Lymphocyte Subpopulations and Expression of Immune Checkpoint Receptors PD-1 and Tim-3 in Patients with Chronic Myeloid Leukemia in a Discontinuation Trial

Introduction: Immunological factors have been associated with deep molecular response (DMR) and treatment-free remission (TFR) in chronic myeloid leukemia (CML). Immune cell functions are restored in patients with DMR and this effect remains after TKI discontinuation. Recently, a multivariable model including CD4+ T cells, PD1+TIM3-CD8+ T cells and neutrophils counts showed ability to predict the likelihood of achieving molecular remission 4.0 (MR4) among other clinical parameters. In this prospective study of TKI discontinuation, we evaluated the expression of two checkpoint receptors, programmed death 1 (PD-1) and T cell immunoglobulin and mucin domain-containing protein 3 (Tim-3), in the T cell population of patients who successfully remained in TFR. We also evaluated lymphocyte subpopulations profile before and during TKI discontinuation. Materials and methods: This study was approved by local ethical committee and registered at the Clinicaltrials.gov (NCT03239886). The inclusion criteria were: age ≥ 18 years, CML chronic phase, treatment with first line imatinib (IM) for at least 36 months, MR4 for at least 12 months confirmed with 3 samples, no previous transplant or resistance to therapy. IM was restarted when loss of major molecular response (MMR) was confirmed by two samples. The primary endpoint was the TFR rate at 24 months. Lymphocyte subpopulations were analyzed in peripheral blood by flow cytometry before discontinuation, IM resumption or in the second year of follow up in patients in TFR. A 6-color flow cytometry panel including CD45, CD3, CD4, CD8, PD-1 and Tim-3 antibodies was also used to study T cell exhaustion phenotype in this population. Results: Thirty-one patients were included in the study from Dec/2016 to Oct/2017. Median age was 54 years (range 29-95), 58% male, 55% with a low Sokal score, 65% with b3a2 BCR-ABL transcripts, 30% with prior use of interferon and 69% were in MR4.5. The median time of IM therapy was 9.4 years (range 3-14.9) and the median time of sustained MR4 was 6.7 years (range 1.6-10.6). One patient died two months after discontinuation due to acute heart failure (not related to CML). In a median follow up of 29 months (range 21-32), the TFR rate was 56% (95% CI 37-72). Thirteen patients (42%) lost MMR, six (46%) of them after six months of discontinuation. After resumption of IM, twelve patients (92%) recovered MR4; one patient achieved MMR. The median time to recover MMR and MR4 was 1 month and 2.4 months respectively. Lymphocytes subpopulations CD3+/CD4+/CD8-, CD3+/CD4-/CD8+ and CD3-/CD56+ (NK cells) proportions were similar among all patients and no variations were observed during the study. The overall median proportion of NK cell was 10.5%, being 13% in the TFR group vs 10% in relapsed patients (p 0.08). Proportion of NK cells and molecular response prior to discontinuation were associated with different rates of TFR as shown in figure 1. T cell exhaustion was evaluated in the TFR group (n=17) during the second year of follow up. The control group (n=13) were the patients that lost MMR during the study, but their samples were collected after they recovered MMR/MR4 with IM. Patients in TFR had a median proportion of PD-1+Tim3-CD8+ T cells of 30.6% (25.1-50.9) vs 18.9% (0.5-53.3) in the control group (p 0.009). No differences were observed in PD-1+Tim3+CD8+, PD-1-Tim3-CD8+ and in CD4+ T cells populations (figure 2). Conclusion: In this prospective cohort the median duration of sustained MR4 was above 5 years, as recommended by most guidelines of TKI discontinuation. Patients with only MR4 and lower counts of NK cells had the lowest probability to remain in TFR (28% vs 72%). This data suggests that the depth of molecular response combined with NK cells proportion might be useful to refine selection of patients for discontinuation trials. PD-1+Tim3-CD8+ T cells proportion was higher in patients who were free of TKI compared to those patients who had to resume imatinib. Further studies are needed to evaluate whether the reversion of T cell exhaustion phenotype is mediated by TKI and how this impacts the CD8+ T cells cytotoxicity of patients in TFR. Disclosures No relevant conflicts of interest to declare.

