Lymphocyte proliferation responses of immunised mice. All groups were intramuscularly immunised four times, and after priming, antigen-stimulated spleen lymphocytes were prepared from three mice per group 2 weeks after the last immunisation, and their subsequent proliferation responses were analysed and expressed as stimulation index (SI) values. Results are presented as the mean of SI values ± SD. (A): Stimulation of rBAG1 antigen; (B): Stimulation of rSRS4 antigen; (C): Stimulation of rSRS9 antigen. The statistical difference between different groups was considered to be significant when the P value was less than 0.05 (* means P < 0.05, ** means P < 0.01 and *** means P <0.001).