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Modulation of Mononuclear Phagocyte Cytotoxicity by Alpha‐Tocopherol (Vitamin E)
Author(s) -
Leb Laszlo,
Beatson Patricia,
Fortier Normand,
Newburger Peter E.,
Snyder L. Michael
Publication year - 1985
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.37.4.449
Subject(s) - antibody dependent cell mediated cytotoxicity , cytotoxicity , monocyte , mononuclear phagocyte system , biology , microbiology and biotechnology , phagocyte , peripheral blood mononuclear cell , vitamin e , phorbol , cytotoxic t cell , in vitro , immunology , biochemistry , immune system , antioxidant , protein kinase c , enzyme
The in vitro effect of colloidal suspensions of alpha‐tocopherol (α‐T) on phorbol‐ myristate‐acetate (PMA)‐induced monocyte cytotoxicity and on antibody‐dependent monocyte cytotoxicity (ADCC) was studied. We observed that 1) in the presence of α‐T, the inhibition was twice as high in the PMA‐induced assay than in ADCC; 2) monocytes preincubated with α‐T were inhibitory in both assays but much less in ADCC, and 3) target erythrocytes preincubated with a‐T decreased the cytotoxicity in the PMA‐induced assay only. Since α‐T preincubated monocytes showed a decreased release of H 2 O 2 but not of O 2 ″, we concluded that one of the mechanisms by which α‐T decreased cytotoxicity could be decreased release of H 2 O 2 . Whereas the role of H 2 O 2 was documented in the PMA‐induced cytotoxicity, in ADCC non‐oxidative injury seems more important. This is supported by 1) lesser inhibition of the assay with α‐T preincubated monocytes; 2) lack of protection with α‐T preincubated erythrocytes, and 3) mild inhibition with protease inhibitor.