Long-lasting balanced immunity and protective efficacy against respiratory syncytial virus in mice induced by a recombinant protein G1F/M2.
Respiratory syncytial virus (RSV) is the primary cause of serious lower respiratory tract illness in young children. We have engineered a recombinant candidate vaccine G1F/M2, consisting of a cytotoxic T lymphocyte (CTL) epitope of RSV-M2 protein and a domain of RSV-G protein. In this study, the long-term immunogenicity and protective effect were evaluated. In G1F/M2-immunized mice, special antibodies lasted for more than 19 weeks, and the IgG1/IgG2a ratio remained a balanced level till the end of the study, suggesting mixed Th1/Th2 type of responses. Concomitantly, G1F/M2 elicited long-lived RSV-specific CTL activity that was detectable at 12 weeks after the final immunization. Stronger CTL responses were induced with immunization once more at 13 weeks after the last immunization in G1F/M2-primed mice than those in F/M2-primed mice. These results suggest that G1F/M2-induced long-lasting balanced humoral and cellular immunity responses, and immunological memory in mice. Furthermore, following RSV challenge, long-term protective efficacy was observed. RSV replication in lungs of G1F/M2-primed mice elicited also mixed Th1/Th2 responses, a property that is considered advantageous for the safety of an RSV vaccine. Therefore, G1F/M2 is a promising RSV subunit vaccine.
Zeng
Ruihong
R
Department of Immunology, Hebei Medical University, Shijiazhuang 050017, China. zengruihong@yahoo.com.cn
Qi
Xiaowen
X
Gong
Wei
W
Mei
Xingguo
X
Wei
Lin
L
Ma
Cuiqing
C
Yin
Xiaolin
X
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology* / Q000517:prevention & control*; D022261:Respiratory Syncytial Virus Vaccines / Q000235:genetics* / Q000276:immunology*; D018113:Respiratory Syncytial Virus, Human / Q000235:genetics* / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D013997:Time Factors; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D011994:Recombinant Proteins; D022261:Respiratory Syncytial Virus Vaccines; D014614:Vaccines, Synthetic; D014764:Viral Proteins