Scientists found New Class of Antibodies Protects against HIV-1 Infection

A group scientists at Texas Biomedical research institute led by Dr.Ruth Ruprecht, they have zeroed in on a new defense against HIV-1 (virus that cause AIDS). They Treated an Animal with an Immunoglobulin M (IgM) for the first time.

90 Percentage of new cases (Worldwide) of HIV-1 are caused through exposure in the mucosal cavities like the inside lining of the rectum or vagina.

Dr.Ruth Ruprecht                             Credit:Texas BioMed

Dr.Ruth Ruprecht and their team focused to develop a vaccine to block HIV at portal entry: mucosal sites. (It is a membrane that various cavities covers the surface of the internal organs and the body)

Rhesus monkeys at the Southwest National Primate Research Centre on the Texas Biomedical research institute campus served as the model for this research.

Animals are first treated with the man-made version of IgM (Produced naturally by the plasma cells which is located under epithelium). Half an hour later, the same animals were exposed to Simian-Human Immunodeficiency Virus (SHIV). SHIV (a retroviruses that cause infections around 45species of African non-human primates). 4 out of 6 animals treated this way were fully against the virus.  The animals were monitored continuously for 82 days.

Dr.Ruth Ruprecht team found that applying Immunoglobulin M (IgM) antibodies resulted in what is called immune exclusion.  Immune exclusion(SIgA antibodies serves as first line defense against microorganism through Immune Exclusion)

IgM clumped up the virus, preventing it from crossing the mucosal barrier and spreading it to the rest of the body.

IgM has a high affinity for its antigens and “grabs them very quickly and does not let go,” Dr.Ruprecht explained. “Our study reveals for the first time the protective potential of mucosal anti-HIV-1 IgM. IgM has a five-times higher ability to bind to virus particles compared to the standard antibody form called IgG. It basically opens up a new area of research. IgM can do more than it has been given credit.”

Dr. Ruprecht has “set off a new wave in evaluating the activity of IgM antibodies in neutralizing HIV-1…[and she and her group] have largely broadened the horizon of  neutralizing HIV-1 antibodies, which, as single or combined agents, may be used for HIV-1 prevention and treatment.”

Reference:  Texas Biomedical Research Institute

Journal ReferenceSiqi Gong, Khamis Tomusange, Viraj Kulkarni, Opeyemi S. Adeniji, Samir K. Lakhashe, Dinesh Hariraju, Amanda Strickland, Elizabeth Plake, Patrice A. Frost, Sarah J. Ratcliffe, Liping Wang, Eileen M. Lafer, Ruth M. Ruprecht. Anti-HIV IgM protects against mucosal SHIV transmission. AIDS. 32(11):F5–F13, JUL 2018, DOI : 10.1097/QAD.0000000000001857

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