Identification of Tigit on Intra-Tumor T Cells As a New Target for Immune Checkpoint Blockade in Follicular Lymphoma

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 917-917 ◽  
Author(s):  
Sarah Gothberg ◽  
Kanutte Huse ◽  
Arne Kolstad ◽  
Ole Christian Lingjærde ◽  
Bjørn Østenstad ◽  
...  

Abstract Background: Follicular lymphoma (FL) is the most common subtype of indolent non Hodgkin's lymphoma (NHL). Median survival is long (>10 years), but current chemo-immunotherapy regimens used for FL are usually not curative. While T cells in the FL tumor microenvironment are considered dysfunctional and associated with disease progression, a better understanding of T-cell signaling may reveal how to productively engage tumor-infiltrating T cells to kill lymphoma B cells. Our previous study showed that expression of the immune checkpoint receptor PD-1 was directly correlated with reduced cytokine signaling in FL T cells (Myklebust et al., Blood 2013). Antibody immunotherapy targeting the PD-1/PD-L1 pathway has shown significant activity in solid tumors, but these benefits have not been as profound in NHLs, including FL. Co-blockade of checkpoint inhibitors may therefore be necessary to generate optimal anti-tumor responses in FL. The hypothesis underlying this study was that characterizing signaling responses in FL tumor-infiltrating T cells will identify new targets for combination of checkpoint blockade. Methods: Surface expression of 9 checkpoint receptors governing T cell function was measured in subsets of CD4 and CD8 T cells from FL lymph node tumors (n = 14) and from healthy donor tonsils (n= 11) and peripheral blood samples (n = 7) using fluorescence flow cytometry. Patterns of checkpoint receptor expression were compared with 1) intracellular phospho-protein signaling response and 2) cytokine production for subsets of T cells infiltrating FL tumors and the corresponding T-cell populations in healthy tonsils. Phospho-specific flow cytometry measured phosphorylation of STATs and T cell receptor (TCR) signaling effectors within minutes following stimulation by IL-4, IL-7, IL-21, or α-CD3+α-CD28 (TCR stimulation) antibodies. Results: CD4 and CD8 T cells infiltrating FL tumors were gated into subsets defined by PD-1 and ICOS protein expression, and compared to cognate T cell subsets in healthy tonsils. FL and tonsil T cells closely matched in their signaling responses to IL-4, IL-7, and IL-21 stimulation, with PD-1 expressing cells (CD4+PD-1hiICOS+ (TFH) and CD8+PD-1int T cells) exhibiting modest phospho-protein signaling responses compared to T cells not expressing PD-1. Furthermore, TCR membrane proximal signaling events (p-CD3ζ, p-SLP76) following TCR stimulation were comparable in FL and tonsil T cells. This contrasted reduced phospho-ERK signaling in all CD4 and CD8 T cell subsets infiltrating FL tumors which distinguished them from tonsillar T cells. IFN-γ production also differed between FL and tonsils, as CD8 T cells infiltrating FL tumors produced less IFN-γ. Reduced IFN-γ production was independent of PD-1 expression, suggesting suppressed function in these T cells which could be due to inhibitory receptors other than PD-1. Of the 9 checkpoint receptors measured, PD-1 and T cell Ig and ITIM domain (TIGIT) were expressed at the highest frequency. In FL, TIGIT was expressed in 58% and 80% of CD8 effector and effector memory cells, respectively, as compared to 43% and 68% of the cognate healthy tonsillar subsets. TIGIT was also frequently expressed in CD4 FL T cells, as 52% and 79% of effector and effector memory cells expressed TIGIT, respectively, as compared to 16% and 59% of the corresponding subsets from healthy tonsils. viSNE analysis demonstrated that TIGIT and PD-1 were frequently co-expressed in FL T cells, and a large fraction of PD-1int T cells had high expression of TIGIT (Figure 1). These results provide a rationale for co-blockade of PD-1 and TIGIT in FL and for investigation of how co-blockade impacts T cell functions. Conclusions: These results reveal specific suppression of cytokine signaling in CD8 effector T cells infiltrating FL tumors and identify TIGIT and PD-1 as strong candidates for co-checkpoint blockade in FL. A deeper understanding of the interplay between checkpoint receptors and key T cell cytokine signaling events in FL will further assist in engineering immuno-therapeutic regiments that improve FL patient clinical outcomes. Disclosures Kolstad: Nordic Nanovector: Other: Membership of Scientific Advisory Board. Levy:Kite Pharma: Consultancy; Five Prime Therapeutics: Consultancy; Innate Pharma: Consultancy; Beigene: Consultancy; Corvus: Consultancy; Dynavax: Research Funding; Pharmacyclics: Research Funding. Irish:Incyte: Research Funding; Janssen: Research Funding; Cytobank, Inc.: Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2012-2012
Author(s):  
Nitin Jain ◽  
Sreyashi Basu ◽  
Beenu Thakral ◽  
Jan Burger ◽  
Philip A Thompson ◽  
...  

