Protective efficacy of a  Mycoplasma pneumoniae  P1C DNA vaccine fused with the B subunit of  Escherichia coli  heat-labile enterotoxin.
In the present study, we investigated the immunomodulatory responses of a DNA vaccine constructed by fusing Mycoplasma pneumoniae P1 protein carboxy terminal region (P1C) with the Escherichia coli heat-labile toxin B subunit (LTB). BALB/c mice were immunized by intranasal inoculation with control DNAs, the P1C DNA vaccine or the LTB-P1C fusion DNA vaccine. Levels of the anti-M. pneumoniae antibodies and levels of interferon-γ and IL-4 in mice were increased significantly upon inoculation of the LTB-P1C fusion DNA vaccine when compared with the inoculation with P1C DNA vaccine. The LTB-P1C fusion DNA vaccine efficiently enhanced the M. pneumoniae-specific IgA and IgG levels. The IgG2a/IgG1 ratio was significantly higher in bronchoalveolar lavages fluid and sera from mice fusion with LTB and P1C than mice receiving P1C alone. When the mice were challenged intranasally with 10(7) CFU M. pneumoniae strain (M129), the LTB-P1C fusion DNA vaccine conferred significantly better protection than P1C DNA vaccine (P < 0.05), as suggested by the results, such as less inflammation, lower histopathological score values, lower detectable number of M. pneumoniae strain, and lower mortality of challenging from 5 × 10(8) CFU M. pneumoniae. These results indicated that the LTB-P1C fusion DNA vaccine efficiently improved protective efficacy against M. pneumoniae infection and effectively attenuated development of M. pneumoniae in mice.
Department of Microbiology and Immunology, Pathogenic Biology Institute, University of South China, Hengyang 421001, China.
Cuiming
C
Zhu
Shiping
S
Wang
Shihai
S
Hu
Minjun
M
Yu
Yanhua
Y
Zeng
Xiaoxing
X
You
Jinhong
J
Xiao
Yimou
Y
Wu
D000276:Adjuvants, Immunologic; D000281:Administration, Intranasal; D000818:Animals; D001427:Bacterial Toxins / Q000737:chemistry* / Q000378:metabolism / Q000627:therapeutic use; D004768:Enterotoxins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000627:therapeutic use; D004926:Escherichia coli / Q000276:immunology; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism / Q000627:therapeutic use; D005260:Female; D006358:Hot Temperature; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009177:Mycoplasma pneumoniae / Q000276:immunology; D011019:Pneumonia, Mycoplasma / Q000517:prevention & control*; D011994:Recombinant Proteins / Q000378:metabolism; D014611:Vaccination / Q000379:methods; D019444:Vaccines, DNA / Q000737:chemistry* / Q000627:therapeutic use
D000276:Adjuvants, Immunologic; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D019444:Vaccines, DNA; D015847:Interleukin-4; D007371:Interferon-gamma; C027538:heat-labile enterotoxin, E coli