LYMPHOPROLIFERATIVE RESPONSES OF SPECIFIC-PATHOGEN-FREE CHICKENS TO MYCOPLASMA-GALLISEPTICUM STRAIN PG31

Mycoplasma gallisepticum (MG) is one of the aetiologic agents of chron ic respiratory disease in chickens and infectious sinusitis in turkeys . We investigated humoral and cellular immune mechanisms following exp erimental infection with four different strains of MG. Peripheral bloo d leukocytes (PBL) obtained from chickens were examined for proliferat ion using antigen preparations of whole cell MG as stimuli in vitro. A consistent lymphoproliferative response was observed against the homo logous whole cell antigens in the group of chickens infected with stra in PG31. Significant lymphoproliferation was detected as early as 1 we ek post-infection. We further characterized antigen-specific prolifera tion by measuring the production of interferon and nitric oxide by the PBL of infected chickens. Consistent with lymphoproliferation, we als o detected the presence of interferon and nitric oxide in vitro in ant igen-stimulated cultures. These results indicate a possible role of ce ll-mediated immune responses in the development of immunity following MG infection in chickens.