Strong Immune Response Observed In Chimps After Hepatitis C Rechallenge.(Brief Article)

2001 JUN 27 - (NewsRx.com & NewsRx.net) --

by Sonia Nichols, senior medical writer - Surprisingly, researchers have found some chimps retain an immune response to hepatitis C virus (HCV) rechallenge long after their original hepatitis infections have cleared.

New study data indicate T cells in chimpanzees strongly react to HCV rechallenge, and the same may be true of humans, which would bode well for scientists in search of vaccines and therapies designed to protect or treat patients with HCV, according to research investigators in Texas and California.

"Animals that had previously cleared HCV infection rapidly cleared homologous and heterologous virus upon rechallenge, indicative of a strong protective immunity," described Suzanne E. Bassett and colleagues at the University of Texas Medical Branch at Galveston, who worked with others at the Southwest Foundation for Biomedical Research and Chiron Corporation to study the chimpanzees.

As long as 16 years had passed between viral clearance and viral rechallenge in some animals, yet upon rechallenge antibody response to HCV proteins in the chimpanzees increased by as much as 1000 times, and viral clearance was hastened, clearly indicating to researchers that long-term immunity against HCV infection is achievable ("Protective immune response to hepatitis C virus in chimpanzee rechallenged following clearance of primary infection," Hepatology, June 2001;33(6):1479-1487).

T-cell response appeared to be the focus point of chimpanzee immunity. "A very early and strong in vitro recall response to HCV nonstructural proteins ...