Toll-like receptors, IFN-γ and IL-12 expression in bovine leukemia virus-infected animals with low or high proviral load

NIETO FARIAS VICTORIA; LENDEZ PAMELA ANAHI; MARIN MAIA; QUINTANA SILVINA; MARTINEZ CUESTA LUCIA; CERIANI MARIA CAROLINA; DOLCINI GUILLERMINA

RESEARCH IN VETERINARY SCIENCE

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2016

0034-5288

Bovine leukemia virus (BLV) infection is widespread mainly in dairy cattle and 5?10% of infected animals will die dueto lymphosarcoma; most cattle remain asymptomatic but 30% develop persistent lymphocytosis (PL). BLV transmissiondepends on infected cell exchange and thus, proviral load is determinant. Understanding the mechanisms which governthe control of viral dissemination will be desirable for the design of effective therapeutic or preventive strategies for BLV.The development of high proviral load (HPL) or low proviral load (LPL) might be associated to genetic factors and humoralimmune responses, however cellular responses are not fully described. We aimed to characterize cytokines andtoll-like receptors (TLR) expression related to the proviral load profiles. IFN-γ and IL-12 mRNA expression level wassignificantly higher in PBMC from infected cattle (LPL n = 6 and HPL n = 7) compared to uninfected animals (n = 5).While no significant differences were observed in IL-12 expression between LPL and HPL group, IFN-γ expression wassignificantly higher in LPL animals. Infected cattle exhibited higher expression levels of TLR3, 7?9. Animals with HPLhad significantly higher expression of TLR7/8 than uninfected cattle. TLR8 and TLR9 were up-regulated in HPL group,and TLR3 was up-regulated in LPL group. This is the first report related to TLR gene expression in BLV infected cattleand represents evidence of the involvement of these receptors in BLV recognition. Further studies on different subpopulationsof immune cells may help clarify their role in response to BLV and its consequences on viral dissemination