CD8A and viral infectious disease: Effector CD8+ T cells are able to attenuate pulmonary inflammation by changing the polarization of T cells to a Th1 phenotype in a Th2 environment [18], however in asthmatic mice with a strong Th2 response to OVA; a concomitant CD8+ T cells response to viral infection may result in an increase of Tc2 cells, causing lung eosinophilia [17].