The ICOS:ICOSL Costimulatory Pathway Plays an Important Role in GVHD and Bone Marrow (BM) Graft Rejection.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 591-591 ◽  
Author(s):  
Patricia Taylor ◽  
Angela Panoskaltsis-Mortari ◽  
Gordon Freeman ◽  
Arlene Sharpe ◽  
Randolph Noelle ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Family Member ◽  
Cd8 T Cells ◽  
Graft Rejection ◽  
Cd4 T Cells ◽  
Fluorescent Protein ◽  
Wild Type ◽  
Activated T Cells ◽  
Effector Cells

Abstract ICOS, a CD28/CTLA-4 family member, is expressed on activated T cells. ICOS Ligand, a B7 family member, is constitutively expressed on B cells, monocytes and some T cells. Through the use of blocking anti-ICOS mAb and ICOS deficient (−/−) mice, we found that ICOS:ICOSL interactions play an important role in GVHD and BM graft rejection. Anti-ICOS mAb (given d-1 to d28 post BMT) significantly delayed or reduced mortality at 2 different T cell doses in a full MHC-disparate GVHD model. ICOS−/− T cells led to delayed or reduced mortality at 3 different cell doses compared to wild-type T cells. ICOS−/− CD4+ or CD8+ T cells infused into class II- or class I-disparate recipients, respectively, revealed that ICOS:ICOSL interactions regulate both CD4+ and CD8+ T cell alloresponses. Anti-ICOS inhibited GVHD in a CD28-independent fashion. Anti-ICOS inhibited GVHD mediated by either stat 4−/− or stat 6−/− T cells indicating that the ICOS pathway regulates both Th2 and Th1-mediated GVHD. In contrast to blockade of the B7:CD28/CTLA-4, CD40L:CD40 or the OX40:OX40L pathway, anti-ICOS mAb inhibited GVHD even when delayed until d5 post BMT, a time when substantial T cell expansion has occurred. A TCR transgenic model of GVHD was used to further study effects of ICOS:ICOSL blockade. All CB6 F1 recipients of anti-host alloreactive 2C CD8+ and TEa CD4+ T cells succumbed to GVHD mortality by d18 after transfer of cells. In contrast, 88% of anti-ICOS-treated mice survived long-term. Evaluation of spleens early after transplant revealed that anti-ICOS mAb reduced the number of TEa CD4+ cells by 44% and 2C CD8+ cells by 83%. Green fluorescent protein (GFP) 2C CD8+ and GFP TEa CD4+ T cells were infused into irradiated CB6 F1 mice and irrelevant or anti-ICOS mAb was administered. Mice were imaged on d4, 7 and 12 after T cell transfer. By d7, pronounced infiltration of GFP+ cells was noted in the peripheral and mesenteric LN, spleen, Peyer’s patches (PP), skin, gingiva, liver, kidney, lung, ileum, and colon of GVHD control mice. In contrast, there were fewer GFP+ cells in the spleen, ileum, colon, kidney, lung, skin and gingiva of anti-ICOS-treated mice, although there was no decrease in GFP+ cells in LNs or PP. To study the role of host ICOS expression in BM graft rejection, wild-type or ICOS−/− mice were sublethally irradiated and given allogeneic BM and evaluated for donor chimerism at 6 weeks post BMT. Five of 10 wild type mice engrafted (ave − 26% donor) in contrast to all 10 of ICOS−/− mice (ave − 71% donor). Collectively, these data indicate that ICOS:ICOSL interactions play an important role in GVHD, whether mediated by CD4+ Th1 or Th2 T cells or CD8+ T cells. Importantly, blockade of ICOS:ICOSL after initiation of alloresponses inhibited GVHD, in contrast to blockade of other costimulatory pathways, suggesting that the ICOS pathway may be a novel therapeutic target in primed transplantation situations. Anti-ICOS interfered with expansion of donor T cells in the spleen early after transplant and reduced the number of effector cells in several GVHD target tissues. These data suggest this pathway may be indicated for therapeutic targeting for the inhibition of GVHD and BM graft rejection.

