HLA-DQB1*0501-restricted Th1 type immune responses to Plasmodium falciparum liver stage antigen 1 protect against malaria anemia and reinfections

Protective immunity against Plasmodium falciparum requires constant exposur e to the pathogen. T cell-mediated immune responses are induced by T cell e pitopes of pre-erythrocytic stage antigens of P. falciparum and involve HLA -restricted CD4 and CD8 cells. Cytotoxic T cell responses to a conserved ep itope of P. falciparum liver stage antigen (LSA) type 1 are restricted by t he HLA class I allele Bw53. The role of HLA class II alleles in mediating c ellular responses against P. falciparum LSA-1 has not yet been demonstrated . In a longitudinal study performed for >4 years, associations were found b etween the HLA class II allele DQB1* 0501 and protection from malaria anemi a and malarial reinfections in Gabonese children. Children carrying DQB1* 0 501 had a higher frequency of interferon-gamma responses to LSA-1 T cell ep itopes, compared with noncarriers.