Depletion of exhausted alloreactive T cells enables targeting of stem-like memory T cells to generate tumor-specific immunity.

Some hematological malignancies such as multiple myeloma are inherently resistant to immune-mediated antitumor responses, the cause of which remains unknown. Allogeneic bone marrow transplantation (alloBMT) is the only curative immunotherapy for hematological malignancies due to profound graft-versus-tumor (GVT) effects, but relapse remains the major cause of death. We developed murine models of alloBMT where the hematological malignancy is either sensitive [acute myeloid leukemia (AML)] or resistant (myeloma) to GVT effects. We found that CD8+ T cell exhaustion in bone marrow was primarily alloantigen-driven, with expression of inhibitory ligands present on myeloma but not AML. Because of this tumor-independent exhaustion signature, immune checkpoint inhibition (ICI) in myeloma exacerbated graft-versus-host disease (GVHD) without promoting GVT effects. Administration of post-transplant cyclophosphamide (PT-Cy) depleted donor T cells with an exhausted phenotype and spared T cells displaying a stem-like memory phenotype with chromatin accessibility present in cytokine signaling genes, including the interleukin-18 (IL-18) receptor. Whereas ICI with anti-PD-1 or anti-TIM-3 remained ineffective after PT-Cy, administration of a decoy-resistant IL-18 (DR-18) strongly enhanced GVT effects in both myeloma and leukemia models, without exacerbation of GVHD. We thus defined mechanisms of resistance to T cell-mediated antitumor effects after alloBMT and described an immunotherapy approach targeting stem-like memory T cells to enhance antitumor immunity.

Peritransplant glucocorticoids redistribute donor T cells to the bone marrow and prevent relapse after haploidentical SCT.

Patients with acute leukemia who are unable to achieve complete remission prior to allogeneic hematopoietic stem cell transplantation (SCT) have dismal outcomes, with relapse rates well in excess of 60%. Haplo-identical SCT (haplo-SCT) may allow enhanced graft-versus-leukemia (GVL) effects by virtue of HLA class I/II donor-host disparities, but it typically requires intensive immunosuppression with posttransplant cyclophosphamide (PT-Cy) to prevent lethal graft-versus-host disease (GVHD). Here, we demonstrate in preclinical models that glucocorticoid administration from days -1 to +5 inhibits alloantigen presentation by professional recipient antigen presenting cells in the gastrointestinal tract and prevents donor T cell priming and subsequent expansion therein. In contrast, direct glucocorticoid signaling of donor T cells promotes chemokine and integrin signatures permissive of preferential circulation and migration into the BM, promoting donor T cell residency. This results in significant reductions in GVHD while promoting potent GVL effects; relapse in recipients receiving glucocorticoids, vehicle, or PT-Cy was 12%, 56%, and 100%, respectively. Intriguingly, patients with acute myeloid leukemia not in remission who received unmanipulated haplo-SCT and peritransplant glucocorticoids also had an unexpectedly low relapse rate at 1 year (32%; 95% CI, 18%-47%) with high overall survival at 3 years (58%; 95% CI, 38%-74%). These data highlight a potentially simple and effective approach to prevent relapse in patients with otherwise incurable leukemia that could be studied in prospective randomized trials.

CMV exposure drives long-term CD57+ CD4 memory T-cell inflation following allogeneic stem cell transplant.

