[1] NIAID, Lab Clin Infect Dis, NIH, 9000 Rockville Pike, Bethesda, MD 20892 USA
[2] NCI, Pediat Oncol Branch, NIH, Bethesda, MD 20892 USA
[3] NIAID, Lab Host Def, NIH, 9000 Rockville Pike, Bethesda, MD 20892 USA
[4] NCI, Expt Transplantat & Immunol Branch, Div Basic Sci, NIH, Bethesda, MD 20892 USA