Molecular analysis of antibody response to malaria sporozoite reported.

2004 NOV 3 - (NewsRx.com & NewsRx.net) -- Scientists report the results of a molecular dissection of the human antibody response to the structural repeat epitope of Plasmodium falciparum sporozoite from a protected donor in a recent issue of Malaria Journal.

According to published research from the United States, "the circumsporozoite surface protein is the primary target of human antibodies against Plasmodium falciparum sporozoites, these antibodies are predominantly directed to the major repetitive epitope (Asn-Pro-Asn-Ala)[subscript]n, (NPNA)[subscript]n. In individuals immunized by the bites of irradiated Anopheles mosquitoes carrying P. falciparum sporozoites in their salivary glands, the anti-repeat response dominates and is thought by many to play a role in protective immunity."

"The antibody repertoire from a protected individual immunized by the bites of irradiated P. falciparum infected Anopheles stephensi was recapitulated in a phage display library," said Jonathan A. Chappel and colleagues at Avanir Pharmaceutical Inc. and the U.S. Naval Medical Research Center. "Following affinity based selection against (NPNA)[subscript]3 antibody fragments that recognized the PfCSP repeat epitope were rescued. Analysis of selected antibody fragments implied the response was restricted to a single antibody fragment consisting of V[subscript]H3 and V[subscript]kappaI families for heavy and light chain respectively with moderate affinity for the ligand."

"The dissection of the protective antibody response against the repeat epitope revealed that the response was apparently restricted to a single V[subscript]H/V[subscript]L pairing ...