title: Estrogen receptor profiles in human peripheral blood lymphocytes.
abstract: Estrogens are well-known regulators of the immune responses. Most of their effects are mediated by two receptors: estrogen receptor (ER)alpha and ERbeta. Up to date the presence of intracellular ER in human immune cells represents a controversial issue, while their surface membrane expression has scarcely been explored. In this study we investigated the intracellular and cell surface expression of ERalpha and ERbeta in human peripheral blood lymphocytes (PBL) by flow and static cytometry as well as by Western Blot. To this aim we used five different commercial antibodies recognizing distinct ER epitopes. We observed that CD4(+) and CD8(+) T lymphocytes, B lymphocytes and NK cells contain intracellular ERalpha and ERbeta, being the ERalpha46 isoform the most represented ER. However, significant differences could be observed among the antibodies studied in terms of immunoreactivity and specificity. Importantly, we also found a cell surface expression of ERalpha46 isoform. We also observed that a membrane-impermeant form of E2 induced a rapid phosphorylation of extracellular signal-regulated kinase (ERK), a significant proliferation of T lymphocytes, and IFN-gamma production by NK cells, thus suggesting the expression of a functional mERalpha. In conclusion our data could provide new insights as concerns the estrogen-related mechanisms of immune system modulation. They also suggest the need for a reappraisal of the experimental conditions for the characterization of the ER expression.
authors.affiliation: Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Pierdominici
authors.forename: Angela
authors.initials: A
authors.lastname: Maselli
authors.forename: Tania
authors.initials: T
authors.lastname: Colasanti
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Giammarioli
authors.forename: Federica
authors.initials: F
authors.lastname: Delunardo
authors.forename: Davide
authors.initials: D
authors.lastname: Vacirca
authors.forename: Massimo
authors.initials: M
authors.lastname: Sanchez
authors.forename: Antonello
authors.initials: A
authors.lastname: Giovannetti
authors.forename: Walter
authors.initials: W
authors.lastname: Malorni
authors.forename: Elena
authors.initials: E
authors.lastname: Ortona
mesh_terms: D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000378:metabolism; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000378:metabolism; D055815:Young Adult
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D020033:Protein Isoforms