Correlation between major depressive disorder and circulating natural killer cells

 Background: Major depressive disorder is a mental disorder characterized by a pervasive and persistent low mood that is accompanied by low self-esteem and loss of interest or pleasure in normally enjoyable activities. Depression is associated with multiple immunological disorders. Aim of the present study was to determine correlation between percentage of circulating NK cells and major depressive disorder.Materials and Methods: Patients older than 18 years with the desire to participate were enrolled in this study. For depression evaluation, we used the Hamilton Depression Rating Scale and for determination of percentage of NK cells in peripheral blood, flow cytometry method was used. Results: Our results showed that in patients with major depressive disorder, numbers of circulating NK cells have significantly reduced. Conclusion: According to our findings, depression is associated with “immune suppression”. NK cells are important in early phase of immunological surveillance versus viral infections and tumors. Indeed, depressive patients are susceptible to cancers and infections

Terminal Deoxynucleotidyl Transferase (TdT) Inhibiti on of Cord Blood Derived B and T Cells Expansion

Purpose: Terminal deoxynucleotidyl transferase(TdT) is a DNA polymerase that is present in immature pre-B and pre-T cells. TdT inserts N-nucleotides to the V (D) J gene segment during rearrangements of genes, therefore, it plays a vital role in the development and variation of the immune system in vertebrates. Here we evaluated the relationship between cytokines like interleukin-2 (IL-2), interleukin-7 (IL-7), and interleukin-15 (IL-15) and TdT expression in cord blood mononuclear cells and also effect of inhibition in the expansion of B and T cells derived from cord blood. Methodes: The cord blood mononuclear cells were cultured with different combination of cytokines for 21days, which they were harvested in definite days (7, 14 and 21) and evaluated by flow cytometry. Results: Our data indicated that TdT expression increased in cord blood mononuclear cells using immune cell key cytokines without being dependent on the type of cytokines. TdT inhibition reduced both the expansion of B and T cells derived from cord blood and also declined the apoptosis and proliferation. Considered together, TdT played an important role in the control of the expansion of B and T cells derived from cord blood. Conclusion: considered together, it was observed that TdT expression was increased by cytokines and TdT inhibition not only reduced B and Tcells derived from cord blood, but it also affected the rate of apoptosis and proliferation