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Role of Recipient CD8+ T Cell Exhaustion in the Rejection of Adoptively Transferred Haploidentical NK Cells

Blood ◽

10.1182/blood.v128.22.503.503 ◽

2016 ◽

Vol 128 (22) ◽

pp. 503-503

Author(s):

Robin Williams ◽

Sarah Cooley ◽

Veronika Bachanova ◽

Thomas A Waldmann ◽

Bruce R. Blazar ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Nk Cells ◽

Cd8 T Cells ◽

Cell Expansion ◽

Nk Cell ◽

Cd8 T Cell ◽

T Cell Exhaustion ◽

Cell Exhaustion ◽

Refractory Aml

Natural killer (NK) cells are cytotoxic innate lymphoid cells, which play a major role in tumor surveillance. We have tested the safety and efficacy of allogeneic NK cell adoptive transfer from heathy haploidentical donors and demonstrate that in vivo expansion and persistence of the adoptively transferred NK cells at Day 14 after infusion correlates with 30-50% remission in patients with refractory AML. However, the factors that influence successful persistence of donor-derived NK cells are unclear. We hypothesized that recipient T cells play a role in the rejection of allogeneic NK cells and a correlation could exist between persistence of donor-derived NK cells and exhaustion in recipient T cells. T cell exhaustion, a well-established state of T-cell dysfunction occurring in response to chronic and continuous antigen stimulation, is well-documented in human cancer, and characterized by progressive and hierarchical loss of effector functions including sustained up-regulation and co-expression of multiple inhibitory receptors such as PD-1 and Tim-3 and altered expression of key transcription factors including the gain of Eomes and T-bet. We used samples from a phase I/II trial of CD3/CD19 depleted, IL-15-activated, haploidentical donor NK cells delivered following conditioning with cyclophosphamide (50mg/kg) and fludarabine (35 mg/m2 x 3days) in adults with chemotherapy refractory AML. Patients received donor NK cells on Day 0 followed by 10 doses of recombinant human (rh) IL-15 (2 mcg/kg/day) manufactured by the NCI and delivered SQ on Days 1-5 and 8-12. A significant proportion of patients experienced donor NK cell expansion at Day 14 (expanders), but there were some that did not (non-expanders). Therapeutic benefit has only been noted among the expanders. We examined samples from a total of 10 patients with refractory AML, 5 expanders and 5 non-expanders, along with their 10 respective donors. Cryopreserved patient PBMCs were thawed and rested overnight in RPMI-1640 with 2% FBS. The cells were stained for viability, for surface markers using antibodies against CD3, CD8, CD56, PD-1, and Tim-3, intracellularly stained for Eomes and T-bet. We evaluated CD8+ T cell expression of PD-1 and Tim-3, in expanders and non-expanders, prior to chemotherapy and at Day 14. Paired donor T cells from the non-mobilized apheresis products served as controls. Prior to chemotherapy, both patient groups had equivalently elevated expression of both PD1 and Tim-3 on CD8+ T cells. However, at Day 14, the expanders had persistence of PD-1 and Tim-3 while expression on non-expander CD8+ T cells fell to donor level (Figure 1A). Furthermore, expanders had a significantly higher proportion of CD8+ T cells that either co-expressed PD-1 and Tim-3 (p=0.017) or had a PD-1high phenotype (p=0.032) at Day 14, both of which are suggestive of an exhausted state, as opposed to an activated one (Figure 1B,C). Next, we examined Eomes and T-bet expression in recipient T cells. While generally low among healthy T cell populations, as T cells become exhausted, they gain expression of these transcription factors. We looked specifically at the expression of these transcription factors in the recipient CD8+ T cell populations with the highest likelihood of being exhausted, i.e. those co-expressing PD-1 and Tim-3 or those with the PD-1high phenotype. Eomes expression in recipient PD-1high CD8+ T cells and in PD-1+Tim-3+ CD8+ T cells at Day 14 was significantly higher (p=0.01 and p=0.04, respectively) among expanders compared to non-expanders (Figure 2A,B). Likewise, T-bet expression was greater (p=0.004) among expanders in the PD-1high population (Figure 2A). There was no difference in the T-bet expression in PD-1+Tim-3+ CD8+ T cells between groups (Figure 2B). While all patients with refractory AML receiving NK cell adoptive transfer had an elevated percentage of CD8+ T cells with an exhausted phenotype prior to therapy, only patients with donor-derived NK cell expansion had persistence of the exhausted T cell phenotype at Day 14. Thus, T cell mediated rejection is a major obstacle to overcome for successful adoptive NK cell transfer which could in part be aided by a link between recipient T cell exhaustion and expansion of NK cells. This might further suggest that IL-15 reverses T cell exhaustion among those who failed to achieve donor-derived NK cell expansion. Disclosures Miller: Fate Therapeutics: Consultancy, Research Funding; Oxis Biotech: Consultancy, Other: SAB.

