RESUMO
To circumvent donor-to-donor heterogeneity which may lead to inconsistent results after treatment of acute graft-versus-host disease with mesenchymal stromal cells generated from single donors we developed a novel approach by generating these cells from pooled bone marrow mononuclear cells of 8 healthy "3(rd)-party" donors. Generated cells were frozen in 209 vials and designated as mesenchymal stromal cell bank. These vials served as a source for generation of clinical grade mesenchymal stromal cell end-products, which exhibited typical mesenchymal stromal cell phenotype, trilineage differentiation potential and at later passages expressed replicative senescence-related markers (p21 and p16). Genetic analysis demonstrated their genomic stability (normal karyotype and a diploid pattern). Importantly, clinical end-products exerted a significantly higher allosuppressive potential than the mean allosuppressive potential of mesenchymal stromal cells generated from the same donors individually. Administration of 81 mesenchymal stromal cell end-products to 26 patients with severe steroid-resistant acute graft-versus-host disease in 7 stem cell transplant centers who were refractory to many lines of treatment, induced a 77% overall response at the primary end point (day 28). Remarkably, although the cohort of patients was highly challenging (96% grade III/IV and only 4% grade II graft-versus-host disease), after treatment with mesenchymal stromal cell end-products the overall survival rate at two years follow up was 71±11% for the entire patient cohort, compared to 51.4±9.0% in graft-versus-host disease clinical studies, in which mesenchymal stromal cells were derived from single donors. Mesenchymal stromal cell end-products may, therefore, provide a novel therapeutic tool for the effective treatment of severe acute graft-versus-host disease.
Assuntos
Doença Enxerto-Hospedeiro/diagnóstico , Doença Enxerto-Hospedeiro/terapia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Doadores de Tecidos , Adolescente , Adulto , Células da Medula Óssea , Técnicas de Cultura de Células , Diferenciação Celular , Proliferação de Células , Criança , Pré-Escolar , Resistência a Medicamentos , Feminino , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/mortalidade , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Terapia de Imunossupressão , Lactente , Masculino , Células-Tronco Mesenquimais/citologia , Pessoa de Meia-Idade , Prognóstico , Índice de Gravidade de Doença , Esteroides/uso terapêutico , Análise de Sobrevida , Resultado do Tratamento , Adulto JovemRESUMO
Chimeric antigen receptor (CAR) T cells are efficacious in patients with B-cell malignancies, while their activity is limited in patients with solid tumors. We developed a novel heterodimeric TCR-like CAR (TCAR) designed to achieve optimal chain pairing and integration into the T-cell CD3 signaling complex. The TCAR mediated high antigen sensitivity and potent antigen-specific T-cell effector functions in short-term in vitro assays. Both persistence and functionality of TCAR T cells were augmented by provision of costimulatory signals, which improved proliferation in vitro and in vivo. Combination with a nanoparticulate RNA vaccine, developed for in vivo expansion of CAR T cells, promoted tightly controlled expansion, survival, and antitumor efficacy of TCAR T cells in vivo. Significance: A novel TCAR is tightly controlled by RNA vaccine-mediated costimulation and may provide an alternative to second-generation CARs for the treatment of solid tumors.
Assuntos
Imunoterapia Adotiva , Neoplasias , Vacinas de mRNA , Humanos , Linfócitos T , Receptores de Antígenos Quiméricos , Complexo CD3 , Proliferação de Células , Vacinas de mRNA/imunologia , Neoplasias/terapia , Vacinas Anticâncer/uso terapêutico , Animais , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Feminino , Linhagem Celular Tumoral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Chimeric antigen receptor (CAR)-T cells have shown efficacy in patients with B cell malignancies. Yet, their application for solid tumors has challenges that include limited cancer-specific targets and nonpersistence of adoptively transferred CAR-T cells. Here, we introduce the developmentally regulated tight junction protein claudin 6 (CLDN6) as a CAR target in solid tumors and a strategy to overcome inefficient CAR-T cell stimulation in vivo. We demonstrate that a nanoparticulate RNA vaccine, designed for body-wide delivery of the CAR antigen into lymphoid compartments, stimulates adoptively transferred CAR-T cells. Presentation of the natively folded target on resident antigen-presenting cells promotes cognate and selective expansion of CAR-T cells. Improved engraftment of CAR-T cells and regression of large tumors in difficult-to-treat mouse models was achieved at subtherapeutic CAR-T cell doses.