Ex vivo stimulation of neonatal porcine peripheral blood mononuclear cells with oligosaccharides found in human milk

Abstract

Infant formulas lack the complex mixture of oligosaccharides (HMO) found in human milk, which may be pivotal to the development of the neonatal microbiota and immune system. Few comprehensive analyses of the direct effects of HMO on immune cells from neonates have been undertaken. Herein, peripheral blood mononuclear cells (PBMC) isolated from 10 and 23 day old (do) sow‐reared pigs were stimulated with HMO (2FL, 3FL, 3SL, 6SL, SL, LNFPIII, LnNT, sLeX and HMO isolated from human milk [iHMO]) for 72h. T cell phenotype, cytokine production and proliferation were measured by flow cytometry, ELISA and 3‐H thymidine incorporation. Of the HMO tested, none had significant effects on any parameters examined. However, developmental differences were found. PBMC from 23do pigs produced more cytokines, had a higher proportion of CD8+CD3+ T cells and proliferated less than those from 10do pigs. PBMC from 23do pigs made more IL‐10 in response to iHMO, PHA or PHA+iHMO than PBMC from 10do pigs. Only PHA or PHA+iHMO stimulation induced IL‐4 secretion, and 10do pigs produced nearly twice as much IL‐4 as 23do pigs. Lastly, PBMC from 10do pigs proliferated 6–10 times more in response to PHA stimulation than did PBMC from 23do pigs. In summary, while appropriate developmental responses were observed, direct effects of HMO on porcine PBMC phenotype, cytokine production or proliferation ex vivo were not detected. (Supported by Abbott Nutrition)