Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Protection against H1N1 influenza challenge by a DNA vaccine expressing H3/H1 subtype hemagglutinin combined with MHC class IIrestricted epitopes | Tan et al. Virology Journal 2010 7 363 http content 7 1 363 J VIROLOGY JOURNAL RESEARCH Open Access Protection against H1N1 influenza challenge by a DNA vaccine expressing H3 H1 subtype hemagglutinin combined with MHC class II-restricted epitopes 2 2 Lei Tan 1 Huijun Lu Dan Zhang 1 Mingyao Tian 1 Bo Hu 1 Zhuoyue Wang 1 Ningyi Jin Abstract Background Multiple subtypes of avian influenza viruses have crossed the species barrier to infect humans and have the potential to cause a pandemic. Therefore new influenza vaccines to prevent the co-existence of multiple subtypes within a host and cross-species transmission of influenza are urgently needed. Methods Here we report a multi-epitope DNA vaccine targeted towards multiple subtypes of the influenza virus. The protective hemagglutinin HA antigens from H5 H7 H9 subtypes were screened for MHC II class-restricted epitopes overlapping with predicted B cell epitopes. We then constructed a DNA plasmid vaccine pV-H3-EHA-H1 based on HA antigens from human influenza H3 H1 subtypes combined with the H5 H7 H9 subtype Th B epitope box. Results Epitope-specific IFN-y ELISpot responses were significantly higher in the multi-epitope DNA group than in other vaccine and control groups P . The multi-epitope group significantly enhanced Th2 cell responses as determined by cytokine assays. The survival rate of mice given the multi-epitope vaccine was the highest among the vaccine groups but it was not significantly different compared to those given single antigen expressing pV-H1HA1 vaccine and dual antigen expressing pV-H3-H1 vaccine P . No measurable virus titers were detected in the lungs of the multi-epitope immunized group. The unique multi-epitope DNA vaccine enhanced virus-specific antibody and cellular immunity as well as conferred complete protection against lethal challenge with A New Caledonia 20 99 H1N1 influenza strain in mice. Conclusions This approach may be a promising .