Abstract Background: Limited data is available on expression levels of checkpoint receptors, respective ligands, and other immune markers in patients with CLL (Ramsay et al. Blood 2012). Checkpoint blockade has been a successful therapy of many cancers including melanoma, and more recently, Hodgkin's lymphoma. Understanding expression patterns of checkpoint receptors and ligands may help in the clinical development of checkpoint blockade as a therapy for patients with CLL. Methods: Between September 2015 and April 2016, we performed 17-color multi-parameter flow-cytometry (MFC) in paired peripheral blood (PB) and bone marrow (BM) samples from 30 patients with CLL who presented as new patients for evaluation at MDACC. Patients may have received prior CLL therapy. We evaluated expression of immune receptors (inhibitory receptors: PD1, CTLA4, LAG3, TIM3; activating receptors: GITR, OX40, 41BB, ICOS) on T cell subsets: CD4 T effector cells [Teff]: CD3+CD4+CD127lo/+Foxp3-, CD4 T regulatory cells [Treg]: CD3+CD4+CD127-Foxp3+, and CD8 T cells. CLL cells were assessed for both immune receptors (as above), and ligands (4-1BBL, B7-1, B7-2, ICOSL, PDL-1, PDL-2, OX40L). These analyses were performed on freshly collected PB and BM samples by the M. D. Anderson Cancer Center Immunotherapy Platform. Results: A total of 30 patients with CLL were enrolled. The median age was 66 years (range, 35-83). Nine were women. Nineteen were treatment-naive. Prognostic markers included FISH [del(17p) = 6; del(13q) = 9, del(11q) = 4, trisomy 12 = 3, negative = 8]. IGHV mutation status was available for 19 patients (13 unmutated IGHV, 6 mutated IGHV). B2M was ≥3.5 in 11 pts. Baseline expression of costimulatory receptors in CD8 T cells in the marrow, and of the ligands in CLL cells in the marrow is shown in Figure 1. In paired PB and BM sample analysis, there was a high correlation between expression level of PD1 on Treg (Pearson correlation, r = 0.90, p<0.00001), Teff (r = 0.87, p<0.00001), CD8+ cells (r = 0.80, p<0.00001), and CLL cells (r = 0.75, p<0.00001). PD-L1 expression on CLL cells was moderately correlated between PB and BM (r = 0.57, p<0.001). Patients with prior therapy had significantly higher expression of PDL1 on the CLL cells in both PB and BM (p=0.01 and p=0.002, respectively) compared to previously untreated patients. OX40 expression on CD8 cells was significantly higher in both PB and BM in previously treated patients (compared to previously untreated patients). Patients with unmutated IGHV (p = 0.003) and del17p (p = .03) had higher PDL1 expression on CLL cells in the marrow. Conclusions: There is a strong correlation in the expression levels of PD1 on various T cell subsets between PB and BM. Clinically targetable checkpoint receptors including PD1, OX40, CTLA4, and ICOS are consistently expressed across patients with CLL, and present on cells in both PB and BM. Disclosures Jain: BMS: Research Funding; Abbvie: Research Funding; ADC Therapeutics: Consultancy, Honoraria, Research Funding; Novimmune: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria, Research Funding; Genentech: Research Funding; Infinity: Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Incyte: Research Funding; Novartis: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Seattle Genetics: Research Funding; Celgene: Research Funding. Burger:Roche: Other: Travel, Accommodations, Expenses; Pharmacyclics, LLC, an AbbVie Company: Research Funding; Janssen: Consultancy, Other: Travel, Accommodations, Expenses; Portola: Consultancy; Gilead: Research Funding. Thompson:Pharmacyclics: Consultancy, Honoraria. Daver:Otsuka: Consultancy, Honoraria; Ariad: Research Funding; Karyopharm: Honoraria, Research Funding; BMS: Research Funding; Sunesis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Kiromic: Research Funding. Wierda:Acerta: Research Funding; Genentech: Research Funding; Gilead: Research Funding; Novartis: Research Funding; Abbvie: Research Funding.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4128-4128 ◽  
Author(s):  
Mark N. Polizzotto ◽  
Irini Sereti ◽  
Thomas S. Uldrick ◽  
Kathleen M. Wyvill ◽  
Stig M. R. Jensen ◽  
...  

