Interleukin-3-deficient mice have increased resistance to blood-stage malaria.

The contribution of interleukin-3 (IL-3), a hematopoietic growth factor and immunoregulatory cytokine, to resistance to blood-stage malaria was investigated by infecting IL-3-deficient (knockout [KO]) mice with Plasmodium berghei NK65. Male IL-3 KO mice, but not female mice, were more resistant to infection than wild-type (WT) mice, as evidenced by lower peak parasitemia and prolonged survival. Both male and female IL-3 KO mice had increased splenomegaly and were more anemic than corresponding WT mice.

Identification of G-protein binding sites of the human interleukin-8 receptors by functional mapping of the intracellular loops.

Interleukin 8 (IL-8) is considered to be a major mediator of the inflammatory response. Recent evidence indicates that a direct physical association occurs between IL-8 receptors and the alpha subunit of guanine nucleotide regulatory protein (Gi(alpha)2) upon stimulation of human neutrophils by IL-8. In the present study, we identified by site-directed mutagenesis key residues within the three intracellular loops of the IL-8RA receptor involved in the interaction with Gi(alpha)2.