CD58/LFA-3 and IL-12 provided by activated monocytes are critical in the in vitro expansion of CD56+ T cells.
A small proportion of human CD3+ T lymphocytes are known to co-express CD56, an antigen usually restricted in its expression to natural killer (NK) cells. Whereas the in vivo function of CD3+ CD56+ T cells remains unknown, we and others have previously shown that both in vitro and in vivo, these cells can mediate a significantly greater degree of MHC-unrestricted cytotoxicitv against a variety of human tumor cells when compared to either CD3+ CD56- T cells or lymphokine activated killer (LAK) cells. While the mechanismns regulating the in vivo expansion of CD56+ T cells are not known, here we demonstrate the importance of CD2-mediated IL-12-dependent signals in the in vitro expansion of CD56+ T cells. Specifically, we show that activated monocytes provide a contact dependent factor (CD58/LFA-3) and a soluble factor (IL-12), both critical for the in vitro expansion of CD56+ T cells. The biological and therapeutic implications of these findings are discussed.
Bone Marrow Transplantation Program, University of Alabama at Birmingham, 35294, USA. richard.lopez@ccc.uab.edu
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D000818:Animals; D018801:CD2 Antigens / Q000378:metabolism; D017252:CD3 Complex / Q000378:metabolism; D019002:CD56 Antigen / Q000378:metabolism*; D018968:CD58 Antigens / Q000502:physiology*; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D003602:Cytotoxicity, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000494:pharmacology; D018664:Interleukin-12 / Q000502:physiology*; D009000:Monocytes / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology*
D018801:CD2 Antigens; D017252:CD3 Complex; D019002:CD56 Antigen; D018968:CD58 Antigens; D018664:Interleukin-12; D007371:Interferon-gamma