Donor and recipient cytomegalovirus (CMV) serostatus correlate with transplant-related mortality that is associated with reduced survival following allogeneic stem cell transplant (SCT). Prior epidemiologic studies have suggested that CMV seronegative recipients (R-) receiving a CMV-seropositive graft (D+) experience inferior outcomes compared with other serostatus combinations, an observation that appears independent of viral reactivation. We therefore investigated the hypothesis that prior donor CMV exposure irreversibly modifies immunologic function after SCT. We identified a CD4+/CD57+/CD27- T-cell subset that was differentially expressed between D+ and D- transplants and validated results with 120 patient samples. This T-cell subset represents an average of 2.9% (D-/R-), 18% (D-/R+), 12% (D+/R-), and 19.6% (D+/R+) (P < .0001) of the total CD4+ T-cell compartment and stably persists for at least several years post-SCT. Even in the absence of CMV reactivation post-SCT, D+/R- transplants displayed a significant enrichment of these cells compared with D-/R- transplants (P = .0078). These are effector memory cells (CCR7-/CD45RA+/-) that express T-bet, Eomesodermin, granzyme B, secrete Th1 cytokines, and are enriched in CMV-specific T cells. These cells are associated with decreased T-cell receptor diversity (P < .0001) and reduced proportions of major histocompatibility class (MHC) II expressing classical monocytes (P < .0001), myeloid (P = .024), and plasmacytoid dendritic cells (P = .0014). These data describe a highly expanded CD4+ T-cell population and putative mechanisms by which prior donor or recipient CMV exposure may create a lasting immunologic imprint following SCT, providing a rationale for using D- grafts for R- transplant recipients.

Airway Telomere Length in Lung Transplant Recipients.

Introduction: Chronic lung allograft dysfunction (CLAD) represents the major impediment to long term survival following lung transplantation. Donor and recipient telomere length have been shown to associate with lung transplant outcomes, including CLAD. In this study we aimed to measure the telomere lengths of bronchial and bronchiolar airway cells in lung allografts early after transplantation and to investigate associations with CLAD and all-cause mortality. Methods: This prospective, longitudinal study was performed at The Prince Charles Hospital, Australia. Airway cells were collected via bronchial and bronchiolar airway brushings at post-transplant bronchoscopies. The relative telomere length in airway cells was determined by quantitative PCR based on the T/S ratio. All patients were censored for CLAD and all-cause mortality in August 2020. Results: In total 231 bronchoscopies incorporating transbronchial brush and bronchial brush were performed in 120 patients. At the time of censoring, 43% and 35% of patients, respectively, had developed CLAD and had died. Airway bronchiolar and bronchial telomere lengths were strongly correlated (r=0.78, p<0.001), confirming conservation of telomere length with airway branch generation. Both the bronchiolar (r = -0.34, p<0.001) and bronchial (r = -0.31, p<0.001) telomere length decreased with age. Shorter airway telomere length was associated with older donor age and higher donor pack-year smoking history. Neither the bronchiolar nor the bronchial airway telomere length were associated with the development of CLAD (HR 0.39 (0.06-2.3), p=0.30; HR 0.66 (0.2-1.7), p=0.39, respectively) or all-cause mortality (HR 0.92 (0.2-4.5), p=0.92; HR 0.47 (0.1-1.9), p=0.28, respectively). Conclusions: In this cohort, airway telomere length was associated with donor age and smoking history but was not associated with the future development of CLAD or all-cause mortality.

Donor T-cell-derived GM-CSF drives alloantigen presentation by dendritic cells in the gastrointestinal tract.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has recently emerged as an important pathogenic cytokine in acute graft-versus-host disease (GVHD), but the nature of the T-cell lineages secreting the cytokine and the mechanisms of action are less clear. Here we used interleukin 17A-fate reporter systems with transcriptional analysis and assays of alloantigen presentation to interrogate the origins of GM-CSF-secreting T cells and the effects of the cytokine on antigen-presenting cell (APC) function after experimental allogeneic stem cell transplantation (SCT). We demonstrated that although GM-CSF-secreting Th17 and non-Th17 cells expanded in the colon over time after SCT, the Th17 lineage expanded to represent 10% to 20% of the GM-CSF secreting T cells at this site by 4 weeks. Donor T-cell-derived GM-CSF expanded alloantigen-presenting donor dendritic cells (DCs) in the colon and lymph nodes. In the mesenteric lymph nodes, GM-CSF-dependent DCs primed donor T cells and amplified acute GVHD in the colon. We thus describe a feed-forward cascade whereby GM-CSF-secreting donor T cells accumulate and drive alloantigen presentation in the colon to amplify GVHD severity. GM-CSF inhibition may be a tractable clinical intervention to limit donor alloantigen presentation and GVHD in the lower gastrointestinal tract.

Pegylated interferon-2α invokes graft-versus-leukemia effects in patients relapsing after allogeneic stem cell transplantation.

