Subtype C SHIV Variant May Be Useful In African Vaccine Development.(Brief Article)

2001 DEC 5 - (NewsRx.com & NewsRx.net) -- by Michael Greer, senior medical writer - Researchers in the United States have developed a simian/human immunodeficiency virus (SHIV) variant for studying potential HIV vaccines tailored to African strains of the virus.

"Human immunodeficiency virus type 1 (HIV-1) subtype C is responsible for more than 56% of all infections in the HIV and AIDS pandemic," explained Thumbi Ndung'u and colleagues at the Harvard AIDS Institute and the Harvard School of Public Health in Boston, Massachusetts. "It is the predominant subtype in the rapidly expanding epidemic in southern Africa."

Because their version of SHIV (SHIV[subscript]MJ4) is based on HIV subtype C, it will provide an relatively accurate model for testing African vaccine candidates, Ndung'u and coworkers said.

The researchers derived SHIV[subscript]MJ4 from a R5 strain found in southern Africa. SHIV[subscript]MJ4 contains parts of three genes that code for key HIV proteins, with most of the env gene, part of the second exon of rev, and all of the tat second exon.

This SHIV variant demonstrated efficient replication in peripheral blood mononuclear cells from humans and a variety of macaques, study data showed. However, SHIV[subscript]MJ4 was unable to replicate in cells from the human lymphocyte cell line CEMx174, Ndung'u and team noted.

...