Innate and adaptive immunity during infection and immunization with inactivated tick-borne encephalitis vaccine

Introduction. Viral infections induce cellular and humoral immunity that provide virus elimination. Extracellular presentation of antigens of formaldehyde-inactivated vaccines causes mainly humoral immune response with risk of persistent infection. The aim of the study. comparison of dynamics of cytokines and antibodies IgMand IgG during infection and immunization of laboratory mice with inactivated vaccine against the tick-borne encephalitis. Methods: reverse transcription - real time PCR (RT2-PCR); ELISA to detect IgM and IgG antibodies. Results: All studied cytokine mRNA were found in the virus-infected mice whereas IL1fi, IL4 and TNFa RNA were missing after vaccination. Cytokine gene expression began in 1-2 days postinfection with maximal values in 4-8 days and subsequent decline, however, after vaccination cytokine RNA were revealed in 14 days only and were detected for 42 days of observations, probably, due to 3 subsequent injections. Antibodies in infected mice were also registered earlier, in 7-14 days postinfection, whereas after immunization later - in 28-42 days after first injection and antibody titers were higher. Conclusion: During viral infection cytokine profiles were more diversified, cytokine RNA transcription and IgM and IgG secretion took place earlier than for vaccination. Titers of antibodies were higher in immunized mice after 2-3 intramuscular injections compared to infection with long-lasting IgM circulation for 42 days.

flaviviral infection, inactivated vaccine, cytokines, antibodies, reverse transcription - real time PCR, ELISA