Implication of Hsc70, PDI and integrin αvβ3 involvement during entry of the murine rotavirus ECwt into small-intestinal villi of suckling mice.

In the present study, a homologous rotavirus, ECwt, infecting small intestinal villi isolated from ICR and BALB/c mice were used as a model for identifying cell-surface molecules involved in rotavirus entry. Small-intestinal villi were treated with anti-Hsc70, anti-PDI, anti-integrin β3 or anti-ERp57 antibodies or their corresponding F(ab')2 fragments before inoculation with rotavirus ECwt, RRV or Wa. Pretreatment of villi decreased virus infectivity by about 50-100 % depending of the rotavirus strain, antibody structure and detection assay used. Similar results were obtained by treating viral inocula with purified proteins Hsc70, PDI or integrin β3 before inoculation of untreated villi. Rotavirus infection of villi proved to be sensitive to membrane-impermeant thiol/disulfide inhibitors such as DTNB and bacitracin, suggesting the involvement of a redox reaction in infection. The present results suggest that PDI, Hsc70 and integrin β3 are used by both homologous and heterologous rotaviruses during infection of isolated mouse villi.