Feline interleukin-8 expression in peripheral blood mononuclear cells induced by egg white derivatives

Expression of biologically active recombinant ferret (Mustela putorius furo) interleukin-8 from Escherichia coli

The authors expressed recombinant ferret interleukin-8 protein (rfrIL-8) in Escherichia coli as a glutathione-S-transferase fusion protein. Western blot analyses revealed that anti-ovine IL-8 antibody reacted with rfrIL-8 at 10 kDa. To confirm that the rfrIL-8 was biologically active, the authors examined chemotaxis and respiratory burst activity of ferret polymorphonuclear blood cells (PMNs) exposed to rfrIL-8. The rfrIL-8 strongly induced chemotactic and respiratory burst activities in a statistically significant manner as compared with a negative control. Thus, the authors were able to successfully express biologically active rfrIL-8.

Trans-10,cis-12-conjugated linoleic acid increases phagocytosis of porcine peripheral blood polymorphonuclear cellsin vitro

Trans-10,cis-12-conjugated linoleic acid (t10c12-CLA) has been shown to alter immune function. PPARγ has been shown to potentially play an important role in regulating inflammatory and immune responses by modulating the activity of monocytes and macrophages. Previous studies have indicated that the phagocytic capacity of porcine peripheral blood polymorphonuclear cells (PMN) was enhanced by the culture supernatant fraction from t10c12-CLA-stimulated porcine peripheral blood mononuclear cells (PBMC) but not by t10c12-CLA itself. In the present study, we examined the effects of t10c12-CLA on PPARγ and TNF-α expression of porcine PBMC and the phagocytic capacity of PMN. t10c12-CLA increased TNF-α mRNA expression and production by PBMC. The phagocytic capacity of porcine PMN was enhanced by either culture supernatant fraction from PBMC treated with t10c12-CLA or recombinant porcine (rp) TNF-α. Anti-rpTNF-α polyclonal antibody inhibited the enhancement of PMN phagocytic capacity. t10c12-CLA also up regulated PPARγ mRNA expression in porcine PBMC. Bisphenol A diglycidyl ether, a PPARγ antagonist, not only completely negated the t10c12-CLA-stimulating effects on TNF-α expression and production by porcine PBMC, but also decreased the enhancement of PMN phagocytic capacity by the t10c12-CLA-stimulated porcine PBMC culture supernatant fraction. These results suggest that t10c12-CLA has an immunostimulating effect on porcine PMN phagocytic capacity, which is mediated by TNF-α from PBMC via a PPARγ-dependent pathway.

Induction of interleukin-8 expression in porcine peripheral blood mononuclear cells by trans10-cis12 conjugated linoleic acid

The chemotaxis of porcine peripheral blood polymorphonuclear cells (PMN) was enhanced by culture supernatant from peripheral blood mononuclear cells (PBMC) treated with trans10-cis12 (10t-12c) conjugated linoleic acid (CLA) or by porcine recombinant (pr) interleukin (IL)-8. To identify this chemotactic inducing factor, the culture supernatant from 10t-12c CLA treated PBMC was partially purified by gel filtration. Only fraction 9 contained enhanced PMN chemotactic activity. The chemotactic activity of fraction 9 was inhibited by an anti-prIL-8 polyclonal antibody (pAb). Porcine IL-8 mRNA expression analyzed by a reverse transcriptase-polymerase chain reaction (RT-PCR) assay was increased in PBMC by the addition of 10t-12c CLA. This study strongly suggests that the immunoenhancing effect of CLA on the chemotactic response of porcine PMN is mediated through IL-8 produced by CLA treated PBMC.

Egg white derivatives induce tumor necrosis factor-α expression in porcine peripheral blood mononuclear cells

Porcine PBMC derived phagocytic activity in peripheral blood polymorphonuclear cells (PMN) induced by egg white derivatives (EWD) treatment was analyzed at the protein and mRNA level. EWD alone failed to induce phagocytic activity of PMN measured by flow cytometry. But PMN phagocytosis was enhanced by culture supernatant from PBMC treated with EWD, human (h)rTNF-alpha and porcine (p)rIL-1beta, respectively. To identify this phagocytic inducing factor, the culture supernatant was partially purified by gel filtration. Only fraction 8 revealed the enhanced PMN phagocytic activity. This fraction also had a high cross-reactivity with anti-prTNF-alpha polyclonal (p)Ab but not with anti-prIL-1beta pAb, as measured by ELISA, indicating that the culture supernatant from PBMC treated with EWD was independent from IL-1beta. The enhanced PMN phagocytic activity of fraction 8 was also inhibited by anti-prTNF-alpha pAb. Both fraction 8 and hrTNF-alpha produced a single protein band between 16 and 18kDa upon analysis by sodium-dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting using anti-prTNF-alpha pAb, suggesting that the promoter of PMN phagocytosis is TNF-alpha, a 16-18 kDa protein produced by EWD-stimulated PBMC. Porcine TNF-alpha mRNA expression in porcine PBMC analyzed by RT-PCR was also increased by addition of EWD. This study strongly suggests that the immunoenhancing effect of EWD on the phagocytic response of porcine PMN is mediated through TNF-alpha produced by PBMC stimulated with EWD. In addition, the expression of porcine TNF-alpha on PBMC is also increased when stimulated with EWD.