[Effects of Mycobacterium smegmatis vaccine on cytokines production and Th1/Th2 responses in mice].
OBJECTIVE
To validate the immunogenicity of Mycobacterium smegmatis and to study the immune modulatory function of Mycobacterium smegmatis vaccine made from Mycobacterium smegmatis by analyzing the effects of the vaccine on immune responses in mice.


METHODS
Spleen cells and peritoneal macrophages from BALB/c mice which were randomized into a control group and Mycobacterium smegmatis vaccine groups (low, middle, and high doses) were cultured in vitro. Then the supernatants were collected and the concentrations of IL-2, IL-4, IL-12, and IFN-gamma were analyzed through ELISA.


RESULTS
(1) IL-12 produced by the control mice and mice immunized with low, middle, high doses of Mycobacterium smegmatis vaccine was (32.6 +/- 22.7), (58.9 +/- 18.6), (77.3 +/- 38.0), (114.7 +/- 9.9) pg/ml respectively, and the middle and high dose group showed significant difference as compared with the control group (P < 0.05). (2) IL-2 produced by the control mice and mice immunized with low, middle, high dose of Mycobacterium smegmatis vaccine was (5.0 +/- 2.6), (13.4 +/- 9.23), (15.3 +/- 9.7), (22.6 +/- 7.5) pg/ml respectively, and the high dose group showed significant difference when compared with the control group (P < 0.01). (3) When the cells were stimulated with ConA in vitro, IFN-gamma produced by the control mice and mice immunized with middle dose of Mycobacterium smegmatis vaccine was (662 +/- 279) and (807 +/- 163) pg/ml, IL-4 produced by the two groups was (407 +/- 127) and (101 +/- 26) pg/ml, but the differences were not statistically significant (P > 0.05). When the cells were stimulated with Mycobacterium smegmatis-purified protein derivative (PPD) in vitro, IFN-gamma produced by the control mice and mice immunized with middle dose of Mycobacterium smegmatis vaccine was (14.0 +/- 6.31) and (55.3 +/- 32.4) pg/ml, the difference being statistically significant (P < 0.05), but IL-4 produced by the two groups was under the limit of detection.


CONCLUSIONS
Mycobacterium smegmatis vaccine made from Mycobacterium smegmatis showed strong immunogenicity promoted Th1 responses and inhibited Th2 response in mice.
Xu
Miao
M
National Institute for the Control of Pharmaceutical and Biological Products, Beijing 100050, China.
Chen
Bao-wen
BW
Shen
Xiao-bing
XB
Su
Cheng
C
Luo
Yong-ai
YA
Wang
Guo-zhi
GZ
D000818:Animals; D001428:Bacterial Vaccines / Q000276:immunology*; D005260:Female; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D017737:Macrophages, Peritoneal / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D020102:Mycobacterium smegmatis / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
D001428:Bacterial Vaccines; D015847:Interleukin-4; D007371:Interferon-gamma