Abstract Background: Despite antiretroviral therapy (ART), people with HIV continue to exhibit immune deficits including failure to fully reconstitute CD4 T cell numbers and function, resulting in increased risks of tumors and infections and reduced response to vaccination. Pomalidomide, a derivative of thalidomide (IMID), has immunomodulatory properties that may be beneficial in this setting. We explored its impact on lymphocyte number and activation in patients with and without HIV treated within a prospective clinical trial for Kaposi sarcoma. Methods: Patients received pomalidomide 5mg orally for 21 days of 28 day cycles. Assessments were performed every 4 weeks for lymphocyte numbers, Kaposi sarcoma associated herpesvirus (KSHV/HHV8) viral load (VL) and HIV VL and at 8 weeks for T cell subsets and activation by immunophenotyping of peripheral blood mononuclear cells (PBMC). KSHV VL in PBMC and HIV VL in plasma were assayed by quantitative PCR; for HIV VL we used an ultrasensitive single copy assay. Changes from baseline were evaluated using the Wilcoxon signed rank test with P<0.005 considered significant given multiple comparisons. Differences in changes between the HIV infected and uninfected groups were evaluated using the Wilcoxon rank sum test. Study registered as NCT1495598. Results: 19 patients (12 HIV infected, 7 uninfected) median age 50 years (range 32-74) were studied. All with HIV were receiving ART for median 48 months (7-227), HIV VL 1.5 copies/mL (<0.5–37), and CD4 378 cells/µl (135–752). At week 4 and 8 of therapy we observed significant increases in CD4 and CD8 counts, with a decline in CD19 B cells and no change in NK cells or HIV VL. A transient increase in KSHV VL was seen at week 4, not sustained at week 8: Abstract 4128. Table 1ParameterBaseline (cells/µl unless noted)Change to Week 4 (Med, range)PChange to Week 8 (Med, range)PCD31143 (525–2305)+264 (-419–1524)0.0028+210 (-496–1455)0.0020CD4429 (135–1171)+107 (-87–650)0.0009+86 (-37–491)0.0015CD8495 (259–1529)+108 (-271–915)0.0085+155 (-495–834)0.0046NK184 (28–557)+30 (-130–117)0.52+2 (-174–127)0.98CD19139 (9–322)-47 (-117–76)0.0039-79 (-169–62)<0.0001KSHV VL 0 copies/PBMC (0–8750)+23 (-92–5250)0.00980 (-92–20850)0.31Plasma HIV VL (infected pts)1.5 copies/mL (<0.5–37)+0.3 (-1.5–3.0)0.75+0.75 (0–28)0.13 In addition, at week 8 both CD4 and CD8 T cells showed significant increases in activation (CD38+, HLADR+ and DR+/38+) and decreases in senescence (CD57+). Both also showed a significant shift towards increased central memory (CM) and away from naive (N) and effector (E) phenotypes, with no change in effector memory (EM) cells: Abstract 4128. Table 2CD4 SubsetsBaseline (%) (med, range)Absolute Change in % at Week 8 (med, range)PRO- 27+ (N)32.6 (13.3–76.5)-6.6 (-35.8–21.6)0.002RO+ 27+ (CM)41.9 (13.6–63.6)+6.4 (-15.5–32.5)0.027RO+ 27- (EM)16.7 (4.6–31.7)+1.7 (-7.2–21.0)0.28RO- 27- (E)3.3 (0.4–14.3)-1.5 (-5.7–0.3)0.000438+34.5 (11.2–67.3)+4.3 (-13.0–19.4)0.024HLA DR+8.9 (3.3–25.0)+8.3 (0.7–19.5)<0.000138+ DR+2.5 (0.6–11.7)+2 (-1.0–8.1)<0.000157+6.3 (0.6–26.6)-1.34 (-16.2–7.6)0.034CD8 SubsetsRO- 27+ (N)21.0 (9.7–70.4)-5.1 (-13.7–14.3)0.019RO+ 27+ (CM)17.1 (2.5–37.9)+8.1 (-8.4–18.6)0.0047RO+ 27- (EM)18.4 (4.6–40.8)+1.0 (-9.4–44.9)0.35RO- 27- (E)31.8 (4.1-63.7)-6.1 (-47.3–22.5)0.0138+33.4 (8.3–66.0)+19.9 (-0.8–40.6)<0.0001HLA DR+19.6 (5.0–46.4)+11.6 (-4.7–32.1)0.000138+ DR+8.0 (0.4–33.3)+8.5 (0.1–22.6)<0.000157+30.8 (2.9–72.9)-11.0 (-28.5–6.1)<0.0001 There were no significant changes in Ki67 or PD-1 expression in either CD4 or CD8 cells. There was no significant difference between HIV infected and uninfected patient groups in the observed effects on any parameter including cell number and phenotype. Conclusions: Pomalidomide induced significant increases in the number of CD4 and CD8 T cells and the proportion of activated and central memory cells and decreased senescence in both HIV infected and uninfected subjects. Effects were not explained by alterations in HIV viremia. The transient early rise in KSHV VL may reflect reactivation of latent infection and enhance immune killing of KSHV infected cells. This analysis sheds light on possible mechanisms of IMID activity in viral-associated tumors. As the first study of immune modulation by IMIDs in vivo in people with HIV it also suggests exploration of IMIDs to augment immune responsiveness in HIV and other immunodeficiencies is warranted. Disclosures Polizzotto: Celgene Corporation: Research Funding. Off Label Use: Pomalidomide for Kaposi sarcoma. Uldrick:Celgene Corporation: Research Funding. Zeldis:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Yarchoan:Celgene Corporation: Research Funding.


