpex correlate with response to immune-checkpoint blockade in solid tumors (Miller et al. 2019). In AML, where the backbone of treatment is chemotherapy, the role of dysfunctional T-cell subsets has yet to be elucidated. Methods Serial bone marrow (BM) samples from 16 AML patients (10 complete responders (Res) and 6 non-responders (NonRes)) at diagnosis and at response assessment after induction chemotherapy and 12 healthy donors (HD) were analyzed by flow cytometry using a 13-color panel. Moreover, we performed single-cell RNA sequencing (scRNAseq) (10X Genomics) on BM samples from 2 HD and 5 AML patients (3 Res, 2 NonRes) at baseline and after chemotherapy. Subsequently, we used a scRNAseq-guided 26-color spectral flow cytometry panel and explored T-cell phenotypes on BM of 22 AML patients (12 Res and 10 NonRes). Custom-made R scripts were employed for high-dimensional flow cytometry and scRNAseq analysis. Results Initial flow-cytometry analysis showed a significant increase in BM PD1 +CD28 + CD8 + T cell subset (p<0.01) in Res vs NonRes at baseline and post-chemotherapy (data not shown). To further investigate these results, we performed 5' VDJ scRNAseq and used gene signatures mapped in two dimensions via UMAP to annotate the T-cell clusters as naive, Tpex, T effector CX3CR1 + (Teff CX3CR1pos), Terminally exhausted 1 (Term_exh1) and Terminally exhausted 2 (Term_exh2) (Fig 1A). Of note, the two most upregulated genes in Tpex were GZMK and IL-7R. We then performed differential abundance analysis to investigate differences in terms of clusters' frequencies across the three conditions (Res, NonRes, HD). At both timepoints Res had an increased frequency of Tpex and Teff CX3CR1pos compared to NonRes. Conversely, Term_exh2 cells were more abundant in NonRes (Fig. 1B). Next, we measured the magnitude of clonal expansion in antigen-experienced CD8 + T cells in Res and NonRes generating an overlay of the position of clonally expanded cells projected onto the UMAP. The most clonally expanded subsets were Tpex and Teff CX3CR1pos in Res (Fig. 1C) and Term_exh2 in NonRes (Fig. 1D) revealing a strong relationship between abundance and clonal expansion of the CD8 + T-cell subsets. Our scRNAseq results were then confirmed at the protein level with spectral flow-cytometry. The FlowSOM algorithm identified a CD8 + GZMK +CD127 + subset to be increased at baseline in Res vs NonRes (Fig. 1E). Remarkably, this cluster was also characterized by the expression of TIGIT, PD1 and TCF-1. These results were subsequently reproduced by manual gating of the GZMK +CD127 + subset which was significantly enriched (p<0.01) in Res vs NonRes (Fig. 1F). Of note, patients with a higher-than-median frequency of GZMK +CD127 +CD8 + T cells experienced significantly (p<0.02) prolonged overall survival after therapy (Fig. 1G). Conclusion Improving our understanding of the immune microenvironment in AML is critical for the rational integration of novel treatment strategies that seek to increase the response rate and/or maintain remission. We identified GZMK +IL7R + CD8 + cells as a distinct entity in the early differentiated CD8 + memory T cell pool that is clonally expanded and more abundant in Res compared to NonRes. This subset has a stem-like signature and may be associated with longer in vivo CD8 + T cell persistence and long-term AML control. An in-depth functional characterization with in vitro experiments and in vivo mouse models is currently ongoing. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Tissue Parenchymal Cell Expression of B7-H1 Inhibits Infiltrating T Cell Expansion and Prevents Persistence of Graft-Versus-Host Disease

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2974-2974
Author(s):  
Xiaofan Li ◽  
Wei He ◽  
Ruishu Deng ◽  
Can Liu ◽  
Miao Wang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Expansion ◽  
Cd8 T Cell ◽  
Target Tissue ◽  
T Cell Expansion ◽  
Parenchymal Cells

