Ot. Keppler et al., REGULATION OF SUSCEPTIBILITY AND CELL-SURFACE RECEPTOR FOR THE B-LYMPHOTROPIC PAPOVAVIRUS BY N-GLYCOSYLATION, Journal of virology, 68(11), 1994, pp. 6933-6939
The host range of the B-lymphotropic papovavirus (LPV) in cultured hum
an cells is limited to a few B-lymphoma-derived cell lines. The consti
tutively expressed cell surface receptor for the virus is a major dete
rminant restricting the LPV host range (G. Haun, O. T. Keppler, C. T.
Beck, M. Herrmann, H. Zentgraf, and M. Pawlita, J. Virol. 67:7482-7492
, 1993). Here we show that human B-lymphoma cells with low-level susce
ptibility are rendered highly susceptible to LPV infection by pretreat
ment with the N glycosylation inhibitor tunicamycin but remain nonsusc
eptible to infection by the related polyomavirus simian virus 40. Amon
g the selective N glycosylation processing inhibitors, deoxymannojirim
ycin, but not deoxynojirimycin, swainsonine, or castanospermine, could
mimic the effect of tunicamycin. Tunicamycin treatment also induced a
drastic enhancement of the cells' LPV-binding capacity, indicating th
at the induction of LPV susceptibility might be mediated by an increas
e in the number of functional cell surface receptors and/or by increas
ed receptor affinity. Sialidase sensitivity of the tunicamycin-induced
LPV receptor showed that oligosaccharides carrying terminal sialic ac
ids are necessary for binding and are likely to be O linked. The const
itutive LPV receptor is also sialic acid dependent, which points to a
possible identity with the sialic acid-dependent tunicamycin-induced L
PV receptor. We conclude that removal or modification of certain N-lin
ked oligosaccharides in human B-lymphoma cells can enhance expression
or functional activity of the sialylated LPV receptor.