Allogeneic stem cell transplantation (SCT) is a curative therapy for patients with hematological malignancies related largely to an immunological graft-versus-leukemia (GVL) effect mediated by donor T cells and natural killer cells. Relapse of disease after SCT represents failure of GVL and is now the major cause of treatment failure. We sought to augment GVL effects in patients (n = 29) relapsing after SCT in a prospective phase I/II clinical trial of dose-escalated pegylated interferon-2α (peg-IFNα). The administration of peg-IFNα after reinduction chemotherapy, with or without subsequent donor lymphocyte infusion (DLI), resulted in a 2-year overall survival (OS) of 31% (95% confidence interval, 17.3%-49.2%), which rejects the null hypothesis of 7% generated by observations in an institutional historical cohort. As expected, peg-IFNα was associated with graft-versus-host disease (GVHD) and hematological toxicity, which was manageable with scheduled dose modifications. Progression-free survival (PFS) was greatest in patients who experienced GVHD, although the majority of those patients still eventually progressed. Higher PFS and OS were associated with pretreatment proportions of immune cell populations with regulatory function, including mucosal invariant T cells, regulatory T cells, and plasmacytoid dendritic cells, independent of any association with GVHD. Peg-IFNα administration after relapse thus constitutes a logical strategy to invoke GVL effects and should be studied in a larger, multicenter cohort. This trial was registered at www.anzctr.org.au as #ACTRN12612000728831.

Phase I Trial of Inducible Caspase 9 T Cells in Adult Stem Cell Transplant Demonstrates Massive Clonotypic Proliferative Potential and Long-term Persistence of Transgenic T Cells.

PURPOSE: Inducible caspase 9 (iCasp9) is a cellular safety switch that can make T-cell therapy safer. The purpose of this phase I trial was to investigate the use of iCasp9-transduced T-cell addback in adult patients undergoing haploidentical stem cell transplantation for high-risk hematologic malignancies. PATIENTS AND METHODS: Patients undergoing myeloablative, CD34-selected haploidentical stem cell transplantation were treated with 0.5-1.0 × 106/kg donor-derived iCasp9-transduced T cells on day +25 or 26 post-transplant, with additional doses allowed for disease relapse, infection, or mixed chimerism. RESULTS: Three patients were enrolled. iCasp9-transduced T cells were readily detectable by 4 weeks post-infusion in all patients and remained at high level (114 cells/µL, 11% of T cells) in 1 patient alive at 3.6 years. One patient developed donor-derived Epstein-Barr virus-associated post-transplant lymphoproliferative disease (EBV-PTLD), which was followed by a marked expansion of iCasp9 T cells and cytokine release syndrome (CRS). These iCasp9-transduced T cells infiltrated the affected lymph nodes and secreted IFNγ and IL-10. They peaked at 1,848 cells/µL and were found to be monoclonal by T-cell receptor (TCR) clonotype and oligoclonal by viral integrant analysis, representing a 6-log in vivo expansion of the dominant T-cell clone. These T cells were not autonomous and contracted with the resolution of EBV-PTLD, which did not recur. CONCLUSIONS: iCasp9-transduced T cells could persist long-term. They retained very high in vivo clonotypic proliferative capacity and function, and could cause CRS in response to de novo lymphoma development.

Myeloma escape after stem cell transplantation is a consequence of T-cell exhaustion and is prevented by TIGIT blockade.

