Cellular immunity to merozoite surface protein 2 (FC27 and 3D7) in Papua New Guinean children. Temporal variation and relation to clinical and parasitological status.
A prospective study in 207 children aged 0.5-15 years was carried out in a highly endemic area of Papua New Guinea to examine the relationship between cellular responses to Plasmodium falciparum merozoite surface protein 2 (MSP2) and malaria infection and morbidity. In vitro proliferation, IFN-gamma and IL-4 induction were measured against two recombinant proteins of MSP2, FC27 and 3D7 as well as against a form of the 3D7 MSP2 lacking the central repetitive sequences (d3D7). The prevalence of proliferative response was generally low, 6% for FC27, 9% for 3D7 and 11% for d3D7. A higher prevalence of IL-4 response was obtained being 27% for FC27, 34% for 3D7 and 30% for d3D7 while the prevalence of IFN-gamma response was 13%, 15% and 18%, respectively. There was no correlation between age and proliferative responses; in contrast cytokine production increased with age for all three antigens. When proliferation or stimulation of either cytokine was used to assess T-cell activation the frequency of responders increased to 39%, 47% and 46% for FC27, 3D7 and d3D7 respectively. Analysis of the relation of T cell responses to concurrent infection and morbidity showed that lymphoproliferative response only to d3D7 was significantly associated with parasitaemia; while lymphoproliferative responses to all 3 MSP2 antigens were highest in the group of clinical malaria cases. There was no significant correlation between proliferation or cytokine production to MSP2 and concurrent or subsequent malaria morbidity.
al-Yaman
F
F
Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.
Genton
B
B
Taraika
J
J
Anders
R
R
Alpers
M P
MP
D000293:Adolescent; D000818:Animals; D000953:Antigens, Protozoan; D000954:Antigens, Surface / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000096:biosynthesis*; D019353:Endemic Diseases; D006801:Humans; D007223:Infant; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000276:immunology*; D010219:Papua New Guinea / Q000453:epidemiology; D010963:Plasmodium falciparum / Q000276:immunology*; D011446:Prospective Studies; D015800:Protozoan Proteins / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000953:Antigens, Protozoan; D000954:Antigens, Surface; D016207:Cytokines; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; C065974:merozoite surface protein 2, Plasmodium; D015847:Interleukin-4; D007371:Interferon-gamma