Quantitative Analysis of Interleukin-6 Expression in Porcine Spleen Cells and Alveolar Macrophages using Real-Time PCR

Expression of Toll-like receptors and downstream genes in lipopolysaccharide-induced porcine alveolar macrophages

The aim of the present study was to determine the age-related kinetic changes of Toll-like receptors (TLRs) and downstream genes expression, and secretion of cytokine in lipopolysaccharide (LPS) stimulated porcine alveolar macrophages (AM). For this purpose, AMs were isolated from 5-day-old newborn piglets and 120-day-old young pigs. mRNA expression and cytokine measurement was determined by quantitative real-time PCR and ELISA, respectively. First, AMs were incubated for 24 h in the absence or presence of increasing concentrations of LPS. Results showed the up-regulation of TLRs 2, 4, 5 and 9 mRNA from all concentrations of LPS used, as compared to non-stimulated cells, and TLR4 was the highest expression in both ages (P<0.05). Furthermore, quantitative analysis demonstrated increased expression of mRNAs encoding TLRs 2, 4, 5 and 9, LBP, CD14, MD2, MyD88, IRAK4 and TRAF6 in both ages in a time-dependant manner (P<0.05). Overall, LPS inducible mRNA for TLR4, LBP, CD14 and MyD88 had higher expression in newborn piglets compared with those of young pigs (P<0.05). The level of cytokine protein IL6 and TNFα in supernatant fluid significantly varied with time of incubation and age of animals. Their concentration increased immediately at 1 h after LPS stimulation and remained significantly higher up to 48 h in both ages. Production of pro-inflammatory cytokine protein IL6 and TNFα in supernatant was significantly higher in young pigs than those of piglets. This study suggests that differential age-related changes in the expression of TLRs and downstream genes, and pro-inflammatory cytokine could contribute to a different age-related innate immune response during pulmonary infection. Further investigation is warranted to determine the precise effects of LPS on porcine AMs by means of a functional study across a wider age range.

The mononuclear phagocyte system of the pig as a model for understanding human innate immunity and disease

The biology of cells of the mononuclear phagocyte system has been studied extensively in the mouse. Studies of the pig as an experimental model have commonly been consigned to specialist animal science journals. In this review, we consider some of the many ways in which the innate immune systems of humans differ from those of mice, the ways that pigs may address the shortcomings of mice as models for the study of macrophage differentiation and activation in vitro, and the biology of sepsis and other pathologies in the living animal. With the completion of the genome sequence and the characterization of many key regulators and markers, the pig has emerged as a tractable model of human innate immunity and disease that should address the limited, predictive value of rodents in preclinical studies.

Cytokine expression in colostrum-deprived pigs immunized and challenged with Haemophilus parasuis

The expression of several cytokines in spleen, pharyngeal lymph nodes, lung and brain after different immunization procedures and a challenge with 5 x 10(9) CFU of Haemophilus parasuis was compared. Five groups of colostrum-deprived pigs were used: vaccinated with (I) a bacterin, (II) an outer-membrane-protein-vaccine, (III) a recombinant transferring-binding protein B, (IV) exposed to a total dose of 10(5) CFU, and (V) not previously immunized. All pigs in groups III and V died, while all animals in group I, most of group IV and half of group II survived until the end of the experiment. IL-1alpha was found in significantly higher levels (p<0.05) in spleen, lymph nodes and brain of dead pigs, which could be explained by the major severity of lesions in these animals. However, IL-4, IL-10, TNF-alpha and IFN-gamma were expressed in significantly higher levels by survivors (for all the four cytokines in lymph nodes; for IL-4, IL-10 and TNF-alpha in spleen; for IL-4, TNF-alpha and IFN-gamma in lung, and only for TNF-alpha in brain), thus suggesting a role of these four cytokines in the adaptive response, which might contribute to protection against H. parasuis infection.

Quantitative analysis of inflammatory cytokines expression in peripheral blood mononuclear cells of the ferret (Mustela putorius furo) using real-time PCR

This study describes the expression pattern of cytokines, interferon-gamma (IFN-gamma), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and IL-10, produced by LPS stimulation in peripheral blood mononuclear cells (PBMCs) of the ferret (Mustela putorius furo). Real-time PCR was used with TaqMan probes, which were modified by dual-labeled probes (TAMRA/FAM), quantitative analysis of cytokine mRNA comparing the cytokine with the housekeeping gene, ferret GAPDH, as the relative C(t) value. Expression peaks of IFN-gamma, TNF-alpha, IL-6 mRNA occurred 2 h after LPS stimulation, whereas the IL-10 peak was 8 h post-LPS. In the present study, peak cytokine expression was detected within 8 h, similar to several other mammalian studies. This current study provides baseline information on inflammatory cytokines of ferret PBMCs.