Autologous stem cell transplantation (SCT) remains a standard of care for multiple myeloma (MM) patients and prolongs progression-free survival. A small cohort of patients achieve long-term control of disease, but the majority of patients ultimately relapse, and the mechanisms permitting disease progression remain unclear. In this study, we used a preclinical model of autologous SCT for myeloma where the disease either progressed (MM relapsed) or was controlled. In the bone marrow (BM), inhibitory receptor expression on CD8+ T cells correlated strongly with myeloma progression after transplant. In conjunction, the costimulatory/adhesion receptor CD226 (DNAM-1) was markedly downregulated. Interestingly, DNAM-1- CD8+ T cells in MM-relapsed mice had an exhausted phenotype, characterized by upregulation of multiple inhibitory receptors, including T-cell immunoglobulin and ITIM domains (TIGIT) and programmed cell death protein 1 (PD-1) with decreased T-bet and increased eomesodermin expression. Immune checkpoint blockade using monoclonal antibodies against PD-1 or TIGIT significantly prolonged myeloma control after SCT. Furthermore, CD8+ T cells from MM-relapsed mice exhibited high interleukin-10 (IL-10) secretion that was associated with increased TIGIT and PD-1 expression. However, while donor-derived IL-10 inhibited myeloma control post-SCT, this was independent of IL-10 secretion by or signaling to T cells. Instead, the donor myeloid compartment, including colony-stimulating factor 1 receptor-dependent macrophages and an IL-10-secreting dendritic cell population in the BM, promoted myeloma progression. Our findings highlight PD-1 or TIGIT blockade in conjunction with SCT as a potent combination therapy in the treatment of myeloma.

Granulocytes Are Unresponsive to IL-6 Due to an Absence of gp130.

IL-6 mediates broad physiological and pathological effects through its receptor signal transducing unit gp130. Due to the reportedly wide cellular expression of gp130, IL-6 is thought to signal ubiquitously via gp130 complex formation with membrane-bound IL-6Rα or soluble IL-6Rα. gp130 signaling primarily induces p-STAT3 and p-STAT1. In contrast to the previous dogma, we show in this article that circulating mouse and human granulocytes are unable to induce p-STAT3 or p-STAT1 after stimulation with IL-6 or an IL-6/soluble IL-6R complex. Furthermore, we demonstrate that this is due to a lack of gp130 expression on mouse and human granulocytes, despite their expression of membrane-bound IL-6R. Importantly, the absence of gp130 is not only a feature of mature granulocytes in healthy individuals, it is also observed after allogeneic stem cell transplantation. Moreover, granulocyte gp130 expression is lost during maturation, because granulocyte-monocyte progenitor cells express gp130 and respond to IL-6. Given that granulocytes constitute 50-70% of circulating leukocytes, this indicates a significantly smaller scope of IL-6 signaling than previously anticipated and has important implications for therapeutic IL-6 inhibition and the mechanisms of action thereof.

Eomesodermin promotes the development of type 1 regulatory T (TR1) cells.

Type 1 regulatory T (TR1) cells are Foxp3- interleukin-10 (IL-10)-producing CD4+ T cells with potent immunosuppressive properties, but their requirements for lineage development have remained elusive. We show that TR1 cells constitute the most abundant regulatory population after allogeneic bone marrow transplantation (BMT), express the transcription factor Eomesodermin (Eomes), and are critical for the prevention of graft-versus-host disease. We demonstrate that Eomes is required for TR1 cell differentiation, during which it acts in concert with the transcription factor B lymphocyte-induced maturation protein-1 (Blimp-1) by transcriptionally activating IL-10 expression and repressing differentiation into other T helper cell lineages. We further show that Eomes induction in TR1 cells requires T-bet and donor macrophage-derived IL-27. Thus, we define the cellular and transcriptional control of TR1 cell differentiation during BMT, opening new avenues to therapeutic manipulation.

Male-to-male sex among men who inject drugs in Delhi, India: overlapping HIV risk behaviours.

BACKGROUND: HIV among people who inject drugs (PWID) is a major public health challenge in India. This paper examines PWID in Delhi who also have male-to-male sex with a focus on overlapping HIV risk behaviours and the psychosocial correlates of a history of male-to-male anal sex. METHODS: We analysed data collected in April-May of 2012 from a community-based sample of 420 male PWID in Delhi obtained using time location sampling. RESULTS: One third (37%) of the men reported a history of anal sex with men, among whom just 16% used a condom at last anal sex. Almost all (93%) participants who had a history of anal sex with men also had sex with women. Chi-square tests revealed that a history of anal sex with men was associated with a higher number of female sexual partners and sharing of needles and syringes. Additionally, unprotected sex at last sex with a male partner was significantly associated with unprotected sex at last sex with regular and paid female partners. Multivariate binary logistic regression revealed that the psychosocial correlates of a history of anal sex with other men were: being aged 18-24 (OR = 2.4, p = 0.014), illiteracy (OR = 1.9, p = 0.033), having never been married (OR = 2.6, p = 0.007), a main source of income of crime/begging (OR = 3.1, p = 0.019), a duration of injecting drug use greater than 20 years (OR = 3.4, p = 0.035) and suicidal ideation (OR = 1.7, p = 0.048). CONCLUSION: Male-to-male sex was associated with psychosocial vulnerability, including a longer history of injecting drug use, suicidal ideation and socio-economic disadvantage. Given the extent of overlapping HIV risk behaviours, HIV programs for PWID would benefit from a strong focus on prevention of sexual HIV transmission, especially among male injectors who also have sex with other men.

