[Immune response and protective efficacy in BALB/c mice induced by DNA vaccine encoding immunogenic protein of Legionella pneumophila].
OBJECTIVE
To study the immune response in mice induced by DNA vaccine encoding immunogenic protein of Lgeionella pneumophila (LP) and to examine its protective efficacy against LP in mice.


METHODS
The eukaryotic expression recombinant plasmid of LP immunogenic protein gene (pcDNA3.1-ip) was constructed and used to immunize BALB/c female mice intramuscularly, and antigen specific antibodies, lymphocyte proliferative response, IFN-gamma production and cytotoxic T-lymphocyte response of the immunized mice were detected. The BALB/c mice immunized by the pcDNA3.1-ip repeatedly were then challenged with LP (10 LD(50)), and the number of survivors in each group was quantitated. Then the mice were sacrificed and lung tissue were harvested for quantitative culture of LP and observation of the pathologic changes.


RESULTS
The DNA vaccine pcDNA3.1-ip could induce specific humoral and cellular immunity in the immunized mice. The results indicated that the immunogenicity of pcDNA3.1-ip was higher than that of pcDNA3.1(+) (P<0.01). The vaccine was effective in protecting mice against infection after LP (10 LD(50)) challenge.


CONCLUSIONS
The DNA vaccine encoding immunogenic protein of LP can be used as a candidate for novel vaccine design.
Yang
Zhi-Wei
ZW
Department of Parasitology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, China. yangzhw0817@163.com
Chen
Jian-Ping
JP
Wang
Tao
T
Tian
Yu
Y
D000818:Animals; D000917:Antibody Formation / Q000235:genetics / Q000276:immunology; D000942:Antigens, Bacterial / Q000235:genetics* / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007111:Immunity, Cellular / Q000235:genetics / Q000276:immunology; D007371:Interferon-gamma / Q000378:metabolism; D016952:Legionella pneumophila / Q000235:genetics* / Q000378:metabolism*; D008168:Lung / Q000378:metabolism / Q000382:microbiology; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids / Q000235:genetics; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism; D019444:Vaccines, DNA / Q000235:genetics* / Q000276:immunology*
D000942:Antigens, Bacterial; D019444:Vaccines, DNA; D007371:Interferon-gamma