Lymphoproliferative responses of specific-pathogen-free chickens to Mycoplasma gallisepticum strain PG31

Abstract

Mycoplasma gallisepticum (MG) is one of the aetiologic agents of chronic respiratory disease in chickens and infections sinusitis in turkeys. We investigated humoral and cellular immune mechanisms following experimental infection with four different strains of MG. Peripheral blood leukocytes (PBL) obtained from chickens were examined for proliferation using antigen preparations of whole cell MG as stimuli in vitro. A consistent lymphoproliferative response was observed against the homologous whole cell antigens in the group of chickens infected with strain PG31. Significant lymphoproliferation was detected as early as 1 week post-infection. We further characterized antigen-specific proliferation by measuring the production of interferon and nitric oxide by the PBL of infected chickens. Consistent with lymphoproliferation, we also detected the presence of interferon and nitric oxide in vitro in antigen-stimulated cultures. These results indicate a possible role of cell-mediated immune responses in the development of immunity following MG infection in chickens.