2022 ◽  
Vol 12 ◽  
Author(s):  
Yufei Mo ◽  
Kelvin Kai-Wang To ◽  
Runhong Zhou ◽  
Li Liu ◽  
Tianyu Cao ◽  
...  

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


Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 815-815
Author(s):  
Farhad Ravandi ◽  
Naval Daver ◽  
Guillermo Garcia-Manero ◽  
Christopher B Benton ◽  
Philip A Thompson ◽  
...  

Abstract Background: Blocking PD-1/PD-L1 pathways enhances anti-leukemia responses by enabling T-cells in murine models of AML (Zhang et al, Blood 2009). PD-1 positive CD8 T-cells are increased in bone marrow (BM) of pts with AML (Daver et al, AACR 2016). PD1 inhibition has shown activity in AML (Berger et al, Clin Cancer Res 2008). We hypothesized that addition of nivolumab to an induction regimen of ara-C and idarubicin may prolong relapse-free survival (RFS) and overall survival (OS); this study was designed to determine the feasibility of this combination. Methods: Pts with newly diagnosed acute myeloid leukemia (by WHO criteria; ≥20% blasts) and high risk MDS (≥10% blasts) were eligible to participate if they were 18-65 yrs of age and had adequate performance status (ECOG ≤3) and organ function (LVEF ≥ 50%; creatinine ≤ 1.5 g mg/dL, bilirubin ≤ 1.5 mg/dL and transaminases ≤ 2.5 times upper limit of normal). Treatment included 1 or 2 induction cycles of ara-C 1.5 g/m2 over 24 hours (days 1-4) and Idarubicin 12 mg/m2 (days 1-3). Nivolumab 3 mg/kg was started on day 24 ± 2 days and was continued every 2 weeks for up to a year. For pts achieving complete response (CR) or CR with incomplete count recovery (CRi) up to 5 consolidation cycles of attenuated dose ara-C and idarubicin was administered at approximately monthly intervals. Eligible pts received an allogeneic stem cell transplant (alloSCT) at any time during the consolidation or thereafter. Results: 3 pts with relapsed AML were treated at a run-in phase with a dose of nivolumab 1 mg/kg without specific drug-related toxicity. Subsequently, 32 pts (median age 53 yrs; range, 26-65) were treated as above including 30 with AML (24 de novo AML, 2 therapy-related AML, 3 secondary AML and 1 therapy-related secondary AML) and 2 high risk MDS. Pre-treatment genetic risk by ELN criteria was 11 adverse, 16 intermediate, and 5 favorable, including 2 FLT3 -ITD mutated, 5 NPM1 mutated, and 7 TP53 mutated. All 32 pts were evaluable for response and 23 (72%) achieved CR/CRi (19 CR, 4 CRi). The 4-week and 8 week mortality was 6% and 6%. The median number of doses of nivolumab received was 6 (range, 0-13); one pt did not receive nivolumab due to insurance issues. 9 pts underwent an alloSCT. After a median follow-up of 8.3 mths (range, 1.5-17.0) the median RFS among the responding pts has not been reached (range, 0.1 - 15.8 mths) and the median OS has not been reached (range 0.5-17.0 mths). Grade 3/4 immune mediated toxicities have been observed in 5 pts and include rash, pancreatitis, and colitis. Other grade 3/4 toxicities thought to be potentially related to nivolumab include cholecystitis in one pt. 9 pts proceeded to an alloSCT. Donor source was matched related in 2, matched unrelated in 6 and haplo-identical in 1 pt. Conditioning regimen was Fludarabine plus busulfan-based in 8, and fludarabine plus melphalan in 1 pt. 4 pts developed graft versus host