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

Journal of Experimental Medicine ◽

10.1084/jem.20081752 ◽

2008 ◽

Vol 205 (13) ◽

pp. 2965-2973 ◽

Cited By ~ 195

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.

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Partial restoration of immune response in Hepatitis C patients after viral clearance by direct-acting antiviral therapy

PLoS ONE ◽

10.1371/journal.pone.0254243 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0254243

Author(s):

Meritxell Llorens-Revull ◽

Maria Isabel Costafreda ◽

Angie Rico ◽

Mercedes Guerrero-Murillo ◽

Maria Eugenia Soria ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

Hepatitis C ◽

T Cell ◽

Cd8 T Cells ◽

Viral Clearance ◽

Cd4 T Cell ◽

Care Hospital ◽

T Cell Exhaustion ◽

Cell Exhaustion

Background & aims HCV CD4+ and CD8+ specific T cells responses are functionally impaired during chronic hepatitis C infection. DAAs therapies eradicate HCV infection in more than 95% of treated patients. However, the impact of HCV elimination on immune responses remain controversial. Here, we aimed to investigate whether HCV cure by DAAs could reverse the impaired immune response to HCV. Methods We analyzed 27 chronic HCV infected patients undergoing DAA treatment in tertiary care hospital, and we determined the phenotypical and functional changes in both HCV CD8+ and CD4+ specific T-cells before and after viral clearance. PD-1, TIM-3 and LAG-3 cell-surface expression was assessed by flow cytometry to determine CD4+ T cell exhaustion. Functional responses to HCV were analyzed by IFN-Ɣ ELISPOT, intracellular cytokine staining (IL-2 and IFN-Ɣ) and CFSE-based proliferation assays. Results We observed a significant decrease in the expression of PD-1 in CD4+ T-cells after 12 weeks of viral clearance in non-cirrhotic patients (p = 0.033) and in treatment-naive patients (p = 0.010), indicating a partial CD4 phenotype restoration. IFN-Ɣ and IL-2 cytokines production by HCV-specific CD4+ and CD8+ T cells remained impaired upon HCV eradication. Finally, a significant increase of the proliferation capacity of both HCV CD4+ and CD8+ specific T-cells was observed after HCV elimination by DAAs therapies. Conclusions Our results show that in chronically infected patients HCV elimination by DAA treatment lead to partial reversion of CD4+ T cell exhaustion. Moreover, proliferative capacity of HCV-specific CD4+ and CD8+ T cells is recovered after DAA’s therapies.

