Immunobiological activity and antiviral regulation efforts of Chinese goose (Anser cygnoides) CD8α during NGVEV and GPV infection.

The CD8 molecule is a cell membrane glycoprotein expressed on cytotoxic T lymphocytes, which are involved in the clearance of viruses. However, the functional characterization of goose CD8α is still unclear. The immunobiological characterization of goose CD8α in goose spleen mononuclear cells (MNCs) was examined by real-time quantitative PCR (qPCR). It was shown that CD8α mRNA levels were significantly up-regulated by in vitro treatment of MNCs with phytohemagglutinin (PHA), concanavalin A (ConA), and polyinosinic-polycytidylic acid (poly I:C) in a dose-dependent way, but lipopolysaccharides (LPSs) did not have this same effect. Moreover, the time-course effect of CD8α expression in response to mitogens (PHA, ConA, and poly I:C) was evaluated in MNCs. A significant increase in the transcriptional levels of CD8α was detected in new type gosling viral enteritis virus (NGVEV)-infected goose MNCs at 48 h postinfection (PI) and in goose parvovirus (GPV)-infected MNCs at 72 h PI. Also, the number of CD8α+ cells was significantly increased during viral infection from 72 h on. The seminal changes in mRNA profiles of antiviral cytokines (IFN-α, IFN-γ, and IL-18) were observed and were significantly increased during late phases of NGVEV and GPV infection. Accordingly, our data not only contribute to the understanding of the immune characteristics of goose CD8α, but they also provide new insight into the innate antiviral immunity of geese.