Pathogenic Old World Arenaviruses Inhibit TLR2/Mal-Dependent Proinflammatory Cytokines In Vitro

Exonuclease Domain of the Lassa Virus Nucleoprotein Is Critical To Avoid RIG-I Signaling and To Inhibit the Innate Immune Response

“…4A). Even though TLR2 has been implicated in the response to lymphocytic choriomeningitis virus (LCMV) and MOPV (21) and the involvement of other TLRs recognizing RNA, such as TLR7, has also been suggested (22), we focused here on the RIG-I-mediated response.…”

Pro-inflammatory cytokines promote viral replication and cell cycle mediators in arenavirus-induced hepatitis.

“…However, both our in vitro research shown in this work and, as mentioned above, these pro-inflammatory responses via this pathway [62]. Thus, it seems possible that different species, human versus murine, respond differently to the virus, especially considering that LCMV's reservoir host is a rodent, as mentioned above.…”

“…Therefore, it is poorly understood why or how LASV and LCMV-WE LCMV-WE infection is immune-suppressive in macrophages [22,26,62,63], the timing and concentration of pro-inflammatory cytokines are two important factors that can lead to profoundly different outcomes, reviewed in [64,65]. In fact, TNF-α levels are increased transiently after surgical partial hepatectomy [56,66,67] and its "priming" effects on preparing hepatocytes for proliferation are gone after 48 hrs [60].…”

“…were shown to inhibit the TLR2/Mal-dependent production of cytokines that the non-pathogenic LCMV-ARM and MOPV did in fact stimulate with productive replication [62]. Therefore, in vitro data regarding pro-inflammatory response induced by pathogenic OW arenaviruses seem to differ according to cell species used (e.g.…”

The involvement of epithelial cells in arenavirus-induced pathogenesis.

“…Viral titers were determined using a standard plaque assay with minor modifications [167]. with a 0.45 micron filter as previously described [173,186].…”