[Immune response induced by Rpf domain from Micrococcus luteus in mice].
OBJECTIVE
To investigate the immunobiology of Rpf domain from Micrococcus luteus.


METHODS
BALB/c mice were immunized with Rpf domain three times at 2-week interval. ELISA was used to detect the title of the anti-Rpf domain antibody titer in the immunized mice sera. The spleen lymphocytes of the immunized mice were separated and the stimulation index (SI) was measured by MTT colorimetry. The levels of secreted IFN-gamma, IL-10 and IL-12 upon specific antigen stimulation was detected by ELISA. The Rpf domain immunized BALB/c mice were intravenously infected with 10(5) CFU MTB H37Rv. The number of CFU in the spleens was determined four weeks after final injection.


RESULTS
The titer of the specific antibody in sera of the immunized BALB/c mice was 1:128 000. The SI of Rpf domain immunized group (2.10+/-0.12) was significantly higher than that of saline immunized group (0.90+/-0.21). The lever of IFN-gamma, IL-10 and IL-12 levels in culture supernatant of spleen lymphocytes from the fusion protein immunized mice was (1 126+/-36) ng/L, (368+/-13) ng/L and (289+/-14) ng/L, respectively, which was markedly higher than that of saline immunized group (P<0.01). Compared with normal saline immunized mice (6.64+/-0.13) four weeks after final injection, dramatic reduction in MTB replication was observed in the spleen (5.03+/-0.11) from the BALB/c mice immunized with fusion proteins.


CONCLUSIONS
Rpf domain can be used as a candidate for a new TB vaccine.
Fan
Ai-Lin
AL
Department of Clinical Laboratory, Fourth Military Medical University, Xi'an 710032, China. fanailin@fmmu.edu.cn
Jian
Wen
W
Shi
Chang-Hong
CH
Su
Ming-Quan
MQ
Bai
Yin-Lan
YL
Ma
Jing
J
Xu
Zhi-Kai
ZK
Hao
Xiao-Ke
XK
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D007371:Interferon-gamma / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016982:Micrococcus luteus / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000276:immunology / Q000472:pathogenicity; D011897:Random Allocation; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000378:metabolism
D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D016207:Cytokines; D011993:Recombinant Fusion Proteins; C113704:resuscitation-promoting factor, bacteria; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma