Spontaneous cytoxicity against virus-infected cells: cellular immunoadsorption on infected cell monolayers
Weston, P.A.; Levy, N.L.; Koren, H.S.
Journal of Immunology 125(3): 1387-1394
1980
ISSN/ISBN: 0022-1767 PMID: 6157727 Document Number: 161582
Peripheral blood lymphocytes of normal adult donors were demonstrated to be cytotoxic in a short-term 51Cr-release assay to a cell line persistently infected with Sendai virus, SV-HEp2, to a far greater extent than to uninfected human epidermoid carcinoma HEp2 cells. The cytotoxicity was not inhibited by Fab fragments of anti-human Fab fragments nor did its occurrence depend upon the presence of fetal calf serum, indicating that antibodies were not required for cytotoxicity. Lymphocytes were separated into adherent and nonadherent fractions by cellular immunoadsorption on SV-HEp2 monolayers. Both fractions were depleted of cytotoxic activity when assayed immediately after the separation; immunoadsorption on uninfected HEp2 monolayers failed to deplete cytotoxic activity. When SV-HEp2-adherent and nonadherent lymphocytes were incubated overnight before assay, the cytotoxic activity of the nonadherent fraction remained low; that of the adherent fraction was increased as much as 4-fold above control levels. Substantial titers of interferon-like antiviral activity were detected in 18-h culture supernatants of SV-HEp2 adherent, but not nonadherent, lymphocytes. The addition of exogenous interferon to the nonadherent fraction failed to augment its cytotoxic activity. Cellular immunoadsorption on SV-HEp2 monolayers removed a population of lymphocytes with cytotoxic potential and interferon induced in the adherent lymphocyte fraction augmented the cytotoxicity of this fraction after overnight incubation.