Open AccessDevelopment of mucosal and systemic lymphoproliferative responses and protective immunity to human group A rotaviruses in a gnotobiotic pig model
Author(s) -
Lucy A. Ward,
Lijuan Yuan,
B I Rosen,
Thanh Long To,
Linda J. Saif
Publication year - 1996
Publication title -
clinical and diagnostic laboratory immunology
Language(s) - English
Resource type - Journals
eISSN - 1098-6588
pISSN - 1071-412X
DOI - 10.1128/cdli.3.3.342-350.1996
Subject(s) - virus , lamina propria , rotavirus , diarrhea , biology , peripheral blood mononuclear cell , spleen , mesenteric lymph nodes , immune system , lymph , immunology , virulence , virology , medicine , pathology , epithelium , biochemistry , genetics , gene , in vitro
Gnotobiotic pigs were orally inoculated with virulent Wa strain (G1P1A[8]) human rotavirus (group 1), attenuated Wa rotavirus (group 2) or diluent (controls) and were challenged with virulent Wa rotavirus 21 days later. On various postinoculation or postchallenge days, virus-specific responses of systemic (blood and spleen) and intestinal (mesenteric lymph node and ileal lamina propria) mononuclear cells (MNC) were assessed by lymphoproliferative assays (LPA). After inoculation, 100% of group 1 pigs and 6% of group 2 pigs shed virus. Diarrhea occurred in 95, 12, and 13% of group 1, group 2, and control pigs, respectively. Only groups 1 and 2 developed virus-specific LPA responses prior to challenge. Group 1 developed significantly greater mean virus-specific LPA responses prior to challenge and showed no significant changes in tissue mean LPA responses postchallenge, and 100% were protected against virulent virus challenge. By comparison, both group 2 and controls had significantly lower LPA responses at challenge and both groups showed significant increases in mean LPA responses postchallenge. Eighty-one percent of group 2 and 100% of control pigs shed challenge virus, and both groups developed diarrhea that was similar in severity postchallenge. The virus-specific LPA responses of blood MNC mirrored those of intestinal MNC, albeit at a reduced level and only at early times postinoculation or postchallenge in all pigs. In a separate study evaluating antibody-secreting-cell responses of these pigs (L. Yuan, L.A. Ward, B.I. Rosen, T.L. To, and L.J. Saif, J. Virol. 70:3075-3083, 1996), we found that the magnitude of a tissue's LPA response positively correlated with the numbers of virus-specific antibody-secreting cells for that tissue, supporting the hypothesis that the LPA assesses T-helper-cell function. The magnitude of LPA responses in systemic and intestinal tissues also strongly correlated with the degree of protective immunity elicited by the inoculum (p = 0.81). We conclude that blood may provide a temporary "window" for monitoring intestinal T cells and that the LPA can be used to assess protective immunity to human rotaviruses.