Abstract Abstract 2974 Alloreactive donor CD8+ T cells facilitate engraftment and mediate graft versus leukemia (GVL) effects but also cause graft versus host disease (GVHD) in murine and human recipients after allogeneic hematopoietic cell transplantation (HCT). B7-H1 (PD-L1) expression by antigen-presenting cells has an important role in tolerizing activated T cells by binding to PD-1. We and others previously reported that disruption of binding between B7-H1 and PD-1 augments acute GVHD. Parenchymal cells do not usually express B7-H1 but can be induced by inflammatory cytokines (i.e. IFN-g) to express B7-H1. The role of B7-H1 expression by parenchymal tissue cells in regulating the expansion and persistence of donor CD8+ cells in tissues of mice with GVHD has not yet been evaluated. In the current studies, we evaluated the role of B7-H1 expression by GVHD target tissues in regulating donor CD8+ T cell function in 3 different experimental GVHD systems, using in vivo bioluminescent imaging (BLI), in vivo BrdU-labeling, and in vitro proliferation assays. The first system evaluated the role of B7-H1 expression in TBI-conditioned recipients. In these recipients, injected donor CD8+ T cells showed two waves of expansion that correlated with two phases of clinical GVHD. The first wave of donor CD8+ T cell expansion was associated with upregulated expression of B7-H1 in GVHD target tissues and only weak clinical GVHD. The second wave of donor CD8+ T cell expansion was associated with loss of B7-H1 expression, vigorous donor CD8+ T proliferation and expansion in the GVHD target tissues, and lethal GVHD. In a gain-of-function experiment, B7-H1 expression was induced in hepatocytes by hydrodynamic injection of B7-H1 cDNA during the second wave of T cell expansion in mice with GVHD; this subsequently decreased T cell expansion in the liver and ameliorated GVHD. The second system evaluated the role of B7-H1 expression in anti-CD3-conditioned recipients. In wild-type recipients, injected donor CD8+ T cells had only a single wave of expansion, and the mice had no signs of GVHD. B7-H1 expression by tissue cells (i.e. hepatocytes) was up-regulated, and the tissue infiltrating donor CD8+ T cells were anergic. In B7-H1−/− recipients, injected donor CD8+ T cells proliferated vigorously in GVHD target tissues and caused lethal GVHD.The third system evaluated the role of B7-H1 in unconditioned Rag-2−/− recipients after administration of blocking anti-B7-H1 and in the B7-H1−/−Rag-2−/− chimeras with B7-H1 sufficient Rag-2−/− bone marrow cells, in which B7-H1 deficiency was only in tissue parenchymal cells. Both blockade of B7-H1 and B7-H1 deficiency in parenchymal cells resulted in vigorous donor CD8+ T proliferation in GVHD target tissues and caused lethal GVHD. Taken together, these results show that expression of B7-H1 in GVHD target tissue parenchymal cells plays an important role in regulating the proliferation of infiltrating donor CD8+ T cells and preventing the persistence of GVHD. Our studies also indicate that TBI but not anti-CD3 conditioning can lead to loss of GVHD target tissue cell expression of B7-H1 and persistence of GVHD. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The lncRNA Snhg1-Vps13D vesicle trafficking system promotes memory CD8 T cell establishment via regulating the dual effects of IL-7 signaling

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Yanyan Zhang ◽  
Baohua Li ◽  
Qiang Bai ◽  
Pengcheng Wang ◽  
Gang Wei ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Expression Pattern ◽  
Cd8 T Cells ◽  
Vesicle Trafficking ◽  
Cd8 T Cell ◽  
T Cell Subsets ◽  
Memory Cd8 T Cells ◽  
Memory Cd8 T Cell

AbstractThe efficient induction and long-term persistence of pathogen-specific memory CD8 T cells are pivotal to rapidly curb the reinfection. Recent studies indicated that long-noncoding RNAs expression is highly cell- and stage-specific during T cell development and differentiation, suggesting their potential roles in T cell programs. However, the key lncRNAs playing crucial roles in memory CD8 T cell establishment remain to be clarified. Through CD8 T cell subsets profiling of lncRNAs, this study found a key lncRNA-Snhg1 with the conserved naivehi-effectorlo-memoryhi expression pattern in CD8 T cells of both mice and human, that can promote memory formation while impeding effector CD8 in acute viral infection. Further, Snhg1 was found interacting with the conserved vesicle trafficking protein Vps13D to promote IL-7Rα membrane location specifically. With the deep mechanism probing, the results show Snhg1-Vps13D regulated IL-7 signaling with its dual effects in memory CD8 generation, which not just because of the sustaining role of STAT5-BCL-2 axis for memory survival, but more through the STAT3-TCF1-Blimp1 axis for transcriptional launch program of memory differentiation. Moreover, we performed further study with finding a similar high-low-high expression pattern of human SNHG1/VPS13D/IL7R/TCF7 in CD8 T cell subsets from PBMC samples of the convalescent COVID-19 patients. The central role of Snhg1-Vps13D-IL-7R-TCF1 axis in memory CD8 establishment makes it a potential target for improving the vaccination effects to control the ongoing pandemic.

