جستجوی مقالات مرتبط با کلیدواژه « immune cells » در نشریات گروه « پزشکی »

Platelets are small anucleated cell fragments that ensure the stopping of bleeding. In blood metastasis of cancer, Platelets are essential. One of the most important aspects of cancer metastasis is the interaction between platelets and circulating tumor cells. Platelets are involved in cancer spread and constitute a hazardous collation with the cancer cells. There are various factors involved in hemostasis and thrombosis, which can be activated by several cancer-related stimuli, including extracellular matrix (ECM), adenosine diphosphate (ADP), and Toll-like receptors (TLRs). Furthermore, it has been previously published that platelets build up inside the main tumors, producing growth factors that encourage tumor growth and angiogenesis. Additionally, tumor cells can interact with platelets through aggregation, further protecting cancer cells. Platelets interact both functionally and physically with different types of tumor cells via integrin and other surface receptors. Platelet integrin’s primary function is to maintain platelet adhesion and aggregation at vascular damage sites. Pharmacological treatments that target integrin have been shown to effectively inhibit experimental metastasis. This review paper summarized the recent advances and progress of mechanisms in platelet activation and its interaction with cancer cells in metastasis.

Avoiding exposure to ionizing radiation due to environmental factors is almost inevitable in daily life. Here, we aimed to investigate the possible immunomodulatory effects of ionizing radiation on NK and T cell activation using Peripheral Blood Mononuclear Cells (PBMC). We measured the pro-inflammatory cytokines INFγ, IL-2 and TNFα, as well as Granzyme B. In addition, we determined the expression levels of CD28, NKG2D (CD314) receptors, which play a key role in the activation of T and NK cells, respectively.

20 ml peripheral blood samples were taken from healthy volunteer donors and exposed to radiation doses of 0, 1, 3 and 5 Gy. ELISA analysis was used to measure Granzyme B, INFy, TNFα and IL2. Expression of CD28, NKG2D (CD314) receptors was measured by qRT-PCR analysis. Apoptosis and necrosis were measured by AnnexinV/7AAD analysis. Catalase activity was measured using hemolysates from irradiated blood samples.

Here we show that IR exposure induces necrotic cell death in PBMCs as the main response. IR exposure significantly induced secretions of Granzyme B, TNFα, IL2, and INFγ in a dose-dependent manner. In addition, mRNA levels of CD28 and NKG2D expressions were increased by 3 Gy IR exposure, but decreased by 5 Gy, while catalase activity increases with 1 Gy IR treatment, 3 and 5 Gy decreases.

Our results suggest that not only high doses but even low doses of radiation can modulate the immune response through cytokine secretion and activation of T and NK cell receptors.

Multiple Sclerosis (MS) is the most prevalent neurological disability in young adults. The pathogenesis of MS is characterized by demyelination and neurodegeneration in the central nervous system (CNS) as the ruinous result of chronic activation of the immune system. All clinical forms of MS, including relapsing-remitting multiple sclerosis (RRMS), secondary progressive multiple sclerosis (SPMS), and the primary progressive MS (PPMS), demonstrate inflammation as a common symptom. In various autoimmune diseases like MS, the ability of the immune system to set a balance between pro-inflammatory and anti-inflammatory responses is lost. In this review, the imbalance between pro-inflammatory and anti-inflammatory responses of immune cells and their role in MS progression is discussed. Disturbing the balance of Th1/Th2 and Th17/Treg cells and M1/M2 phenotypes of macrophages and microglial plays a key role in the development and progression of MS. In this review, we first depict an outline of regulatory immune cells involved in inflammation. Second, we discuss shreds of evidence that confirm how B cells play both pathogenic and protective roles in MS disease. Third, we point out the pros and cons of B cell/T cell-targeted therapies in clinical trials.

Severe Acute Respiratory Syndrome (SARS) associated with SARS-CoV-2, causes a severe form of the respiratory illness known as Coronavirus Disease-19 (COVID-19). COVID-19 has emerged as a worldwide pandemic with a high number of fatalities. Approximately 112,654,202 people have been infected so far with this disease which has led to the death of more than one point seven million (2,496,749) till 24th Feb, 2021. Measures to counter this disease have led to a global economic slowdown. Multiple drug trials are ongoing and several putative candidates for vaccination against the virus have been approved and are in the pipeline. Many studies have also characterized the immunological profile of patients infected with COVID-19. Some studies suggest that the severity of the COVID-19 infection is directly associated with the cytokine storm. In this review, we aim to compile the available knowledge and describe the nature of immune responses in patients infected with COVID-19 in different age groups, comorbidity, and immune-compromised state and their association with disease severity.

Lichen planus (LP) is a common inflammatory skin disease. Pathogenesis of LP includes two possible mechanisms; related or unrelated to antigen. Regarding different clinical features of cutaneous and mucosal types of LP, for the first time, we decided to perform a qualitative and quantitative study of immune cells in different types of cutaneous LP and in comparison with normal skin. A total of 88 specimens (60 cases of cutaneous LP, 28 cases of normal skin) were selected from 2016 to 2017 in Kerman, Iran. Evaluation of immune cells was carried out based on qualitative and quantitative analysis. These findings were statistically calculated by descriptive statistical tests including frequency and mean ± standard deviation. Quantitative data were analyzed by independent t-test, chi-square, and analysis of variance (ANOVA). Data were analyzed using SPSS16 (SPSS Inc., Chicago, IL, USA). A p value less than 0.05 was considered statistically significant. Our study demonstrated that the mean number of immune cells was significantly higher in lichen planus group in comparison with the control group. Number and staining intensity of Langerhans cells (LCs) in the LP group were significantly greater in epidermal than dermal region. Mastocytes were located mostly within the deep dermis in the LP group. Hypertrophic and atrophic LP had the highest and the lowest number of immune cells (i.e., mastocytes, LCs, and CD3 positive cells), respectively, with a significant difference. Our study demonstrated that immune cells were seen in larger numbers in the hypertrophic type of cutaneous LP which is consistent with the chronicity of this disease.

