Immune Cell Dysfunction in Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL)

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3875-3875 ◽  
Author(s):  
Marion E Cole ◽  
Alexander MacFarlane ◽  
Mowafaq Jillab ◽  
Mitchell R Smith ◽  
Adam D Cohen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Nk Cell ◽  
Granzyme B ◽  
Immune Dysfunction ◽  
T Cell Subsets ◽  
Cell Compartment

Abstract Abstract 3875 Introduction: Immunologic environment influences progression of lymphoid malignancies. Specifically, shifts in subsets of natural killer (NK) and T cells as well as tumor expression of inhibitory ligands may contribute to ability to evade host detection. Immune dysfunction may be particularly important in CLL/SLL, as prevalent circulating tumor cells engage in persistent, widespread interactions with immune cells; commonly-used mAb therapies (e.g. rituximab, alemtuzumab) rely upon ADCC mediated by NK cells and other innate effectors; and disease course is highly variable and not fully accounted for by tumor-intrinsic prognostic factors. Therefore, to better characterize the immune system in CLL/SLL, we prospectively assessed NK and T cell frequency, phenotype, and function in a series of CLL/SLL patients. Methods: Serial blood samples (up to 3 samples each, 3–6 months apart) were collected from 31 untreated CLL/SLL patients (median age 66) and 15 healthy age-matched controls (HC), and peripheral blood lymphocytes (PBL) analyzed directly ex vivo by multiparameter flow cytometry (160 distinct parameters evaluated, primarily on T and NK cells). NK cell-mediated natural and antibody-dependent cytotoxicity were also assessed by CD107a degranulation assay following PBL co-culture with rituximab, 721.221 EBV-transformed lymphoma cells, or both. Differences in parameters between patients and controls, or between progressors and non-progressors [categorized based on updated NCI-WG criteria (Blood 2008;111:5446)] were analyzed by Wilcoxon rank-sum test. All subjects signed IRB approved informed consent forms. Results: CLL/SLL VS. HC: CLL/SLL samples displayed a marked decrease in the ability of the cytolytic CD56dim NK cells to degranulate in response to tumor, both with or without rituximab (Table 1). CD56dim NK cells from CLL/SLL patients also displayed a more immature phenotype (↓CD57, ↓NKG2D, ↑CD27, ↓KIR) than those from HC, suggesting either a block in differentiation or elimination of the most-differentiated cells. NK cell expression of NKp44, CD69, CD62L, CD137, granzyme B, perforin, or PD-1, as well as tumor-induced NK cell production of IFNγ, did not differ. CLL/SLL patients had increased total T cells with a decreased CD4:CD8 ratio, associated with increased total number of CD8 T cells, greater activation of naive CD4 T cells and transition to a memory phenotype. Treg (CD4+CD25+FoxP3+) frequency was significantly higher in CLL/SLL patients (4.5% vs. 1.8% of CD4 T cells, p=0.005), as was PD-1 expression on both CD4 and CD8 T cells, while CD137 and ICOS expression was similar in both groups. PROGRESSORS VS. NON-PROGRESSORS: With median follow-up of 16.5 months (range 1–37), 7 of 31 patients have met criteria for progression. Compared to non-progressors, progressors showed changes in the CD56bright NK cell compartment suggestive of increased activation and accelerated differentiation, with increased expression of CD69, granzyme B, perforin, CD16, and KIR. However, no significant functional differences in NK cells, or consistent differences in T cell subsets, have been observed to date. Conclusions: CLL/SLL patients have a shift toward less mature NK cells, associated with deficits in NK cell degranulation against tumor targets, compared with healthy donors. Those CLL/SLL patients who progressed had greater CD56 bright NK cell phenotypic aberrancies than non-progressors, though these findings require confirmation with a larger cohort. Taken together, our findings support the hypothesis that immune dysfunction in CLL/SLL may be due in part to a block in NK cell differentiation or loss of more mature cells, and current studies are exploring these possibilities and potential mechanisms. Given these findings, along with the immunosuppressive changes observed in the T cell compartment (↑Tregs, ↑PD-1), these data support therapeutic strategies in CLL/SLL aimed at augmenting NK and/or T cell function. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Immunological Monitoring of CML Patients during First-Line Bosutinib and Imatinib Treatment