Blocking VIP Signaling Abrogates Upregulation Of PD1 and Increases Proliferation Of Allo-Reactive T-Cells In a Mixed Lymphocyte Reaction

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1041-1041
Author(s):  
Emily R Summerbell ◽  
Cynthia R. Giver ◽  
Sravanti Rangaraju ◽  
Katarzyna Anna Darlak ◽  
Edmund K. Waller
Keyword(s):  
Flow Cytometry ◽  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
T Cell Immunity ◽  
T Cell Proliferation ◽  
Cell Immunity

Abstract Introduction Vasoactive intestinal peptide (VIP) is a neuropeptide hormone that suppresses Th1 immunity and inhibits antiviral immunity. Decreased Th1 immunity is problematic for allogeneic bone marrow transplant (allo-BMT) patients requiring T-cell immunity against blood cancers (Graft-versus-Tumor) and against secondary infections such as CMV. VIPhyb, a modified VIP peptide, is a VIP receptor antagonist that decreases VIP signaling. VIP-knockout mice and mice treated with VIPhyb after allo-BMT are known to have better antiviral immunity and survival after CMV infection without increasing GvHD (Li et al. PLoS One. 2013 May 27;8(5):e63381) (Li et al. Blood. 2013 Mar 21;121(12):2347-51.), thus making VIPhyb of interest for pharmacological use in humans to improve the efficacy of allo-BMT The effects of VIPhyb on T-cell immunity are not yet fully profiled. This study aimed to analyze the effects of VIPhyb on CD4+ and CD8+ T-cell proliferation and activation in order to better understand the mechanistic implications of VIP inhibition on T-cell adaptive immunity. This study also aimed to show that mixed lymphocyte reactions (MLRs), an in vitro allo-BMT model, could be used to provide rapid and reliable results that are consistent with in vivo data. It was hypothesized that VIPhyb would increase T-cell immunity as profiled by: increased T-cell proliferation, CD69 and PD1 co-upregulation in early T-cell activation, and PD1 downregulation in T-cells after initial activation. Methods Splenocytes from two histoincompatible mice were cultured together at 37°C in a 1:1 ratio in a one-way MLR. BALB/c splenocytes (stimulators) were irradiated at 20Gy, and Pepboy splenocytes (responders) were labeled with CFSE to trace proliferation. VIPhyb was added daily to the cell cultures in doses of 0.1μM, 0.3μM, 1μM, or 3μM. Treatment groups were compared to a PBS control. Proliferation, CD69, and PD1 were assessed by flow cytometry on the BD FACSAria. All results are shown as mean ± SEM (n=3). One-way ANOVA tests with Dunnett post-tests were calculated using Prism software. *p < 0.05; **p < 0.01; ***p < 0.001 Results VIPhyb increased CD4+ and CD8+ T-cell proliferation: 3, 5, and 7 days after initiating a one-way MLR, CFSE expression of Pepboy responder T-cells was assessed using flow cytometry (Figure 1). As the VIPhyb dose increased, the percentage of initial splenocytes that underwent proliferation increased in both CD4+ and CD8+ T-cells. VIPhyb increased early T-cell CD69 expression and abrogated later PD1 upregulation in CD8+ T-cells: 3, 5, and 7 days after initiating a one-way MLR, expression levels of CD69 and PD1 on Pepboy responder T-cells were assessed by flow cytometry. Significant upregulation of CD69 on CD4+ and CD8+ T-cells on day 3 occurred with increasing VIPhyb doses (Figures 2A and 2B). PD1 was co-upregulated with CD69 during early activation, and VIPhyb significantly decreased PD1 expression on CD8+ T-cells on days 5 and 7 (Figures 2C and 2D). Conclusions VIPhyb increased T-cell proliferation; CD8+ T-cells were affected more significantly. VIPhyb increased early co-upregulation of CD69 and PD1 in all T-cells and significantly decreased later CD8+ T-cell PD1 expression, indicating that VIPhyb increases T-cell activation. We hypothesize that the decreased PD1 expression will be critical for understanding the pathways involved in VIP inhibition. Importantly, since it has been shown in vivo that VIPhyb does not increase GvHD, then it can be assumed that the VIPhyb-induced T-cell proliferation and activation will increase GvL and adaptive immunity without increasing alloreactivity. Notably, these results are consistent with published in vivo data, which demonstrates that the MLR can be used as a faster method of analyzing pharmacological compounds than in vivo experiments. Given these results, VIPhyb is still of interest as a potential therapy for allo-BMT patients. Disclosures: No relevant conflicts of interest to declare.

