Search

Immune semaphorins are key players in regulating immune mediated inflammation. Semaphorin3A (sema3A) a secreted and membrane bound member of this family, is well reported for its properties in maintaining self-tolerance. Semaphorin3A was recognized to be a marker for T-regulatory cells (Tregs), and as such is a useful tool for assessing the status of these cells in preventing immune mediated diseases. This study was designed aiming to evaluate how sema3A is possibly involved in bronchial asthma. Here, we found sema3A serum levels and the expression of sema3A on Tregs significantly lower in patients with moderate to severe asthma when compared to healthy individuals. Co-culture of condition medium with 2mcg/ml of recombinant human sema3A with CD4+ T cells, increased the expression of FoxP3 in Tregs, suggesting sema3A a potent immune-regulator of inflammation including that of asthma. Further in-vivo studies will better establish the beneficial effect of sema3A in regulating inflammation in asthma., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objectives: Semaphorin 3A (sema3A) plays a regulatory role in immune responses with effects on both T and B regulatory cells. Familial Mediterranean fever (FMF) is an autoinflammatory disease, yet a possible role for regulatory T and B cells has been described., Methods: 17 FMF patients during attack and then in remission, 8 FMF patients with smoldering disease and 12 healthy controls were enrolled. Sema3A in serum and its expression on regulatory T and B cells was evaluated. Clinical parameters of FMF patients were assessed., Results: Semaphorin 3A serum level was lower in FMF patients during attack, smoldering disease or remission than healthy controls, (242.3±9.8 ng/ ml vs. 258.9±11.5 ng/ml vs. 232.5±22.7 ng/ml vs. 323.3±160.2 ng/ml, respectively p<0.05). This decrease was specifically noted on regulatory B and T cells in FMF patients during attack and in smoldering disease and normalized in remission., Conclusions: Sema3A expression on T and B regulatory lymphocytes is low in FMF patients during attack and in smoldering disease compared to the expression in remission and healthy controls. These results are in line with previous descriptions suggesting a possible role of regulatory T cells in termination of FMF attacks. Further studies are needed to verify these preliminary findings.

Abstarct: Semaphorin 3A (sema3A) plays a regulatory role in immune responses, mainly affecting the activation of regulatory T cells. It has been found to correlate with disease activity in rheumatoid arthritis and systemic lupus erythematosus (SLE). To investigate the expression of sema3A in patients with systemic sclerosis (SSc) compared to healthy controls and SLE disease controls and to correlate it with clinical characteristics, 27 SSc patients, 42 SLE patients and 28 healthy controls were enrolled. Serum level of sema3A was measured by ELISA, and expression of sema3A on regulatory T cells was evaluated by FACS analysis. SSc patients were evaluated for demographics, clinical manifestations, routine laboratory results, nailfold videocapillaroscopy, pulmonary function tests, echocardiograms, modified Rodnan skin score, and disease activity and severity scores. Serum levels of semaphorin 3A were lower in SSc compared to healthy controls 14.38 ± 5.7 versus 27.14 ± 8.4 ng/ml, p < 0.0001 and similar to SLE 15.7 ± 4.3 ng/ml. The expression of semaphorin 3A on regulatory T cells was also lower in SSc compared to healthy controls 61.7 ± 15.7 versus 88.7 ± 3. 7 % (p < 0.0001). Semaphorin 3A serum level inversely correlated with the duration of disease: r = -0.4, p = 0.036 and with low C4 level r = 0.66, p = 0.026. SCL-70 antibody positivity was associated with a lower semaphorin 3A level (difference in mean of 3.44, p = 0.06). Sema3A expression is low in SSc serum and more specifically on regulatory T cells. This may help explain the reduced activation of regulatory T cells in SSc.