Abrogation of Donor T Cell IL-21 Signaling Leads to Tissue-Specific Modulation of Immunity and Separation of Gvhd From GVL

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 729-729
Author(s):  
Alan M. Hanash ◽  
Lucy W. Kappel ◽  
Nury L. Yim ◽  
Rebecca A. Nejat ◽  
Gabrielle L. Goldberg ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Inflammatory Cytokine ◽  
Wild Type ◽  
Mesenteric Lymph Nodes ◽  
Mesenteric Lymph ◽  
Donor T Cells

Abstract Abstract 729 Allogeneic hematopoietic transplantation is frequently the only curative therapy available to patients with hematopoietic malignancies, however transplant success continues to be limited by complications including graft vs. host disease (GVHD) and disease relapse. Separation of GVHD from graft vs. leukemia/lymphoma (GVL) responses continues to be a major goal of experimental and clinical transplantation, and better understanding of T cell immunobiology may lead to novel strategies to accomplish this goal. Interleukin 21 (IL-21) is a pro-inflammatory cytokine produced by Th17 helper T cells, and abrogation of IL-21 signaling has recently been demonstrated to reduce GVHD while retaining GVL. However, the mechanisms by which IL-21 may lead to a separation of GVHD and GVL are incompletely understood. In order to characterize the effect of IL-21 on GVH and GVL T cell responses, we compared wild type and IL-21 receptor knockout (IL-21R KO) donor T cells in a C57BL/6 into BALB/c murine MHC-mismatched bone marrow transplant (BMT) model. Lethally irradiated BMT recipients of IL-21R KO T cells demonstrated decreased GVHD-related morbidity (p<.05) and mortality (p<.01), and decreased histopathologic evidence of GVHD within the small intestine (p<.05). While this reduction in IL-21R KO T cell-mediated GVHD was associated with increased donor regulatory T cells two to three weeks post-BMT (p<.001), IL-21 signaling in both donor CD4 and donor CD8 T cells was found to contribute to GVHD mortality (p<.01 for CD4, p<.05 for CD8). Analysis of IL-21R expression by wild type T cells demonstrated receptor upregulation upon polyclonal activation in vitro and upon alloactivation in vivo (p<.01). However, this IL-21R upregulation was not required for in vivo alloactivation, as IL-21R KO and wild type donor T cells demonstrated equivalently greater proliferation in allogeneic vs. syngeneic recipients (p<.001), equivalent upregulation of CD25 (p<.001), and equivalent downregulation of CD62L (p<.01 for CD8 T cells). Despite this equivalent alloactivation, IL-21R KO T cells demonstrated decreased infiltration within the small intestine (p<.05), decreased infiltration in mesenteric lymph nodes (p<.05 for CD8 T cells, p<.001 for CD4 T cells), and decreased inflammatory cytokine-producing CD4 T cells within mesenteric lymph nodes (p<.01 for IFN-g, p<.001 for TNF-a, Figure 1A). Consistent with this, transplanted IL-21R KO donor T cells demonstrated decreased expression of a4b7 integrin (LPAM, p<.05), a molecule known to be involved in homing of GVHD-mediating donor T cells to the gut. However, in contrast to the reduced inflammatory cytokine-producing CD4 T cells observed in mesenteric lymph nodes, IL-21R KO helper T cell cytokine production was maintained in spleen (Figure 1B) and peripheral lymph nodes, and IL-21R KO T cells were able to protect recipient mice from lethality due to A20 lymphoma (p<.001). In summary, abrogation of IL-21 signaling in donor T cells leads to tissue-specific modulation of immunity, such that gastrointestinal GVHD is reduced, but peripheral T cell function and GVL capacity are retained. Targeting IL-21 for therapeutic intervention is an exciting strategy to separate GVHD from GVL, and this novel approach should be considered for clinical investigation to improve transplant outcomes and prevent malignant relapse. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Activation of naive and memory T cells by interleukin-15

Blood ◽  
1996 ◽  
Vol 88 (1) ◽  
pp. 230-235 ◽  
Author(s):  
H Kanegane ◽  
G Tosato
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Biological Activities ◽  
Growth Stimulation ◽  
T Cell Subsets ◽  
Beta Chain ◽  
Activated T Cells ◽  
Interleukin 15