Differential use of FasL- and perforin-mediated cytolytic mechanisms by T-cell subsets involved in graft-versus-myeloid leukemia responses

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 1047-1055 ◽  
Author(s):  
Michael H. Hsieh ◽  
Robert Korngold
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Myeloid Leukemia ◽  
T Cell Subsets ◽  
Leukemia Cell Line ◽  
Deficient Mice

In graft-versus-leukemia (GVL) responses, the cellular subsets and effector mechanisms responsible for cytotoxicity against leukemic cells in vivo remain poorly characterized. A murine model of syngeneic GVL that features CD4+ and CD8+T-cell responses against the MMB3.19 myeloid leukemia cell line has been previously described. MMB3.19 expresses high levels of functional Fas and tumor necrosis factor (TNF) receptors that do not transduce proapoptotic signals. Through the use of perforin- and Fas ligand (FasL)-deficient mice, it was demonstrated that CD4+ T cells mediate anti-MMB3.19 effects in vivo primarily through the use of FasL and secondarily through perforin mechanisms. Conversely, CD8+ T cells induce GVL effects primarily through the use of perforin and minimally through FasL mechanisms. Although the in vivo observations of CD8+ T cells were reflective of their in vitro cytotoxic T lymphocyte (CTL) activity, for CD4+ T cells, in vitro responses were dominated by the perforin pathway. In addition, the diminished capacity of T cells from perforin- and FasL-deficient mice to lyse MMB3.19 target cells appeared directly related to their deficient cytotoxic functions rather than to defects in activation because these cells were fully capable of mounting proliferative responses to the tumor cells. These findings demonstrate that GVL responses of T-cell subsets can involve preferential use of different cytotoxic mechanisms. In particular, these findings identify a role for both FasL-employing CD4+CTLs and the more novel perforin-utilizing CD4+ T-cell subset in responses against a myeloid leukemia.

Differential use of FasL- and perforin-mediated cytolytic mechanisms by T-cell subsets involved in graft-versus-myeloid leukemia responses

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 1047-1055 ◽  
Author(s):  
Michael H. Hsieh ◽  
Robert Korngold
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Myeloid Leukemia ◽  
T Cell Subsets ◽  
Leukemia Cell Line ◽  
Deficient Mice

Abstract In graft-versus-leukemia (GVL) responses, the cellular subsets and effector mechanisms responsible for cytotoxicity against leukemic cells in vivo remain poorly characterized. A murine model of syngeneic GVL that features CD4+ and CD8+T-cell responses against the MMB3.19 myeloid leukemia cell line has been previously described. MMB3.19 expresses high levels of functional Fas and tumor necrosis factor (TNF) receptors that do not transduce proapoptotic signals. Through the use of perforin- and Fas ligand (FasL)-deficient mice, it was demonstrated that CD4+ T cells mediate anti-MMB3.19 effects in vivo primarily through the use of FasL and secondarily through perforin mechanisms. Conversely, CD8+ T cells induce GVL effects primarily through the use of perforin and minimally through FasL mechanisms. Although the in vivo observations of CD8+ T cells were reflective of their in vitro cytotoxic T lymphocyte (CTL) activity, for CD4+ T cells, in vitro responses were dominated by the perforin pathway. In addition, the diminished capacity of T cells from perforin- and FasL-deficient mice to lyse MMB3.19 target cells appeared directly related to their deficient cytotoxic functions rather than to defects in activation because these cells were fully capable of mounting proliferative responses to the tumor cells. These findings demonstrate that GVL responses of T-cell subsets can involve preferential use of different cytotoxic mechanisms. In particular, these findings identify a role for both FasL-employing CD4+CTLs and the more novel perforin-utilizing CD4+ T-cell subset in responses against a myeloid leukemia.