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3069-3069
Author(s):  
Anna Kreutzman ◽  
Perttu Koskenvesa ◽  
Kasanen Tiina ◽  
Ulla Olsson-Strömberg ◽  
Jesper Stentoft ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Research Funding ◽  
Nk Cell ◽  
T Cell Subsets ◽  
Imatinib Treatment ◽  
First Line

Abstract Background: Tyrosine kinase inhibitors (TKIs) used in the treatment of chronic myeloid leukemia (CML) are not entirely selective for the BCR-ABL1 kinase but also inhibit a variety of other kinases, sometimes triggering unpredicted biological effects. As an example, the TKIs dasatinib and bosutinib both inhibit Src-kinases, which are important mediators of T-cell function. Earlier in vitro data has shown that dasatinib can suppress activation and proliferation of T and NK cells, but it can also elicit signs of immunostimulation in patients, including rapid mobilization of lymphocytes and LGL lymphocytosis. No extensive analyses of the immunological in vivoeffects of bosutinib have been performed thus far. Therefore, we aimed at characterizing T and NK cell phenotypes and functional features in CML patients in a clinical setting in the context of first-line bosutinib and imatinib treatment. Methods:Peripheral blood samples were obtained from newly diagnosed CML CP patients enrolled in the BFORE clinical trial (NCT02130557), receiving bosutinib (n=13) or imatinib (n=20) as frontline TKI treatment. Samples were drawn at diagnosis and following 3 and 12 months of therapy. Detailed immunophenotyping of NK and T cells was performed with multicolor flow cytometry. In addition, mononuclear cells were used to study the function of NK and T cells (CD107ab degranulation upon stimulation with K562 cells and detection of IFN-γ/TNF-α secretion after stimulation with anti-CD3/anti-CD28 antibodies, respectively). Moreover, blood differential counts were taken before and 2 hours after drug intake at 3 and 12 months to examine the direct effects on lymphocyte counts (mobilization). Results: No significant changes were observed in absolute white blood cell or lymphocyte counts directly (2 hours) after bosutinib or imatinib intake, in contrast to what has been observed in dasatinib treated patients. Analysis of T cell subsets during bosutinib treatment revealed that the proportion of CD4+ cells increased after the start of treatment (median dg. 60.0% vs. 3 months 62.0% p=0.06; vs. 12 months 72.8% p=0.03), but no significant changes were observed in the phenotype. Correspondingly, the proportion of CD8+ T-cells decreased moderately (dg. 31.6% vs. 3 months 25.5% p=0.01) after the therapy start. Interestingly, the proportion of PD1+ (dg. 19.6% vs. 3 months 11.9%, p=0.06; vs. 12 months 14.3%, p=0.11) and DNAM+ CD8+ T-cells decreased (dg. 73.1% vs. 3 months 66.2% p=0.004; vs. 12 months 64.6% p=0.02). No changes in the cytokine production of any of the studied subgroups of T-cells was observed. Moreover, the proportion, phenotype and function of NK-cells were not affected by bosutinib treatment. In contrast, during imatinib treatment the proportion of CD56+CD16+ NK-cells significantly increased (dg 4.3% vs. 3 months 9.9% p=0.0005; vs 12 months 14.4% p=0.002; 8.1% in bosutinib treated patients). Moreover, in imatinib patients NK-cells downregulated CD27 (dg 9.0% vs. 3 months 5.2% p=0.004; vs. 12 months 4.9%; p=0.002). Further, NK-cells from imatinib-treated patients expressed more CD107ab upon stimulation with K562 at 3 and 12 months, when compared to samples from diagnosis (dg 13.0% vs. 3 months 16.1%, p=0.01; vs. 12 months 23.2%, p=0.008). The proportion of CD4+ T-cells increased 3 months after the start of imatinib treatment (dg 60.1% vs. 3 months 63.5% p=0.01), whereas the percentage of CD8+ T-cells decreased (dg. 38.6% vs. 3 months 31.5% p=0.02). Decreased expression of DNAM (dg 73.5% vs. 3 months 67.9% p=0.0008; vs. 12 months 62.4% p=0.002) was observed in the CD4+ T-cells. Similarly as in bosutinib treated patients, the proportion of PD1+ CD8+ cells decreased during imatinib treatment (dg 18.2% vs. 3 months 14.7%, p=0.02; vs. 12 months 14.8%, p=0.03). Both CD4+ and CD8+ T-cell subsets from imatinib-treated patients secreted less cytokines after the start of treatment when compared to the pre-treatment samples. Conclusions: Despite of the Src-kinase inhibitory profile of bosutinib, no major changes were observed in T- or NK-cell phenotype or function during first-line bosutinib treatment. In contrast, in imatinib treated patients the proportion of NK-cells increased and their degranulation responses were significantly higher than in untreated CML patients. Comparison of these data with the clinical variables and treatment outcome is warranted. Disclosures Stentoft: Novartis: Research Funding; Bristol-Myers-Squibb: Research Funding; Pfizer: Research Funding; Ariad: Research Funding. Gjertsen:BerGenBio AS: Consultancy, Research Funding. Janssen:Pfizer: Honoraria; Novartis: Research Funding; Ariad: Honoraria; BMS: Honoraria. Brümmendorf:Pfizer: Research Funding; Novartis: Research Funding. Richter:BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Ariad: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding. Mustjoki:Pfizer: Honoraria, Research Funding; Ariad: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Novartis: Honoraria, Research Funding.