Abstract Interleukin-15 (IL-15), a product of monocytes and other cells, has biological activities similar to those of IL-2, including growth stimulation of activated T cells, induction of cytolytic effector cells, and B-cell costimulation for proliferation and lg production. We report that IL-15 at optimal concentrations rapidly induced memory (CD45RO+) CD4+ and CD8+ T cells and naive (CD45RO-) CD8+ T cells to express the CD69 activation marker followed by proliferation. By contrast, IL-15 failed to induce naive (CD45RO-) CD4+ T cells to express CD69 or to proliferate. Similar findings were obtained with IL- 2. Unlike the other T-cell subsets, CD4+ T cells with a naive phenotype expressed little or no IL-2R beta chain, a shared component of the IL-2 and IL-15 receptors required for receptor function. A monoclonal antibody to the IL-2R beta chain, Mik beta 1, reduced CD69 expression and proliferation in CD4+ memory, CD8+ memory, and CD8+ naive T cells activated by IL-15. These results confirm the biological similarities of IL-2 and IL-15. They further document that the pool of naive CD4+ cells, unlike the pool of memory CD4+, memory CD8+, and naive CD8+ cells, is not regulated directly by the T-cell growth factors IL-2 or IL-15.

Detuning CD8+ T lymphocytes by down-regulation of the activating receptor NKG2D: role of NKG2D ligands released by activated T cells

Blood ◽  
2009 ◽  
Vol 113 (13) ◽  
pp. 2955-2964 ◽  
Author(s):  
Cristina Cerboni ◽  
Michele Ardolino ◽  
Angela Santoni ◽  
Alessandra Zingoni
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Cultures ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Γδ T Cells ◽  
Activated T Cells ◽  
Cell Functions ◽  
Major Player ◽  
Activating Receptor

Abstract NKG2D is an activating receptor expressed on CD8+αβ+ T cells, γδ+ T cells, natural killer (NK) cells, and some CD4+ T cells. For a long time, the interaction of NKG2D with its ligands (NKG2DLs) MICA, MICB, and ULBP1-3 has been considered a mechanism for recognition and elimination of tumor, infected, or otherwise “stressed” cells. However, a new role for NKG2D as an immunoregulatory receptor is emerging. Here, we show that NKG2D is strongly down-modulated on antigen-activated CD8+ T cells but only if CD4+ T cells are present. Down-modulation was caused by soluble factors produced by CD4+ T cells, and in particular soluble NKG2DLs were found in the supernatants of antigen-activated T-cell cultures. MICB was the ligand released at higher levels when CD4+ T cells were present in the cell cultures, suggesting that it could be the major player of NKG2D down-modulation. CD8+ T cells expressing low levels of NKG2D had impaired effector functions, as evaluated by proliferation, cytokine production, and cytotoxicity assays after combined triggering of NKG2D and TCR-CD3 complex. These findings show that activated CD4+ T cells expressing NKG2DLs can efficiently prevent NKG2D-mediated CD8+ T-cell functions, and suggest that the NKG2D/NKG2DL interaction can regulate immune responses.

scholarly journals Activation of naive and memory T cells by interleukin-15

Blood ◽  
1996 ◽  
Vol 88 (1) ◽  
pp. 230-235 ◽  
Author(s):  
H Kanegane ◽  
G Tosato
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Biological Activities ◽  
Growth Stimulation ◽  
T Cell Subsets ◽  
Beta Chain ◽  
Activated T Cells ◽  
Interleukin 15

Interleukin-15 (IL-15), a product of monocytes and other cells, has biological activities similar to those of IL-2, including growth stimulation of activated T cells, induction of cytolytic effector cells, and B-cell costimulation for proliferation and lg production. We report that IL-15 at optimal concentrations rapidly induced memory (CD45RO+) CD4+ and CD8+ T cells and naive (CD45RO-) CD8+ T cells to express the CD69 activation marker followed by proliferation. By contrast, IL-15 failed to induce naive (CD45RO-) CD4+ T cells to express CD69 or to proliferate. Similar findings were obtained with IL- 2. Unlike the other T-cell subsets, CD4+ T cells with a naive phenotype expressed little or no IL-2R beta chain, a shared component of the IL-2 and IL-15 receptors required for receptor function. A monoclonal antibody to the IL-2R beta chain, Mik beta 1, reduced CD69 expression and proliferation in CD4+ memory, CD8+ memory, and CD8+ naive T cells activated by IL-15. These results confirm the biological similarities of IL-2 and IL-15. They further document that the pool of naive CD4+ cells, unlike the pool of memory CD4+, memory CD8+, and naive CD8+ cells, is not regulated directly by the T-cell growth factors IL-2 or IL-15.

