HLA-A2 supertype-restricted cell-mediated immunity by peripheral blood mononuclear cells derived from Malian children with severe or uncomplicated Plasmodium falciparum malaria and healthy controls

Infect Immun. 2005 Sep;73(9):5799-808. doi: 10.1128/IAI.73.9.5799-5808.2005.

Abstract

Understanding HLA-restricted adaptive host immunity to defined epitopes of malarial antigens may be required for the development of successful malaria vaccines. Fourteen epitopes of preerythrocytic malarial antigens known to mediate cytotoxic T-lymphocyte responses against target cells expressing HLA-A2-restricted epitopes were synthesized and pooled based on antigen: thrombospondin-related anonymous protein (TRAP), circumsporozoite protein (CSP), and export protein 1 (Exp-1) peptides. HLA-A2 supertype (*0201, *0202, *0205, *6802) peripheral blood mononuclear cells collected from 774 Malian children, aged 3 months to 14 years, with severe Plasmodium falciparum malaria matched to uncomplicated malaria or healthy controls were stimulated with the HLA-A2-restricted peptide pools. Significant gamma interferon production, determined by enzyme-linked immunospot assay to at least one of the three peptide pools, was observed in 24/58 (41%) of the severe malaria cases, 24/57 (42%) of the uncomplicated malaria cases, and 34/51 (67%) of the healthy controls. Significant lymphoproliferation to these peptides was observed in 12/44 (27%) of the severe malaria cases, 13/55 (24%) of the uncomplicated malaria cases, and 18/50 (36%) of the healthy controls. Responses to individual peptide pools were limited. These studies confirm the presence of adaptive cell-mediated immunity to preerythrocytic malaria antigens in volunteers from Mali and demonstrate that suballeles of the HLA-A2 supertype can effectively present antigenic epitopes. However, whether these immune responses to TRAP, CSP, and Exp-1 malarial proteins play a substantial role in protection remains a matter of controversy.

MeSH terms

  • Adolescent
  • Alleles
  • Animals
  • Antigen Presentation / genetics
  • Antigen Presentation / immunology*
  • Child
  • Child, Preschool
  • Enzyme-Linked Immunosorbent Assay
  • Epitopes / immunology
  • Erythrocytes / immunology
  • Erythrocytes / parasitology
  • HLA-A2 Antigen / genetics
  • HLA-A2 Antigen / immunology*
  • Histocompatibility Testing
  • Humans
  • Immunity, Cellular / genetics
  • Infant
  • Interferon-gamma / biosynthesis
  • Leukocytes, Mononuclear / immunology*
  • Leukocytes, Mononuclear / metabolism
  • Malaria, Falciparum / epidemiology
  • Malaria, Falciparum / immunology*
  • Malaria, Falciparum / parasitology
  • Mali / epidemiology
  • Plasmodium falciparum / immunology*
  • Severity of Illness Index

Substances

  • Epitopes
  • HLA-A2 Antigen
  • Interferon-gamma