Natural Killer Cell Immune Reconstitution Predicts Outcomes for Patients with Chronic Lymphocytic Leukemia Undergoing Allogeneic Stem Cell Transplantation

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3300-3300
Author(s):  
Don Benson ◽  
Leslie Andritsos ◽  
Mehdi Hamadani ◽  
Thomas Lin ◽  
Joseph Flynn ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Cd8 T Cells ◽  
Immune Reconstitution ◽  
Nk Cell ◽  
Disease Status ◽  
Lymphocytic Leukemia ◽  
T Cell Subsets ◽  
Cell Recovery

Abstract Introduction: Chronic lymphocytic leukemia (CLL), the most common form of leukemia in the Western hemisphere, is associated with severe innate, adaptive and humoral immune dysregulation. CLL remains essentially incurable, with the potential exception of allogeneic stem cell transplantation (ASCT). Natural killer (NK) cells are CD56(+), CD3(−) large granular lymphocytes that comprise a key cellular subset of the innate immune system. Preliminary in vitro data suggest an NK cell versus CLL effect exists, similar to that observed in acute myeloid leukemia (AML) and other blood cancers. Novel immune therapies for CLL (e.g., rituximab, alemtuzumab) likely exert anti-tumor effect, in part, through NK cells, in fact. Although NK cells contribute to the graft-versus-tumor effect following ASCT for other blood cancers, little is known regarding the potential role NK cells may play in the clinical allogeneic transplant setting for CLL. Herein, we provide, to our knowledge, the first report regarding NK cell immune reconstitution following ASCT for CLL. Methods: 27 CLL patients underwent reduced intensity conditioning (RIC) with ASCT. Median age was 52 years (43–69), median number of prior therapies was 3 (2–11). 55% had chemotherapy-refractory disease, and 55% had “high-risk” cytogenetics by FISH (deletion 17p or 11q22-23 abnormality). 14 patients had sibling donors, 15 had volunteerunrelated donors. Conditioning regimens included Fludarabine/TBI/Alemtuzumab (n=8), Fludarabine/Busulfan with (n=9) or without ATG (n=6), and Fludarabine/Cyclophosphamide (n=4). GVHD prophylaxis consisted of tacrolimus/MMF (n=8) or tacrolimus/methotrexate (n=19). Patients underwent bone marrow assessment prior to day +75 following ASCT. Marrow was studied for engraftment, donor chimerism, and disease status as well as lymphoid immune reconstitution by percentage of total lymphocytes and absolute lymphocyte counts by multi-color flow cytometry. Results: NK cell immune reconstitution was predicted by disease status at transplantation. Patients in complete or partial remission at the time of ASCT had more robust NK cell recovery (mean = 45% of total lymphocytes +/− SEM 5%) as compared to patients entering transplant with refractory disease (16% +/− 1, p < 0.01). No differences were observed in CD4(+) or CD8(+) T cells and no lymphocyte subset recovery was associated with CD34(+) or CD3(+) cell dosage. Achieving complete donor chimerism by day +60 was associated with robust NK cell recovery (55% +/− 1 versus 7% +/−1, p = 0.02), recovery of CD4 and CD8 T cells was not associated with chimerism status, however. Patients who went onto exhibit a complete response to ASCT had greater early NK cell reconstitution (31% +/− 3) as compared to those who had no response (8% +/− 1, p = 0.01). No differences in T cell subsets were associated with response. Patients who ultimately achieved complete remission following transplant had a lower CLL:NK cell ratio in marrow (0.35 +/− 0.07) than those who did not (8.1 +/− 1, p = 0.01). However, differences in CLL:CD4(+) and CLL:CD8(+) T cells were not predictive of response. Trends to improvement in progression free survival and overall survival were observed for patients with NK cell reconstitution above the median for the group as compared to those below; no such trends were observed regarding T cell subsets. Greater NK cell reconstitution trended towards ultimate eradication of minimal residual disease following ASCT, but no such trends were observed for T cell subsets. Conclusions: Early NK cell recovery predicts survival following autologous and allogeneic SCT in a number of hematologic malignancies; however, little is known regarding this phenomenon in CLL. To our knowledge, these are the first findings to implicate a potentially important therapeutic role for early NK cell compartment recovery in CLL following ASCT. Further research into restoring and augmenting NK cell function following RIC/ASCT for CLL is warranted.

