In vivo IL-4 prevents allo-antigen driven CD8+ CTL development

Donor Treg expansion by liposomal α-galactosylceramide modulates Tfh cells and prevents sclerodermatous chronic graft-versus-host disease

Background and Aim

Chronic graft‐versus‐host disease (cGVHD) is a major cause of nonrelapse morbidity and mortality following hematopoietic stem cell transplantation (HSCT). α‐Galactosylceramide (α‐GC) is a synthetic glycolipid that is recognized by the invariant T‐cell receptor of invariant natural killer T (iNKT) cells in a CD1d‐restricted manner. Stimulation of iNKT cells by α‐GC leads to the production of not only immune‐stimulatory cytokines but also immune‐regulatory cytokines followed by regulatory T‐cell (Treg) expansion in vivo.

Methods

We investigated the effect of iNKT stimulation by liposomal α‐GC just after transplant on the subsequent immune reconstitution and the development of sclerodermatous cGVHD.

Results

Our study showed that multiple administrations of liposomal α‐GC modulated both host‐ and donor‐derived iNKT cell homeostasis and induced an early expansion of donor Tregs. We also demonstrated that the immune modulation of the acute phase was followed by the decreased levels of CXCL13 in plasma and follicular helper T cells in lymph nodes, which inhibited germinal center formation, resulting in the efficient prevention of sclerodermatous cGVHD.

Conclusions

These data demonstrated an important coordination of T‐ and B‐cell immunity in the pathogenesis of cGVHD and may provide a novel clinical strategy for the induction of immune tolerance after allogeneic HSCT.

Helper T cell-dominant tertiary lymphoid structures are associated with disease relapse of advanced colorectal cancer

Tertiary lymphoid structures (TLSs), clusters of immune cells found around tumor tissue, have been shown to be associated with anti-tumor immunity, but the cellular composition within each TLS and whether the cellular composition of a TLS affects a patient’s prognosis are poorly understood. In the present study, each TLS was categorized according to its cellular composition determined by a system of multiplex immunohistochemical staining and quantitative analysis, and the correlation between the category and prognosis was examined. Sixty-seven patients with curatively resected stage II/III colorectal cancer (CRC) were enrolled. A TLS, consisting of germinal center B cells, follicular dendritic cells, T helper (Th) cells, B cells, cytotoxic T cells, and macrophages, was confirmed in the tumor tissue of 58 patients (87%). The densities of Th cells and macrophages were significantly higher in relapsed patients than in not-relapsed patients (p = .043 and p = .0076). A higher ratio of Th cells was the most significant independent risk factor for disease relapse on multivariate analysis. The subset increasing in Th cells was GATA3⁺ Th2. A total of 353 TLSs was divided into five clusters according to immune cell composition. Among them, the Th-rich type TLS was significantly increased (p = .0009) in relapsed patients. These data suggest the possibility that Th cell-dominant composition might disturb the anti-tumor immune response, and the function of each TLS might differ depending on its composition.

In Vivo MR Imaging of Glioma Recruitment of Adoptive T-Cells Labeled with NaGdF4 -TAT Nanoprobes

Adoptive T lymphocyte immunotherapy is one of the most promising methods to treat residual lesions after glioma surgery. However, the fate of the adoptively transferred T-cells in vivo is unclear, hampering the understanding of this emerging therapy. Thus, it is highly desirable to develop noninvasive and quantitative in vivo tracking of these T-cells to glioma for better identification of the migratory fate and to provide objective evaluation of outcomes of adoptive T-cell immunotherapy targeting glioma. In this work, ultrasmall T₁ MR-based nanoprobes, NaGdF₄ -TAT, as molecular probes with high longitudinal relaxivity (8.93 mm^-1 s^-1 ) are designed. By means of HIV-1 transactivator (TAT) peptides, nearly 95% of the adoptive T-cells are labeled with the NaGdF₄ -TAT nanoprobes without any measurable side effects on the labeled T-cells, which is remarkably superior to that of the control fluorescein isothiocyanate-NaGdF₄ concerning labeling efficacy. Labeled adoptive T-cell clusters can be sensitively tracked in an orthotopic GL261-glioma model 24 h after intravenous infusion of 10⁷ labeled T-cells by T₁ -weighted MR imaging. Both in vitro and in vivo experiments show that the NaGdF₄ -TAT nanoprobes labeling of T-cells may be a promising method to track adoptive T-cells to improve our understanding of the pathophysiology in adoptive immunotherapy for gliomas.

Selection of PD1/PD-L1 X-Aptamers

Specific, chemically modified aptamers (X-Aptamers) were identified against two immune checkpoint proteins, recombinant Programmed Death 1 (PD-1) and Programmed Death Ligand 1 (PD-L1). Selections were performed using a bead-based X-Aptamer (XA) library containing several different amino acid functional groups attached to dU at the 5-position. The binding affinities and specificities of the selected XA-PD1 and XA-PDL1 were validated by hPD-1 and hPD-L1 expression cells, as well as by binding to human pancreatic ductal adenocarcinoma tissue. The selected PD1 and PDL1 XAs can mimic antibody functions in in vitro assays.