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We demonstrated that γδ T cells of patients given HLA-haploidentical HSCT after removal of αβ+T cells and CD19+B cells are endowed with the capacity of killing leukemia cells afterex vivotreatment with zoledronic acid (ZOL). Thus, we tested the hypothesis that infusion of ZOL in patients receiving this type of graft may enhance γδ T-cell cytotoxic activity against leukemia cells. ZOL was infused every 28 d in 43 patients; most were treated at least twice. γδ T cells before and after ZOL treatments were studied in 33 of these 43 patients, till at least 7 mo after HSCT by high-resolution mass spectrometry, flow-cytometry, and degranulation assay. An induction of Vδ2-cell differentiation, paralleled by increased cytotoxicity of both Vδ1 and Vδ2 cells against primary leukemia blasts was associated with ZOL treatment. Cytotoxic activity was further increased in Vδ2 cells, but not in Vδ1 lymphocytes in those patients given more than one treatment. Proteomic analysis of γδ T cells purified from patients showed upregulation of proteins involved in activation processes and immune response, paralleled by downregulation of proteins involved in proliferation. Moreover, a proteomic signature was identified for each ZOL treatment. Patients given three or more ZOL infusions had a better probability of survival in comparison to those given one or two treatments (86% vs. 54%, respectively,p= 0.008). Our data indicate that ZOL infusion in pediatric recipients of αβ T- and B-cell-depleted HLA-haploidentical HSCT promotes γδ T-cell differentiation and cytotoxicity and may influence the outcome of patients. [ABSTRACT FROM AUTHOR]

In αβ T-cell/CD19 B-cell depleted hematopoietic stem cell transplantation (αβhaplo-HSCT) recipients, antithymocyte globulin (ATG; Thymoglobulin) is used for preventing graft rejection and graft-versus-host disease (GVHD). The optimal dosing remains to be established, however. Here we present the first comparative analysis of 3 different ATG dosing strategies and their impact on immune reconstitution and GVHD. Our study aimed to evaluate the effects of 3 distinct dosing strategies of ATG on engraftment success, αβ + and γδ + T cell immune reconstitution, and the incidence and severity of acute GVHD in recipients of αβhaplo-HSCT. This comparative analysis included 3 cohorts of pediatric patients with malignant (n = 36) or nonmalignant (n = 8) disease. Cohorts 1 and 2 were given fixed ATG doses, whereas cohort 3 received doses via a new nomogram, based on absolute lymphocyte count (ALC) and body weight (BW). Cohort 3 showed a 0% incidence of day 100 grade II-IV acute GVHD, compared to 48% in cohort 1 and 27% in cohort 2. Furthermore, cohort 3 (the ALC/BW-based cohort) had a significant increase in CD4 + and CD8 + naïve T cells by day 90 (P = .04 and .03, respectively). Additionally, we found that the reconstitution and maturation of γδ + T cells post-HSCT was not impacted across all 3 cohorts. Cumulative ATG exposure in all cohorts was lower than previously reported in T cell-replete settings, with a lower pre-HSCT exposure (<40 AU*day/mL) correlating with engraftment failure (P = .007). Conversely, a post-HSCT ATG exposure of 10 to 15 AU*day/mL was optimal for improving day 100 CD4 + (P = .058) and CD8 + (P = .03) immune reconstitution without increasing the risk of relapse or nonrelapse mortality. This study represents the first comparative analysis of ATG exposure in αβhaplo-HSCT recipients. Our findings indicate that (1) a 1- to 2-fold ATG to ATLG bioequivalence is more effective than previously established standards, and (2) ATG exposure post-HSCT does not adversely affect γδ + T cell immune reconstitution. Furthermore, a model-based ATG dosing strategy effectively reduces graft rejection and day 100 acute GVHD while also promoting early CD4 + /CD8 + immune reconstitution. These insights suggest that further optimization, including more distal administration of higher ATG doses within an ALC/BW-based strategy, will yield even greater improvements in outcomes., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Abstract: Despite therapeutic advancements, graft-versus-host disease (GVHD) is a major complication of hematopoietic stem cell transplantation (HSCT). In current models of GVHD, tissue injury induced by cytotoxic conditioning regimens, along with translocation of microbes expressing pathogen-associated molecular patterns, result in activation of host antigen-presenting cells (APCs) to stimulate alloreactive donor T lymphocytes. Recent studies have demonstrated that in many pathologic states, tissue injury results in the release of mitochondria from the cytoplasm to the extracellular space. We hypothesized that extracellular mitochondria, which are related to archaebacteria, could also trigger GVHD by stimulation of host APCs. We found that clinically relevant doses of radiation or busulfan induced extracellular release of mitochondria by various cell types, including cultured intestinal epithelial cells. Conditioning-mediated mitochondrial release was associated with mitochondrial damage and impaired quality control but did not affect the viability of the cells. Extracellular mitochondria directly stimulated host APCs to express higher levels of major histocompatibility complex II (MHC-II), costimulatory CD86, and proinflammatory cytokines, resulting in increased donor T-cell activation, and proliferation in mixed lymphocyte reactions. Analyses of plasma from both experimental mice and a cohort of children undergoing HSCT demonstrated that conditioning induced extracellular mitochondrial release in vivo. In mice undergoing MHC-mismatched HSCT, administration of purified syngeneic extracellular mitochondria increased host APC activation and exacerbated GVHD. Our data suggest that pre-HSCT conditioning results in extracellular release of damaged mitochondria, which increase alloreactivity and exacerbate GVHD. Therefore, decreasing the extracellular release of damaged mitochondria after conditioning could serve as a novel strategy for GVHD prevention., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Lifelong immunosuppression is required for allograft survival after kidney transplantation but may not ultimately prevent allograft loss resulting from chronic rejection. We developed an approach that attempts to abrogate immune rejection and the need for post-transplantation immunosuppression in three patients with Schimke immuno-osseous dysplasia who had both T-cell immunodeficiency and renal failure. Each patient received sequential transplants of αβ T-cell-depleted and CD19 B-cell-depleted haploidentical hematopoietic stem cells and a kidney from the same donor. Full donor hematopoietic chimerism and functional ex vivo T-cell tolerance was achieved, and the patients continued to have normal renal function without immunosuppression at 22 to 34 months after kidney transplantation. (Funded by the Kruzn for a Kure Foundation.)., (Copyright © 2022 Massachusetts Medical Society.)