Suicidal ideation and attempts among men who inject drugs in Delhi, India: psychological and social risk factors.

OBJECTIVE: Suicide is major public health problem in India. The objective of the analyses presented in this paper is to examine depressive and anxiety symptoms and socio-demographic indicators as correlates of suicidal ideation and attempts among people who inject drugs (PWID), a high-risk group for suicide. METHOD: We analysed data collected in April-May of 2012 from a community-based sample of 420 PWID in Delhi using time location sampling. Self-report symptom scales were used to measure the severity of symptoms of depression (PHQ-9) and anxiety (GAD-2) within the preceding 2 weeks. We assessed the presence of suicidal thoughts within the past 12 months. RESULTS: Depressive and anxiety symptoms were associated with suicidal ideation, as were a range of social stressors including poor physical health, length of injecting drug use, housing insecurity, and experiences of violence and sexual abuse. However, depressive and anxiety symptoms were not associated with suicide attempts. Factors associated with suicide attempts among ideators were housing insecurity and relational dynamics including a poor relationship with family and, interestingly, being married. CONCLUSION: Suicide prevention interventions among this population should address not only individual mental health and addiction support needs but also the overwhelmingly poor psychosocial circumstances of this group.

Association of depression, anxiety, and suicidal ideation with high-risk behaviors among men who inject drugs in Delhi, India.

BACKGROUND: Sharing of needles and syringes and unprotected sex remain a common practice among people who inject drugs (PWID) in India and are important drivers of new HIV infections. Whether engagement in risk behaviors among PWID is associated with symptoms of common mental disorders in India is unknown. METHODS: We analyzed the data collected in April and May of 2012 from a community-based sample of 420 PWID in Delhi using time location sampling. Self-report symptom scales were used to measure the severity of symptoms of depression (Patient Health Questionnaire 9) and anxiety (Generalized Anxiety Disorder scale 2) within the preceding 2 weeks. We assessed the presence of suicidal thoughts within the past 12 months. RESULTS: PWID with severe depressive symptoms and those with suicidal thoughts were 4 and 2 times more likely to share needles/syringes, respectively. PWID experiencing suicidal thoughts had 82% more female sexual partners and were 5 times more likely to have had unprotected sex at last sex with a paid female partner. Conversely, symptoms of anxiety were associated with a 30% decrease in the likelihood of needle/syringe sharing and a 70% decrease in the likelihood of unprotected sex at last sex with a paid female partner. CONCLUSIONS: We found a high prevalence of symptoms of depression, anxiety, and suicidal ideation among men who inject drugs in Delhi and that depression and suicidal ideation are independently positively associated with HIV risk behaviors, whereas anxiety is associated with a reduction in such behaviors. Ameliorating mental health problems among PWID in India may aid in reducing HIV infections.

Quality of life, depression, anxiety and suicidal ideation among men who inject drugs in Delhi, India.

