Immunological correlations between ontogenesis and oncogenesis: theoretical implications and suggestions for tumor immunotherapy.
The previously hypothesized paraembryonal nature of tumor cells (1) leads one to suggest, immunologically, the presence in a tumor of two main cell populations: one consisting of either genotypically or phenotypically paraembryonal cells (PECs), with no differentiation MHC (major histocompatibility complex) antigens, and representing the stem tumor cells; the other consisting of phenotypically differentiated-paraembryonal cells (DPECs), with either embryonal or differentiated antigens, rising from neighbour genotypically normal cells induced by PECs. PECs, without MHC antigens, might escape alpha beta TCR (T-cell alpha beta receptor) lymphocyte immunosurveillance, since alpha beta TCR T-cells recognize only MHC-restricted antigens, such as DPEC antigens. On the other hand, PECs might be recognized by gamma delta TCR lymphocytes, known to constitute a more primitive immunosurveillance system, able to recognize non-MHC-restricted antigens. On this ground, several immunological aspects of the tumors are analysed and suggestions for a more effective tumor immunotherapy are given.
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D000818:Animals; D002454:Cell Differentiation; D004622:Embryo, Mammalian / Q000166:cytology; D006128:Growth; D006801:Humans; D007167:Immunotherapy; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D009369:Neoplasms / Q000209:etiology* / Q000276:immunology / Q000628:therapy