Antigen-specific B-cell responses to porcine reproductive and respiratory syndrome virus infection.
Porcine reproductive and respiratory syndrome virus (PRRSV) causes an acute, viremic infection of 4 to 6 weeks, followed by a persistent infection lasting for several months. We characterized antibody and B-cell responses to viral proteins in acute and persistent infection to better understand the immunological basis of the prolonged infection. The humoral immune response to PRRSV was robust overall and varied among individual viral proteins, with the important exception of a delayed and relatively weak response to envelope glycoprotein 5 (GP5). Memory B cells were in secondary lymphoid organs, not in bone marrow or Peyer's patches, in contrast to the case for many mammalian species. Potent anti-PRRSV memory responses were elicited to recall antigen in vitro, even though a second infection did not increase the B-cell response in vivo, suggesting that productive reinfection does not occur in vivo. Antibody titers to several viral proteins decline over time, even though abundant antigen is known to be present in lymphoid tissues, possibly indicating ineffective antigen presentation. The appearance of antibodies to GP5 is delayed relative to the resolution of viremia, suggesting that anti-GP5 antibodies are not crucial for resolving viremia. Lastly, viral infection had no immunosuppressive effect on the humoral response to a second, unrelated antigen. Taking these data together, the active effector and memory B-cell responses to PRRSV are robust, and over time the humoral immune response to PRRSV is effective. However, the delayed response against GP5 early in infection may contribute to the prolonged acute infection and the establishment of persistence.
Mulupuri
Prasad
P
Department of Veterinary & Biomedical Sciences, University of Minnesota, 1971 Commonwealth Avenue, St. Paul, MN 55108, USA.
Zimmerman
Jeffrey J
JJ
Hermann
Joseph
J
Johnson
Craig R
CR
Cano
Jean Paul
JP
Yu
Wanqin
W
Dee
Scott A
SA
Murtaugh
Michael P
MP
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D001854:Bone Marrow Cells / Q000276:immunology; D007156:Immunologic Memory / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D014066:Palatine Tonsil / Q000166:cytology / Q000276:immunology; D010581:Peyer's Patches / Q000166:cytology / Q000276:immunology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013552:Swine; D013997:Time Factors; D014764:Viral Proteins / Q000276:immunology; D014766:Viremia
D000914:Antibodies, Viral; D000956:Antigens, Viral; D014764:Viral Proteins