Generation of cytotoxic T lymphocytes in vitro. II. Effect of repeated exposure to alloantigens on the cytotoxic activity of long-term mixed leukocyte cultures - PubMed (original) (raw)

Generation of cytotoxic T lymphocytes in vitro. II. Effect of repeated exposure to alloantigens on the cytotoxic activity of long-term mixed leukocyte cultures

H R Macdonald et al. J Exp Med. 1974.

Abstract

Mouse cytotoxic T lymphocytes (CTL) were generated in unidirectional mixed leukocyte cultures (MLC) using normal C57BL/6 spleen cells as responding cells and irradiated DBA/2 spleen cells as stimulating cells. Cytotoxicity was assayed on (51)Cr-labeled P-815 (DBA/2) target cells, and the relative frequency of CTL in individual cell populations was estimated from dose-response curves. Upon inclusion of 2-mercaptoethanol in the culture medium, it was found that significant CTL activity could be detected for as long as 3 wk in primary MLC. Reexposure of MLC cells to the original stimulating alloantigens after 14-41 days in culture resulted in significant cell proliferation and rapid regeneration of high levels of immunologically specific cytotoxicity. CTL activity in these secondary cultures increased dramatically within the first 24 h and reached higher peak levels than those found at the peak of the primary response. Furthermore, proliferation and reappearance of CTL activity could be demonstrated following each of as many as four sequential alloantigenic stimulations of the same initial cell population at 20-day intervals. Interestingly, cells recovered from MLC at the peak of the primary response on day 4 were insensitive to further allogeneic stimulation. Taken together, these results are consistent with the hypothesis that CTL differentiate in MLC to become long-lived memory cells which gradually lose their cytotoxic activity. Upon reexposure to specific alloantigen, such memory CTL rapidly regain their functional activity and proliferate to generate an expanded CTL population.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Immunology. 1968 Feb;14(2):181-96 - PubMed
    1. Nature. 1970 Dec 26;228(5278):1308-9 - PubMed
    1. J Exp Med. 1971 Mar 1;133(3):442-53 - PubMed
    1. Cell Immunol. 1972 Feb;3(2):213-30 - PubMed
    1. Cell Immunol. 1972 May;4(1):39-50 - PubMed

MeSH terms

Substances

LinkOut - more resources