Protective T-cell epitope in p15[superscript]gag of leukemia virus identified.

2004 AUG 11 - (NewsRx.com & NewsRx.net) -- Scientists have identified a protective CD4+ T-Cell epitope in p15[superscript]gag of Friend murine leukemia virus.

"Recent studies have demonstrated an essential role of Gag-specific CD4+ T-cell responses for viral control in individuals infected with human immunodeficiency virus type 1. However, little is known about epitope specificities and functional roles of the Gag-specific helper T-cell responses in terms of vaccine-induced protection against a pathogenic retroviral challenge. We have previously demonstrated that immunization with Friend murine leukemia virus (F-MuLV) Gag proteins protects mice against the fatal Friend retrovirus (FV) infection," investigators in Japan report.

"We report here the structure of a protective T helper cell (Th) epitope, (I)VTWEAIAVDPPP, identified in the p15 (MA) region of F-MuLV Gag," said Daisuke Sugahara and colleagues at Kinki University. "In mice immunized with the Th epitope-harboring peptide or a vaccinia virus-expressed native full-length MA protein, FV-induced early splenomegaly regressed rapidly. In these mice, FV-infected cells were eliminated within 4 weeks and the production of virus-neutralizing antibodies was induced rapidly after FV challenge, resulting in strong protection against the virus infection."

"Interestingly, mice immunized with the whole NIA mounted strong CD4+ T-cell responses to the identified Th epitope, whereas ...