Comparison of the effector cells in human spontaneous cellular cytotoxicity and antibody-dependent cellular cytotoxicity: differential sensitivity of effector cells to in vivo and in vitro corticosteroids
Parrillo, J.E.; Fauci, A.S.
Scandinavian Journal of Immunology 8(2): 99-107
1978
ISSN/ISBN: 0300-9475 PMID: 705262 Document Number: 138941
The effector cells mediating antibody dependent cellular cytotoxicity (ADCC) and spontaneous cellular cytotoxicity (SCC) in humans were reported to possess similar characteristics. Multiple cell separation techniques were employed to physically separate and distinguish the effector cells in these 2 types of cellular cytotoxicity. Subpopulations of mononuclear cells obtained by a variety of fractionation procedures which enriched or depleted monocytes, lymphocytes bearing a receptor for sheep erythrocytes (SRBC), a receptor for complement (CRL) or an Fc receptor for IgG always had similar effects on ADCC and SCC. Aggregated .gamma.-globulin blockade of Fc receptors produced similar dose-dependent depressions of ADCC and SCC. Despite the inability to physically separate the effector cells of ADCC and SCC, administration of in vivo dexamethasone caused a relative increase in ADCC but a profound decrease in SCC. In vitro dexamethasone in pharmacologic and suprapharmacologic concentrations caused no change in ADCC but significantly decreased SCC. Although the effector cells cannot be physically separated, ADCC and SCC are differentially sensitive to corticosteroids and are functionally distinct due to different subsets of effector cells with similar surface markers or different mechanisms of cytotoxicity by the same effector cell.