scholarly journals NK cells negatively regulate CD8 T cells to promote immune exhaustion and chronic Toxoplasma gondii infection

2019 ◽  
Author(s):  
Daria L. Ivanova ◽  
Ryan Krempels ◽  
Stephen L. Denton ◽  
Kevin D. Fettel ◽  
Giandor M. Saltz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Toxoplasma Gondii ◽  
Nk Cells ◽  
Cell Population ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Chronic Phase ◽  
Cd8 T Cell ◽  
Cell Compartment

AbstractNK cells regulate CD4+ and CD8+ T cells in acute viral infection, vaccination and the tumor microenvironment. NK cells also become exhausted in chronic activation settings. The mechanisms causing these ILC responses and their impact on adaptive immunity are unclear. CD8+ T cell exhaustion develops during chronic Toxoplasma gondii (T. gondii) infection resulting in parasite reactivation and death. How chronic T. gondii infection impacts the NK cell compartment is not known. We demonstrate that NK cells do not exhibit hallmarks of exhaustion. Their numbers are stable and they do not express high PD1 or LAG3. NK cell depletion with anti-NK1.1 is therapeutic and rescues chronic T. gondii infected mice from CD8+ T cell exhaustion dependent death, increases survival after lethal secondary challenge and reduces parasite reactivation. Anti-NK1.1 treatment increased polyfunctional CD8+ T cell responses in spleen and brain and reduced CD8+ T cell apoptosis. Chronic T. gondii infection promotes the development of a modified NK cell compartment, which does not exhibit normal NK cell behavior. This splenic CD49a-CD49b+NKp46+ NK cell population develops during the early chronic phase of infection and increases through the late chronic phase of infection. They are Ly49 and TRAIL negative and are enriched for expression of CD94/NKG2A and KLRG1. They do not produce IFNγ, are IL-10 negative, do not increase PDL1 expression, but do increase CD107a on their surface. They are also absent from brain. Based on the NK cell receptor phenotype we observed NKp46 and CD94-NKG2A cognate ligands were measured. Activating NKp46 (NCR1-ligand) ligand increased and NKG2A ligand Qa-1b expression was reduced. Blockade of NKp46 also rescued the chronically infected mice from death. Immunization with a single dose non-persistent 100% protective T. gondii vaccination did not induce this cell population in the spleen, suggesting persistent infection is essential for their development. We hypothesize chronic T. gondii infection induces an NKp46 dependent modified NK cell population that reduces functional CD8+ T cells to promote persistent parasite infection in the brain. NK cell targeted therapies could enhance immunity in people with chronic infections, chronic inflammation and cancer.

