Research Article Diethylstilbestrol Exposure in Neonatal Mice Induces Changes in the Adulthood in the Immune Response to Taenia crassiceps without Modifications of Parasite Loads Karen E. Nava-Castro, 1 Jorge Morales-Montor, 2 Alejandra Ortega-Hernando, 2 and Ignacio Camacho-Arroyo 1 1 Facultad de Qu´ ımica, Departamento de Biolog´ ıa, Universidad Nacional Aut´ onoma de M´ exico, Ciudad Universitaria, 04510 M´ exico, DF, Mexico 2 Departamento de Inmunolog´ ıa, Instituto de Investigaciones Biom´ edicas, Universidad Nacional Aut´ onoma de M´ exico, 04510 M´ exico, DF, Mexico Correspondence should be addressed to Karen E. Nava-Castro; karenelizabeth.navacastro@gmail.com and Ignacio Camacho-Arroyo; camachoarroyo@gmail.com Received 29 April 2014; Revised 17 July 2014; Accepted 1 August 2014; Published 28 August 2014 Academic Editor: Luis I. Terrazas Copyright © 2014 Karen E. Nava-Castro et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Industrial growth has increased the exposition to endocrine disruptor compounds (EDC’s), which are exogenous agents with agonist or antagonist action of endogenous steroid hormones that may afect the course of parasite infections. We wanted to determine if the exposure to diethylstilbestrol (DES), an estrogen agonist, to both male and female mice afected the immune response and their susceptibility to T. crassiceps cysticercosis. In all infected groups, females showed higher parasite loads than males, and neonatal DES administration did not modify this pattern. In the spleen, noninfected mice showed sex-related diferences in the percentage of the CD8+ subpopulation, but DES decreased the percentage of CD3+, CD19+, and CD8+ subpopulations in infected mice. In the mesenteric lymphatic node (MNL), DES showed a dimorphic efect in the percentage of CD19+ cells. Regarding estrogen receptor alpha (ER-) expression, DES treatment induced a reduction in the expression of this receptor in both noninfected female and male mice in the spleen, which was decreased only in males in CD3+ and CD8+ lymphocytes in MNL cell subpopulations. Our study is the frst one to demonstrate that DES neonatal treatment in male and female mice afects the immune cell percentage, without efect on the susceptibility to T. crassiceps cysticercosis. 1. Introduction Endocrine disruptor compounds (EDC’s) are exogenous agents that interfere with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body with agonist or antagonist action of endogenous hor- mones. EDCs are from natural sources such as xenoestrogens or have a chemical origin such as diethylstilbestrol (DES), Bisphenol A (BPA), TCDD, and DTT among others [1]. In particular, DES was administered to millions of pregnant women to prevent miscarriages caused by progesterone defciency between 1940 and 1971 [2]. Studies on neona- tal treatment with DES in animal models have reported negative efects on the normal morphology and physiology of the reproductive tract [3, 4]. Several studies have also demonstrated that DES exposure during the fetal and pre- natal stages induces tumor formation on estrogen-sensitive tissue in several mice and hamsters models. In adult mice, DES administration also induces cancer in mammary gland, cervix, and uterus. It can also increase the incidence of leukemia and lymphoid tissue tumors [2, 5]. Te efect of EDC’s on the immune cell function has been barely studied. In humans, prenatal exposure to some EDC’s such as DES increased lymphocyte proliferation in response to some chemical mitogens such as Concanavalin A or phytohemagglutinin [5]. DES administration at gestational eighteen day in mice also reduces thymocyte number without changes in thymocyte subpopulations [6]. Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 498681, 9 pages http://dx.doi.org/10.1155/2014/498681