Vaccination of Lewis rats with temperature-sensitive mutants of Mycoplasma pulmonis : adoptive transfer of immunity by spleen cells but not by sera. Infect Immun 59

Temperature-sensitive mutant vaccines protect rats against Mycoplasma pulmonis infection. The role of the humoral or cellular immune response in resistance to mycoplasma infection was investigated by adoptive-transfer experiments. Spleen cells from Lewis rats vaccinated but not challenged with wild-type organisms (vaccinated) and spleen cells from rats vaccinated (or not) and challenged were effective in preventing syngeneic recipients from developing respiratory disease. There was also a significant reduction in the incidence and number of challenging organisms in the respiratory system. In contrast, sera from the same donors had no detectable effect on the number of mycoplasmas recovered or on lesion development in the respiratory tract. We conclude that cellular immunity rather than humoral immunity generated in vaccinated rats confers protection against subsequent infection. Mycoplasma pulmonis is one of the most important dis-eases in both conventionally maintained and specific-patho-gen-free rodent colonies. Studies of the immune mechanisms in experimentally induced murine respiratory mycoplasmo-sis (MRM) should provide useful information for the control of MRM infections. To develop suitable vaccines, it i