A protein fraction from aged garlic extract enhances cytotoxicity and proliferation of human lymphocytes mediated by interleukin-2 and concanavalin A.
Fraction 4 (F4), a protein fraction isolated from aged garlic extract, enhanced cytotoxicity of human peripheral blood lymphocytes (PBL) against both natural-killer (NK)-sensitive K562 and NK-resistant M14 cell lines. Although F4 treatment alone increased cytotoxicity, the effect was more remarkable when F4 was administered together with suboptimal doses of interleukin-2 (IL-2); combination treatment of 5 micrograms/ml F4 plus 10 U/ml IL-2 for 72 h generated lymphokine-activated killer activity equivalent to that produced by 100 U/ml IL-2 alone against M14. F4 enhanced IL-2-induced proliferation and IL-2 receptor (Tac) expression of PBL without significant increase of IL-2 production. The enhancement of cytotoxicity both by F4 alone and by F4 plus IL-2 was abolished by anti-IL-2 antibody. F4 also enhanced concanavalin-A(ConA)-induced proliferation of PBL. Radiolabeled-ConA binding assays revealed that F4 treatment greatly augmented the affinity and slightly increased the number of ConA binding sites in PBL. F4 also enhanced ConA-induced IL-2 receptor (Tac) expression and IL-2 production of PBL. Anti- IL-2 antibody inhibited the effect of F4 on ConA-induced proliferation. These data suggest that IL-2 is involved in augmentative effects of F4. Our results indicate that F4 is a very efficient immunopotentiator and may be used for immunotherapy.
Morioka
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N
Division of Surgical Oncology, UCLA School of Medicine 90024.
Sze
L L
LL
Morton
D L
DL
Irie
R F
RF
D003208:Concanavalin A / Q000494:pharmacology*; D016207:Cytokines / Q000096:biosynthesis; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D005737:Garlic / Q000502:physiology*; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000276:immunology*; D010936:Plant Extracts / Q000737:chemistry; D037121:Plant Lectins; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D010946:Plants, Medicinal; D015375:Receptors, Interleukin-2 / Q000032:analysis; D014407:Tumor Cells, Cultured
D016207:Cytokines; D007376:Interleukin-2; D010936:Plant Extracts; D037121:Plant Lectins; D010940:Plant Proteins; D015375:Receptors, Interleukin-2; D003208:Concanavalin A