Ovariectomized OVA-sensitized mice display increased frequency of CD4(+)Foxp3(+) T regulatory cells in the periphery

• Published in: PloS one Vol. 8; no. 6; p. e65674
• Main Authors: Ligeiro de Oliveira, Ana Paula, Peron, Jean Pierre Schatzmann, Santos Franco, Adriana Lino, Golega, Beatriz Acceturi, Vieira, Rodolfo Paula, Ibanez, Olga Célia Martinez, Ribeiro, Orlando Garcia, Cabrera, Wafa Hanna Koury, De Franco, Marcelo, Oliveira-Filho, Ricardo Martins, Rizzo, Luiz Vicente, Vargaftig, Bernardo Boris, de Lima, Wothan Tavares
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 17-06-2013; Public Library of Science (PLoS)
• Subjects: 17β-Estradiol; Allergies; Alveoli; Animal models; Animals; Antigens; Asthma; Biology; Bronchoalveolar Lavage Fluid; Bronchus; CD4 antigen; CD4 Antigens - immunology; Cytokines; Cytokines - metabolism; Cytometry; Explants; Female; Flow Cytometry; Forkhead Transcription Factors - immunology; Foxp3 protein; Gonadal Steroid Hormones - physiology; Hormones; Hydrocarbons; Hypersensitivity; Hypersensitivity - immunology; Immune response; Immune system; Immunoregulation; Inflammation; Interleukin 10; Interleukin 13; Interleukin 17; Interleukin 4; Interleukin 5; Laboratories; Lavage; Lung - immunology; Lungs; Lymph nodes; Lymph Nodes - immunology; Lymphocytes; Lymphocytes T; Medicine; Menstruation; Mice; Mice, Inbred BALB C; Organs; Ovalbumin; Ovalbumin - administration & dosage; Ovariectomy; Pathogenesis; Pharmacology; Rodents; Sex; Sex hormones; Spleen; Spleen - immunology; T-Lymphocytes, Regulatory - immunology; Thymus
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0065674

It is well established that female sex hormones have a pivotal role in inflammation. For instance, our group has previously reported that estradiol has proinflammatory actions during allergic lung response in animal models. Based on these findings, we have decided to further investigate whether T regulatory cells are affected by female sex hormones absence after ovariectomy. We evaluated by flow cytometry the frequencies of CD4(+)Foxp3(+) T regulatory cells (Tregs) in central and peripheral lymphoid organs, such as the thymus, spleen and lymph nodes. Moreover, we have also used the murine model of allergic lung inflammation a to evaluate how female sex hormones would affect the immune response in vivo. To address that, ovariectomized or sham operated female Balb/c mice were sensitized or not with ovalbumin 7 and 14 days later and subsequently challenged twice by aerosolized ovalbumin on day 21. Besides the frequency of CD4(+)Foxp3(+) T regulatory cells, we also measured the cytokines IL-4, IL-5, IL-10, IL-13 and IL-17 in the bronchoalveolar lavage from lungs of ovalbumine challenged groups. Our results demonstrate that the absence of female sex hormones after ovariectomy is able to increase the frequency of Tregs in the periphery. As we did not observe differences in the thymus-derived natural occurring Tregs, our data may indicate expansion or conversion of peripheral adaptive Tregs. In accordance with Treg suppressive activity, ovariectomized and ovalbumine-sensitized and challenged animals had significantly reduced lung inflammation. This was observed after cytokine analysis of lung explants showing significant reduction of pro-inflammatory cytokines, such as IL-4, IL-5, IL-13 and IL-17, associated to increased amount of IL-10. In summary, our data clearly demonstrates that OVA sensitization 7 days after ovariectomy culminates in reduced lung inflammation, which may be directly correlated with the expansion of Tregs in the periphery and further higher IL-10 secretion in the lungs.