Persistence of Recipient-Derived Antiviral T cells Severely Influence Donor Chimerism Post Allogeneic HSCT,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3240-3240
Author(s):  
Sylvia Borchers ◽  
Michael Stadler ◽  
Susanne Luther ◽  
Tina Ganzenmueller ◽  
Brigitte Pabst ◽  
...  

Abstract Abstract 3240 Analysis of donor chimerism is a well established technique to monitor engraftment and detect pending relapse in patients after allogeneic hematopoietic stem cell transplantation (HSCT). Over the last decade, use of unrelated and/or mismatched donors as well as alternative grafts like cord blood (CB) has increased, and, in addition reduced intensity conditioning regimens are widely applied. Thus, recipients are increasingly being exposed to both persistent mixed chimerism and infectious complications because of delayed immune reconstitution. Donor chimerism is analyzed routinely from peripheral blood cells in all recipients. In addition, in a prospective study to evaluate usefulness of subset chimerism, T cell chimerism is analyzed in selected patients since 2007. Reconstitution of CMV-specific CD8 T cells (CMV-CTL) is monitored by multimers (multimeric dye-labeled recombinant-MHC-I-peptide-complexes) since 2006 to evaluate CMV-specific immune reconstitution post HSCT. Using this method, HLA-restriction of the multimers enables detection of residual recipient CMV-CTLs in mismatched transplantations. Interestingly, we found that CMV reactivation is accompanied by a decline in donor chimerism in some patients and that recipient CMV-CTLs persisting post HSCT expand upon CMV reactivation. Table 1 summarizes first data of this analysis in patients transplanted between 2007 and 2011 in our centre. Table 1: Data from patients transplanted between 2007 and 2011 at MHH # underlying disease R/D gender Donor Conditioning regimen GvHD prophylaxis Graft 1 AML f/f MMUD Flamsa(TBI)/ATG CSA/MMF PBPC 2 AML f/f MMRD Flu/Melph/Thiotepa/ATG TCD PBPC 3 AML m/m MMUD Flamsa(TBI)/Thymo CSA/MMF PBPC 4 NHL m/f MUD Flu/Cy/Thymo CSA/MMF PBPC 5 ALL m/m MMUD TBI/Cy/ATG CSA/MMF PBPC 6 AA f/m hla-ident sibl. Flu/Cy/TBI/Thymo CSA/MTX BM 7 MDS m/m MMUD Flu/Cy/TBI/ATG CSA/MMF cord blood 8 NHL m/m MMUD Flu/Cy/ATG CSA/MTX PBPC # R/D CMV-serostatus aGvHD CMV reactivation (CMV-R) leukocyte chimerism decline post CMV-R T cell chimerism decline post CMV-R persisting recipient CMV-CTLs 1 R+D- yes 40, 61 yes yes 2 R+D- no 27, 90, 188 no yes 3 R+D+ yes no no yes 4 R+D+ no 18 yes yes yes 5 R+D- suspected 34, 90 no no yes 6 R+D- no 55 yes yes 7 R+D- yes 85, 113 yes yes yes* 8 R+D- no (HvG) 33 yes yes yes* * confirmed by chimerism analysis in enriched CMV-CTL Patient 7 received a double mismatched cord-blood graft. As expected the recipient-CMV-CTLs declined after HSCT and by day +50 post-HSCT no CMV-CTLs (A*0201-NLVP multimer) could be detected anymore. The patient had a CMV reactivation on day +85 as shown by pp65 antigenemia assay. On day +90, 72 CMV-CTLs/μl were detected, further increasing to over 200/μl by day +152. To further analyze the origin and functionality, CMV-CTLs detected on day +90 were enriched by MACS to a purity of 97% in the CD3+CD8+ T cells. Donor chimerism was only 4%. After reconstitution of autologous CMV-CTLs, the patient experienced an additional subclinical CMV reactivation on day +113, not requiring any treatment at this time. In patient 8 a subclinical CMV reactivation on day +33 led to proliferation of CMV-CTLs and HLA-A*24 restricted and -B*35 restricted CMV-CTLs rose from 0 cells/μl (A*24 0.05%, B*35 0.04% of CD3CD8 T-cells) to 1 cell/μl and 21 cells/μl (A*24 0.28%, B*35 4.05% of CD3CD8 T-cells), respectively. Donor chimerism decreased from 51% on day +33 to 0% by day +62. Chimerism analysis of T-cell subsets on day +62 and of CMV-CTLs on day +69 revealed a 0% donor chimerism in these subsets. We speculate that in this patient CMV reactivation led to an inflammatory environment, which might have promoted loss of the graft. Our data indicate that T cell-subset chimerism analyses may contribute to a better understanding of chimerism kinetics. Furthermore, recipient-derived CMV-CTLs may be able to control CMV reactivation, especially after reduced intensity conditioning but also after standard conditioning regimens (i.e. in patient 5), but can severely influence donor chimerism and thus might have negative effects as well. We are currently investigating donor chimerism in T cell subsets and CMV-CTL reconstitution to gain insight into the complex immune responses and reconstitution processes occurring after allogeneic HSCT or CB-SCT. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4575-4575
Author(s):  
Miki Iwamoto ◽  
Ken-ichi Matsuoka ◽  
Yusuke Meguri ◽  
Takeru Asano ◽  
Takanori Yoshioka ◽  
...  

