IMMUNITY TO PORCINE RUBULAVIRUS INFECTION IN ADULT SWINE

The immune response against the porcine rubulavirus was analyzed in ex perimentally infected adult pigs. High titers of virus neutralizing an d hemagglutinating inhibitory antibodies were identified in infected a nimals. The antibody specificity was directed towards HN, M, and NP ru bula virion proteins; immunodominance of HN proteins was demonstrated. Peripheral blood mononuclear cells from infected, but not from non-in fected pigs proliferated in vitro in response to virus antigenic stimu li, showing a bell-shaped plot with the highest peak at 5 weeks post-i nfection. Virus-induced lymphoblasts expressed CD4(+)CD8(+) phenotype, whereas lectin-induced lymphoblasts were mainly identified as CD4(+)C D8(-) cells. Phenotype analysis of freshly prepared PBMC revealed incr eased number of both monocytes (PoM1(+)) and total T lymphocytes (CD2( +)) early during infection, with reduced values of B lymphocytes at 4 weeks post-infection. Decrease in CD4(+)CD8(-) blood cells was observe d at 3 weeks post-infection, whereas both CD4(-)CD8(+) and CD4(+)CD8() cells increased 1 and 4 weeks post-infection, respectively. This wor k discusses the relevance of CD4(+)CD8(+) T cells in the control of po rcine rubulavirus infection. (C) 1998 Elsevier Science B.V. All rights reserved.