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644 Tumor-mediated suppressive signaling and hypoxia supports altered chromatin landscapes that limit the transcriptional and functional potential of terminal T cell exhaustion

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-sitc2021.644 ◽

2021 ◽

Vol 9 (Suppl 3) ◽

pp. A673-A673

Author(s):

Rhodes Ford ◽

Natalie Rittenhouse ◽

Nicole Scharping ◽

Paolo Vignali ◽

Greg Delgoffe ◽

...

Keyword(s):

Gene Expression ◽

T Cells ◽

T Cell ◽

Tumor Microenvironment ◽

Histone Modifications ◽

Cd8 T Cells ◽

Tumor Hypoxia ◽

T Cell Subsets ◽

T Cell Exhaustion ◽

Cell Exhaustion

BackgroundCD8+ T cells are a fundamental component of the anti-tumor response; however, tumor-infiltrating CD8+ T cells (TIL) are rendered dysfunctional by the tumor microenvironment. CD8+ TIL display an exhausted phenotype with decreased cytokine expression and increased expression of co-inhibitory receptors (IRs), such as PD-1 and Tim-3. The acquisition of IRs mark the progression of dysfunctional TIL from progenitors (PD-1Low) to terminally exhausted (PD-1+Tim-3+). How the chromatin landscape changes during this progression has not been described.MethodsUsing a low-input ChIP-based assay called Cleavage Under Targets and Release Using Nuclease (CUT&RUN), we have profiled the histone modifications at the chromatin of tumor-infiltrating CD8+ T cell subsets to better understand the relationship between the epigenome and the transcriptome as TIL progress towards terminal exhaustion.ResultsWe have identified two epigenetic characteristics unique to terminally exhausted cells. First, we have identified a unique set of genes, characterized by active histone modifications that do not have correlated gene expression. These regions are enriched for AP-1 transcription factor motifs, yet most AP-1 family factors are actively downregulated in terminally exhausted cells, suggesting signals that promote downregulation of AP-1 expression negatively impacts gene expression. We have shown that inducing expression of AP-1 factors with a 41BB agonist correlates with increased expression of these anticorrelated genes. We have also found a substantial increase in the number of genes that exhibit bivalent chromatin marks, defined by the presence of both active (H3K4me3) and repressive (H3K27me3) chromatin modifications that inhibit gene expression. These bivalent genes in terminally exhausted T cells are not associated with plasticity and represent aberrant hypermethylation in response to tumor hypoxia, which is necessary and sufficient to promote downregulation of bivalent genes.ConclusionsOur study defines for the first time the roles of costimulation and the tumor microenvironment in driving epigenetic features of terminally exhausted tumor-infiltrating T cells. These results suggest that terminally exhausted T cells have genes that are primed for expression, given the right signals and are the basis for future work that will elucidate that factors that drive progression towards terminal T cell exhaustion at the epigenetic level and identify novel therapeutic targets to restore effector function of tumor T cells and mediate tumor clearance.

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Phase 1 Study of Subcutaneous Recombinant Human (rh) Interleukin-15 and Intravenous Alemtuzumab in Patients with Rrelapsed/Refractory T-Cell Lymphoma

Blood ◽

10.1182/blood-2020-142065 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 23-24

Author(s):

Milos D. Miljkovic ◽

Kevin C Conlon ◽

Jennifer Albert ◽

Deborah Allen ◽

Thomas A. Waldmann

Keyword(s):

