A non-stick coating for a substance found in semen dramatically lowers the rate of infection of immune cells by HIV a new study has found.

The new material is a potential ingredient for microbicides designed to reduce transmission of HIV, a team from the University of Rochester Medical Center and the University of California, San Diego reports in a forthcoming issue of the Journal of Biological Chemistry.

The coating clings to fibrous strings and mats of protein called SEVI – for semen-derived enhancer of viral infection – which was first discovered just three years ago. SEVI seems to attract the virus and deposit it onto the surface of T-cells, components of the immune system that are the primary target of HIV infection, and may play an important role in sexual transmission of HIV.

Like the fibrous strings that bind senile plaques associated with Alzheimer’s disease, SEVI is a kind of protein superstructure called an amyloid.

Jerry Yang, associate professor of chemistry at UC San Diego and his research group developed non-stick coatings for amyloids as a potential treatment for Alzheimer’s disease in 2006. Their idea was to minimize damage by preventing amyloid proteins from interacting with other molecules in the brain.

When this new amyloid, SEVI, was discovered in 2007, Yang was interested in testing whether the coating strategy might interfere with SEVI’s role in promoting HIV infection.

Yang’s group teamed up with a researchers led by Stephen Dewhurst, chair of the microbiology and immunology department at the University of Rochester Medical Center, who studies HIV.

“We tested one of our molecules out on SEVI and found it was able to stop SEVI-enhanced infection of HIV in cells,” Yang said. “It works in semen too. Something in semen enhances viral infection – SEVI and maybe other things. This molecule stops that.”

When the researchers added the molecule that forms non-stick coatings to a mix of SEVI, virus and cells, rates of infection dropped to levels observed when SEVI was absent. They saw a similar effect with semen as well, evidence that this potential microbicide supplement works to inhibit infection within a mixture of proteins and other molecules found in seminal fluid.

The coating molecule is a modified form of thioflavin-T, a dye that stains amyloid proteins. It fits in between the individual small proteins that cluster to form SEVI and blocks SEVI’s interactions with both the virus and the target immune cells.

“Other people have tried to do the same thing by targeting the virus or the cells it infects. What we do is target the mediator between the virus and the cells,” Yang said. “By neutralizing SEVI, we prevent at least one way for HIV to attach to the cells.”

The new molecule has another advantage. Unlike many current microbicide candidates aimed at reducing HIV infection, this one doesn’t cause inflammation in cervical cells.

“Recent studies have shown for the first time that a topical microbicide gel can protect women from HIV-1 infection. This is a huge step forward but not a perfect solution. We need to figure out ways to further improve protection – and our studies suggest one way of doing so,” said Dewhurst, who is the corresponding author of the report. “It may be possible to produce a next-generation microbicide that includes both an antiviral agent, as has been used in the past, and an agent that targets SEVI. We’re very excited about exploring this idea.”

The National Institutes of Health and the National Science Foundation funded this work.

Additional co-authors include Joanna Olsen, Caitlin Brown, Todd Doran, Rajesh Srivastava, Changyong Feng and Bradley Nilsson of the University of Rochester, and Christina Capule and Mark Rubinshtein of the University of California, San Diego.

Source: University of California — San Diego
via MedicalNewsToday

Nonstick Coating Of A Protein Found In Semen Reduces HIV Infection, Nursing Resource Admin

Increasing rate of HIV/STD disease is being reported among ‘men who have sex with men’ with high risk behaviors in Africa and Asia, according to a groundbreaking paper in the April issue of Sexually Transmitted Diseases, official journal of the American Sexually Transmitted Diseases Association. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health, a leading provider of information and business intelligence for students, professionals, and institutions in medicine, nursing, allied health, and pharmacy.

The epidemic of HIV/STD in men who have sex with men (MSM) has been perceived as a public health problem occurring mainly in the Western world. However, three articles in the April issue of the Journal of Sexually Transmitted Diseases, highlight the fact that increasing HIV/STD disease is being reported in MSM with high risk behaviors in Africa and Asia.

In one article, Dr. Yang and colleagues address the associated factors and increasing spread of HIV among MSM in Nanjing, China. Using respondent-driven sampling methods, he reported an HIV incidence rate of 5.12 cases per 100 person years. In a commentary, Dr. Chen et. al. summarize the rapid increase of HIV and syphilis infections among MSM in China which they consider could lead to a potential pandemic in the country. They stress that in recent years, China has considered “MSM as a priority population for HIV prevention and control.”

An editorial by Dr. Mayer and his colleagues points out that MSM exists in all populations. They stress that the simple compartmentalization of the HIV epidemic into one that affects MSM in industrialized countries and is a heterosexual epidemic in developing or less developed countries is not valid. They document the high prevalence of HIV/STD in some MSM populations in Africa and Asia, and emphasize the need to act now to prevent the massive spread of disease. Certainly an epidemic of HIV in MSM can help drive an epidemic among heterosexuals.

That HIV/STD disease transmission in MSM is often hidden in resource poor countries, which may reflect failure of public health programs, or homophobia that stigmatizes MSM behaviors and inhibits MSM seeking medical care. The new research reported in three scholarly articles in the April issue of Sexually Transmitted Diseases demonstrate that MSM high risk behaviors are global and should be acknowledged, so HIV/STD control and prevention programs can be made available for this population. Comprehensive prevention programs for HIV/STD in MSM are necessary to help control spread. Concealing or denying this behavior simply leads to more disease.

Source
MedicalNewsToday

High Rate Of HIV Among Men Who Have Sex With Men In China, Nursing Resource Admin