disease (GVHD)(grade I/II in 3, grade III/IV in 1), which responded to treatment in 3. Multicolor flow-cytometry studies are conducted by the Immunotherapy Platform on baseline (prior to first dose of nivolumab) and on-treatment BM aspirate and peripheral blood to assess the T-cell repertoire and expression of co-stimulatory receptors and ligands on T-cell subsets and leukemic blasts, respectively. The baseline BM was evaluated on 23 of the 32 evaluable pts, including 18 responders and 5 non-responders. Pts who achieved a CR/CRi had a trend of higher frequency of live CD3+ total T cell infiltrate as compared to non-responders in the baseline BM aspirates (Fig 1A). We evaluated expression of immune markers on T cell subsets: CD4 T effector cells [Teff]: CD3+CD4+CD127lo/+Foxp3-, CD4 T regulatory cells [Treg]: CD3+CD4+CD127-Foxp3+, and CD8 T cells. At baseline, BM of non-responders had significantly higher percentage of CD4 T effector cells co-expressing the inhibitory markers PD1 and TIM3 (p&lt;0.05) and a trend towards higher percentage of CD4 T effector cells co-expressing PD1 and LAG3 compared to responders (Fig 1B). Co-expression of TIM3 or LAG3 on PD1+ T cells have been shown to be associated with an exhausted immune phenotype in AML (Zhou et al., Blood 2011). Conclusion: Addition of nivolumab to ara-C and anthracycline induction chemotherapy is feasible and safe in younger pts with AML. Among the pts proceeding to alloSCT the risk of GVHD is not significantly increased. Figure 1 Figure 1. Disclosures Daver: Pfizer Inc.: Consultancy, Research Funding; Otsuka America Pharmaceutical, Inc.: Consultancy; Sunesis Pharmaceuticals, Inc.: Consultancy, Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; Bristol-Myers Squibb Company: Consultancy, Research Funding; Kiromic: Research Funding; Karyopharm: Consultancy, Research Funding; Jazz: Consultancy; Immunogen: Research Funding; Daiichi-Sankyo: Research Funding; Incyte Corporation: Honoraria, Research Funding. Thompson: Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees. Jabbour: Bristol-Myers Squibb: Consultancy. Takahashi: Symbio Pharmaceuticals: Consultancy. DiNardo: Novartis: Honoraria, Research Funding; Daiichi-Sankyo: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Agios: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Sharma: Jounce: Consultancy, Other: stock, Patents & Royalties: Patent licensed to Jounce; Astellas: Consultancy; EMD Serono: Consultancy; Amgen: Consultancy; Astra Zeneca: Consultancy; GSK: Consultancy; Consetellation: Other: stock; Evelo: Consultancy, Other: stock; Neon: Consultancy, Other: stock; Kite Pharma: Consultancy, Other: stock; BMS: Consultancy. Cortes: BMS: Consultancy, Research Funding; Sun Pharma: Research Funding; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Research Funding; ImmunoGen: Consultancy, Research Funding; ARIAD: Consultancy, Research Funding. Kantarjian: Delta-Fly Pharma: Research Funding; Amgen: Research Funding; ARIAD: Research Funding; Novartis: Research Funding; Bristol-Meyers Squibb: Research Funding; Pfizer: Research Funding.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0258743
Author(s):  
Nathella Pavan Kumar ◽  
Chandrasekaran Padmapriyadarsini ◽  
Anuradha Rajamanickam ◽  
Perumal Kannabiran Bhavani ◽  
Arul Nancy ◽  
...  