Histone Deacetylase 6 (HDAC6) Influences T-Cell Activation and Survival: Implications For Cancer Immunotherapy

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1050-1050
Author(s):  
Andressa Sodre Laino ◽  
David M Woods ◽  
Fengdong Cheng ◽  
Hongwei Wang ◽  
Eduardo M. Sotomayor
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Survival ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Wild Type ◽  
T Cell Survival

Abstract The role of histone deacetylases (HDACs) as epigenetic regulators of immune function is becoming increasingly clear. Recently, the role of specific HDACs in orchestrating T-cell maturation, survival and function has begun to emerge, giving rationale to selective therapy to direct immune responses in different disease settings, including cancer. In particular, HDAC6 has recently been characterized as a negative regulator of regulatory T-cell suppressive activity (de Zoeten, Molecular and Cellular Biology, 2011). Here we report an expanded, novel role of HDAC6 in regulating T-cell survival and activation. First, the relative expression of the eleven classic HDACs was evaluated in resting and activated T-cells from mouse and human samples. It was found that the majority of HDACs decrease in expression following activation, including HDAC6. Next, in a HDAC6KO mouse model, it was found that T-cells lacking HDAC6 had skewed survival when compared to wild-type murine T-cells. This difference seems to be the result of an increased CD4+ T-cells population in the lymph nodes, with a concomitant decrease in viable CD8+ T-cells. To determine whether this population skewing was the consequence of defects in HDAC6KO mice T-cell development, wild-type murine T-cells were treated with an isotype-selective HDAC6 inhibitor. The results seen in HDAC6KO T-cells were recapitulated when wild-type T-cells were activated and treated with HDAC6 specific inhibitors, indicating a role of HDAC6 outside of thymic development in promoting CD4+ T-cell survival at the expense of CD8+ T-cells. Interestingly, it was found that activated CD4+ T-cells displayed decreased expression of the apoptosis signaling receptor FAS after HDAC6 inhibition while no differences were observed in CD8+ T-cells under the same conditions. In addition to these results implicating HDAC6 in regulating T-cell survival, expression of surface markers was altered in both CD8+ and CD4+ T-cells, including enhanced expression of the activation molecule CD69 in stimulated T-cells treated with an isotype-selective HDAC6 inhibitor. Finally, in vivo studies in tumor-bearing HDAC6KO mice revealed a significantly delayed in tumor progression. Similar results were observed in lymphoma-bearing mice treated with HDAC6 specific inhibitors. Taken together, this data shows that HDACs are dynamic in expression with regards to T-cell activation state. More specifically, we have unveiled hereto-unexplored roles of HDAC6 in regulating T-cell survival and function, pointing at this specific HDAC as an appealing target to harness T-cell immunity in hematologic malignancies. Disclosures: No relevant conflicts of interest to declare.

scholarly journals 643 Vasoactive intestinal peptide as a novel immune checkpoint molecule in activated T cells

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A672-A672
Author(s):  
Sruthi Ravindranathan ◽  
Tenzin Passang Fnu ◽  
Edmund Waller
Keyword(s):  
T Cells ◽  
T Cell ◽  
Vasoactive Intestinal Peptide ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Immune Checkpoint ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Checkpoint Inhibitors ◽  
Activated T Cells