scholarly journals IL-7 and IL-15 differentially regulate CD8+ T-cell subsets during contraction of the immune response

Blood ◽  
2008 ◽  
Vol 112 (9) ◽  
pp. 3704-3712 ◽  
Author(s):  
Mark P. Rubinstein ◽  
Nicholas A. Lind ◽  
Jared F. Purton ◽  
Pauline Filippou ◽  
J. Adam Best ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
T Cell Subsets ◽  
Interleukin 7 ◽  
High Level ◽  
Cd127 Expression

Although it is known that interleukin-7 (IL-7) and IL-15 influence the survival and turnover of CD8+ T cells, less is known about how these cytokines affect different subsets during the course of the immune response. We find that IL-7 and IL-15 differentially regulate CD8+ T-cell subsets defined by KLRG1 and CD127 expression during the contraction phase of the immune response. The provision of IL-15, or the related cytokine IL-2, during contraction led to the preferential accumulation of KLRG1hiCD127lo CD8+ T cells, whereas provision of IL-7 instead favored the accumulation of KLRG1loCD127hi cells. While IL-7 and IL-15 both induced proliferation of KLRG1lo cells, KLRG1hi cells exhibited an extraordinarily high level of resistance to cytokine-driven proliferation in vivo despite their dramatic accumulation upon IL-15 administration. These results suggest that IL-15 and IL-2 greatly improve the survival of KLRG1hi CD8+ T cells, which are usually destined to perish during contraction, without inducing proliferation. As the availability of IL-15 and IL-2 is enhanced during periods of extended inflammation, our results suggest a mechanism in which a population of cytokine-dependent KLRG1hi CD8+ T cells is temporarily retained for improved immunity. Consideration of these findings may aid in the development of immunotherapeutic strategies against infectious disease and cancer.

scholarly journals IL-2, IL-7, IL-15 and IL-6 Induce Differential Activation of Naive and Memory T Cell Subsets

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3425-3425 ◽  
Author(s):  
Masahiro Hirakawa ◽  
Tiago R Matos ◽  
Edouard Forcade ◽  
Kathy S. Wang ◽  
Eduardo L Espada ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
T Cell Subsets ◽  
Low Concentrations ◽  
High Concentrations ◽  
Very High

