CD5 Is Dissociated from the B-Cell Receptor in B Cells from Bovine Leukemia Virus-Infected, Persistently Lymphocytotic Cattle: Consequences to B-Cell Receptor-Mediated Apoptosis
AUTOR(ES)
Cantor, Glenn H.
FONTE
American Society for Microbiology
RESUMO
Bovine leukemia virus (BLV), a retrovirus related to human T-cell leukemia virus types 1 and 2, can induce persistent nonneoplastic expansion of the CD5+ B-cell population, termed persistent lymphocytosis (PL). As in human CD5+ B cells, we report here that CD5 was physically associated with the B-cell receptor (BCR) in normal bovine CD5+ B cells. In contrast, in CD5+ B cells from BLV-infected PL cattle, CD5 was dissociated from the BCR. In B cells from PL cattle, apoptosis decreased when cells were stimulated with antibody to surface immunoglobulin M (sIgM), while in B cells from uninfected cattle, apoptosis increased after sIgM stimulation. The functional significance of the CD5-BCR association was suggested by experimental dissociation of the CD5-BCR interaction by cross-linking of CD5. This caused CD5+ B cells from uninfected animals to decrease apoptosis when stimulated with anti-sIgM. In contrast, in CD5+ B cells from PL animals, in which CD5 was already dissociated from the BCR, there was no statistically significant change in apoptosis when CD5 was cross-linked and the cells were stimulated with anti-sIgM. Disruption of CD5-BCR interactions and subsequent decreased apoptosis and increased survival in antigenically stimulated B cells may be a mechanism of BLV-induced PL.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=114078Documentos Relacionados
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