30 Aug 2016
ICI 2016 Dy 5: insight by Hyon-Xhi Tan
Day 5 of ICI 2016 started out with a series of in-depth talks on the current status of the Zika virus outbreak. This session began with Professor Jorge Kalil of the Butantan Institute speaking on recent Zika virus vaccine developments in Brazil, including the use of inactivated Zika virus and DNA vaccines as safe approaches for vaccination of pregnant women. He also touched on recent developments of studying the Zika virus as an add-on to an already rolled out Phase III trial for a Dengue virus vaccine with 17,000 participants recruited, which could highlight critical findings on the immunological interactions of the two related flaviviruses.
Professor Cameron Simmons of the Doherty Institute subsequently gave a comprehensive talk on the historical and contemporary epidemiological aspects of the Zika virus. Interventions using Wolbachia for the control of dengue virus was also described, specifically with efforts trialled in both Northern Australia and several countries in South East Asia. These results have so far shown significant efficacy in the reduction of dengue virus burden in Aedes aegypti mosquito populations and overall lower prevalence of dengue fever. It was suggested to be an effective strategy that could be used in efforts to combat the spread of the Zika virus.
The series of Zika-related talks was ended by Dr Giovanna Barba-Spaeth of the Institut Pasteur in Paris. In her talk, she presented strategies to induce cross-neutralising antibodies towards dengue and Zika viruses by use of specific E protein epitopes. Mechanistic binding of these antibodies was shown in detailed crystallography-based structures, which may lead to the development of more effective vaccines.
In the following symposium sessions, Dr Kylie Quinn from Monash University presented her findings on the age-related defects of CD8 T-cells. In her studies, she found that a T-virtual memory population was significantly enriched in aged mice. This population of CD8 T-cells displayed altered respiratory capacity, which resulted in a diminished ability of these cells to engage and eliminate target cells.
The lunchtime plenary lecture consisted of a presentation from Professor Michel Nussenzweig of The Rockefeller University, in which he described the current developments in HIV-1 vaccine strategies that seek to induce broadly neutralising antibodies. Serial vaccination with HIV-1 envelope antigens that contained specific modifications was shown to rapidly select for B-cells in mice that resulted in the production of broadly neutralising antibodies. Although impractical as a vaccine formulation, these studies highlight crucial understandings in B-cell biology and antibody-based vaccine approaches for HIV-1. Data from current human trials utilising passive infusion of 3BNC117 broadly neutralising antibody were also presented. In addition to the demonstrated safety in humans, these antibodies were also shown to elicit clearance of infected cells and enhanced host humoral immunity against HIV-1.
In the afternoon poster sessions, Josh Glass, a PhD candidate from the Kent Laboratory at the Doherty Institute presented models developed for the prediction of bio-nano interactions in primary human blood samples. Using these standardised models, he demonstrated properties of nanoparticles that can significantly influence immune activation and leukocyte uptake. These findings could benefit in the rational design of novel nano-medicines.
In the closing plenary sessions, University of Pavia, Professor Antonio Lanzavecchia presented fascinating findings in the mechanism of diversification for broadly neutralising antibodies. One such mechanism presented was an unusual DNA transposition event facilitating the fusion of heterologous protein domains onto antibody structures in malaria-infected patients. These findings demonstrate a novel pathway for the generation of antibodies with highly unusual structures that have enhanced binding onto target pathogens, and may be used in contemporary approaches for the design of effective antibody-based vaccines.
The entire conference was concluded with a closing ceremony chaired by Professor José Villadangos, who was also the President of the 16th International Congress of Immunology Organising Committee. In his speech, he acknowledged and celebrated the “wonderful six days of science” that brought together world-class immunologists to the heart of Melbourne. Immunologists will look forward to the next International Congress of Immunology to be held in Beijing, China in 2019. Congratulations to the organising committee on a smooth and successful ICI 2016 conference!