Abstract Post-transplant expansion of donor-derived T cells has crucial impact on the early clinical events including graft engraftment and acute graft-versus-host disease. Flowcytometry-based method enables us to analyze the lymphocyte chemerism in the very early phase after HSCT and recent reports have shown that T-cell achieved donor-chimerism in the first two weeks in the majority cases. However, the very early dynamics of each T-cell subset, including CD4+Foxp3+ regulatory T cells (Tregs), has not been well characterized. Since the early expansion of Tregs and other CD4+ and CD8+ conventional T cells (Tcons) are immunologically competitive and might important for the stabilization of immunity in the early phase, we hereby investigated the early dynamics of donor-Treg chimerism comparing with Tcons within each individual patient. Laboratory studies were undertaken in 11 adult patients who received HLA-mismatched allogeneic graft; unrelated cord blood (n=5), unrelated peripheral blood (n=1) and related peripheral blood (n=5). Blood samples were obtained before and at 1, 2, 4, and 6 weeks after HSCT. Peripheral blood mononuclear cells (PBMCs) were isolated from blood samples by density gradient centrifugation and cryopreserved before being analyzed. After thawing, to analyze the subset-specific chimerism, PBMCs were stained with anti-HLA monoclonal antibodies and other subset-specific antibodies as follows: Pacific Blue conjugated anti-CD4, eFluor450 conjugated anti-CD3, PE-Cy7 conjugated anti-CD25, anti-CD14, APC conjugated anti-CD127, anti-CD56, and APC-eFluor780 conjugated anti-CD8a, anti-CD19. Gated lymphotes (CD4+Tcons, CD4+Tregs, CD8+T cells, B cells, NK cells, Monocytes) were analyzed their chimerism by flowcytometry. All 11 patients achieved donor-dominant chimerism of T cells, NK cells and Monocytes (>90%) by 4 weeks after HSCT. As for T-cell subsets, donor-chimerisms of Tregs at the first week were higher than that of CD4+ and CD8+ Tcons in all 5 patients after PBSCT (Average %donor chimerisms: Tregs 81.3%, CD4+Tcon 66.0%, CD8+Tcon 75.2%). Of interest, patients after cord blood transplantation (CBT) showed marked contrast to PBSCT where donor-chimerism of Tregs at the first week was much lower than that of CD4+ and CD8+ Tcons (Average %donor chimerism: Tregs 27.2%, CD4+Tcon 53.2%, CD8+Tcon 47.0%), and it is significantly lower than that of PBSCT (P=0.009). At 4 weeks when Treg achieved complete donor-chimerism in all patients, Treg percentage of total CD4 T cells after CBT was lower than that after PBSCT (average %Treg at w4: 7.8% vs 12.6%, respectively). Clinically, 3 patients with delayed donor-Treg achievement in the first week after CBT developed pre-engraftment immune reaction (PIR) which was followed by the onset of acute GVHD, although patients with donor-Treg dominant recovery in the first week after PBSCT did not develop clinical PIR. These data suggest that cord blood-derived Tregs expanded less aggressively in the very early phase and achieve donor-chimerism behind Tcons within each individual patient. Slower rising-up of cord blood-derived Treg in the first week appears to be associated with the low percentage of Treg at 4 weeks after CBT. In good contrast, PBSC-derived Tregs achieved donor-chimerism prior to Tcons. Taken together, our results suggest that early dynamics of donor-Treg chimerism after HLA-mismatched HSCT might significantly vary according to the donor sources and be critically linked to the clinical immune events in the early phase after HSCT. The careful monitoring of early Treg reconstitution from the point of view might provide a novel strategy to promote immune tolerance in the early phase after transplantation. Disclosures Maeda: Mundipharma KK: Research Funding.



