CD8A and infection: Virus titres in BAL increased 100-fold from day 1 to day 6, and infection resulted in increased numbers of macrophages, CD4+ and CD8+ cells, and levels of IFNγ, IL-8, MCP-1, MIP-1α, RANTES, and surfactant protein A (SP-A) mRNA increased in the lungs [60], [62].