Open AccessExtracellular acidic pH modulates oxygen‐dependent cytotoxic responses mediated by polymorphonuclear leucocytes and monocytes
Author(s) -
GEFFNER J. R.,
TREVANI A. S.,
MINNUCCI F.,
PALERMO M. S.,
MAUGERI N.,
ISTURIZ M. A.
Publication year - 1993
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1111/j.1365-2249.1993.tb03373.x
Subject(s) - cytotoxicity , zymosan , cytotoxic t cell , concanavalin a , respiratory burst , chemistry , extracellular , stimulation , n formylmethionine leucyl phenylalanine , immune system , biochemistry , immunology , neutrophile , biology , in vitro , endocrinology
SUMMARY In the present study, we compared the ability of human neutrophils and monocytes to display oxygen‐dependent cytotoxic responses at pH 7.4 and 6.2. Our results show that cytotoxicity induced by immune complexes (IC), zymosan, N‐formyl‐methionyl‐leucyl‐phenylalanine (FMLP) and concanavalin A (Con A) were markedly increased when they were carried out at pH 6.2 instead of pH 7.4. Cytotoxicity induced by phorbol myristate acetate (PM A), on the contrary, was significantly decreased at pH 6.2. It is noteworthy that cytotoxic responses induced by IC, zymosan and Con A were also increased when, 2 h after effector cell stimulation at pH 6.2, cytotoxicity was measured at pH 7.4. Finally, when we examined possible mechanisms involved in the augmentation of cytotoxicity, we observed that the oxidative response of IC‐stimulated neutrophils, measured as chemiluminescence emission, was not increased at pH 6.2, on the contrary, it was significantly decreased. The relevance of these results is discussed.