2020 ◽  
Vol 4 (1) ◽  
pp. 191-202 ◽  
Author(s):  
Ioannis Politikos ◽  
Jessica A. Lavery ◽  
Patrick Hilden ◽  
Christina Cho ◽  
Taylor Borrill ◽  
...  

Abstract Quality of immune reconstitution after cord blood transplantation (CBT) without antithymocyte globulin (ATG) in adults is not established. We analyzed immune recovery in 106 engrafted adult CBT recipients (median age 50 years [range 22-70]) transplanted for hematologic malignancies with cyclosporine/mycophenolate mofetil immunoprophylaxis and no ATG. Patients were treated predominantly for acute leukemia (66%), and almost all (96%) underwent myeloablation. Recovery of CD4+ T cells was faster than CD8+ T cells with median CD4+ T-cell counts exceeding 200/mm3 at 4 months. Early post-CBT, effector memory (EM), and central memory cells were the most common CD4+ subsets, whereas effector and EM were the most common CD8+ T-cell subsets. Naive T-cell subsets increased gradually after 6 to 9 months post-CBT. A higher engrafting CB unit infused viable CD3+ cell dose was associated with improved CD4+ and CD4+CD45RA+ T-cell recovery. Cytomegalovirus reactivation by day 60 was associated with an expansion of total, EM, and effector CD8+ T cells, but lower CD4+ T-cell counts. Acute graft-versus-host disease (aGVHD) did not significantly compromise T-cell reconstitution. In serial landmark analyses, higher CD4+ T-cell counts and phytohemagglutinin responses were associated with reduced overall mortality. In contrast, CD8+ T-cell counts were not significant. Recovery of natural killer and B cells was prompt, reaching medians of 252/mm3 and 150/mm3 by 4 months, respectively, although B-cell recovery was delayed by aGVHD. Neither subset was significantly associated with mortality. ATG-free adult CBT is associated with robust thymus-independent CD4+ T-cell recovery, and CD4+ recovery reduced mortality risk.



Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1158-1158
Author(s):  
Miguel Perales ◽  
Ying Taur ◽  
Ingrid Leiner ◽  
Marissa N Lubin ◽  
Boze Susac ◽  
...  

