Polyamine supplementation in infant formula: Influence on lymphocyte populations and immune system-related gene expression in a Balb/cOlaHsd mouse model Carlos Gómez-Gallego a, ⁎, Rafael Frias b , Gaspar Pérez-Martínez c , María José Bernal d , María Jesús Periago a , Seppo Salminen e , Gaspar Ros a , María Carmen Collado c a Department of Food Science and Nutrition, Faculty of Veterinary Sciences, University of Murcia, Campus de Espinardo, 30071 Espinardo, Murcia, Spain b Central Animal Laboratory, University of Turku, It. Pitkäkatu 4B, 20014 Turku, Finland c Institute of Agrochemistry and Food Technology, Spanish National Research Council (IATA-CSIC), 46980 Paterna, Valencia, Spain d Global Technology Centre for Infant Nutrition, Hero Group, 30820 Alcantarilla, Murcia, Spain e Functional Foods Forum, University of Turku, It. Pitkäkatu 4A, 20014 Turku, Finland abstract article info Article history: Received 19 November 2013 Accepted 30 January 2014 Available online 7 February 2014 Keywords: Breastfeeding Immune system Infant formula Polyamines Mouse model The aim of this work was to study whether the proportion of polyamine found in human milk, administered with a commercial infant formula, affected the maturation of the immune system in a BALB/cOlaHsd mouse model. Forty-eight pups (14-days old) were randomly assigned to four-day intervention groups: 1) breast-fed (normal lactation); 2) fed infant formula; and 3) two different groups fed with infant formula supplemented with two different amounts of polyamines. The influence of polyamine administration on lymphocyte populations in the blood, spleen, and mesenteric lymph nodes, as well as on the modulation of immune system-related gene expres- sion in the small intestine, was analyzed. The results demonstrated that polyamine supplementation induced an increase in splenic B cells to levels observed during normal lactation when compared with formula without supplementation. The correlation coefficients for the splenic lymphocyte populations increased with polyamine supplementation, with a dose-dependent effect. Our results demonstrate that polyamines influence gene expres- sion profile, mainly Cd1d1, Cd40, Hdac5, Hdac7, Clcf1 and Tlr4 compared with normal lactation. In general, the gene expression results verified that the expression of genes associated with immune system was similar in the group with high polyamine supplementation to that observed in the group with normal lactation. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction In the early period of life, both humans and rodents are exposed to a wide variety of microorganisms and dietary antigens, which drive the complete maturation of the intestinal and systemic immune system (Brandtzaeg, 2003). Breast milk contains bioactive substances, such as polyamines, which are known to be important for the development of the neonate's immune system by providing protection against infections, promoting oral tolerance, and controlling inflammatory responses (Newburg & Walker, 2007). Specific polyamines, including spermine (SPM), spermidine (SPD), and putrescine (PUT) have been identified in the breast milk of mammalian species, but their levels in most infant formulas are significantly lower than those in human milk (Buts, De Keyser, De Raedemaeker, Collette, & Sokal, 1995; Pollack, Koldousky, & Nishioka, 1992; Romain, Dandrifosse, Jeusette, & Forget, 1992). Dietary polyamines are rapidly absorbed in the small intestine (Seiler & Raul, 2007). They are essential for cell proliferation and differ- entiation (Löser, 2000) and are involved in DNA, RNA, and protein syn- thesis (Seiler & Raul, 2007). Previous studies have reported the essential role of polyamines in the development of the intestine (Sabater-Molina et al., 2009), the modulation of intestinal microbiota by polyamines (Gómez-Gallego et al., 2012), and positive effects on the developing spleen in mice (Jolois et al., 2002). The previously reported effects of milk polyamines on the maturation of the intestinal and systemic immune system (Pérez-Cano, González-Castro, Castellote, Franch, & Castell, 2010; Steege, Buurman, & Forget, 1997) suggest that supple- mentation of manufactured infant formulas with polyamines might improve immune functions of human infants in a manner similar to that observed by breastfeeding. Only a few studies (Jolois et al., 2002; Pérez-Cano et al., 2010; Steege et al., 1997) on the effects of polyamines during lactation in rodents have been reported. These were performed by orally administering a single polyamine and the pups continuing to be fed by their mothers. Thus, they were not well controlled for real polyamine ingestion due Food Research International 59 (2014) 8–15 Abbreviations: FACS, fluorescence-activated cell sorting; FITC, Fluorescein isothiocya- nate; HDAC, hystone deacetylase; PE, phycoerythrin; PUT, putrescine; SPD, spermidine; SPM, spermine. ⁎ Corresponding author. Tel.: +34 868 884798; fax: +34 868 888497. E-mail address: carlosgg@um.es (C. Gómez-Gallego). 0963-9969/$ – see front matter © 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodres.2014.01.066 Contents lists available at ScienceDirect Food Research International journal homepage: www.elsevier.com/locate/foodres