BCG vaccination is known to induce innate immune memory, which confers protection against heterologous infections. However, the effect of BCG vaccination on the conventional adaptive immune cells subsets is not well characterized. We investigated the impact of BCG vaccination on the frequencies of T cell subsets and common gamma c (γc) cytokines in a group of healthy elderly individuals (age 60–80 years) at one month post vaccination as part of our clinical study to examine the effect of BCG on COVID-19. Our results demonstrate that BCG vaccination induced enhanced frequencies of central (p<0.0001) and effector memory (p<0.0001) CD4+ T cells and diminished frequencies of naïve (p<0.0001), transitional memory (p<0.0001), stem cell memory (p = 0.0001) CD4+ T cells and regulatory T cells. In addition, BCG vaccination induced enhanced frequencies of central (p = 0.0008), effector (p<0.0001) and terminal effector memory (p<0.0001) CD8+ T cells and diminished frequencies of naïve (p<0.0001), transitional memory (p<0.0001) and stem cell memory (p = 0.0034) CD8+T cells. BCG vaccination also induced enhanced plasma levels of IL-7 (p<0.0001) and IL-15 (p = 0.0020) but diminished levels of IL-2 (p = 0.0033) and IL-21 (p = 0.0020). Thus, BCG vaccination was associated with enhanced memory T cell subsets as well as memory enhancing γc cytokines in elderly individuals, suggesting its ability to induce non-specific adaptive immune responses.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1071-1071
Author(s):  
Melody M. Smith ◽  
Cynthia R. Giver ◽  
Edmund K. Waller ◽  
Christopher R. Flowers

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


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2349-2349
Author(s):  
Claudia Brandao ◽  
Alexander M. de Bruin ◽  
Martijn A. Nolte

Abstract Abstract 2349 After immune activation, effector/memory T cells, including virus-specific CD8 T cells, are known to migrate to the bone marrow (BM), where they can be maintained by the production of IL-15 by the stroma; however, it is not yet known whether these T cells also have a function at this site. Since depletion of T cells from allogenic BM grafts compromises HSC engraftment, we hypothesize that T cells can directly influence the balance between differentiation and self-renewal of hematopoietic stem cells (HSCs). To test the ability of T cells to affect hematopoiesis, we performed co-cultures of HSCs and T cells isolated from murine BM. We found that T cells localized in the BM are able to enhance HSC differentiation as well as their self-renewal capacity. This feature is specific for BM central memory (CM) CD8 T cells, since other T cell subsets are not able to affect HSCs to the same extent. Moreover, depletion of CM CD8 T cells from the total BM T cell pool abrogates the impact on HSC differentiation and self-renewal, indicating that this particular T cell population is both sufficient and required for the observed effects. BM CM CD8 T cells do not affect quiescence of HSCs, but do enhance their proliferative capacity, and we found that supernatant from CM CD8 T cells is sufficient for this effect. Interestingly, competitive transplantation assays showed that HSCs cultured with CM CD8 T cells-derived supernatant contribute much better to leukocyte formation than medium-treated HSCs. This effect is seen in both the myeloid and lymphoid compartment, indicating that CM CD8 T cells are able to release soluble factors that support and enhance the multilineage reconstitution capacity of HSCs. Functional studies with blocking antibodies or knock-out mice showed that the supernatant-mediated effect is not caused by the hematopoietic cytokines IL3, IL6, IL21, GM-CSF, RANTES, TNFα or IFNγ. Preliminary data indicate that this feedback mechanism of the immune system on the hematopoietic process in the bone marrow is also present in the human situation, since autologous BM T cells increase the numbers of human HSCs, as well as their differentiation capacity. Overall, these findings demonstrate that T cells have an important function in the BM and that especially CD8 TCM cells can directly influence HSC homeostasis. We postulate that this feedback mechanism of the immune system on the hematopoietic process in the BM is particularly relevant during viral infection, as the efficient migration of virus-specific CD8 T cells to the BM could well benefit the replenishment of the HSC/progenitor cell compartment and restoration of blood cell numbers that got lost upon infection. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4352-4352
Author(s):  
Mohammad Raeiszadeh ◽  
Matthew Verney ◽  
Charles Craddock ◽  
Harald Wajant ◽  
Paul Moss ◽  
...  