T Cells ◽

T Cell ◽

Adverse Events ◽

Nk Cells ◽

Cd8 T Cells ◽

Cell Lymphoma ◽

T Cell Lymphoma ◽

Interleukin 15 ◽

Grade 3 ◽

Dose Levels

BACKGROUND: Interleukin-15 (IL-15) is a member of the 4-α helix bundle family of cytokines. Administration of single-agent IL-15 to patients with cancer produced substantial increases and activation of natural killer (NK) cells and CD8+ T cells, but no clinical responses. Subsequent studies showed that IL-15 enhances the efficacy of anti-tumor monoclonal antibodies that work through antibody-dependent cell cytotoxicity, a process mediated by NK cells. In the MET-1 xenograft mouse model, the combination of IL-15 and the anti-CD52 antibody alemtuzumab led to significantly more durable responses than each agent by itself. Here we report the final results of the phase I trial of IL-15 and alemtuzumab in patients with relapsed and refractory T-cell lymphoma (NCT02689453). METHODS: In this phase I single-center trial IL-15 was given subcutaneously 5 days per week for 2 weeks in a standard 3+3 dose escalation scheme (DL1: 0.5μg/kg, DL2: 1μg/kg, DL3: 2μg/kg), followed by alemtuzumab 30mg intravenously three times weekly for 4 weeks. Primary endpoints were type and frequency of adverse events and the maximum tolerated dose of IL-15. RESULTS: A total of eleven patients (pts) were treated at DL1 (3), DL2 (4) and DL3 (4). Seven pts had acute adult T-cell leukemia (ATL), two had chronic ATL, and two had peripheral T-cell lymphoma not otherwise specified (PTCL-NOS). There were no dose-limiting toxicities through the maximum planned dose of 2μg/kg/day. Two pts both with acute subtype ATL were unable to complete treatment due to rapidly progressive disease early in their treatment course, but there was no evidence tumor simulation or expansion of circulating ATL cell numbers during the period of IL-15 administration Hematologic AEs included lymphopenia (all 11 pts, 7 with grade 3/4), neutropenia (8 pts, 2 with grade 3), anemia (10 pts, 1 with grade 3), and thrombocytopenia (4 pts, 1 with grade 3). The most common non-hematologic AEs were infusion-related reactions experienced by 10 of the 11 pts during alemtuzumab infusion, and urticaria (4, pts, 2 with grade 3, both of whom at MTD). Two pts had incidental findings of a catheter-associated thrombus and pulmonary emboli, necessitating institution of prophylactic anticoagulation for subsequent pts after which no additional thromboembolic events were seen. Infectious adverse events included one case each of CMV reactivation without end-org involvement, HSV reactivation, Zoster, bacterial sinusitis, and cellulitis (in a patient with ATL and skin involvement), all grade 2. There was no evidence of graft versus host disease in two pts with previous allogeneic stem cell transplantation, and there were no serious adverse events attributable to IL-15. Administration of IL-15 resulted in a median 2.1-fold increase (range 1.2-3.4) in absolute lymphocyte count, 2.5-fold (1-5.9) increase in the number of circulating CD8+ T cells, and 7.2-fold (1.1-17.1) increase in NK cells across all dose levels (Figure 1A). At the MTD, the median ALC, CD8+ T cell, and NK cell increases were 2, 2.1, and 15.3-fold respectively. The overall response rate was 45% with 2/11 complete responses (CR) and 3/11 partial responses (PR) (Figure 1B). Notably, all pts with leukemic disease attained CR in the blood (Figure 1C), with varying response in other compartments. A patient with acute ATL had a CR at first restaging but developed central nervous system relapse after four weeks; this remained the only site of disease until the patient's death 8 months later. A patient with PTCL-NOS had a delayed response, with a PR at 3 and CR at 5 months which was ongoing at 12-month follow-up. Two pts with chronic ATL had PRs which lasted 10 and 4 months, and a patient with acute ATL had a PR at first restaging which was ongoing at the end of treatment. In all pts, response was correlated with normalization of serum LDH and soluble CD25. Analysis of peripheral blood mononuclear cells from responders and non-responders using single-cell RNA-seq is under way and will be presented. CONCLUSION: Combination of IL-15 and alemtuzumab was safe at all dose levels administered with no evidence of treatment related disease stimulation. The contribution of IL-15 to the known clinical efficacy of alemtuzumab in relapsed/refractory T-cell malignancies needs to be assessed in a randomized trial. Further evaluation of IL-15 in the post-allogeneic transplant setting, particularly prior to donor lymphocyte infusion, is also planned. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: alemtuzumab for T-cell lymphoma