BackgroundOnly a fraction of cancer patients responds to current antibody-based immune checkpoint inhibitors.1 Our lab has identified vasoactive intestinal peptide-receptor (VIP-R) signaling as a targetable immune checkpoint pathway in cancer. VIP is a small neuropeptide with known immunosuppressive effects on T cells, in particular, CD4+ T cells.2–5 However, little is known about VIP-R signaling in CD8+ T cells. To define mechanisms by which VIP limits T cell activation and function, we studied the regulation of VIP and VIP receptors (VIP-R) in T cells following their activation in vitro and in mouse models of cancer.MethodsT cells from healthy human donors and murine splenocytes were activated using anti-CD3 coated plates. Western blots measured intracellular pre-pro-VIP, along with its cognate receptors; VPAC1 and VPAC2. Purified cultures of CD4+ and CD8+ T cells were used to interrogate the protein expression on specific T cell subsets. Activation and chemokine receptor expression was assessed by flow cytometry to evaluate T cell response to VIP-R antagonists in vitro and in tumor-bearing mice engrafted with pancreatic cancer cell lines.ResultsBoth murine and human T cells upregulate pre-pro-VIP following TCR stimulation with similar kinetics of VIP receptors between species. VIP expression is upregulated in vivo following treatment of tumor-bearing mice with anti-PD1 MoAb. VIP expression is temporally correlated with the upregulation of other co-inhibitory molecules. VPAC1 expression modestly increased in activated T cells while VPAC2 expression decreased. A non-canonical high molecular weight (HMW) form of VPAC2-related protein robustly and transiently increase in activated T cells. Expression of HMW form of VPAC2 is only detected in activated CD4+ T cells. Of note, activated CD4+ but not CD8+ T cells upregulate pre-pro-VIP. Pharmacological inhibition of VIP-R signaling significantly increased CD69+, OX40+, Lag3+, and PD1+ expression in CD4+ subsets compared to activated T cells without VIP-R antagonists (p < 0.05). In contrast, CD8+ T cells upregulate VPAC1 but not VPAC2 receptor following activation. VIP-R antagonist treatment of activated CD8+ T cells significantly decreased CXCR4+ expression (p < 0.05). CXCR3 and CXCR5 expression were not affected by VIP-R antagonist treatment.ConclusionsVIP-R signaling is a novel immune autocrine and paracrine checkpoint pathway in activated CD4+ T cells. Activated CD4+ and CD8+ T cells demonstrate different kinetics of VPAC1 and VPAC2 expression, suggesting different immune-regulatory responses to VIP-R antagonists. Understanding VIP-R signaling induced during T cell activation can lead to specific drugs that target VIP-R pathways to enhance cancer immunotherapy.AcknowledgementsWe thank healthy volunteers for blood samples. The authors also thank the shared resources at Emory University, namely, Emory Flow Cytometry Core (EFCC) and Integrated Cellular Imaging Core (ICI) and Yerkes Nonhuman Primate Genomics Core that provided services or instruments at subsidized cost to conduct some of the reported experiments. This work was supported in part by Katz Foundation funding, Georgia Research Alliance, and Emory School of Medicine Dean's Imagine, Innovate and Impact (I3) venture award to Edmund K. Waller.ReferencesDarvin P, Toor SM, Sasidharan Nair V, Elkord E. Immune checkpoint inhibitors: recent progress and potential biomarkers. Experimental and Molecular Medicine 2018.Wang HY, Jiang XM, Ganea D. The Neuropeptides VIP and PACAP Inhibit IL-2 Transcription by Decreasing c-Jun and Increasing JunB Expression in T Cells. J Neuroimmunol 2000;104(1):68–78.Delgado M. Vasoactive intestinal peptide generates CD4+CD25+ regulatory T Cells in Vivo. J Leukoc Biol 2005.Anderson P, Gonzalez-Rey E. Vasoactive intestinal peptide induces cell cycle arrest and regulatory functions in human T cells at multiple levels. Mol Cell Biol 2010.Delgado M, Ganea D. Vasoactive intestinal peptide: a neuropeptide with pleiotropic immune functions. Amino Acids. NIH Public Access July 2013, 25–39.Ethics ApprovalDe-identified blood samples from consented healthy volunteers (IRB 00046063) were obtained with approval from Institutional Review Boards.

scholarly journals CD8 T Cells Require Bcl-3 for Maximal Gamma Interferon Production upon Secondary Exposure to Antigen

2006 ◽  
Vol 74 (7) ◽  
pp. 4180-4189 ◽  
Author(s):  
Paula M. Chilton ◽  
Thomas C. Mitchell
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Survival Function ◽  
Ectopic Expression ◽  
Gamma Interferon ◽  
Wild Type ◽  
Activated T Cells ◽  
Ifn Γ

