Open AccessDefective stimulus-response coupling in human monocytes infected with Leishmania donovani is associated with altered activation and translocation of protein kinase C.
Author(s) -
Martin Olivier,
Roger W. Brownsey,
Neil E. Reiner
Publication year - 1992
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.89.16.7481
Subject(s) - protein kinase c , leishmania donovani , biology , kinase , microbiology and biotechnology , respiratory burst , phosphorylation , chromosomal translocation , intracellular , biochemistry , immunology , visceral leishmaniasis , leishmaniasis , gene
Stimulus-response coupling through protein kinase C (PKC) was shown to be defective in mononuclear phagocytes (M phi) infected with Leishmania donovani. Phorbol 12-myristate 13-acetate (PMA)-induced oxidative burst activity and protein phosphorylation were markedly attenuated in infected M phi. These results were not explained either by quantitative alterations in amounts of PKC or by altered phorbol ester binding but were related to defects in kinase activation. Analysis in vitro of the kinetic properties of PKC from infected M phi revealed an approximately 2-fold increase in the concentration of 1,2-dioleoyl-rac-glycerol required to achieve half-maximal kinase activation. Evidence for abnormal PKC activation in vivo was reflected by attenuation of PMA-induced translocation of enzyme to the particulate fraction of infected cells. These results provide direct evidence that infection with Leishmania inhibits activation of, and therefore intracellular signaling dependent on, PKC. Inhibition of stimulus-response coupling through PKC provides a basis for understanding impairment of cellular activation by Leishmania and may contribute to chronic infection.