Author Interviews, Dengue, Duke, Vaccine Studies / 21.09.2019

MedicalResearch.com Interview with: Dr Shee-Mei Lok, PhD Professor in the Emerging Infectious Disease program Duke-NUS, a school of National University of Singapore MedicalResearch.com: What is the background for this study? Response: Dengue virus consists of four different serotypes (DENV1-4) and within each serotypes, there are multiple strains. In terms of the viral particle shape, our previous research work using some laboratory adapted strains showed these DENV2 strains are very interesting in that it can change shape from the smooth spherical surface particles when grown at mosquito physiological temperature (29oC) and then becomes bumpy surfaced particles when incubated at human physiological temperature (37oC). This ability to transform into different virus surface structures helps the virus to escape from the immune system of the human host. Hence understanding the mechanism of how this occur is important for therapeutics and vaccine development. Here we also identified a laboratory adapted virus strain that do not showed this structural changes. We showed some differences in their amino acid sequences and We showed some differences in their amino acid sequences and mutating these residues coupled with observing their surface structures showed which residues are important for this temperature induced structural change. Results showed that subtle mutations at different places on the envelope protein can destabilize the virus allowing them to change in structure when temperature is elevated. Due to the poor selection pressure of the artificial laboratory tissue culture system, gradual mutations of the virus is accumulated causing the virus to have bumpy surface morphology. (more…)
Author Interviews, HIV, Microbiome, PLoS, Sexual Health / 16.04.2019

MedicalResearch.com Interview with: Brent E. Palmer, PhD Associate Professor of Medicine Director, ClinImmune and ACI/ID Flow Cytometry Facility Division of Allergy and Clinical Immunology University of Colorado Anschutz Medical College Aurora, Colorado 80045  MedicalResearch.com: What is the background for this study? What are the main findings?  Response: Previous studies showed that in western populations, men who have sex with men (MSM) have a distinct gut microbiome composition when compared with men who have sex with women (MSW). We wanted to understand how these microbiome differences in MSM could impact their immune system. To test this, we transferred feces from healthy MSW and MSM to gnotobiotic (germ-free) mice and examined the immune system in the mice post-transplant. In mice that received transfers from MSM, there were higher frequencies of activated T cells in gut tissues, which are the primary targets of HIV. This result suggested that gut microbes associated with MSM sexual behavior may actually contribute to HIV transmission by driving activation of HIV target cells. In fact, when we stimulated human gut derived cells with gut microbes isolated from MSM and MSW, cells that were stimulated with microbes from MSM were infected at a higher rate. (more…)