Proliferative Responses of T Subsets from Malaria-naive Human Donors [CD4⁺, CD8⁺, and Naive T Cell (CD45RA⁺)-enriched and Memory T Cell (CD45RO⁺)-enriched Subpopulations], to Plasmodium falciparum Polypeptide Antigens Isolated from the Merozoite Stage

Abstract

Mononuclear cells, CD2⁺ T cells and T subsets (CD4⁺, CD8⁺) from HLA-typed malaria-naive donors were stimulated with isolated surface antigens (Ags) from Plasmodium falciparum merozoites (MSP1₈₃, MSP1₃₆, MSP2). Cell responses in lymphocyte proliferation assays were MHC-class II and mainly DR restricted. Donors could be grouped into high, non or low responders according to the proliferative response. The high responders possessed the combination DR7/DRw53 as a common HLA-restriction element. Non and low responders did not have this Ag combination, but some were characterized by DQw1.
Individual donors did not show any Ag dependent response. CD45RA⁺ (naive, non-stimulated) enriched T cells from high-responders were strongly stimulated by the merozoite Ags, whereas stimulation of CD45R0⁺ (memory) enriched T cells was much lower.