2 CLOSELY-RELATED ADENOVIRUS GENOME TYPES WITH KIDNEY OR RESPIRATORY-TRACT TROPISM DIFFER IN THEIR BINDING TO EPITHELIAL-CELLS OF VARIOUS ORIGINS

The host-cell interactions of the genome types Ad11p and Ad11a of huma n adenovirus serotype 11, displaying kidney or respiratory tropism, we re compared using FAGS analysis. Kinetic experiments indicated that th e virus binding started immediately and reached a plateau after 30 min . The binding of biotinylated virions to seven continuous cell lines: A549, A498, J82, HeLa, CHO, MDCK, and human diploid fibroblasts (HEDF) , was quantitated by FAGS analysis. The binding capacities of the two viruses to all human cell lines but A549 cells appeared to differ. Ad1 1p virions manifested high affinities, whereas Ad11a virions presented low affinities. Neither of the two viruses bound to CHO or MDCK cells . Reciprocal competition experiments showed that the Ad11a virions cou ld be weakly blocked by the Ad11p virions, whereas the Ad11p virions c ould not be competed at all by the Ad11a virions. The binding of the A d11p virions to cells could be blocked by the rfiber antiserum of Ad11 p, but not by the corresponding antiserum against Ad11a or Ad35p. A co mparison of the cytopathogenicity of the seven cell lines infected by Ad11p and Ad11a demonstrated that the efficiency of the initial event of an adenovirus infection directly affects the outcome of the viral i nfection. The Ad11a in the A498, J82, HeLa, or HEDF cells that present ed lower affinity and receptor concentration showed 100 times less inf ectivity than that in A549 cells displaying high affinity and receptor concentration. These results indicate that the cell susceptibility to Ad11p and Ad11a infection strongly depends on both the number of fibe r receptors on the host cells and the receptor affinity for ligands on the fiber knob. Our findings also suggest that the receptors for Ad11 p and Ad11a on the surface of different cell types may be different or on different sites. (C) 1998 Academic Press.