title: The sterile and tolerogenic fetal niche does not restrict the generation of CD4 T memory cells.
abstract: T-cell activation requires a sequence of signals derived from co-stimulatory receptors and from immunogens that may or may not be of infectious origin. This scenario provides the threshold of inflammatory stimulus needed for the induction of antigen-specific T cell responses. One of the dogmas of immunology stipulates that the activation of T lymphocytes is prevented in immunosuppressed or tolerogenic environments. However, it was shown recently that a healthy uterine environment that is considered sterile, therefore not exposed to infection, is capable of generating T memory cells with the capacity to differentiate lineage-specific inflammatory effector T-cell responses. The implications of this finding are discussed in this editorial.
authors.affiliation: Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21.941-590, Brazil.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Morrot
keywords: Memory T cells; immunological tolerance; placenta; pregnancy