Natural killer-cell activity under conditions reflective of tumor micro-environment.
Natural-killer(NK) activity was examined in the presence of low oxygen tension, low glucose concentration and acidic pH, to determine whether physical conditions present in the tumor micro-environment could play a role in down-regulating cytolytic activity of tumor-infiltrating lymphocytes with NK phenotype. Anoxia (0% O2), but not hypoxia (1% O2), significantly reduced NK activity, as did acidic pH (6.4 or 6.7). Low glucose concentration (6 mg/dl) did not impair NK activity. Combinations of either moderate (1% O2, 26 mg/dl glucose, pH 6.7) or extreme (0% O2, 6 mg/dl glucose, pH 6.4) alteration of physical conditions significantly reduced NK activity. This study indicates that the physico-chemical conditions present within solid tumors are capable of down-regulating NK activity.
Loeffler
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E. Walter Albachten Department of Immunology, Michigan Cancer Foundation, Detroit 48201.
Juneau
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Heppner
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D000818:Animals; D002460:Cell Line; D003470:Culture Media; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D005260:Female; D005947:Glucose / Q000494:pharmacology; D000860:Hypoxia; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D007700:Kinetics; D008213:Lymphocyte Activation / Q000187:drug effects; D008223:Lymphoma / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011070:Poly I-C / Q000494:pharmacology
D003470:Culture Media; D005947:Glucose; D011070:Poly I-C