Endogenous interleukin-10 modulates proinflammatory response in Plasmodium falciparum malaria.
Tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, and IL-6 are implicated in the pathogenesis of severe Plasmodium falciparum malaria. In this study, the effect of IL-10 on their production by peripheral blood mononuclear cells (PBMC) from acutely infected patients was examined. Exogenous IL-10 inhibited malarial antigen-induced cytokine production by reducing mRNA accumulation. Maximal inhibition occurred when IL-10 was added in the first 2 h of stimulation. Conversely, the addition of anti-IL-10 markedly enhanced TNF-alpha, IL-1beta, and IL-6 production. The effect was significantly greater on PBMC from patients with uncomplicated infection than PBMC from patients with severe disease. Kinetics studies showed that TNF-alpha, IL-6, and IL-1beta were produced within 2-4 h of stimulation, while IL-10 was first detectable after 8 h. These findings suggest that IL-10 counter-regulates the proinflammatory response to P. falciparum. Severe falciparum malaria may be associated with an inadequate negative feedback response by IL-10.
Ho
M
M
Department of Microbiology & Infectious Diseases, University of Calgary, Canada. mho@acs.ucalgary.ca
Schollaardt
T
T
Snape
S
S
Looareesuwan
S
S
Suntharasamai
P
P
White
N J
NJ
D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis / Q000276:immunology* / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000276:immunology; D016778:Malaria, Falciparum / Q000097:blood / Q000276:immunology*; D010963:Plasmodium falciparum / Q000276:immunology*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D000911:Antibodies, Monoclonal; D000953:Antigens, Protozoan; D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10