Abstract Introduction: Double-unit cord blood transplantation (DCBT) is a viable therapy for adults with high-risk hematologic malignancies who lack an adult donor. However, lack of transfer of memory T cells in the graft is associated with an increased risk of viral infections. To study immune reconstitution, we recently described a novel method that combines 5' rapid amplification of complementary DNA ends (RACE) PCR and deep sequencing to quantify T cell receptor (TCR) diversity after allogeneic hematopoietic stem cell transplant (van Heijst, Nat Med 2013). In that study, we showed that recipients of DCBT recover TCR diversity comparable to healthy donors by 12 months. We now report results of a prospective analysis of CD4+ and CD8+ T cell repertoire recovery in DCBT recipients and correlation with clinical outcomes. Methods: We prospectively collected samples from 33 DCBT recipients. The median age was 45 years (range 26-71), 18 (55%) were CMV seropositive, and the majority (n = 17, 52%) had non-European ancestry. Diagnoses included 20 (61%) acute leukemias and 13 (39%) lymphomas. Conditioning was myeloablative (n=1, 3%), reduced intensity (n=28, 85%), or non-myeloablative (n=4, 12%), and all patients received GVHD prophylaxis with cyclosporine-A and mycophenolate mofetil and no ATG. Patients received double-unit CB grafts (4-6/6 HLA-A,-B antigen, -DRB1 allele donor-recipient matched); this was supplemented with haploidentical CD34-selected PBSC in 18 patients. The 66 units had a median donor-recipient HLA-allele match of 6/8 (range 3-8). Infused total nucleated cell doses were 2.3 (1.7-3.3) and 1.9 (1.3-2.5) for the larger and smaller units, respectively. Samples were collected from the DCB grafts, recipient day+21 bone marrow, and peripheral blood at days +30, 60, 90, 120, 180 and 365 post-transplant. TCR-β sequences from each sample were amplified and sequenced using the Illumina/MiSeq sequencing platform after isolation of CD4+ and CD8+ T cells. TCR abundances were assessed at the level of clonotype and TCR diversity was calculated using inverse Simpson index. Results: Of the 33 patients, long-term samples were obtained in 25 patients, short-term samples (≤ day 100) in 6 patients who died early after DCBT, and no samples other than the graft for 2 patients. The remainder of the results focuses on 25 patients with complete samples. As previously shown, there is a 1-2-log increased diversity in CD4+ vs. CD8+ T cells (Figure). Furthermore, median CD4+ steady-state diversity is achieved early by day 60. In contrast, there is a higher rate of clonal dominance in CD8+ compared to CD4+ T cells (24/25 vs. 11/25, p=0.0001 by Fisher test). Several patterns of clonal dominance were observed, including two main patterns in CD8+ T cells. In 7/24 patients, clonal dominance is established by day 60 and persists throughout, whereas in 12/24 patients, clonal dominance fluctuates throughout follow-up. In CD4 +T cells, where less dominance is observed, a similar distribution is seen, though prolonged clonal dominance is rare. Interestingly, some of the dominant clones can be detected in the graft and are present in the day 21 marrow sample. Persistent clonal dominance in CD8+ T cells was seen 6/9 patients with CMV reactivation, whereas ongoing fluctuation was seen in 9/12 patients without CMV reactivation. In 2 patients with fluctuating clones who reactivated CMV, 1 had low level and the other a late viremia. In contrast, no link to a specific pattern was observed in patients with HHV6 viremia or acute GVHD. Finally, when we assessed similarity in clonal distribution between time points, there was more similarity in CD8+ than CD4+ T cells. Conclusions: This novel deep TCR repertoire sequencing provides a quantitative picture of T cell recovery after DCBT and supports the following: 1) separate analysis of CD4+ and CD8+ T cell populations is critical given different patterns of recovery in T cell subsets; 2) there is significant turnover in CD4+ clones but with overall limited dominance, whereas there is less turnover in CD8+ clones; 3) although the grafts contain predominantly naïve T cells, the clonal evolution of CD8+ T cells strongly suggests generation of virus-specific T cells that control viral infection; and 4) CMV appears to be an important driver of CD8+ T cell clonal expansion after CBT. Ongoing analyses are correlating immune recovery with cord blood unit dominance as well as the biology of GVHD and relapse. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.



Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2926-2926
Author(s):  
Satoshi Takahashi ◽  
Jun Ooi ◽  
Akira Tomonari ◽  
Nobuhiro Tsukada ◽  
Takaaki Konuma ◽  
...  

Abstract The one of crucial questions in cord blood transplantation (CBT) is whether naïvity of cord blood lymphocytes could gain antigen-specific cellular immunity during early phase of transplant. Cytomegalovirus (CMV) infection is serious clinical problem in allogeneic transplant recipients and T cell immunity has known to have an important role in control of virus replication and prevention. During 1998 and 2006, 111 adults has received myeloablative regimens including 12 Gy of total body irradiation followed by CBT and a standard cyclosporine and methotrexate combination as GVHD prophylaxis in our institute. Patients also received intravenous immunoglobulin from day −3 to day 120 if the immunoglobulin level in the serum was less than 500 mg/dl. CMV antigenemia assay was performed twice a week after neutrophil recovery until day 120. Once CMV antigenemia is positive, patients received 5 mg/kg ganciclovir (GCV) once daily for at least 2 weeks as preemptive therapy. Ninety-two patients achieved engraftment with full donor chimerism and survived without disease relapse at the time of 120 days after CBT (82.8%). None of these 92 recipients had CMV disease during first 4 months after CBT. We have investigated the association of CMV reactivation status and their immune reconstitution process for 4 months after CBT in 39 patients who received CBT from 2002 to 2006 in our institute. CMV-specific CD4+ and CD8+ T cell recoveries were assessed by detection of interferon-g (IFN-g) producing cells with CMV antigen stimulation using intracellular cytokine staining. The positive was defined as more than 0.1% IFN-g positive cells among CD4+ or CD8+ T cell population. Six of 39 patients were CMV sero-negative and 33 patients were sero-positive. None of 6 CMV sero-negative receipients and 31 of 33 CMV sero-positive recipients observed CMV reactivation and received GCV therapy within the first 4 months. CMV-specific CD4+ T cells were detected in 30 of 31 recipients with positive CMV antigenemia (% positive: 55% at 1 month and 85% at 2 month), on the other hand, CMV-specific CD8+ T cells were detected in 14 out of 31 cases (% positive: 14% at 1 month and 22% at 2 month), both of which were comparable to post-bone marrow or peripheral blood transplants (CMV-specific CD4+ T cells were detected 18 of 21 recipients with positive CMV antigenemia and CMV-specific CD8+ T cells were detected in 12 out of 21). These data suggest that post-thymic naive T lymphocytes in cord blood might obtain memory and effector function in vivo with antigen-specific manner during early phase of post-transplant.



2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A586-A586
Author(s):  
Sara Schad ◽  
Andrew Chow ◽  
Heng Pan ◽  
Levi Mangarin ◽  
Roberta Zappasodi ◽  
...  