ABSTRACT Adjuvant-induced survival of T cells after antigen activation correlates with increased expression of Bcl-3. Bcl-3 is an NF-κB/IκB family member and has been implicated in transcriptional regulation in several cell types. We tested the ability of mice deficient in Bcl-3 (Bcl-3 KO) to exhibit T-cell adjuvant-induced survival after challenge with the superantigen staphylococcal enterotoxin B (SEB), using lipopolysaccharide (LPS) as a natural adjuvant. These studies showed that Bcl-3 is required for secondary gamma interferon (IFN-γ) production by CD8 T cells but not for adjuvant-induced survival effects. Specifically, wild-type and Bcl-3 KO mice exhibited comparable long-term increases in the Vβ8+ T-cell populations, indicating no lack of survival in response to adjuvant stimulation in the Bcl-3 KO activated T cells. Ectopic expression of the Bcl-3-related molecules IκBα, IκBβ, and IκBε in SEB-activated T cells increased survival during in vitro culture in the absence of adjuvant, suggesting that these IκB molecules could exert a survival function in antigen-activated T cells in place of Bcl-3. However, Vβ8+ CD8 T cells from SEB- plus LPS-treated Bcl-3 KO mice produced less IFN-γ upon in vitro restimulation than Vβ8+ CD8 T cells from wild-type mice. Therefore, Bcl-3 plays a unique role in the regulation of IFN-γ production in this model system.

Assessing the Role of Tissue Infiltrating APCs in Graft-Versus-Host Disease Through Two Photon Intravital Microscopy

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 342-342
Author(s):  
Christian Wysocki ◽  
Sarah Morin-Zorman ◽  
David Gonzalez ◽  
Ann Haberman ◽  
Warren Shlomchik
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Fluorescent Protein ◽  
Cd8 T Cell ◽  
Skin Lesions ◽  
Two Photon

Abstract Abstract 342 Graft-versus-host disease (GVHD) limits the broader application of allogeneic bone marrow transplantation. While initial T cell activation in GVHD occurs predominantly in secondary lymphoid organs, we have consistently observed MHCII+ donor-derived APCs in histopathologic GVHD lesions in tissues such as skin and intestine, frequently adjacent to infiltrating T cells. We hypothesized that productive interactions occur between donor APCs and T cells in situ in GVHD target tissues, which propagate disease. To address this hypothesis we utilized two photon intravital microscopy to analyze interactions between fluorescently labeled donor CD8+ T cells and tissue infiltrating donor dendritic cells (DCs), within skin lesions of living mice in a murine GVHD model. Lethally irradiated 129 mice received T cell-depleted (TCD) marrow from C57BL6 (B6) mice expressing yellow fluorescent protein (YFP) driven by the CD11c promoter (B6-CD11cYFP), B6 red fluorescent protein (RFP)+ CD8+ T cells and WT (unlabeled) B6 CD4+ T cells. The skin of the ear was imaged in anesthetized, living mice, between days 21 and 28 post-transplant, using a LaVision two photon laser scanning microscope, scanning 60uM thick z-stacks every 30 seconds for 1 hour. Individual RFP+ CD8+ T cells were tracked over time throughout the 3 dimensional image. Detailed surface maps of the YFP+ dendritic cell (DC) network were generated. A distance transformation to calculate the distance of each RFP+ CD8+ T cell from the surface of the YFP+ DC network at all times was performed. Through these analyses, we observed both highly motile donor CD8+ T cells making contact with donor DCs (defined as <=2μM between RFP+ CD8+ T cell and YFP+ DC surface), and a proportion which make long term, stable contact (continuous contact between RFP+ CD8+ T cell and YFP+ DC for at least 30 minutes, during which the RFP+ CD8+ T cell speed is below 5.5μM/min). To test whether CD8+ T cell:DC interactions required cognate TCR:MHCI interactions, lethally irradiated 129 mice received a 1:1 mixture of WT B6 and MHCI-deficient B6 BM. In group 1, labeled marrow was from B6-CD11cYFP, and unlabeled marrow from B6-β2-microglobulin (β2m)−/− donors. In group 2, labeled marrow was from B6-CD11cYFP/β2m−/− mice, and unlabeled marrow from B6. In addition to these bone marrow mixtures, all mice received B6 RFP+ CD8+ T cells and unlabeled B6 CD4+ T cells. Mice were imaged as above. Long lasting contacts between donor RFP+ CD8+ T cells and YFP+ donor DCs in skin lesions were less frequent when YFP+ DCs were β2m−/−, and therefore MHCI-deficient. We have also examined whether MHCII-dependent interactions occur between CD4+ T cells and DCs in situ in skin lesions. In preliminary experiments 129 mice received B6-CD11cYFP bone marrow, B6 RFP+ CD4+ T cells, and B6 unlabeled CD8+ T cells. After 1 hour of imaging, mice received anti-MHCII antibody or isotype control and imaging was continued for 2 hours thereafter. RFP+ CD4+ T cell motility increased after anti-MHCII but not after isotype control antibody treatment. Because GVL occurs primarily in BM and spleen, targeting of tissue-infiltrating APCs could represent a unique strategy to ameliorate GVHD while preserving GVL. Disclosures: No relevant conflicts of interest to declare.

