Lack of correlation between red cell invasion by merozoites and anti-heat shock protein-70 antibody levels in malaria patients' sera.
A total of 172 sera samples were collected from individuals who were living in Piyawli-Jaitwarpur village in Ghaziabad district (U.P.), India. They had suffered from falciparum malaria attack, and were cured with antimalarial drugs 1-2 weeks prior to sample collection. These samples were divided into nine groups according to their age. The pooled sera from each group were tested for the presence of anti-schizont and anti-heat shock protein (hsp)-70 antibodies, as well as for parasite growth inhibition in vitro. All sera samples showed significant levels of antibodies against schizont antigens and these levels increased with age. The sera also contained anti-hsp-70 antibodies but at lower levels and did not follow the same age-related pattern as seen with schizont antibodies. The sera from each group significantly inhibited merozoite invasion in vitro. However the same was not true for other blood stage parasites; the 2-15 years age group sera did not show significant growth inhibition of rings, trophozoites and schizonts. No correlation was observed between anti-hsp-70 antibody levels and inhibition of merozoite invasion. It is therefore concluded that the antibodies preventing the merozoite invasion could be other than anti-hsp-70 antibodies. The candidature of hsp-70 for P. falciparum malaria vaccine thus needs to be re-evaluated.
Biswas
S
S
Malaria Research Centre, Delhi, India.
Sharma
Y D
YD
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004912:Erythrocytes / Q000469:parasitology*; D006360:Heat-Shock Proteins / Q000276:immunology*; D006801:Humans; D007223:Infant; D008288:Malaria / Q000097:blood*; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000276:immunology*
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D006360:Heat-Shock Proteins