1. School of Medicine, Universidad Autonoma del Estado de México, Paseo Tollocan y Venustiano Carranza s/n, Col. Moderna de la Cruz, 50180 Toluca, State of Mexico, Mexico
2. Laboratory of Mucosal Immunity, Research and Graduate Section, Superior School of Medicine, Instituto Politecnico Nacional. Av. Plan de San Luis s/n, Col. Casco de Santo Tomas, Miguel Hidalgo 11350, Mexico City, Mexico