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Single-Cell Transcriptome Analysis Reveals RGS1 as a New Marker and Promoting Factor for T-Cell Exhaustion in Multiple Cancers

Frontiers in Immunology ◽

10.3389/fimmu.2021.767070 ◽

2021 ◽

Vol 12 ◽

Author(s):

Yunmeng Bai ◽

Meiling Hu ◽

Zixi Chen ◽

Jinfen Wei ◽

Hongli Du

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Poor Prognosis ◽

Effector T Cells ◽

T Cell Exhaustion ◽

Cell Exhaustion ◽

Cell Transcriptome ◽

Cancer Tissues ◽

Single Cell Transcriptome

T-cell exhaustion is one of the main reasons of tumor immune escape. Using single-cell transcriptome data of CD8+ T cells in multiple cancers, we identified different cell types, in which Pre_exhaust and exhausted T cells participated in negative regulation of immune system process. By analyzing the coexpression network patterns and differentially expressed genes of Pre_exhaust, exhausted, and effector T cells, we identified 35 genes related to T-cell exhaustion, whose high GSVA scores were associated with significantly poor prognosis in various cancers. In the differentially expressed genes, RGS1 showed the greatest fold change in Pre_exhaust and exhausted cells of three cancers compared with effector T cells, and high expression of RGS1 was also associated with poor prognosis in various cancers. Additionally, RGS1 protein was upregulated significantly in tumor tissues in the immunohistochemistry verification. Furthermore, RGS1 displayed positive correlation with the 35 genes, especially highly correlated with PDCD1, CTLA4, HAVCR2, and TNFRSF9 in CD8+ T cells and cancer tissues, indicating the important roles of RGS1 in CD8+ T-cell exhaustion. Considering the GTP-hydrolysis activity of RGS1 and significantly high mRNA and protein expression in cancer tissues, we speculated that RGS1 potentially mediate the T-cell retention to lead to the persistent antigen stimulation, resulting in T-cell exhaustion. In conclusion, our findings suggest that RGS1 is a new marker and promoting factor for CD8+ T-cell exhaustion and provide theoretical basis for research and immunotherapy of exhausted cells.

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Unraveling the Multifaceted Nature of CD8 T Cell Exhaustion Provides the Molecular Basis for Therapeutic T Cell Reconstitution in Chronic Hepatitis B and C

Cells ◽

10.3390/cells10102563 ◽

2021 ◽

Vol 10 (10) ◽

pp. 2563

Author(s):

Valeria Barili ◽

Andrea Vecchi ◽

Marzia Rossi ◽

Ilaria Montali ◽

Camilla Tiezzi ◽

...

Keyword(s):

T Cells ◽

Chronic Hepatitis ◽

T Cell ◽

Hepatitis B ◽

Chronic Hepatitis B ◽

Cd8 T Cells ◽

Stress Responses ◽

T Cell Exhaustion ◽

Virus Infections ◽

Cell Exhaustion

In chronic hepatitis B and C virus infections persistently elevated antigen levels drive CD8+ T cells toward a peculiar differentiation state known as T cell exhaustion, which poses crucial constraints to antiviral immunity. Available evidence indicates that T cell exhaustion is associated with a series of metabolic and signaling deregulations and with a very peculiar epigenetic status which all together lead to reduced effector functions. A clear mechanistic network explaining how intracellular metabolic derangements, transcriptional and signaling alterations so far described are interconnected in a comprehensive and unified view of the T cell exhaustion differentiation profile is still lacking. Addressing this issue is of key importance for the development of innovative strategies to boost host immunity in order to achieve viral clearance. This review will discuss the current knowledge in HBV and HCV infections, addressing how innate immunity, metabolic derangements, extensive stress responses and altered epigenetic programs may be targeted to restore functionality and responsiveness of virus-specific CD8 T cells in the context of chronic virus infections.

