Systemic administration of the integrin activator 7HP349 as a vaccine adjuvant significantly improved control of parasite burden and tissue fibrosis in a mouse model of Chagas disease.
Does systemic administration of 7HP349 enhance vaccine efficacy against T. cruzi infection in a mouse model of Chagas disease?
Systemic administration of the integrin activator 7HP349 enhances T cell-mediated immune responses and improves the efficacy of a DNA vaccine in a mouse model of Chagas disease.
Abstract The development of suitable safe adjuvants to enhance appropriate antigen-driven immune responses remains a challenge. Here we describe the adjuvant properties of a small molecule activator of the integrins αLβ2 and α4β1, named 7HP349, which can be safely delivered systemically independent of antigen. 7HP349 directly activates integrin cell adhesion receptors crucial for the generation of an immune response. When delivered systemically in a model of Chagas disease following immunization with a DNA subunit vaccine encoding candidate T. cruzi antigens, TcG2 and TcG4, 7HP349 enhanced the vaccine efficacy in both prophylactic and therapeutic settings. In a prophylactic setting, mice immunized with 7HP349 adjuvanted vaccine exhibited significantly improved control of acute parasite burden in cardiac and skeletal muscle as compared to vaccination alone. When administered with vaccine therapeutically, parasite burden was again decreased, with the greatest adjuvant effect of 7HP349 being noted in skeletal muscle. In both settings, adjuvantation with 7HP349 was effective in decreasing pathological inflammatory infiltrate, improving the integrity of tissue, and controlling tissue fibrosis in the heart and skeletal muscle of acutely and chronically infected Chagas mice. The positive effects correlated with increased splenic frequencies of CD8 + T effector cells and an increase in the production of IFN-γ and cytolytic molecules (perforin and granzyme) by the CD4 + and CD8 + effector and central memory subsets in response to challenge infection. This demonstrates that 7HP349 can serve as a systemically administered adjuvant to enhance T cell-mediated immune responses to vaccines. This approach could be applied to numerous vaccines with no reformulation of existing stockpiles.
Lokugamage et al. (Wed,) conducted a other in Chagas disease. 7HP349 (integrin activator) as a vaccine adjuvant vs. Vaccination alone was evaluated on Parasite burden in cardiac and skeletal muscle. Systemic administration of the integrin activator 7HP349 as a vaccine adjuvant significantly improved control of parasite burden and tissue fibrosis in a mouse model of Chagas disease.