Abstract: To investigate the effect of porcine circovirus type2 (PCV2) infection on immune function of porcine alveolar macrophages (PAM), forty-day-old healthy piglets infected with PCV2 were used to detect the kinetics of pattern recognition receptors(PRR) mRNA of PAM. Results showed that the trends of TRL2, TRL4 and CD16 mRNA were similar. Compared to the control, these molecules from the infected groups increased at 3 and 7 d, and decreased at 14 d, with significant differences (P<0.01) of TLR4 and CD16 at 3d and a significant difference (P<0.05) of TLR2 at 14 d. The transcription of CD18 mRNA lowered with significant difference PRR (P<0.05) at 3 d, and went up with significant difference (P<0.05) at 7 d. All these suggested that the recognition and phagocytosis functions of PAM on foreign object post-infected with PCV2 and thereafter its signal transduction function could be disorders, which influence the abilities of phagocytosis and clear microorganisms of PAM.

Key words: porcine circovirus type2 (PCV2); pulmonary alveolar macrophages (PAM); pattern recognition receptor (PRR)