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Transient and persistent effects of IL-15 on lymphocyte homeostasis in nonhuman primates

Blood ◽

10.1182/blood-2010-03-275438 ◽

2010 ◽

Vol 116 (17) ◽

pp. 3238-3248 ◽

Cited By ~ 72

Author(s):

Enrico Lugli ◽

Carolyn K. Goldman ◽

Liyanage P. Perera ◽

Jeremy Smedley ◽

Rhonda Pung ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Nk Cells ◽

T Cell Activation ◽

Cd8 T Cells ◽

Cell Activation ◽

Nk Cell ◽

The Body ◽

Effector Memory ◽

Memory Cd8 T Cells

Abstract Interleukin-15 (IL-15) is a cytokine with potential therapeutic application in individuals with cancer or immunodeficiency to promote natural killer (NK)– and T-cell activation and proliferation or in vaccination protocols to generate long-lived memory T cells. Here we report that 10-50 μg/kg IL-15 administered intravenously daily for 12 days to rhesus macaques has both short- and long-lasting effects on T-cell homeostasis. Peripheral blood lymphopenia preceded a dramatic expansion of NK cells and memory CD8 T cells in the circulation, particularly a 4-fold expansion of central memory CD8 T cells and a 6-fold expansion of effector memory CD8 T cells. This expansion is a consequence of their activation in multiple tissues. A concomitant inverted CD4/CD8 T-cell ratio was observed throughout the body at day 13, a result of preferential CD8 expansion. Expanded T- and NK-cell populations declined in the blood soon after IL-15 was stopped, suggesting migration to extralymphoid sites. By day 48, homeostasis appears restored throughout the body, with the exception of the maintenance of an inverted CD4/CD8 ratio in lymph nodes. Thus, IL-15 generates a dramatic expansion of short-lived memory CD8 T cells and NK cells in immunocompetent macaques and has long-term effects on the balance of CD4+ and CD8+ T cells.

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PD-1 up-regulation is correlated with HIV-specific memory CD8+ T-cell exhaustion in typical progressors but not in long-term nonprogressors

Blood ◽

10.1182/blood-2006-09-044826 ◽

2007 ◽

Vol 109 (11) ◽

pp. 4671-4678 ◽

Cited By ~ 207

Author(s):

Ji-Yuan Zhang ◽

Zheng Zhang ◽

Xicheng Wang ◽

Jun-Liang Fu ◽

Jinxia Yao ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd8 T Cells ◽

Cd8 T Cell ◽

Effector Memory ◽

T Cell Exhaustion ◽

Cell Exhaustion ◽

Specific Memory ◽

Memory Cd8 T Cell

Abstract The immunoreceptor PD-1 is significantly up-regulated on exhausted CD8+ T cells during chronic viral infections such as HIV-1. However, it remains unknown whether PD-1 expression on CD8+ T cells differs between typical progressors (TPs) and long-term nonprogressors (LTNPs). In this report, we examined PD-1 expression on HIV-specific CD8+ T cells from 63 adults with chronic HIV infection. We found that LTNPs exhibited functional HIV-specific memory CD8+ T cells with markedly lower PD-1 expression. TPs, in contrast, showed significantly up-regulated PD-1 expression that was closely correlated with a reduction in CD4 T-cell number and an elevation in plasma viral load. Importantly, PD-1 up-regulation was also associated with reduced perforin and IFN-γ production, as well as decreased HIV-specific effector memory CD8+ T-cell proliferation in TPs but not LTNPs. Blocking PD-1/PD-L1 interactions efficiently restored HIV-specific CD8+ T-cell effector function and proliferation. Taken together, these findings confirm the hypothesis that high PD-1 up-regulation mediates HIV-specific CD8+ T-cell exhaustion. Blocking the PD-1/PD-L1 pathway may represent a new therapeutic option for this disease and provide more insight into immune pathogenesis in LTNPs.

