We have modeled a 3D structure for the C-type
lectin domain of the African swine fever virus protein
EP153R, based on the structure of CD69, CD94 and Ly49A
cell receptors, and this model predicts that a dimer of
EP153R may establish an asymmetric interaction with one
MHC-I molecule. A functional consequence of this interaction
could be the modulation of MHC-I expression. By
using both transfection and virus infection experiments, we
demonstrate here that EP153R inhibits MHC-I membrane
expression, most probably by impairing the exocytosis
process, without affecting the synthesis or glycosylation of
MHC antigens. Interestingly, the EP153-mediated control
of MHC requires the intact configuration of the lectin
domain of the viral protein, and specifically the R133
residue. Interference of EP153R gene expression during
virus infection and studies using virus recombinants with
the EP153R gene deleted further support the inhibitory role
of the viral lectin on the expression of MHC-I antigens.This work was supported by grants from the Spanish Ministerio de
Ciencia y Tecnología (BFU2007-63110/BMC), from the European
Community’s Seventh Framework Programme (FP7/2007-2013)
under grant agreement KBBE- 211691- ASFRISK and from Laboratorios
del Dr. Esteve, SA, and also by institutional grants from the
Fundación Ramón Areces and Banco Santander Central Hispano.
C.H. and A.G.G. also acknowledge financial support from the Centro
de Investigación en Sanidad Animal (CISA).Peer reviewe