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 Characterization of the DNAM-1, TIGIT and TACTILE Axis on Circulating NK, NKT-Like and T Cell Subsets in Patients with Acute Myeloid Leukemia

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2171
Author(s):  
Isabel Valhondo ◽  
Fakhri Hassouneh ◽  
Nelson Lopez-Sejas ◽  
Alejandra Pera ◽  
Beatriz Sanchez-Correa ◽  
...  
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
T Cell ◽  
Healthy Volunteers ◽  
Nk Cells ◽  
Myeloid Leukemia ◽  
Cell Activation ◽  
Nk Cell ◽  
T Cell Subsets ◽  
Acute Myeloid

Background: Acute myeloid leukemia (AML) remains a major clinical challenge due to poor overall survival, which is even more dramatic in elderly patients. TIGIT, an inhibitory receptor that interacts with CD155 and CD112 molecules, is considered as a checkpoint in T and NK cell activation. This receptor shares ligands with the co-stimulatory receptor DNAM-1 and with TACTILE. The aim of this work was to analyze the expression of DNAM-1, TIGIT and TACTILE in NK cells and T cell subsets in AML patients. Methods: We have studied 36 patients at the time of diagnosis of AML and 20 healthy volunteers. The expression of DNAM-1, TIGIT and TACTILE in NK cells and T cells, according to the expression of CD3 and CD56, was performed by flow cytometry. Results: NK cells, CD56− T cells and CD56+ T (NKT-like) cells from AML patients presented a reduced expression of DNAM-1 compared with healthy volunteers. An increased expression of TIGIT was observed in mainstream CD56− T cells. No differences were observed in the expression of TACTILE. Simplified presentation of incredibly complex evaluations (SPICE) analysis of the co-expression of DNAM-1, TIGIT and TACTILE showed an increase in NK and T cells lacking DNAM-1 and co-expressing TIGIT and TACTILE. Low percentages of DNAM-1−TIGIT+TACTILE+ NK cells and DNAM-1− TIGIT+TACTILE+ CD56− T cells were associated with a better survival of AML patients. Conclusions: The expression of DNAM-1 is reduced in NK cells and in CD4+ and CD8+ T cells from AML patients compared with those from healthy volunteers. An increased percentage of NK and T cells lacking DNAM-1 and co-expressing TIGIT and TACTILE is associated with patient survival, supporting the role of TIGIT as a novel candidate for checkpoint blockade.

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

Blood ◽  
2010 ◽  
Vol 116 (17) ◽  
pp. 3238-3248 ◽  
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.

Ex Vivo Fludarabine Selectively Depletes Human Naive T-Cell Subsets: A Step Toward Modifying Donor Lymphocyte Infusion.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1071-1071
Author(s):  
Melody M. Smith ◽  
Cynthia R. Giver ◽  
Edmund K. Waller ◽  
Christopher R. Flowers
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Memory T Cells ◽  
Ex Vivo ◽  
T Cell Subsets ◽  
Effector Memory ◽  
Naïve T Cell ◽  
Naive T Cell

Abstract Ex vivo modification of donor lymphocytes with purine analogs (mDL) may help to minimize graft versus host disease (GvHD) while providing beneficial graft versus leukemia (GvL) effects. In a murine model system, we have shown that allogeneic donor splenocytes, treated with fludarabine ex vivo have significantly reduced GvHD activity when transferred to irradiated recipient mice, and retain anti-viral and GvL activities (Giver, 2003). This effect appears to be mediated by relative depletion of donor CD4 CD44low, “naive” T-cells. As a first step toward developing mDL for use in patients, we sought to evaluate the effects of ex vivo fludarabine exposure on human T-cell subsets, and to determine the minimum dose of fludarabine required to achieve this effect. Methods: Peripheral blood mononuclear cell samples from 6 healthy volunteers were evaluated at 0, 24, 48, and 72 hour time points after ex vivo incubation in varying dosages of fludarabine: 2, 5, and 10(n=3) mcg/ml. Fludarabine incubated samples were compared to samples that received no fludarabine (untreated). The total viable cell number was determined and the fractions and absolute numbers of viable CD4 and CD8 naïve and memory T-cells were determined using flow cytometry after incubation with 7-AAD (dead cell stain), CD4, CD8, CD45RA, CD62L, and CCR7 antibodies, and measuring the total viable cells/ml. Results: The numbers of viable CD4 and CD8 T-cells remained relatively stable in control cultures. Without fludarabine, the average viability at 72 hr of naive and memory T-cells were 92% and 77% for CD4 and 86% and 63% for CD 8 (Fig. 1A). Naive CD4 T-cells were more sensitive to fludarabine-induced death than memory CD4 cells. At 72 hr, the average viability of fludarabine-treated naive CD4 T-cells was 33% at 2 mcg/ml (8.2X the reduction observed in untreated cells) and 30% at 5 mcg/ml, while memory CD4 T-cells averaged 47% viability at 2 mcg/ml (2.3X the reduction observed in untreated cells) (Fig. 1B) and 38% at 5 mcg/ml. The average viability of naive CD8 T-cells at 72 hr was 27% at 2 mcg/ml and 20% at 5 mcg/ml, while memory CD8 T-cell viability was 22% at 2 mcg/ml and 17% at 5 mcg/ml. Analyses on central memory, effector memory, and Temra T-cells, and B-cell and dendritic cell subsets are ongoing. The 5 and 10 mcg/ml doses also yielded similar results in 3 initial subjects, suggesting that 2 mcg/ml or a lower dose of fludarabine is sufficient to achieve relative depletion of the naive T-cell subset. Conclusions: Future work will determine the minimal dose of fludarabine to achieve this effect, test the feasibility of using ex vivo nucleoside analog incubation to reduce alloreactivity in samples from patient/donor pairs, and determine the maximum tolerated dose of mDL in a phase 1 clinical trial with patients at high risk for relapse and infectious complications following allogeneic transplantation. Figure Figure

