Comparative Biochemical and Functional Analysis of Viral and Human Secreted Tumor Necrosis Factor (TNF) Decoy Receptors

Abstract

Background: Poxvirus encodes up to four TNF decoy receptors (vTNFRs) that mimic etanercept, an anti-TNF drug used in the clinic. Results: vTNFRs display differences in ligand specificity and inhibitory potency. Conclusion: Some vTNFRs are more specific and potent TNF inhibitors than etanercept. Significance: This study may help to understand the role of vTNFRs in pathogenesis and improve the anti-TNF treatments.

Poxvirus-encoded TNF decoy receptors inhibit the biological activity of transmembrane TNF

“…The summary of the mean fluorescent intensities presented in Fig. 1(d) shows that CPXV CrmC was the vTNFR with the lowest tmTNF binding capacity, which agrees with the lower affinity for human sTNF (VARV CrmB, K D 0.28 nM; ECTV CrmD, K D 0.41 nM; CPXV CrmC, K D 2.42 nM) as reported previously by us (Pontejo et al, 2015).…”

“…These vTNFRs have been identified as TNF only, for CrmE and CrmC (Reading et al, 2002;Saraiva & Alcami, 2001;Smith et al, 1996), or as TNF and lymphotoxin a (LTa) inhibitors, for CrmB and CrmD (Hu et al, 1994;Loparev et al, 1998). In addition, we recently identified LTb as a new ligand for CrmD and CrmB (Pontejo et al, 2015). Importantly, CrmB and CrmD, but not CrmC and CrmE, contain an extended Cterminal chemokine-binding domain termed SECRET (Alejo et al, 2006).…”

“…However, CPXV strains express three to four different vTNFRs (Alzhanova & Früh, 2010). We recently defined and compared the inhibitory and affinity properties of all these vTNFRs for their soluble TNFSF ligands (Pontejo et al, 2015). Here, we tested the tmTNF binding and blocking ability of ECTV CrmD, VARV CrmB, CrmE from the CPXV strain Elephantpox and the three vTNFRs expressed by the CPXV strain Brighton Red, CrmB, CrmC and CrmD.…”

“…2b). The protein hTNFR2 was purified as described previously (Pontejo et al, 2015). To check that this cytotoxicity was not induced by remaining traces of sTNF in the fixed RAW 264.7 cell preparation, an equivalent cell volume of supernatant from fixed LPS-induced RAW 264.7 cells after the PBS washes was added to L929 cells and, as expected, no cytotoxic effect was detected (medium, +LPS) (Fig.…”

“…Here, we tested the tmTNF binding and blocking ability of ECTV CrmD, VARV CrmB, CrmE from the CPXV strain Elephantpox and the three vTNFRs expressed by the CPXV strain Brighton Red, CrmB, CrmC and CrmD. All these genes were cloned in frame with a Cterminal V5-His tag for their expression using recombinant baculoviruses and purified as described previously (Pontejo et al, 2015).…”