Pretransplant rinse of hearts preserved with colloid-free UW solution and more effective heart preservation: studies in a rat abdominal heart transplant model

A spontaneous multifunctional hydrogel vaccine amplifies the innate immune response to launch a powerful antitumor adaptive immune response

Substantial progress has been made with cancer immunotherapeutic strategies in recent years, most of which mainly rely on enhancing the T cell response. However, sufficient tumor antigen information often cannot be presented to T cells, resulting in a failed effector T cell response. The innate immune system can effectively recognize tumor antigens and then initiate an adaptive immune response. Here, we developed a spontaneous multifunctional hydrogel (NOCC-CpG/OX-M, Ncom Gel) vaccine to amplify the innate immune response and harness innate immunity to launch and maintain a powerful adaptive immune response. Methods: Ncom Gel was formed by a Schiff base reaction between CpG-modified carboxymethyl chitosan (NOCC-CpG) and partially oxidized mannan (OX-M). The effects of the Ncom Gel vaccine on DCs and macrophages in vitro and antigen-specific humoral immunity and cellular immunity in vivo were studied. Furthermore, the antitumor immune response of the Ncom Gel vaccine and its effect on the tumor microenvironment were evaluated. Results: The Ncom Gel vaccine enhanced antigen presentation to T cells by facilitating DC uptake and maturation and inducing macrophages to a proinflammatory subtype, further leading to a T cell-mediated adaptive immune response. Moreover, the innate immune response could be amplified via the promotion of antigen-specific antibody production. The Ncom Gel vaccine reversed the tumor immune microenvironment to an inflamed phenotype and showed a significant antitumor response in a melanoma model. Conclusions: Our research implies the potential application of injectable hydrogels as a platform for tumor immunotherapy. The strategy also opens up a new avenue for multilayered cancer immunotherapy.

Inhibition of arterial allograft intimal hyperplasia using recipient dendritic cells pretreated with B7 antisense peptide

Background. Low expression or absence of dendritic cell (DC) surface B7 molecules can induce immune tolerance or hyporesponse. Whether DCs could induce indirect allogeneic-specific cross-tolerance or hyporesponse to recipient T cells remains unclear. Methods. Generated from C3H/He mice bone marrow cells pulsed with donor antigen from C57BL/6 mice, recipient DCs were incubated with B7 antisense peptide (B7AP). Immune regulatory activities were examined in vitro by a series of mixed lymphocyte reactions. Murine allogeneic carotid artery orthotopic transplantation was performed from C57BL/6 to C3H/He. Recipients were given B7AP-treated DCs 7 days before transplantation. Allograft pathological analysis was done 2 months after transplantation. Results. B7AP-pretreated DCs markedly inhibited T-cell proliferation compared with untreated group. Pretreated T cells exhibited markedly reduced response to alloantigen versus third-party antigen. Pathological analysis of arterial allografts demonstrated significant reduction of intimal hyperplasia in B7-AP pretreated group versus control. Conclusion. Blockade of B7 molecules by B7AP could induce indirect allogeneic-specific hyporesponse and inhibit arterial allograft intimal hyperplasia, which may be involved in future strategies for human allograft chronic rejection.