Abstract Recent evidence suggests that Tumor Necrosis Factor (TNF) can selectively kill antigen-specific autoreactive CD8+ T-cells through engagement with TNF Receptor 2 (TNFR2) (1). Within the immune system, TNFR2 expression is restricted to subsets of T-cells, a profile which is in marked contrast to the ubiquitous pattern of expression of TNFR1. However, the spectrum and physiological significance of TNFR2 expression by CD8+ T-cell subpopulations is unknown. In this study we analysed the expression of TNFR2 by CD8 T-cell subsets isolated from normal healthy donors by flow cytometry. In addition, in order to understand the physiological significance of TNFR2 expression on recently activated T cells, we further studied expression on CMV-specific CD8 T-cells which expanded in stem cell transplant patients in response to episodes of CMV reactivation. The expression of TNFR2 was compared to that of other common gamma chain receptors including IL2R and IL7R, and to the expression of a receptor for inflammatory cytokine IL6. TNFR2 expression was found to increase during differentiation of CD8+ T cells. In particular, TNFR2 expression was seen on 6.5% of naïve, 14.6% of central memory, 37.9% of effector memory and 45.2% of CD45RA-revertant effector memory (TEMRA) CD8+ T cells. In contrast, common gamma chain cytokine receptor expression was skewed towards less differentiated T-cell subsets. For example, IL-7R was expressed by 63% of central memory populations but only 18.4% of the TEMRA subset. Comparable expression of IL2R was 12.1% on TCM and 2% on TEMRA. Of interest, IL-6 receptor expression was predominantly expressed by naïve CD8 T-cells (69.5%). In support of these results, we went on to show that expression of TNFR2 was inducible on primary T cells following activation with anti-CD3 and IL-2 in vitro. Healthy CMV seropositive donors had a larger median number of CD8+ T cells expressing TNFR2 (53%) in comparison to CMV seronegative donors (15%), (p<0.0001), consistent with the known accumulation of differentiated T-cells within CMV seropositive individuals.The expression of TNFR2 was then examined on CMV-specific CD8 T-cells which were undergoing acute expansion in response to viremia in six haemopoietic stem cell transplant patients. The expansion of CMV-specific CD8 T-cells was accompanied by an increase in the intensity of TNFR2 expression which later decreased during the retraction of antigen-specific T-cells during resolution of viremia. In order to explore the functional significance of TNFR2 expression, T-cells isolated from healthy donors were treated with recombinant TNFR2-specific ligand. This induced cell loss ranging from 13% to 60% of all CD8 T-cells in relation to untreated control cells, with selective depletion of the TNFR2+ population. A similar proportion of CMV-specific T-cells from transplant patients were eliminated by ex vivo stimulation of TNFR2. In conclusion our work shows that TNFR2 expression increases during differentiation of CD8+ T cells. In addition, we were able to utilize virus-specific T cells from SCT patients to show that expression is increased during the acute response to stimulation with antigen. We also provide evidence that TNFR2 activation can lead to the partial elimination of antigen-specific CMV-specific T-cells and it may thus play an important role in the ‘deflation’ of a pathogen-specific T-cell immune response following resolution of infection. These data suggest that TNFR2 expression may act as a ligand to signal activation-induced cell death in late differentiated populations of CD8+ T cells. Further investigations are required to assess the molecular pathways of TNFR2 signalling that are activated following receptor ligation in vivoand whether or not these are disrupted in disorders associated with chronic CD8+ T cell lymphproliferation. (1) L. Ban et al, PNAS 2008, 105: 3644 Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 904-904
Author(s):  
Rebecca Austin ◽  
Megan Bywater ◽  
Jasmin Straube ◽  
Leanne T Cooper ◽  
Madeleine Headlam ◽  
...  

