In order to ensure that the in vitro interaction of lung derived neutrophils with effector T cells as closely as possible mimicked the interaction in vivo, we used as a defined source of effector CD8+ T cells for in vitro co-culture with neutrophils, PR8 (HA533–41 epitope) specific CD8+ TCR transgenic (tg) clone 4 (Cl-4) T cells isolated from PR8 infected lungs 8 days after adoptive transfer and virus infection. This evidence concerns the gene CD8A and viral infectious disease.