title: Impact of Estrogen Therapy on Lymphocyte Homeostasis and the Response to Seasonal Influenza Vaccine in Post-Menopausal Women.
abstract: It is widely recognized that changes in levels of ovarian steroids modulate severity of autoimmune disease and immune function in young adult women. These observations suggest that the loss of ovarian steroids associated with menopause could affect the age-related decline in immune function, known as immune senescence. Therefore, in this study, we determined the impact of menopause and estrogen therapy (ET) on lymphocyte subset frequency as well as the immune response to seasonal influenza vaccine in three different groups: 1) young adult women (regular menstrual cycles, not on hormonal contraception); 2) post-menopausal (at least 2 years) women who are not receiving any form of hormone therapy (HT) and 3) post-menopausal hysterectomized women receiving ET. Although the numbers of circulating CD4 and CD20 B cells were reduced in the post-menopausal group receiving ET, we also detected a better preservation of naïve B cells, decreased CD4 T cell inflammatory cytokine production, and slightly lower circulating levels of the pro-inflammatory cytokine IL-6. Following vaccination, young adult women generated more robust antibody and T cell responses than both post-menopausal groups. Despite similar vaccine responses between the two post-menopausal groups, we observed a direct correlation between plasma 17β estradiol (E2) levels and fold increase in IgG titers within the ET group. These findings suggest that ET affects immune homeostasis and that higher plasma E2 levels may enhance humoral responses in post-menopausal women.
authors: Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, California, United States of America.
authors: Flora
authors: F
authors: Engelmann
authors: Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, California, United States of America.
authors: Andrea
authors: A
authors: Rivera
authors: Division of Biostatistics, Department of Public Health and Preventive Medicine, Oregon Health and Science University, Portland, Oregon, United States of America.
authors: Byung
authors: B
authors: Park
authors: Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, Oregon, United States of America.
authors: Marci
authors: M
authors: Messerle-Forbes
authors: Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, Oregon, United States of America.|Division of Reproductive Sciences, Oregon National Primate Research Center, Beaverton, Oregon, United States of America.
authors: Jeffrey T
authors: JT
authors: Jensen
authors: Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, California, United States of America.|Division of Reproductive Sciences, Oregon National Primate Research Center, Beaverton, Oregon, United States of America.|Division of Pathobiology and Immunology, Oregon National Primate Research Center, Beaverton, Oregon, United States of America.
authors: Ilhem
authors: I
authors: Messaoudi
mesh_terms: D000917:Antibody Formation / Q000187:drug effects; D018791:CD4 Lymphocyte Count; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000097:blood; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D005260:Female; D006706:Homeostasis / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007252:Influenza Vaccines / Q000276:immunology*; D007378:Interleukins / Q000097:blood; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000187:drug effects* / Q000502:physiology; D008593:Menopause / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D008875:Middle Aged; D011374:Progesterone / Q000097:blood
chemical_list: D007252:Influenza Vaccines; D007378:Interleukins; D011374:Progesterone; D004958:Estradiol