T Cells from Chronic Lymphocytic Leukemia (CLL) Patients Display Dysregulated Expression of Immune Checkpoint Molecules and Activation Markers Mainly Restricted to CD4+ Cells and Correlated with Disease Activity

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4132-4132
Author(s):  
Marzia Palma ◽  
Giusy Gentilcore ◽  
Fariba Mozaffari ◽  
Kia Heimersson ◽  
Barbro Näsman-Glaser ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Immune Checkpoint ◽  
Cd4 T Cells ◽  
Research Funding ◽  
Immune Checkpoints ◽  
Activated T Cells ◽  
Activation Markers ◽  
Cd8 Cells

Abstract Background CLL patients (pts) have impaired humoral and cellular immune functions, which is largely due to profound defects of T-cells. Regulation and activation of T lymphocytes depend not only on T cell receptor signaling but also on co-signaling receptors delivering either inhibitory or stimulatory signals, known as immune checkpoints. CTLA-4 (cytotoxic T lymphocyte-associated antigen-4) is transiently expressed on activated T cells, binding the same ligands as CD28, inhibiting T-cell activation. Similarly, programmed cell death protein 1 (PD-1) is expressed on activated CD4+ and CD8+ T cells inhibiting T-cell functions upon binding to the ligands B7-H1 (PD-L1, CD274) and B7-DC (PD-L2, CD273). CD137 is an inducible costimulatory receptor expressed by activated T cells. Dysregulated expression of immune checkpoint receptors on T cells of CLL pts may have an impact on T-cell responsiveness and might be a mechanism for the immune deficiency in the disease. Aim To evaluate the expression of the immune checkpoint molecules CTLA-4, PD-1 and CD137 as well as of the cell proliferation marker Ki67, the activation marker CD69 and of CD103, a marker expressed on regulatory T cells, in T cells from CLL pts in different disease phases. Methods Peripheral blood samples were obtained from 69 CLL pts and 13 healthy control donors (HD). Pts were sub-grouped according to disease phase: indolent vs progressive (i.e. fulfilling criteria for active disease). The expression of CTLA-4, PD-1, PD-L1, CD69, CD103, CD137 and Ki-67 was assessed by flow-cytometry on CD4+ and CD8+ T cells. We also analysed the change in expression of these markers on T cells after 72 hours of PHA stimulation. Results CLL pts (n=17) had a significanty higher percentage of proliferating (Ki67+) CD3+ cells compared to HD (n=7) (median 3.7% in progressive vs 1.7% in indolent CLL vs 0.9% in HD, p=0.004 and p=0.04, respectively) (Fig.1). Progressive CLL pts had a significantly higher percentage Ki67+ CD4+ compared to indolent pts as well as HD (p=0.007 and p=0.001, respectively). Both indolent and progressive pts had higher percentage of Ki67+ CD8+ T cells compared to HD (p=0.01 and p=0.03, respectively). The percentage of CTLA-4+ CD4+ and CTLA-4+ CD8+ cells was low in CLL pts as well as in HD. However, the percentage of PD-1+ CD4+ T cells was significantly higher in progressive (n=32) as compared to indolent (n=35) CLL pts (median 40.3% vs 23.3%, p<0.0001) and HD (n=13) (median 21.5%, p<0.0001) (Fig.2) and correlated positively to the white blood cell counts (WBC) at the time of testing (r=0.29, p=0.03), while no difference was found with regard to the percentage of PD-1+ CD8+ T cells. No difference was observed between CLL pts and HD regarding the expression of PD-L1 on T cells. Both the percentage of CD69+ CD4+ and CD137+ CD4+ T cells were significantly higher in progressive as compared to indolent disease and correlated positively to WBC while no difference was found seen in CD8+ T cells. The percentage of CD103+ T cells was significantly lower in progressive compared to and HD within both the CD4+ (p=0.02) and the CD8+ subpopulations (p=0.02). After 72-hrs of PHA stimulation, PD-1 and CTLA-4 expression increased in CD4+ and CD8+ cells to a similar extent in CLL pts and HD, while PD-L1 increased in HD but not in progressive CLL pts (p=0.03 and p=0.007 for CD4+ and CD8+ cells, respectively). CD69 expression increased to a similar extent in CLL pts and HD, while CD137 expression increased more in T cells from progressive pts compared to HD (p=0.03 and 0.01 for the CD4+ and CD8+ cells, respectively). No increase in CD103 on CD8+ T-cells was observed in CLL pts compared to HD (p=0.04 and p=0.01 for the indolent and progressive pts, respectively). Conclusions Progressive CLL pts have more proliferating (Ki67+) T cells in both the CD4+ and CD8+ compartments compared to HD. CD4+ T-cells in progressive CLL pts display an activated phenotype (CD69+) and express the immune co-stimulatory molecule CD137 at a significantly higher level compared to indolent pts and HD. Nevertheless, the expression of the inhibitory immune checkpoint molecule PD-1 is so high that it is reasonable to assume that these cells are heavily impaired in their immune functions. The differences observed in the expression of immune checkpoints and activation markers between CLL pts in different phases of the disease suggest that major changes occur in the CD4+ T-cell compartment during disease progression. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Hansson: Jansse Cilag: Research Funding. Österborg:Janssen, Pharmacyclics, Gilead: Consultancy, Research Funding; Novartis: Research Funding.