Abstract Introduction: Cytokines play important roles in the activation, proliferation, differentiation and survival of T cells. Previous studies have revealed that individual cytokines selectively activate different T cell populations and also function at specific stages of T cell differentiation. For example, IL-2 supports the development of CD4 regulatory T cells. IL-7 is required for naive conventional CD4 T cell (Tcon) homeostasis, whereas naive CD8 T cell homeostasis requires both IL-7 and IL-15. In contrast, IL-6 promotes Th17 T cell differentiation. The functions of each cytokine are partly defined by the differential expression of specific multi-unit receptors but the selective homeostatic effects of individual cytokines are still incompletely understood. Methods: We stimulated peripheral blood mononuclear cells from healthy donors with varying concentrations of IL-2, IL-7, IL-15 and IL-6 for 15 min in vitro. Single cell mass cytometry (CyTOF) with a panel of 33 markers was used to simultaneously examine signaling pathways activated by each cytokine in distinct T cell subsets. viSNE, a cytometry analysis tool, was used to visualize high-dimensional cytometry data on a two-dimensional map. Expression of pSTAT5 was used to monitor activation induced by IL-2, IL-7 and IL-15; pSTAT3 was used to monitor activation by IL-6. Results: In CD4 Tcon, relatively high concentrations of IL-2 (100-1000 IU/ml) are required to induce pSTAT5 (Figure 1). However even at high concentrations, IL-2 activation was selective for memory Tcon subsets. In contrast, IL-7 induced pSTAT5 at very low concentrations (1-10 IU/ml). Although all Tcon were affected, activation was more robust in memory than naive Tcon subsets at all IL-7 concentrations. IL-15 activation of pSTAT5 required at least 10 IU/ml and only memory Tcon subsets were activated even at high IL-15 concentrations. Whereas IL-2, IL-7 and IL-15 preferentially activated memory Tcon subsets, IL-6 selectively activated pSTAT3 in naive and central memory (CM) Tcon subsets at low concentrations (10 IU/ml). At high IL-6 concentrations (100-1000 IU/ml) effector memory (EM) Tcon were also activated. CD8 T cells (Figure 2) are relatively insensitive to IL-2, and only CM CD8 T cells are activated at high IL-2 concentrations (100 IU/ml). Although all CD8 T cell subsets were activated at very high IL-2 concentrations (1000 IU/ml), pSTAT5 activation remained most evident in CM CD8 T cells. Similar to Tcon, IL-7 induced pSTAT5 in CD8 T cells at very low IL-7 concentrations (1-10 IU/ml). However unlike Tcon, pSTAT5 activation was most prominent in naive and CM CD8 T cells. EM CD8 T cells were activated at higher IL-7 concentrations but TEMRA CD8 T cells were resistant to IL-7 stimulation. IL-15 induced pSTAT5 equally in all CD8 T cell subsets but relatively high concentrations (100-1000 IU/ml) were required. Similar to CD4 Tcon, IL-6 induced selective pSTAT3 activation in naive CD8 T cells. Activation of naive CD8 T cells was observed at low concentrations of IL-6 and both EM and TEMRA were resistant to very high IL-6 concentrations (100-1000 IU/ml). Conclusion: This detailed analysis of cytokine signaling has identified differential effects of IL-2, IL-7, IL-15 and IL-6 on different subsets of CD4 Tcon and CD8 T cells. Whereas CD4 Treg are activated at low IL-2 concentrations, CD4 Tcon and CD8 T cells are relatively resistant to IL-2. At high IL-2 concentrations, activation was most prominent for memory CD4 Tcon and CM CD8 T cells. In contrast, low concentrations of IL-7 are sufficient to activate both CD4 Tcon and CD8 T cells. Within these populations, memory Tcon and naive CD8 cells were preferentially activated at low IL-7 concentrations. Within the CD8 T cell population, IL-15 activated all subsets equally. Within CD4 Tcon, IL-15 preferentially activates memory subsets. IL-6 acts at low concentrations and primarily on naive cells in both CD4 Tcon and CD8 T cells. In all experiments, these effects do not require TCR antigen activation and therefore reflect the potency and differential activity of homeostatic signals supported by these cytokines. Importantly, high concentrations used for in vitro experiments are not likely achieved in vivo but may reflect toxicities of high dose exogenous cytokine therapies or cytokine release syndromes. In contrast, differential effects observed at low concentrations more likely reflect physiologic homeostatic effects of these cytokines in vivo. Disclosures No relevant conflicts of interest to declare.

scholarly journals DNAM-1 promotes activation of cytotoxic lymphocytes by nonprofessional antigen-presenting cells and tumors

2008 ◽  
Vol 205 (13) ◽  
pp. 2965-2973 ◽  
Author(s):  
Susan Gilfillan ◽  
Christopher J. Chan ◽  
Marina Cella ◽  
Nicole M. Haynes ◽  
Aaron S. Rapaport ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Adhesion Molecules ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Cd8 T Cell ◽  
Antigen Presenting

Natural killer (NK) cells and CD8 T cells require adhesion molecules for migration, activation, expansion, differentiation, and effector functions. DNAX accessory molecule 1 (DNAM-1), an adhesion molecule belonging to the immunoglobulin superfamily, promotes many of these functions in vitro. However, because NK cells and CD8 T cells express multiple adhesion molecules, it is unclear whether DNAM-1 has a unique function or is effectively redundant in vivo. To address this question, we generated mice lacking DNAM-1 and evaluated DNAM-1–deficient CD8 T cell and NK cell function in vitro and in vivo. Our results demonstrate that CD8 T cells require DNAM-1 for co-stimulation when recognizing antigen presented by nonprofessional antigen-presenting cells; in contrast, DNAM-1 is dispensable when dendritic cells present the antigen. Similarly, NK cells require DNAM-1 for the elimination of tumor cells that are comparatively resistant to NK cell–mediated cytotoxicity caused by the paucity of other NK cell–activating ligands. We conclude that DNAM-1 serves to extend the range of target cells that can activate CD8 T cell and NK cells and, hence, may be essential for immunosurveillance against tumors and/or viruses that evade recognition by other activating or accessory molecules.