Myeloid Chimerism Reflects Engraftment of Donor Hematopoiesis, Whereas T Cell Chimerism Reflects Survival and Expansion of Donor and Recipient Residual Mature T Cells Early After T Cell Depleted Allogeneic Stem Cell Transplantation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4475-4475
Author(s):  
Jessica C. Harskamp ◽  
Esther H.M. van Egmond ◽  
Hans L. Vos ◽  
Stijn J.M. Halkes ◽  
Roel Willemze ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Cell ◽  
Stem Cell Transplantation ◽  
Cd8 T Cells ◽  
Nk Cell ◽  
Median Frequency ◽  
Cell Compartment ◽  
Hematopoietic Lineage ◽  
Chimerism Analysis

Abstract Abstract 4475 Allogeneic stem cell transplantation (alloSCT) is frequently complicated by life-threatening graft versus host disease (GVHD). Previous studies demonstrated that T cell depletion (TCD) of the graft significantly decreases the incidence and severity of GVHD, and is associated with a higher percentage of patients with mixed chimerism (MC). In most studies chimerism analysis is performed on the total bone marrow (BM) leukocyte fraction, and changes in chimerism are related to engraftment. In this study we investigated whether MC in the total BM leukocyte fraction truly reflects engraftment or if it is influenced by survival and expansion of donor and recipient residual mature T cells, and whether hematopoietic lineage specific chimerism analysis is therefore a better method to determine engraftment. It is likely that chimerism analysis of the stem cell compartment is best reflected in peripheral blood (PB) in those cells that are continuously produced and short lived, such as monocytes and granulocytes, and therefore PB myeloid chimerism primarily reflects engraftment. In contrast, previous studies have shown by T cell receptor excision circle analysis that T cell neogenesis is virtually absent in the first 6 months after alloSCT, and that predominantly memory T cells are present in PB and BM. Therefore, we hypothesize that MC of these long lived T cells merely reflects survival and expansion of recipient and donor residual T cells. Since the life span of B and NK cells is longer than myeloid cells, but shorter than T cells, we anticipate that in the first 6 months after alloSCT, B and NK cell chimerism reflects a combination of survival and neogenesis. To analyze these hypotheses we performed hematopoietic lineage specific chimerism analysis on PB cells of 22 patients (median age 52 years, range 23-73, 11 males) receiving a TCD alloSCT between June and November 2008 after a myeloablative (n=11) or non myeloablative conditioning regimen (n=11) for AML, ALL, high risk MDS, multiple myeloma, CML, CLL or NHL. At intervals of 6 weeks PB was collected, and monocytes, granulocytes, B and NK cells, CD4+ and CD8+ T cells were sorted. The total leukocyte fraction was obtained by erythrocyte lysis of BM. DNA was isolated to perform chimerism analysis using short tandem repeats - PCR. Our results show that in the BM leukocyte fraction 47% of the patients were MC at 3 months after alloSCT, with a median frequency of patient cells of 4%. However, of the patients with MC in the total leukocyte fraction, 67% was complete chimeric in the myeloid subsets and MC in the T cell compartment. In the PB myeloid subsets (monocytes and granulocytes) less than 28% of the patients were MC during the first 6 months after alloSCT with a median frequency of patient cells less than 5%. In the B and NK cell subsets, at most time points more patients were MC (7-43%) with higher frequencies of patient cells (2-14%) compared to the myeloid subsets. The CD4 and CD8 T cell subsets showed the highest frequencies of MC in numbers of patients (31-61%) as well as the highest MC frequencies of patient cells (13-80%). Phenotypic analysis of the T cell compartment showed that 98% of the CD4 and CD8 T cells were memory cells during the first 6 months after alloSCT. Preliminary data indicate that the median percentage of donor derived T cells increased during the first 6 months after alloSCT, correlating with development of mild GVHD, suggesting that T cell chimerism is influenced by immunogenic triggers. In conclusion, these results illustrate that for engraftment and neogenesis of donor hematopoiesis, myeloid chimerism analysis provides more accurate information than total BM leukocyte chimerism analysis, since the results are greatly influenced by T cell chimerism. Since almost all T cells were memory cells within the first 6 months after alloSCT, T cell chimerism analysis reflects survival and expansion of mature donor as well as recipient T cells, and can therefore not be used to measure engraftment. Disclosures: No relevant conflicts of interest to declare.