scholarly journals Reduced immune-regulatory molecule expression on human colonic memory CD4 T cells in older adults

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Stephanie M. Dillon ◽  
Tezha A. Thompson ◽  
Allison J. Christians ◽  
Martin D. McCarter ◽  
Cara C. Wilson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Older Persons ◽  
Age Groups ◽  
T Cell Immunity ◽  
Cd4 T Cell ◽  
Cell Immunity ◽  
Memory Cd4 T Cells

Abstract Background The etiology of the low-level chronic inflammatory state associated with aging is likely multifactorial, but a number of animal and human studies have implicated a functional decline of the gastrointestinal immune system as a potential driver. Gut tissue-resident memory T cells play critical roles in mediating protective immunity and in maintaining gut homeostasis, yet few studies have investigated the effect of aging on human gut T cell immunity. To determine if aging impacted CD4 T cell immunity in the human large intestine, we utilized multi-color flow cytometry to measure colonic lamina propria (LP) CD4 T cell frequencies and immune-modulatory marker expression in younger (mean ± SEM: 38 ± 1.5 yrs) and older (77 ± 1.6 yrs) adults. To determine cellular specificity, we evaluated colon LP CD8 T cell frequency and phenotype in the same donors. To probe tissue specificity, we evaluated the same panel of markers in peripheral blood (PB) CD4 T cells in a separate cohort of similarly aged persons. Results Frequencies of colonic CD4 T cells as a fraction of total LP mononuclear cells were higher in older persons whereas absolute numbers of colonic LP CD4 T cells per gram of tissue were similar in both age groups. LP CD4 T cells from older versus younger persons exhibited reduced CTLA-4, PD-1 and Ki67 expression. Levels of Bcl-2, CD57, CD25 and percentages of activated CD38+HLA-DR+ CD4 T cells were similar in both age groups. In memory PB CD4 T cells, older age was only associated with increased CD57 expression. Significant age effects for LP CD8 T cells were only observed for CTLA-4 expression, with lower levels of expression observed on cells from older adults. Conclusions Greater age was associated with reduced expression of the co-inhibitory receptors CTLA-4 and PD-1 on LP CD4 T cells. Colonic LP CD8 T cells from older persons also displayed reduced CTLA-4 expression. These age-associated profiles were not observed in older PB memory CD4 T cells. The decline in co-inhibitory receptor expression on colonic LP T cells may contribute to local and systemic inflammation via a reduced ability to limit ongoing T cell responses to enteric microbial challenge.

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