scholarly journals Mitochondrial Dysfunction Associates With Acute T Lymphocytopenia and Impaired Functionality in COVID-19 Patients

2022 ◽  
Vol 12 ◽  
Author(s):  
Yufei Mo ◽  
Kelvin Kai-Wang To ◽  
Runhong Zhou ◽  
Li Liu ◽  
Tianyu Cao ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mitochondrial Dysfunction ◽  
Cd8 T Cells ◽  
Functional Impairment ◽  
Cell Loss ◽  
Cd8 T Cell ◽  
Underlying Mechanism ◽  
T Cell Subsets ◽  
Effector Memory

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in rapid T lymphocytopenia and functional impairment of T cells. The underlying mechanism, however, remains incompletely understood. In this study, we focused on characterizing the phenotype and kinetics of T-cell subsets with mitochondrial dysfunction (MD) by multicolor flow cytometry and investigating the association between MD and T-cell functionality. While 73.9% of study subjects displayed clinical lymphocytopenia upon hospital admission, a significant reduction of CD4 or CD8 T-cell frequency was found in all asymptomatic, symptomatic, and convalescent cases. CD4 and CD8 T cells with increased MD were found in both asymptomatic and symptomatic patients within the first week of symptom onset. Lower proportion of memory CD8 T cell with MD was found in severe patients than in mild ones at the stage of disease progression. Critically, the frequency of T cells with MD in symptomatic patients was preferentially associated with CD4 T-cell loss and CD8 T-cell hyperactivation, respectively. Patients bearing effector memory CD4 and CD8 T cells with the phenotype of high MD exhibited poorer T-cell responses upon either phorbol 12-myristate-13-acetate (PMA)/ionomycin or SARS-CoV-2 peptide stimulation than those with low MD. Our findings demonstrated an MD-associated mechanism underlying SARS-CoV-2-induced T lymphocytopenia and functional impairment during the acute phase of infection.

scholarly journals Adrenergic signaling controls early transcriptional programs during CD8+ T cell responses to viral infection

2021 ◽  
Author(s):  
Leonardo Estrada ◽  
Didem Agac Cobanoglu ◽  
Aaron Wise ◽  
Robert Maples ◽  
Murat Can Cobanoglu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Receptor Activation ◽  
Cell Development ◽  
Primary Response ◽  
Cell Responses

Viral infections drive the expansion and differentiation of responding CD8+ T cells into variegated populations of cytolytic effector and memory cells. While pro-inflammatory cytokines and cell surface immune receptors play a key role in guiding T cell responses to infection, T cells are also markedly influenced by neurotransmitters. Norepinephrine is a key sympathetic neurotransmitter, which acts to suppress CD8 + T cell cytokine secretion and lytic activity by signaling through the beta2-adrenergic receptor (ADRB2). Although ADRB2 signaling is considered generally immunosuppressive, its role in regulating differentiation of effector T cells in response to infection has not been investigated. Using an adoptive transfer approach, we compared the expansion and differentiation of wild type (WT) to Adrb2-/- CD8 + T cells throughout the primary response to vesicular stomatitis virus (VSV) infection in vivo. We measured the dynamic changes in transcriptome profiles of antigen-specific CD8 + T cells as they responded to VSV. Within the first 7 days of infection, WT cells out-paced the expansion of Adrb2-/- cells, which correlated with reduced expression of IL-2 and the IL-2Ralpha; in the absence of ADRB2. RNASeq analysis identified over 300 differentially expressed genes that were both temporally regulated following infection and selectively regulated in WT vs Adrb2-/- cells. These genes contributed to major transcriptional pathways including cytokine receptor activation, signaling in cancer, immune deficiency, and neurotransmitter pathways. By parsing genes within groups that were either induced or repressed over time in response to infection, we identified three main branches of genes that were differentially regulated by the ADRB2. These gene sets were predicted to be regulated by specific transcription factors involved in effector T cell development, such as Tbx21 and Eomes. Collectively, these data demonstrate a significant role for ADRB2 signaling in regulating key transcriptional pathways during CD8 + T cells responses to infection that may dramatically impact their functional capabilities and downstream memory cell development.

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