First Author | Browne EP | Year | 2013 |
Journal | J Virol | Volume | 87 |
Issue | 13 | Pages | 7357-66 |
PubMed ID | 23616654 | Mgi Jnum | J:198442 |
Mgi Id | MGI:5496745 | Doi | 10.1128/JVI.00788-13 |
Citation | Browne EP (2013) Toll-Like Receptor 7 Inhibits Early Acute Retroviral Infection through Rapid Lymphocyte Responses. J Virol 87(13):7357-66 |
abstractText | Early events during retroviral infection play a critical role in determining the course of infection and pathogenesis, but the mechanisms that regulate this phase of infection are poorly understood. Toll-like receptor 7 (TLR7) is required for promoting germinal center reactions and virus-specific neutralizing antibodies at later time points postinfection, but TLR7's role in early acute infection has not been determined. By infecting TLR7-deficient mice with a retroviral pathogen, Friend virus (FV), I determined that TLR7 potently inhibits retroviral replication during the first 5 days of infection and is required for rapid secretion of virus-specific IgM and interleukin-10 (IL-10) in response to infection. Although the IgM response was nonneutralizing, plasmas from wild-type mice but not TLR7-deficient mice inhibited FV replication when passively transferred to infected mice, suggesting an indirect mechanism of antibody function. Interestingly, IL-10 was secreted primarily by CD4 T cells, and IL-10-deficient mice also exhibited accelerated early virus spread, demonstrating that this response inhibits acute infection. Surprisingly, TLR7-deficient mice exhibited normal or elevated secretion of proinflammatory cytokines during acute infection, revealing the existence of a TLR7-independent retrovirus-sensing pathway that drives inflammatory cytokine secretion. Together, these results establish a previously unappreciated role for lymphocytes in mediating rapid TLR7-dependent inhibition of early retroviral infection through nonneutralizing IgM and IL-10. |