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A Prospective Evaluation of the Effects of Extracorporeal Photopheresis on Important Immunological Markers in Chronic Graft Versus Host Disease.

Blood ◽

10.1182/blood.v104.11.5125.5125 ◽

2004 ◽

Vol 104 (11) ◽

pp. 5125-5125

Author(s):

John Bladon ◽

Peter C. Taylor

Keyword(s):

T Cells ◽

T Cell ◽

Nk Cells ◽

Natural Killer ◽

Graft Versus Host Disease ◽

Cd8 T Cells ◽

Chronic Gvhd ◽

Extracorporeal Photopheresis ◽

Graft Versus Host ◽

Testing Stage

Abstract A major complication of allogeneic bone marrow or stem cell transplantation is the development of acute and chronic graft versus host disease (GvHD). Initial treatment includes corticosteroids and immunosuppressive agents. However, for steroid-refractory patients other non-conventional therapies are utilised. Recently, extracorporeal photopheresis (ECP) has shown efficacy for the treatment of acute and chronic GvHD unresponsive to standard therapy. ECP involves exposing white cells, harvested by selective leucopheresis, to 8 methoxypsoralen (8-MOP) and UVA light. The irradiated white cells are subsequently re-infused. The aetiology of GvHD involves the stimulation of proinflammatory cytokines; the levels of tumour necrosis factor alpha (TNFα) and Interferon gamma (IFNγ) have been closely linked to GvHD progression. The successful treatment of GvHD has also demonstrated changes in the ratio of CD4/CD8 T cells. The T-cell activation marker CD134 (OX40) has been observed in rats experiencing acute GvHD (aGvHD) and indicated to be a marker of steroid resistant acute and chronic GvHD. Natural Killer (NK) cells are believed to play an active role in suppressing GvHD. NK activity can be reduced in chronic GvHD (cGvHD) and animal models demonstrate GvHD suppression following NK cell transfer. Inhibitory natural killer cell receptors (NKRs) on NK cells can regulate NK and T cell function, including down-regulating target cell lysis. High levels of the NKR CD94 has been observed on patients without cGvHD. This prospective study was designed to determine if peripheral immunophenotypic markers associated with cGvHD are significantly altered by long term ECP therapy. New cGvHD referrals were tested prior to beginning therapy (0 months) and after 3, 6 and 12 months of treatment. On each occasion peripheral blood were tested for: CD4+, CD8+, CD4+/CD134+, CD8+CD134+, CD3+/CD94+, CD8+/CD94+, CD3−/CD56+ (NK), CD3+/IFNγ+, CD3+/TNFα and CD14+/TNFα. For 0–3 months n=16, for 0–6 months n=9 and for 0–12 months n=5. From 0–3 months a fall (p=0.031) in CD8 levels was observed, whilst CD4+ T cells increased from 0–12 months (p=0.040). At each testing stage an increase in the ratio of CD4/CD8 was observed, although these changes were not statistically significant. The percentage of CD4+/CD134+ and CD8+/CD134+ T cells decreased at each subsequent test, however significance was only observed between 0 and 12 months (p= 0.018 for both). NK cells (CD3−/CD56+) increased at 3, 6 and 12 months, however significance was only detected at 3 months (p=0.038). The percentage of CD3+ and CD8+ T cells expressing CD94 remained unchanged. A fall in T cells positive for IFNγ was observed at 3 months (p=0.047), however at each other testing stage the levels of CD3+/IFNγ+, CD3+/TNFα and CD14+/TNFα showed no significant change. Therefore, although increases in CD4/CD8 have been observed in cGvHD treated by ECP, this response remains controversial with many reports demonstrating conflicting data. Reduction of CD134 was observed following ECP, however at the tradition evaluation stage of 3 months no significant difference was observed. The levels of NK cells increased, consistent with previous reports, however CD94 expression was unaltered by ECP therapy. In the absence of a consistent phenotypic marker to demonstrate cGvHD response to ECP, continued monitoring will be based on clinical observations.

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