Archaeosome mediated Th1/Th2 bias was ascertained by determining cytokine response in splenocyte culture supernatant belonging to various immunized groups at different time points; (A) IFN-γ, (B) IL-12. To activate splenocytes belonging to group of animals immunized with free Rv3619c, free form of 20 µg Rv3619c was used while lymphocytes isolated from group of animals immunized with physical mixture of sham archaeosome and Rv3619c were activated with physical mixture of 20 µg of free Rv3619c and sham archaeosome (∼1.5 mg archaebacterial lipid) splenocytes isolated from animals immunized with archaeosome entrapped Rv3619c group, were co-cultured with archaeosome entrapped Rv3619c (20 µg antigen). To further confirm the Th1/Th2 polarization upon immunization with archaeosome encapsulated Rv3619c, the sera of immunized animals were analysed for the presence of IgG2a and IgG1 isotype by sandwich ELISA method (C). The data represent mean of three determinants± S.D. and are representative of two different experiments with similar observation. Various immunized groups were compared to determine statistical significance of the data using student's t test analysis with p<0.05 (*), p<0.01(**), P<0.001(***) level of significance. PB (post booster), PC (post challenge), NS (not significant).