PD-1+ T Cell Subsets in Follicular Lymphoma Tumor Microenvironment and Their Implications for Prognosis and Therapy

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2648-2648
Author(s):  
Fuliang Chu ◽  
Wencai Ma ◽  
Tomohide Yamazaki ◽  
Myriam Foglietta ◽  
Durga Nattama ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Follicular Lymphoma ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
T Cell Subsets ◽  
Prognostic Impact ◽  
T Cell Exhaustion ◽  
Cell Exhaustion

Abstract Abstract 2648 Background: Programmed death (PD)-1, a coinhibitory receptor expressed by effector T cells (Teffs) is highly expressed on intratumoral T cells (mean 61%, range 34–86% for CD4+ T cells and mean 44%, range 31–69% for CD8+ T cells) in follicular lymphoma (FL), a finding associated with impaired ability to recognize autologous tumor (Nattamai et al, ASH 2007). Hence, PD-1 expression would be expected to confer an unfavorable prognosis in FL. However, correlation of PD-1 with clinical outcome in FL has been inconsistent with two studies showing favorable (Carreras et al, J Clin Oncol 2009; Wahlin et al, Clin Cancer Res 2010) and one study showing unfavorable (Richendollar et al, Hum Pathol 2011) outcome. While differences in method of analysis and type of treatment may explain the disparate results, a more complex model may be necessary to understand the prognostic impact of PD-1 in FL as PD-1 is expressed not only on antitumor Teffs but also on protumor follicular helper T cells (Tfh) and regulatory T cells (Tregs). Methods: To determine the nature of PD-1+ T cells in FL we performed comprehensive genomic and immunologic studies. By flow cytometry, we observed that the intratumoral CD4+ T cells in FL may be categorized into 3 subsets based on PD-1 expression - PD-1 high (PD-1hi), intermediate (PD-1int), and low (PD-1lo). The intratumoral CD8+ T cells consisted of PD-1int and PD-1lo subsets. The 3 CD4+ T cell subsets were FACSorted from FL tumors (n=3) and whole genome gene expression profiling (GEP) was performed. T cell subsets sorted similarly from tonsils served as controls for reactive follicular hyperplasia (FH) (n=3). Differentially expressed genes in GEP studies were confirmed at the mRNA level by real-time PCR (n=5) and at the protein level by flow cytometry when antibodies were available (n=5–10). Results: Our results suggested that CD4+PD-1hi T cells are Tfh cells (CXCR5hiBcl6hi ICOShiCD40LhiSAPhiPRDM1loIL-4hiIL-21hi); the CD4+PD-1int T cells consisted of a mixture of activated Teffs (CD45RO+CD45RA−) including Th1 (Tbet+IFNg+), Th2 (IL-10+), and Th17 cells (RORc+IL-17+), and Tregs (Foxp3+CD25hiCD127lo); and the CD4+PD-1lo T cells consisted of a mixture of activated Teffs (CD45RO+CD45RA− but IFNg−IL-4−IL-10−IL-17−), Tregs, and naïve T cells (CD45RO−CD45RA+CCR7+). Although these subsets were present in both FL and FH, there were important differences. IL-4 expression was significantly higher in Tfh in FL vs. FH and may play a role in the pathogenesis of FL. IL-17 expression was low and expression of coinhibitory molecules BTLA and CD200 was high in CD4+PD-1int T cells in FL vs. FH. BTLA and CD200 were also increased in CD8+PD-1int T cells in FL vs. FH. However, other coinhibitory molecules (LAG-3, Tim-3, CD160, CTLA-4, CD244, KLRG1) were not significantly different between FL and FH. CD4+PD-1int T cells also had higher expression of BATF, a transcription factor associated with T cell exhaustion in FL vs. FH. Together, these results suggest that the CD4+PD-1int T cells in FL may be in a state of T cell exhaustion whereas the CD4+PD-1int T cells in FH may represent recently activated Teffs. Consistent with this, blocking PD-1 with anti-PD-1 blocking antibody significantly enhanced proliferation and the production of Th1 (IFNg, TNFa) but not Th2 (IL-4, IL-5, IL-10, IL-13) cytokines by intratumoral CD4+ and CD8+ T cells in response to stimulation with autologous FL tumor cells (n=3). As expected, Tregs were increased in number in FL vs. FH and were present in the PD-1int and PD-1lo T cell subsets. We found 74% (range 40–97%) of FL Tregs expressed PD-1. Among the CD4+PD-1lo and CD8+PD-1lo T cells, there were more activated Teffs and fewer naïve T cells in FL vs. FH. Conclusions: Our results suggest that the PD-1+ T cells in FL are comprised of a mixture of antitumor Teffs and protumor Tfh and Tregs. The prognostic impact of PD-1+ T cells in FL may dependent on the relative frequency of these subsets as ligation of PD-1 may produce favorable (inhibition of protumor Tfh and Tregs) or unfavorable (inhibition of antitumor Teffs) outcomes by inhibiting or promoting tumor growth, respectively. Conversely, our results imply that agents that block PD-1/PD-ligand pathway may have the opposite effect on these T cell subsets and enumeration of the intratumoral PD-1+ T cell subsets may serve as biomarker to predict response to these agents in FL and possibly other B-cell malignancies. Disclosures: Dong: GSK: Consultancy; Genentech: Honoraria; Tempero: Consultancy; Ono: Consultancy; AnaptysBio: Consultancy. Neelapu:Cure Tech Ltd: Research Funding.

