Effect of polyoxyethylene and polyoxypropylene nonionic block copolymers on performance and recruitment of immune cell subsets in weaned pigs

Abstract

BackgroundBecause European-wide directives are restricting the non-clinical use of antibiotics as in-feed growth promotors in swine production, there is an intensive search for alternative strategies for control and prevention of losses among young pigs. With the growing knowledge of the porcine immune system and its endogenous modulation, it has been clearly established that exogenous immunomodulation using adjuvants and immune response modifiers (IRMs) represents an important prophylactic/therapeutic approach in the prevention/treatment of both stress- and microbial-induced disorders that accompaning weaning. However, it is essential to select a fully evaluated agent which may act either as a nonspecific IRM or synergistically as an adjuvant with vaccines. The synthetic macromolecules with a long history as adjuvant and IRM are nonionic block copolymers which consist of polyoxyethylene (POE) and polyoxypropylene (POP) molecules.MethodsThe aim of this work was to evaluate the effectiveness of POE-POP given as a single peroral dose on productivity parameters such as body weight gain, feed intake and feed conversion ratio, and systemic and intestinal immune parameters by assessing the proportions of CD45+ lymphoid cells, CD4+ and CD8+ T cells, and CD21+ B cells in the peripheral blood as well as the number of CD45RA+ naive lymphoid cells residing in the ileal mucosa in weaned pigs during a follow-up study 5 weeks after the treatment.ResultsPigs treated with POE-POP had better feed intake (+ 14.57%), higher average body mass at the end of the experiment (20.91 kg vs. 17.61 kg), and higher body weight gain in relation to Day 0 (191.63% vs. 144.58%) as well as in relation to nontreated pigs (+ 18.74%), with a lower feed conversion ratio (− 30.26%) in comparison to the control pigs. A much lower diarrhea severity score (5 vs. 54) was recorded in pigs treated with POE-POP (− 90.74%) than in the control pigs. A higher average diarrhea severity (ADS) was recorded in the control pigs (1.54 vs. 0.14), whereas the treatmant group had much a lower ADS ratio (− 90.91%) after 35 days of the experiment. The pigs that were treated with POE-POP had an increased proportion of CD45+, CD4+ and CD8+ cells at Day 21 (at p < 0.05, p < 0.05 or p < 0.01, respectively), Day 28 (at p < 0.01, respectively) and Day 35 (at p < 0.01, p < 0.05 or p < 0.01, respectively) as well as of CD21+ cells at Day 28 (p < 0.05) and Day 35 of the experiment (p < 0.01). Also, these pigs had more numerous CD45RA+ cells in interfollicular (p < 0.05) and follicular areas (p < 0.01) of the ileal Peyer’s patches than did control pigs.ConclusionThis property of POE-POP to induce recruitment of circulating and intestinal immune cell subsets in weaned pigs may allow the use of IRM-active block copolymers as adjuvants for vaccines, particularly those orally delivered and targeted to the gut-associated lymphoid tissues that are well known to promote rather tolerogenic than protective immune responses.

In-feed supplementation of clinoptilolite favourably modulates intestinal and systemic immunity and some production parameters in weaned pigs

“…Since we did not find any data on the influence of dietary CPL on cellular immune responses either within porcine peripheral blood or the GALT, we can only discuss our results in relation to our previous research obtained following a single per os administration of the synthetic immunomodulators polyoxyethylene and polyoxypropylene (POE-POP) and levamisole (LEVA) as potential alternatives to in-feed AGP in the same model of weaned pigs (Valpotic et al 2013;Valpotic et al 2014 + T cells. The proportion of the latter subset was slightly increased on Day 35 of the experiment, but we did not follow-up these parameters further.…”

“…In the past two decades intensive efforts have been focused on the development of alternatives to AGP to maintain swine health and performance. Many research papers and excellent reviews have been published on this subject, describing immunomodulators of natural (Gallois and Oswald 2008;Gallois et al 2009) and synthetic origin (Valpotic et al 2013;Valpotic et al 2014), probiotics (Cho et al 2011), prebiotics (Halas and Nochta 2012) as well as less traditional alternatives such as selected organic acids, amino acids, protein sources, plant extracts (Lalles et al 2009), peptides, clay minerals, egg yolk antibodies, essential oils, fatty acids, rare earth elements (Thacker 2013) and naturally extracted clay smectite or artificially composed zeolite with antibacterial activities in the gut (Almeida et al 2013;Islam et al 2014). However, only a small number of these have been shown to be effective.…”

Effect of mannan oligosaccharide supplementation on blood and intestinal immune cells, bacteria numbers and performance in weaned pigs

“…Many bioactive substances of either natural (such as the yeast derivatives glucans and mannans, herbaceous and ligneous plant extracts, seaweed extracts, animal products and by-products, i.e. colostrum, lactoferrin and spray-dried plasma) or synthetic origin (such as levamisole and polyoxyethylenepolyoxypropylene copolymer) have been investigated as alternatives to AGP but only few have been shown to be effective (Gallois et al 2009;Valpotić et al 2013;Valpotić et al 2014). Among these, a variety of polysaccharides from different natural sources, such as yeast derivatives β-glucans and mannans are known to modulate the composition and activity of gut microbiota, stimulate immune functions and improve disease resistance (Šperanda et al 2008;Yin et al 2008).…”

Effect of stress on performance and physiological functions in pigs

“…Метою дослідження Н. Valpotić та співавт. (Valpotić et al, 2013) було оцінити ефективність згодовування відлученим поросятам поліоксиетиленуполіоксипропілену (ПOE-ПOП) у вигляді одноразової пероральної дози. Під час дослідження враховували продуктивність, приріст маси тіла, кількість спожитого корму та коефіцієнт його перетравності, системні та травні імунні параметри.…”