title: Protective immune responses in mice induced by intramuscular and intranasal immunization with a  Mycoplasma pneumoniae  P1C DNA vaccine.
abstract: Mycoplasma pneumoniae  is an important causative agent of atypical pneumonia. This study was to determine the ability of a DNA expression vector, which encodes the carboxy terminal region of the M. pneumoniae P1 protein (P1C), to induce humoral and cellular immune responses and to protect against M. pneumoniae infection in BALB/c mice. Mice were immunized with pcDNA3.1/P1C by either intramuscular injection (i.m.) or intranasal inoculation (i.n.). Our results showed that p1c DNA immunization generates detectable antibodies specific to M. pneumoniae, and elicits high levels of IgG1, IgG2a, and IgG2b isotypes (P < 0.01). The levels of IFN-γ and IL-4 in spleen cells of the immunized mice were significantly elevated by immunization via both the i.m. and i.n. methods. Moreover, p1c DNA-immunized mice exhibited detectable protection against M. pneumoniae infection. The lung tissue inflammation was relieved and the histopathologic score (HPS) of pcDNA3.1/P1C-immunized mice was significantly decreased than those in phosphate-buffed saline (PBS) or vaccine-vector-immunized mice (P < 0.01), whereas there were no significant differences in HPS between i.m. and i.n. vaccination (P > 0.05). Our results suggest that pcDNA3.1/P1C could be useful for developing a vaccine against M. pneumoniae infection.
authors.affiliation: Xiangya School of Medicine, Central South University, Changsha 410078, People's Republic of China.
authors.forename: Cuiming
authors.initials: C
authors.lastname: Zhu
authors.forename: Yimou
authors.initials: Y
authors.lastname: Wu
authors.forename: Sufang
authors.initials: S
authors.lastname: Chen
authors.forename: Minjun
authors.initials: M
authors.lastname: Yu
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Zeng
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: You
authors.forename: Jinhong
authors.initials: J
authors.lastname: Xiao
authors.forename: Shiping
authors.initials: S
authors.lastname: Wang
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000276:immunology*; D000281:Administration, Intranasal; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001428:Bacterial Vaccines / Q000235:genetics / Q000276:immunology*; D049109:Cell Proliferation; D006367:HeLa Cells; D006801:Humans; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D007074:Immunoglobulin G / Q000276:immunology; D007273:Injections, Intramuscular; D007371:Interferon-gamma / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D008168:Lung / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009177:Mycoplasma pneumoniae / Q000276:immunology; D011019:Pneumonia, Mycoplasma / Q000276:immunology / Q000517:prevention & control*; D013154:Spleen / Q000166:cytology / Q000276:immunology; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*
chemical_list: D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D007074:Immunoglobulin G; D019444:Vaccines, DNA; C035471:adhesin, Mycoplasma pneumoniae; D015847:Interleukin-4; D007371:Interferon-gamma