Cytotoxic effectors in human peripheral blood mononuclear cells induced by a mannoprotein complex of Candida albicans: a comparison with interleukin 2-activated killer cells.
In this study, the major histocompatibility complex-unrestricted cytotoxic effectors elicited in human peripheral blood mononuclear cells (PBMC) by a mannoprotein (MP) component from the cell wall of the human indigenous microorganism Candida albicans have been compared with those obtained by stimulation with interleukin 2. (Interleukin 2-activated killer cells: LAK). It has been found that MP-induced lytic effectors were substantially similar to LAK in potency, target specificity, and type of precursor/effector cells. In both cases, natural killer (NK)-susceptible and NK-resistant targets as well as fresh tumor (glioma) cells were efficiently killed by a population of effectors showing a predominant CD3-, CD16+ phenotype. However, the precursors of MP-induced killers were highly sensitive to the lysosomotropic toxic drug L-leucine methyl ester (Leu-OME) whereas the generation of LAK cells was unaffected by this drug. The Leu-OME sensitivity of MP-induced cytotoxicity generation was not due to a nonspecific effect on antigen-presenting cells or inhibition of cell proliferation. In addition, the generation of MP-induced killer cells was totally abrogated by treatment with CD16 antibodies and complement, whereas a minor but significant fraction of LAK precursors was not susceptible to the above treatment. These results indicate that a defined component(s) of the cell wall of C. albicans has some properties of biological response modifiers in cultures of human PBMC in vitro.
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Istituto CNR di Tipizzazione Tissutale e Problemi della Dialisi, L'Aquila, Italy.
Palma
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Spagnoli
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Piazza
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Casciani
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CU
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D000954:Antigens, Surface / Q000032:analysis; D002176:Candida albicans / Q000502:physiology*; D003602:Cytotoxicity, Immunologic; D006412:Hematopoietic Stem Cells / Q000276:immunology; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D010641:Phenotype
D000954:Antigens, Surface; D007376:Interleukin-2; D008562:Membrane Glycoproteins; C025363:mannoproteins