CD4 T lymphocytes are primed to express Fas ligand by CD4 cross-linking and to contribute to CD8 T-cell apoptosis via Fas/FasL death signaling pathway

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 195-202 ◽  
Author(s):  
Masaki Tateyama ◽  
Naoki Oyaizu ◽  
Thomas W. McCloskey ◽  
Soe Than ◽  
Savita Pahwa
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Interleukin 2 ◽  
Cd8 T Cell ◽  
T Cell Subsets ◽  
Cross Linking ◽  
Induced Apoptosis ◽  
Hiv 1

CD4 molecules serve as coreceptors for the T-cell receptor (TCR)/CD3 complex that are engaged coordinately with TCR and facilitate antigen-specific T-cell activation leading to interleukin 2 (IL-2) production and proliferation. However, cross-ligation of CD4 molecules prior to TCR stimulation has been shown to prime CD4 T cells to undergo apoptosis. Although in vivo and in vitro experiments have implicated the involvement of Fas/FasL interaction in this CD4 cross-linking (CD4XL)-induced apoptosis, detailed mechanisms to account for cell death induction have not been elucidated. In the present study, we demonstrate that CD4XL in purified T cells not only led to Fas up-regulation but also primed CD4 T cells to express FasL upon CD3 stimulation and rendered the T cells susceptible to Fas-mediated apoptosis. Notably, in addition to CD4+ T cells, CD4XL-induced sensitization for apoptosis was observed in CD8+ T cells as well and was associated with Bcl-x down-modulation. Both CD4 and CD8 T-cell subsets underwent apoptosis following cell–cell contact with FasL+ CD4 T cells. CD28 costimulation abrogated CD4XL/CD3-induced apoptosis with restoration of IL-2 production and prevented Bcl-x down-modulation. As CD4 molecules are the primary receptors for human immunodeficiency virus 1 (HIV-1), we conclude that HIV-1 envelope mediated CD4XL can lead to the generation of FasL-expressing CD4+ T cells that can lead to apoptosis of CD4 as well as CD8 T cells. These findings implicate a novel mechanism for CD8 T-cell depletion in HIV disease.

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