γδ T cells have recently gained considerable attention as an attractive tool for cancer adoptive immunotherapy due to their potent anti-tumor activity and unique role in immunosurveillance. The remarkable success of engineered T cells for the treatment of hematological malignancies has revolutionized the field of adoptive cell immunotherapy. Accordingly, major efforts are underway to translate this exciting technology to the treatment of solid tumors and the development of allogeneic therapies. The unique features of γδ T cells, including their major histocompatibility complex (MHC)-independent anti-cancer activity, tissue tropism, and multivalent response against a broad spectrum of the tumors, render them ideal for designing universal 'third-party' cell products, with the potential to overcome the challenges of allogeneic cell therapy. In this review, we describe the crucial role of γδ T cells in anti-tumor immunosurveillance and we summarize the different approaches used for the ex vivo and in vivo expansion of γδ T cells suitable for the development of novel strategies for cancer therapy. We further discuss the different transduction strategies aiming at redirecting or improving the function of γδ T cells, as well as, the considerations for the clinical applications.

Prostate Cancer (PCa)-related deaths are mostly due to metastasization of poorly differentiated adenocarcinomas often endowed with neuroendocrine differentiation (NED) areas.The SNAI2/Slug gene is a major regulator of cell migration and tumor metastasization. We here assessed its biological significance in NED, and metastatic potential of PCa.SNAI2 expression was down-regulated in most PCa epithelia, in association with gene promoter methylation, except for cell clusters forming: a. the expansion/invasion front of high-grade PCa, b. NED areas, or c. lymph node metastasis.Knockdown of SNAI2 in PC3 cells down-regulated the expression of neural-tissue-associated adhesion molecules, Neural-Cadherin, Neural-Cadherin-2, Neuronal-Cell-Adhesion-Molecule, and of the NED marker Neuron-Specific Enolase, whereas it abolished Chromogranin-A expression. The metastasis-suppressor genes, Nm23-H1 and KISS1, were up-regulated, while the pluripotency genes SOX2, NOTCH1, CD44v6, WWTR1/TAZ and YAP1 were dramatically down-regulated. Over-expression of SNAI2 in DU145 cells substantiated its ability to regulate metastasis-suppressor, NED and pluripotency genes. In PCa and lymph node metastasis, expression of SOX2 and NOTCH1 was highly related to that of SNAI2.In conclusion, I. SNAI2 silencing in PCa may turn-off the expression of NED markers and pluripotency genes, while turning-on that of specific metastasis-suppressors, II. SNAI2 expression in selected PCa cells, by regulating their self-renewal, NED and metastatic potential, endows them with highly malignant properties. SNAI2 may thus constitute a key target for modern approaches to PCa progression.

