Interleukin-6 protects ductal breast carcinoma cells from MHC-unrestricted cell-mediated cytotoxicity.
Interleukin-6 (IL-6) has various biological activities including growth stimulation and maturation of B cells into antibody-producing cells, growth stimulation of murine hybridoma and plasmacytoma cells, induction of acute phase proteins, activation of T cell functions, triggering differentiation of various hematopoietic cells, and inhibition of growth of the human ductal breast carcinoma cell line T-47. Recently it was found that IL-6 also has the ability to enhance natural killer (NK) cell activity. In the present study the possible role of IL-6 as a regulator of NK cell-mediated cytotoxicity (NK-CMC) was evaluated. It was found that IL-6 reduced the sensitivity of T-47 cells (a ductal breast carcinoma cell line) to NK-CMC. The mechanism of IL-6-induced protection was studied. IL-6 had no effect on the level of conjugate formation between T-47 cells and NK cells. However, IL-6 reduced the number of dead conjugated T-47 cells. IL-6-treated T-47 cells were also found to be as sensitive as the nontreated cells to the lytic effect of NK cytotoxic factor (NKCF). However, IL-6 appeared to reduce the ability of T-47 cells to induce release of NKCF from NK cells following conjugate formation. Therefore, it is suggested that IL-6 protects T-47 cells from natural killing by the same mechanism as interferon.
Reiter
Z
Z
Department of Molecular Genetics and Virology, Weizmann Institute of Science, Rehovot, Israel.
Chen
L
L
Revel
M
M
Rubinstein
M
M
D001943:Breast Neoplasms / Q000276:immunology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000276:immunology*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D005260:Female; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D007700:Kinetics; D008285:Major Histocompatibility Complex; D011994:Recombinant Proteins / Q000494:pharmacology; D013997:Time Factors
D007370:Interferon Type I; D015850:Interleukin-6; D011994:Recombinant Proteins; D007371:Interferon-gamma