Analysis of antitumor properties of effector cells stimulated with a cell wall preparation (WPG) of Bifidobacterium infantis.
Intestinal Bifidobacterium species are thought to be beneficial in animal and human intestines. We studied the mechanisms of Bifidobacteria in antitumor activity using a cell wall preparation (WPG) of B. infantis (Cancer Res., 45, 1300, (1985)). WPG enhanced the in vitro antitumor activities of mouse peritoneal exudate cells elicited with proteose-peptone (P-PEC) and thioglycollate broth (TG-PEC), determined by cytostatic ([3H]thymidine uptake inhibition) and cytolytic ([3H]uridine release) assays. Tumor necrosis factor-alpha (TNF-alpha) and reactive nitrogen intermediates (RNI) play a role in such augmented cytotoxicity, because anti-TNF-alpha antibody almost completely blocked the increased cytolytic activity of P-PEC in the presence of WPG. Moreover, WPG induced RNI in the supernatant of TG-PEC in a dose-dependent manner. The mRNA expression of several cytokines (IL-1 beta, IL-6, IL-10, IFN-alpha and TNF-alpha) was induced in BALB/c mouse peritoneal cells 3 h after an intraperitoneal injection of WPG (3 h WPG-PEC). However, this expression disappeared from 24 h WPG-PEC, except for that of IFN-alpha. IFN-gamma was not induced. Kinetic studies of the tumor neutralizing activities of the WPG-PECs by means of the in vivo Winn assay revealed that the activity emerged at 1.5 h, became maximal at 3 h and disappeared at 24h. These results indicated that Bifidobacterial WPG is a Biological Response Modifier (BRM) with characteristics similar to those of other bacterial BRMs.
Sekine
K
K
Bio-Chemical Research Laboratory, Morinaga Milk Industry Co., Ltd., Kanagawa.
Ohta
J
J
Onishi
M
M
Tatsuki
T
T
Shimokawa
Y
Y
Toida
T
T
Kawashima
T
T
Hashimoto
Y
Y
D000818:Animals; D001483:Base Sequence; D001644:Bifidobacterium / Q000737:chemistry* / Q000648:ultrastructure; D002470:Cell Survival / Q000187:drug effects; D002473:Cell Wall / Q000737:chemistry*; D003470:Culture Media; D016207:Cytokines / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008969:Molecular Sequence Data; D009573:Nitrites / Q000378:metabolism; D010457:Peptidoglycan / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010461:Peptones / Q000494:pharmacology; D010529:Peritoneal Cavity / Q000166:cytology; D016133:Polymerase Chain Reaction; D012194:RNA-Directed DNA Polymerase; D012513:Sarcoma, Experimental / Q000188:drug therapy*; D013268:Stimulation, Chemical; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects* / Q000648:ultrastructure; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D003470:Culture Media; D016207:Cytokines; D009573:Nitrites; D010457:Peptidoglycan; D010461:Peptones; D014409:Tumor Necrosis Factor-alpha; D012194:RNA-Directed DNA Polymerase