We prospectively assessed functional and phenotypic characteristics of γδ T lymphocytes up to 7 months after HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) depleted of αβ(+) T cells and CD19(+) B cells in 27 children with either malignant or nonmalignant disorders. We demonstrate that (1) γδ T cells are the predominant T-cell population in patients during the first weeks after transplantation, being mainly, albeit not only, derived from cells infused with the graft and expanding in vivo; (2) central-memory cells predominated very early posttransplantation for both Vδ1 and Vδ2 subsets; (3) Vδ1 cells are specifically expanded in patients experiencing cytomegalovirus reactivation and are more cytotoxic compared with those of children who did not experience reactivation; (4) these subsets display a cytotoxic phenotype and degranulate when challenged with primary acute myeloid and lymphoid leukemia blasts; and (5) Vδ2 cells are expanded in vitro after exposure to zoledronic acid (ZOL) and efficiently lyse primary lymphoid and myeloid blasts. This is the first detailed characterization of γδ T cells emerging in peripheral blood of children after CD19(+) B-cell and αβ(+) T-cell-depleted haplo-HSCT. Our results can be instrumental to the development of clinical trials using ZOL for improving γδ T-cell killing capacity against leukemia cells. This trial was registered at www.clinicaltrials.gov as #NCT01810120., (© 2015 by The American Society of Hematology.)

Current therapies for Non-Small Cell Lung Cancer (NSCLC) still fail to significantly increase its survival rate. Here we asked whether Interleukin(IL)-27, which has revealed powerful antitumor activity and is toxicity-free in humans, is a promising therapeutic choice for NSCLC patients. IL-27's effects were tested on Adenocarcinoma (AC) and Squamous Cell Carcinoma (SCC) cell lines and xenograft models. IL-27Receptor(R) expression was assessed in lung tissues from 78 NSCLC patients. In vitro, IL-27 was ineffective on cancer cell proliferation or apoptosis, but fostered CXCL3/GROγ/MIP2β expression. In vitro and in vivo, IL-27 down-regulated stemness-related genes, namely SONIC HEDGEHOG in AC cells, and OCT4A, SOX2, NOTCH1, KLF4 along with Nestin, SNAI1/SNAIL, SNAI2/SLUG and ZEB1, in SCC cells. In vivo, IL-27 hampered both AC and SCC tumor growth in association with a prominent granulocyte- and macrophage-driven colliquative necrosis, CXCL3 production, and a reduced pluripotency- and EMT-related gene expression. Myeloablation of tumor-bearing hosts mostly abolished IL-27's antitumor effects. In clinical samples, IL-27R expression was found in AC, SCC, pre-cancerous lesions and tumor infiltrating myeloid cells, and correlated with advanced stages of disease. Our data suggest that even immunocompromised or advancer NSCLC patients may benefit from IL-27's antitumor properties based on its ability to drive myeloid cells towards antitumor activities, and down-regulate stemness- and EMT-related genes in cancer cells.

Myelin sheath is a lipid-rich membrane, consisting of 70% lipid and 30% proteins, that is involved in physiological and pathological processes. For this reason its protein composition has been often investigated, principally by two-dimensional electrophoresis; however, the consistent lipid content makes it difficult to obtain good proteins separation. To improve the resolution of myelin proteins in a denaturing monodimensional gel electrophoresis, we examined several mixtures for the denaturation of the sample, utilizing different detergents and reducing agents. The definition of the protein pattern was analyzed by both "Blue Silver" Coomassie staining and Western Blot analysis against myelin basic protein, one of the most represented myelin proteins. The best resolution is observed when the sample was incubated with a mixture containing 1.25% dithiothreitol, 4 M urea, and 1% dodecyl maltoside or 1 % 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate, prior to addition of denaturing agents. In conclusion, this work describes a novel method to improve the separation of myelin proteins in a monodimensional gel electrophoresis. It may be also useful for investigating other lipid-rich samples.