HEL-FLU - AN INFLUENZA-VIRUS CONTAINING THE HEN EGG LYSOZYME EPITOPE RECOGNIZED BY CD4(-CELLS FROM MICE TRANSGENIC FOR AN ALPHA-BETA TCR() T)

Reverse genetics was used to modify the influenza virus genome by inse rting the p46-63 sequence of hen egg lysozyme (HEL) into the neuramini dase stalk of the virus. The resulting virus, HEL-Flu, contained the e pitopes recognized by CD4(+) T cells from 3A9-TCR transgenic mice (C3H Tg). Here, we show that HEL-FlU was infectious in the respiratory trac t of both C3H and C3HTg mice, the latter animals showing an early, tra nsient morbidity. Splenic dendritic cells and certain cloned populatio ns of splenic macrophages and brain microglia constitutively presented infectious and inactivated HEL-Flu to the T cells in an Ag-specific a nd MHC class Ii-restricted manner. These results demonstrate the utili ty of HEL-FlU in assessing the APC activity for naive T cells; they al so extend the previous studies showing that discrete populations of ma crophages and microglia constitutively process and present Ag to naive T cells.