ASTMH 2016, Joao Aguiar: “Immunomechanism of protection for E140, a pre-erythrocytic vaccine candidate”

In collaboration with ASTMH, Image Audiovisuals, and session presenters, MESA brings you this webcast from the 65th ASTMH annual meeting in Atlanta, November 2016.

Title: “Immunomechanism of protection for E140, a pre-erythrocytic vaccine candidate”

Speaker: Joao Aguiar, Camris International, Bethesda, USA (replacement speaker for Emily Smith, Henry M. Jackson Foundation, USA)

Session information: Scientific Session 34: Malaria: Vaccines – Diverse Approaches

Monday, 14 November, 1:45 – 3:30pm, Marriott – Marquis C

Abstract:

A malaria vaccine to prevent infection is greatly needed and essential for a comprehensive malaria eradication program. Pre-erythrocytic (PE) antigens are capable of inducing an immune response resulting in sterile protection, as shown by the RTS,S vaccine. Plasmodium falciparum PE antigens are also targeted by efficacious whole sporozoite vaccines and could be the basis of a subunit vaccine. We have identified a single PE P. yoelii antigen (E140) capable of sterilely protecting CD1 mice in the range of 71% to 100%, alone and in combination with other antigens, respectively. Initial examination of E140-specific immune responses showed significant CD4+ and CD8+ T cell responses upon DNA-prime/Ad5-boost immunization. We also observed an antibody response that statistically correlated with sterile protection. We have further characterized the T cell responses to E140 immunization evaluating the function of CD4+ and CD8+ T cells, including IFN-gamma, TNF, IL-2, and MIP1alpha. In vivo T cell depletion experiments in mice are being conducted to ascertain the requirement of these cell types for protection. We are also conducting concomitant antibody transfer studies in mice to establish the role of anti-E140 antibodies to protection. These promising data are evidence of the potential of E140 and support further development of the P. falciparum E140 ortholog in a subunit malaria vaccine.