In vitro and in vivo effects of an immunomodulator composed of Escherichiacoli lipopolysaccharide and Propionibacterium granulosum-inactivated cellsin pigs

The in vitro cytokine profiles of porcine alveolar macrophages and peripher al blood mononuclear cells (PBMC) were examined ly reverse transcription-po lymerase chain reaction or enzyme-linked immunosorbent assay after stimulat ion with the immunomodulatory compound INMD [lipopolysaccharide (LPS) and P ropionibacterium granulosum]. Expression of interleukin-1 (IL-1), IL-6, IL- 12 and tumour necrosis factor-alpha (TNF-alpha), but not of IL-10, was dete cted in INMD-stimulated alveolar macrophages. Stimulated PBMC expressed IL- 1, IL-2, IL-4, IL-6, IL-10 and IL-12 and secreted interferon-gamma (IFN-gam ma). In all cases, the level of response was lower with INMD than with E co li LPS alone, except for IFN-gamma, which was secreted in higher levels in INMD-stimulated cells. In a second experiment, the ex vivo effect of the ad ministration of INMD was evaluated using the product as a coadjuvant of a l ire attenuated Aujeszky's disease virus (ADV) vaccine. For this purpose, 85 8-10-week-old crossbred pigs were assigned to two groups (group A = 43 and group B = 42) and vaccinated with ADV. Group B received, simultaneously wi th the first dose of vaccine, an intramuscular dose of INMD equivalent to 2 0 mug/ml LPS and 250 mug/ml P. granulosum, while group A was given sterile saline solution as a placebo. At the time of vaccination, 97.6% (42 of 43) and 95.2% (40 of 42) of animals of groups A and B, respectively, had anti-g B maternal antibiotics. Of those animals, anti-gE ADV antibiotics were dete cted in 11.6% of animals of group A (five of 43) and 19% of group B (eight of 42). All animals were boosted with ADV vaccine alone 4 weeks later. Pigs tl, which INMD was administered together with the vaccine showed higher pr imary humoral responses than the vaccine-alone animals (P < 0.005). However , after boosting significant differences disappeared (P > 0.05).