Abstract Immunotherapy has revolutionised therapeutic approaches to fight cancer and, in certain diseases dramatically improves survival. Clinical responses to immune checkpoint blockade have in part been attributed to high mutational burden of tumours such as melanoma. High-risk acute myeloid leukaemia (AML) is defined by molecular and cytogenetic factors. AML has a low prevalence of somatic mutations and is predicted to have low immunogenicity. We aimed to determine how AMLs driven from different classes of oncogenes interact with endogenous anti-leukemic immune responses. Methods and Results We generated three oncogenically distinct models of AML: BCR-ABL+NUP98-HOXA9 (BA/NH9), MLL-AF9 (MA9), and AML1-ETO+NRASG12D (AE/NRAS), using retroviral transduced bone marrow transplanted into immune-competent, non-irradiated C57BL/6J (B6) mice or immune-deficient Rag2-/-γc-/- mice. Immunologic control of AML was dependent on the driver oncogene, as AE/NRAS AML was effectively controlled in B6, but not Rag2-/-γc-/-recipients, whereas survival of BA/NH9 AML recipients was similar between B6 and Rag2-/-γc-/-. MA9 AML had an intermediate phenotype (Figure 1A-C). To examine the mechanisms underlying immune escape in AE/NRAS, AML from immune-deficient or immune-competent hosts, was passaged through immune-competent hosts. Prior exposure to an intact immune system dramatically accelerated disease progression of AE/NRAS AML in subsequent B6 recipients, but this was not seen in passage through Rag2-/-γc-/- recipients. This demonstrates specific, functional immunoediting of AML resulting in evasion of immune control. Despite evidence of disease attenuation in immune competent hosts, functional immunoediting was not observed in MA9 AML. Antibody-mediated immune cell depletion experiments demonstrated that natural killer (NK) cells and T cells both contribute to the control AE/NRAS AML, whereas MA9 immune control was dependent on NK cells. As immunoediting was only seen in AE/NRAS model, this suggests that functional immunoediting in this model is primarily mediated by T cells. To characterise the mechanisms regulating immunoediting, we integrated proteomic and transcriptional analysis of immunoedited and non-immunoedited AE/NRAS AML. There was strong correlation between increased protein expression and transcriptional regulation. There was distinct regulation of inflammatory pathways between immunoedited and non-immunoedited AML. Immunoedited AE/NRAS cells showed increased IFN-γ-dependent response signatures, consistent with direct targeting of the leukemic cells by the immune system. Transcriptional analysis also showed modulation of expression of immune checkpoint molecules including upregulation of suppressive molecules Tim-3 and CD39 and downregulation of activating ligand CD137L. These findings were confirmed by cell-surface flow cytometry. Immunoedited AE/NRAS downregulated RAS signalling transcriptionally, with coordinate activation of MYC targets. In the murine AE/NRAS model, CD4+ and CD8+ T effector memory (TEM) cells (CD44+ CD62L-) demonstrated increased PD-1 expression compared to naïve mice. In addition, mice with high disease burden also had increased frequency of T cells co-expressing exhaustion markers PD-1, Tim-3 and LAG-3, consistent with suppression of the anti-leukemic effector immune response. To understand if these findings were relevant to AML in the clinic, we obtained single cell RNA-sequencing data from the CD45+ CD34- non-leukemic fraction of bone marrow in a patient with AML1-ETO AML at diagnosis compared to that in normal marrow. Single cell type classification and clustering using tSNE demonstrated remodelling of the immune microenvironment in AML with loss of NK cells, pre-B cells and skewing of T cell subsets. There was depletion of CD8+ TEM cells and greater proportions of CD4+ and CD8+ TEM cells expressing activation and exhaustion markers (IFN-γ, PD-1, LAG-3, TIM-3). Conclusions These data demonstrate that immune responses in AML are oncogene-specific and provide evidence that AE/NRAS AML cells undergo immunoediting over time in the presence of a competent immune microenvironment. Since AML is associated with alterations in T cell subsets, and changes in T cell activation and exhaustion states, these findings may inform translational strategies to use immunotherapies for patients with AML. Disclosures Smyth: Bristol Myers Squibb: Other: Research agreement; Tizona Therapeutics: Research Funding. Lane:Janssen: Consultancy, Research Funding; Celgene: Consultancy; Novartis: Consultancy.


2018 ◽  
Author(s):  
Jinyun Yuan ◽  
Janice Tenant ◽  
Thomas Pacatte ◽  
Christopher Eickhoff ◽  
Azra Blazevic ◽  
...  

AbstractFailure of the most recent tuberculosis (TB) vaccine trial to boost BCG mediated anti-TB immunity despite highly durable Th1-specific central (TCM) and effector (TEM) memory cell responses, highlights the importance of identifying optimal T cell targets for protective vaccines. Here we describe a novel, Mycobacterium tuberculosis (Mtb)-specific IFN-γ+CD4+ T cell population expressing surface markers characteristic of naïve T cells (TNLM), that were induced in both human (CD45RA+CCR7+CD27+CD95-) and murine (CD62L+CD44-Sca-1+CD122-) systems in response to mycobacteria. In BCG vaccinated subjects and those with latent TB infection, TNLM cells, compared to bonafide naïve CD4+ T cells were identified by absence of CD95 expression and had increased expression CCR7 and CD27, the activation markers T-bet, CD69 and PD-1 and the survival marker CD74. Increased TNLM frequencies were noted in the lung and spleen of wild type C57BL6 mice at 2 weeks after infection with Mtb, and progressively decreased at later time points, a pattern not seen in TNF-α+CD4+ T cells expressing naïve cell surface markers. Importantly, adoptive transfer of highly purified TNLM from vaccinated ESAT-61-20-specific TCR transgenic mice conferred superior protection against Mtb infection in Rag-/- mice when compared with total meory populations (central and effector memory cells). Thus, TNLM cells may represent a memory T cell population that if optimally targeted may significantly improve future TB vaccine responses.


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