CD4 and pneumonia: Beneficial effects against infections (e.g., the influenza virus), including increased helper T cells in the lung parenchyma.Reduce the recruitment of granulocytes and the expression of the proinflammatory cytokines that inhibit the development of pneumonia virus.Increase interferon-γ and interleukin-2. Prevents virus replication.Increase the proportions of total, helper (CD4+), and activated (CD25+) T cells and NK cells in the blood.Activate plasmacytoid dendritic cells.Reduce the tissue damage caused by inflammation in TGEV (gastroenteritis coronavirus).