BACKGROUND: Mental disorders such as depression, anxiety and suicide represent an important public health problem in India. Elsewhere in the world a high prevalence of symptoms of common mental disorders have been found among people who inject drugs (PWID). Research in India has largely overlooked symptoms of common mental disorders among this high risk group. This paper reports on the results of a survey examining quality of life, depression, anxiety and suicidal ideation among adult males who inject drugs living in Delhi. METHODS: Participants (n = 420) were recruited from needle and syringe programs using time location sampling and were interviewed using an interviewer-administered questionnaire. Self-report symptom scales were used to measure the severity of symptoms of depression (PHQ-9) and anxiety (GAD-2) within the preceding 2 weeks. We assessed the presence of suicidal thoughts and attempts within the past 12 months. RESULTS: The mean length of injecting career was 20.9 years indicating a sample of chronic injecting drug users, of whom only one-third (38%) were born in Delhi. The level of illiteracy was very high (62%), and just 2% had completed class 12. Scavenging / rag picking was the main form of income for 48%, and many were homeless (69%). One-third (33%) had been beaten up at least twice during the preceding 6 months, and many either never (45%) or rarely (27%) attended family events. We found a high prevalence of depressive (84%, cut-off ≥10) and anxiety (71%, cut-off score of ≥3) symptoms. Fifty-three percent thought about killing themselves in the past 12 months, and 36% had attempted to kill themselves. CONCLUSIONS: Our findings revealed a socially excluded population of PWID in Delhi who have minimal education and are often homeless, leaving them vulnerable to physical violence, poverty, poor health, imprisonment and disconnection from family. The high prevalence of psychological distress found in this study has implications for programmes seeking to engage, treat and rehabilitate PWID in India.

Suicidal ideation and HIV risk behaviors among a cohort of injecting drug users in New Delhi, India.

BACKGROUND: Data on mental health among injecting drug users in South Asia is scarce yet poor mental health among users has significant implications for the success of HIV prevention and treatment programmes. A cohort of 449 injecting drug users in Delhi was examined on the following issues (1) examine trends in suicidal ideation, suicide plan and suicidal attempts over a 12-month period, (2) examine association between injecting practices (receive and give used syringes) and suicidal ideation over a 12 month study period. METHODS: An observational study was conducted providing phased interventions with follow up interviews every 3 months to 449 injecting drug users (IDUs), from August 2004 to November 2005. The study was conducted in Yamuna Bazaar, a known hub of drug peddling in Delhi. Interventions included nutrition, basic medical services, needle exchange, health education, HIV voluntary counseling and testing, STI diagnosis and treatment, oral buprenorphine substitution, and detoxification, each introduced sequentially. RESULTS: Suicidal ideation and suicide attempts, did not significantly change over 12 months of observation, while suicide plans actually increased over the time period. Keeping other factors constant, IDUs with suicidal ideation reported more giving and receiving of used syringes in the recent past. CONCLUSIONS: Mental health services are warranted within harm reduction programmes. Special attention must be paid to suicidal IDUs given their higher risk behaviours for acquiring HIV and other blood borne infections. IDU intervention programmes should assess and address suicide risk through brief screening and enhanced counseling.

Prevalence of drug resistant tuberculosis among patients at high-risk for Hiv attending outpatient clinics in Delhi, India.

We sought to determine tuberculosis (TB) prevalence including multidrug resistant (MDR)-TB among a cohort of high risk patients at two directly observed treatment short course (DOTS) clinics in Delhi, India. We also aimed to compare the sensitivity of acid-fast bacilli (AFB) smear tests for patients with HIV using sputum cultures as the gold standard. A cross-section study was conducted among adult patients (> or = 18 years old) with prolonged cough (greater than two weeks), night sweats, fever, and/or weight loss suspected of pulmonary TB between February and March 2006. Sputum samples were obtained and processed for 165 patients; 53 (32.1%) were culture positive for TB. Patients with TB were predominantly male (92.1%), young (median age of 32 years), and the HIV-seroprevalence was high (41.5%). In the multivariable analysis adjusted for age, HIV infection was significantly associated (POR = 2.0, p < 0.05) with the presence of TB disease. Among Mycobacterium tuberculosis isolates recovered from 53 cases, 25 (47.2%) were resistant to > or = 1 first line anti-TB drugs and 7 (13.2%) were MDR-TB. The sensitivity of AFB smears among HIV negative and positive participants was 35.5% and 18.0%, respectively. Our findings demonstrated that the sensitivity of AFB smears to detect TB among HIV positive patients was low. Additionally, we found that even in regions where population drug resistance estimates are low, sentinel surveillance of MDR-TB in high-risk populations is useful to prioritize target groups in need of additional prevention, monitoring and health outreach.