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Anti-tumor necrosis factor VNAR single domains reduce lethality and regulate underlying inflammatory response in a murine model of endotoxic shock

2013; BioMed Central; Volume: 14; Issue: 1 Linguagem: Inglês

10.1186/1471-2172-14-17

1471-2172

Rafael Bojalil, María Teresa Mata-González, Fausto Sánchez‐Muñoz, Yepci Yee, Iván Argueta, Lucía Bolaños, Luis Manuel Amezcua-Guerra, Tanya A. Camacho-Villegas, Edna Sánchez‐Castrejón, Walter Jakob García-Ubbelohde, Alexei F. Licea-Navarro, Ricardo Márquez-Velasco, Jorge Paniagua-Solís,

Influenza Virus Research Studies

Abstract Background In sepsis, tumor necrosis factor (TNF) is the key factor triggering respiratory burst, tissue injury and disseminated coagulation. Anti-TNF strategies based on monoclonal antibodies or F(ab’) 2 fragments have been used in sepsis with contradictory results. Immunoglobulin new antigen receptors (IgNAR) are a unique subset of antibodies consisting of five constant ( C NAR) and one variable domains ( V NAR). V NAR domains are the smallest, naturally occurring, antibody-based immune recognition units, having potential use as therapy. Our aim was to explore the impact of an anti-TNF V NAR on survival in an experimental model of endotoxic shock. Also, mRNA expression and serum protein of several inflammatory molecules were measured. Results Endotoxic shock was induced by lipopolysaccharide (LPS) in male Balb/c mice. Animals were treated with anti-TNF V NAR domains, F(ab’) 2 antibody fragments, or saline solution 15 minutes before, 2 h and 24 h after lethal dose 100 (LD 100 ) LPS administration. TNF blockade with either V NAR domains or F(ab’) 2 fragments were associated with lower mortality (60% and 75%, respectively) compared to LD 100 . Challenge with LPS induced significant production of serum TNF and interleukins -10 and -6 at 3 h. After that, significant reduction of IL-6 at 24 h (vs 3 h) was shown only in the V NAR group. Nitrites level also increased in response to LPS. In liver, TNF and IL-10 mRNA expression showed a pro-inflammatory imbalance in response to LPS. Blocking TNF was associated with a shift towards an anti-inflammatory status; however, polarization was more pronounced in animals receiving F(ab’) 2 fragments than in those with V NAR therapy. With regard to IL-6, gene expression was increased at 3 h in all groups. TNF blockade was associated with rapid and sustained suppression of IL-6 expression, even more evident in the V NAR group. Finally, expression of inducible-nitric oxide synthase (iNOS) increased in response to LPS at 3 h, but this was decreased at 24 h only in the anti-TNF V NAR group. Conclusions Anti-TNF V NAR single domains improved survival in a murine model of endotoxic shock. Protection was associated with regulation in the TNF/IL-10 balance, attenuation of IL-6 and iNOS gene expression in the liver as well as decreased serum IL-6 concentration.