When needed, 5?g/ml rhGH was added

When needed, 5?g/ml rhGH was added. Enzyme-Linked Immunoassay Microtiter plates were coated with chicken type II collagen in PBS (5?g/ml; 90?min, 37C). reduced the severity of established CIA as well as the inflammatory environment, which also shows a GH effect on arthritis progression. These results indicate that GH prevents inflammatory joint destruction in CIA. Our Drospirenone findings demonstrate a modulatory GH role in immune system function that contributes to alleviating CIA symptoms and underlines the importance Drospirenone of endocrine regulation of the immune response. and studies also demonstrate GH involvement in immune regulation, and the GH receptor is expressed by several leukocyte subpopulations (6). GH mediates thymic development (7), promotes T cell engraftment in severe combined immunodeficiency mice (8), improves B cell responses and antibody production (9, 10), and modulates NK cell (11) and macrophage activity (12) as well as Th1/Th2 and humoral immune responses (13). Some reports describe beneficial effects of GH administration in autoimmunity. GH administration and neutralization of TNF reduce mucosal inflammation in experimental colitis (14); by altering tolerization mechanisms such as the cytokine environment, macrophage polarization, activation of the suppressor T cell population, and Th17?cell plasticity, GH also reduces type I diabetes development (15). Rheumatoid arthritis (RA) is the most prevalent inflammatory autoimmune disease worldwide. Its main clinical feature is chronic inflammation in joints, associated with bone and cartilage destruction (16). The RA spectrum and disease progression are governed by immune, genetic, and environmental factors (17). Its origin nonetheless lies in an inappropriate inflammatory reaction derived from deregulation of the adaptive and/or innate branches of the immune response. During RA development, there is active proliferation of endothelial cells and synovial fibroblasts; the synovium displays features of chronic inflammation, including massive leukocyte infiltration of innate (macrophages, NK, and dendritic cells; DC) and adaptive (CD4+ T and B cells) immune response cells (16). Using collagen-induced arthritis (CIA) as a model of RA, we observed that GH transgenic (GHTg) mice were protected against disease development, whose onset was delayed and severity reduced. Our data demonstrated an inhibitory role of GH in the induction phase of the disease. The anti-collagen response was severely impeded in Drospirenone GHTg mice, as was the synthesis of inflammatory cytokines, suggesting impairment of Th17/Th1?cell plasticity toward a pathological phenotype. GH also modulated the CIA progression phase, shown by reduced severity of established disease in collagen-immunized DBA/1J mice following exogenous GH administration. Our data demonstrate that GH administration ameliorates CIA symptoms pointing out an important role of this hormone tuning the immune response. Altogether, our results underline the interrelationship between the endocrine and the immune systems that regulate the immune response and support a potential use of endogenous endocrine mediators for the treatment of inflammatory and autoimmune diseases. Materials and Methods Mice Mice transgenic for bovine GH (bGH) under the control of the phosphoenolpyruvate carboxykinase promoter on a C57BL/6J background (18) were maintained by continuous backcrosses on C57BL/6J females. Drospirenone 35 transgenic mice (GHTg) and 33 control littermates (10C14?weeks old) were used, with matched sex ratios in each experiment. DBA/1J mice (50 males) were obtained from Charles River Laboratories International. Three OVA-specific TCR-transgenic mice (OT-II) were donated by Dr. C. Ardavn (Centro Nacional de Biotecnologa, Madrid, Spain). Mice were handled according to national and European Union guidelines, and experiments were approved by the Comit tico de Experimentacin Animal, Centro Nacional de Biotecnologa/CSIC and the Regional Government (PROEX 250-16). CIA Induction and Treatment Two-month-old GHTg mice, control littermates, or DBA/1J mice were immunized intradermally (i.d.) at the tail base with an emulsion of chicken type II collagen (CII) in citrate buffer and Freunds complete adjuvant (19). Arthritis was assessed daily by scoring each limb on a 0C4 scale, where 0?=?normal, 1?=?erythema and mild swelling confined to the tarsals or ankle joint, 2?=?erythema and mild swelling extending from the ankle to the tarsals, 3?=?erythema and moderate swelling extending Drospirenone from the ankle to metatarsal joints, and 4?=?erythema and severe swelling encompassing the ankle, foot, and digits, or ankylosis of the limb, yielding a maximum score of 16 per mouse. In some cases, on appearance of the first signs of CIA (score ~2?=?day 0), affected DBA/1J mice were separated into two groups; one group received a daily subcutaneous (s.c.) rhGH injection (2?g/ml, 200?l, Genotonorm, Pfizer) until day 9 and the other received only PBS as control. Clinical scores (Cst) CD28 were re-evaluated daily. Histochemistry At the.