BackgroundCD4 and CD8 T cells are genetically and functionally distinct cell subsets of the adaptive immune system that play pivotal roles in immune surveillance and disease control. During development in the thymus, transcription factors ThPOK and Runx3 regulate the differentiation and maturation of these two lineages into single positive T cells that enter the periphery with mutually exclusive expression of either the CD4 or CD8 co-receptor.1–2 Despite our expectation that these two cell fates are fixed, mature CD4+CD8+ double positive (DP) T cells have been described in the context of numerous immunological responses, including cancer, but their molecular and functional properties and therapeutic relevance remain controversial and largely unknown.3–5MethodsOur lab has identified and characterized a heterogenous DP T cell population in murine and human melanoma tumors comprised of CD4 and CD8 T cells re-expressing the opposite co-receptor and a parallel uptake in the opposite cell type’s phenotype and function. Using CD4 (Trp1) and CD8 (Pmel) transgenic TCR T cells specific to B16 melanoma antigens gp75 and gp100 respectively, we demonstrate the re-expression of the opposite co-receptor following adoptive T cell transfer in B16 melanoma tumor bearing mice.ResultsSpecifically, up to 50% of transferred CD4 Trp1 T cells will re-express CD8 to become a DP T cell in the tumor microenvironment. Further, these CD4 derived DP T cells upregulate CD8 lineage regulator Runx3 and cytolytic genes Gzmb, Gzmk, and Prf1 to become potent cytotoxic T cells. Alternatively, a subset of CD8 Pmel T cells differentiate into DP T cells characterized by the increased expression of CD4, ThPOK, and regulatory marker FoxP3 (figure 1). In addition, we utilized 10x single cell and ATAC sequencing to further characterize these divergent DP T cell populations among open repertoire T cells isolated from murine and human melanoma tumors.ConclusionsOur findings highlight the capability of single positive T cells to differentiate in response to antigen and local stimuli into novel T cell subsets with polyfunctional characteristics. The resulting cell subsets will potentially affect the tumor microenvironment in distinct ways. Our studies may inform therapeutic approaches to identify antigen specific T cells as well as innovative signaling pathways to target when genetically engineering T cells to optimize cytotoxic function in the setting of adoptive cell therapy.Ethics ApprovalThe human biospecimen analyses were approved by Memorial Sloan Kettering Cancer Center IRB #06-107ReferencesEllmeier W, Haust L & Tschismarov R. Transcriptional control of CD4 and CD8 coreceptor expression during T cell development. Cell Mol Life Sci 2013;70:4537–4553.Luckey MA, et al. The transcription factor ThPOK suppresses Runx3 and imposes CD4+ lineage fate by inducing the SOCS suppressors of cytokine signaling. Nature Immunology 2014; 15, 638–645.Bohner P, et al. Double positive CD4(+)CD8(+) T Cells are enriched in urological cancers and favor T Helper-2 polarization. Front Immunol 2019; 10, 622.Nascimbeni M, Shin E-C, Chiriboga L, Kleiner DE & Rehermann B. Peripheral CD4(+)CD8(+) T cells are differentiated effector memory cells with antiviral functions. Blood 2004;104:478–486.Nishida K, et al. Clinical importance of the expression of CD4+CD8+ T cells in renal cell carcinoma. Int Immunol 2020;32:347–357.



2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A673-A673
Author(s):  
Rhodes Ford ◽  
Natalie Rittenhouse ◽  
Nicole Scharping ◽  
Paolo Vignali ◽  
Greg Delgoffe ◽  
...  

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.



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<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.



1994 ◽  
Vol 14 (2) ◽  
pp. 1084-1094
Author(s):  
Z Hanna ◽  
C Simard ◽  
A Laperrière ◽  
P Jolicoeur

The CD4 protein plays a critical role in the development and function of the immune system. To gain more insight into the mechanism of expression of the human CD4 gene, we cloned 42.2 kbp of genomic sequences comprising the CD4 gene and its surrounding sequences. Studies with transgenic mice revealed that a 12.6-kbp fragment of the human CD4 gene (comprising 2.6 kbp of 5' sequences upstream of the transcription initiation site, the first two exons and introns, and part of exon 3) contains the sequences required to support the appropriate expression in murine mature CD4+ CD8- T cells and macrophages but not in immature double-positive CD4+ CD8+ T cells. Expression in CD4+ CD8+ T cells was found to require additional regulatory elements present in a T-cell enhancer fragment recently identified for the murine CD4 gene (S. Sawada and D. R. Littman, Mol. Cell. Biol. 11:5506-5515, 1991). These results suggest that expression of CD4 in mature and immature T-cell subsets may be controlled by distinct and independent regulatory elements. Alternatively, specific regulatory elements may control the expression of CD4 at different levels in mature and immature T-cell subsets. Our data also indicate that mouse macrophages contain the regulatory factors necessary to transcribe the human CD4 gene.



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