Entecavir (ETV) is an antiviral medication effective in suppressing hepatitis B virus (HBV) replication and improving liver function. However, the relationship between antiviral effect and immune modulation after ETV therapy is not clearly understood. The objective of this study is to investigate the immunoregulatory effect of ETV treatment in patients with chronic hepatitis B (CHB). The frequencies of immune cells, including IFN-γ-producing CD4+ and CD8+ T cells, Th9 cells, regulatory T (Treg) cells, and myeloid-derived suppressor cells (MDSC) were determined in the peripheral blood from treatment-naïve and ETV-treated CHB patients. The plasma levels of IL-10, TGF-β, IL-9, TNF-α, IFN-γ, and Arg-1 were measured using enzyme-linked immunosorbent assay. The results showed that ETV treatment significantly reduced the levels of liver function indices as well as HBV DNA loads in CHB patients. However, no significant difference in the immune cells percentage was found between the treatment-naïve and ETV-treated patients. Additionally, ETV treatment did not influence the production of TGF-β, IL-9, Arg-1, IFN-γ, and TNF-α. In contrast, the level of IL-10 was remarkably reduced after ETV therapy. IL-10 was a more sensitive effector to ETV-induced inhibition of HBV replication in chronic HBV patients.

Multiple Sclerosis (MS) is a chronic autoimmune disease of young adults with an unknown etiology, but cellular immune responses and inflammation has a pivotal role in this regard. The higher incidence of MS among women indicates the possible involvement of female sex hormones on the disease course. Progesterone and estrogen are the most important sexual hormones in women. They exert different immunomodulatory effects through both nuclear and membrane associated receptors present in different immune cells. The immunological effects include shifting the immune response towards Th2, stimulating Treg production, inhibiting pro-inflammatory cytokine production, prohibiting cell migration into Central Nervous System (CNS), suppressing proinflammatory immune cells, stabilizing the neuronal environment, and promoting neuronal survival, all of which might ameliorate the condition in women suffering from MS. Some clinical trials have reported a correlation between the use of Oral Contraceptives (OCs), which contain estrogen and progesterone, and MS among women. Some of these studies show a positive effect of OC usage on the onset and severity of the disease while others have found no significant impact. In this review, we collected articles published between 1995 and 2017 from PubMed Central and Google Scholar for evaluating effects of estrogen and progesterone on different immune cells related to MS.

In an effort to understand what limits the virulence of malaria para­sites in relation to the host genetic and immunogenic background, we investi­gated the possibility that the parasite and host genotype crossover interac­tions constrain virulence. Two groups of mice from different genotypes were used (C57BL/6 (B6) and DBA/2 mice). The mice were infected with a virulent parasite line Plasmo­dium yoelii17XL (P. yoelii17XL). Parasitemia, hematocrit value and lympho­cytes yielded by livers and spleens were evaluated. Fluorescence Activated Cell Sorting (FACS) analysis illustrated phenotypic characterization of lymphocytes. Infection with P. yoelii17XL did not result in thedeath of DBA/2 mice. In contrast,B6 mice developed significantly high parasitemia and succumbed to death. Using (FACS) analysis, DBA/2 mice were found to experience a marked expansion of interleukin (IL)-2Rb+ CD3int cells and gd T cells in the liver, espe­cially in the recovery phase. The expansion of unconventional T cells (i.e. B220+ T cells) was also marked in DBA/2 mice. The outcome of murine malaria infections depends on the dynamic interplay between the immune-mediator and the genotype of the host.

Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cell (HSC) transplantation for the treatment of patients with leukemia if matched donor is not available. CD34 is a pan marker for human hematopoietic stem cells, including umbilical cord blood stem cell. In comparison to other sources, cord blood CD34 cells proliferate more rapidly and produce large number of progeny cells. For ex vivo expansion of Umbilical Cord Blood- HSCs/HPCs, different combinations of cytokines have been used in many laboratories. IL2rg cytokines, including IL2, IL7 and IL15, are key cytokines in the regulation of differentiation, proliferation and survival of immune cells. IL2 is important cytokine for T cell survival and proliferation, IL7 involve in B cell development and IL15 is a key cytokine for NK cell development. In this study we evaluated the generation of T cells derived from CD34 and CD34- cord blood mononuclear cells by using combination of cytokines including IL2, IL7 and IL15.
Cultured cord blood mononuclear cells were evaluated at distinct time points during 21 days by using flow cytometry.
Present study showed that differentiation of T cells derived from CD34 cord blood mononuclear cells increased by using IL2 and IL7 at different time points. In the other hand IL15 did not show any significant role in generation of T cells from CD34 cord blood mononuclear cells.
Taken together, our data illustrated that either IL2 or IL7 versus other cytokine combinations, generate more T cell from cord blood CD34 cells, probably this cytokines can be the best condition for ex vivo expansion of UCB HSCs.

Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cell transplantation (HSCT), used in Leukemia treatment. CD26+ cells, a fraction of CD34+cells, are a major population of UCB cells which negatively regulate the in vivo homing and engraftment of HSCs. CD26 is highly expressed in various cells such as HSCs, immune cells, fibroblasts, and epithelial cells. It has been shown that the inhibition of the CD26 on CD34+ cells improves the efficiency of Hematopoietic Stem and Progenitor Cell (HPC) transplantation.

To evaluate the relationship between the production of B, T, and NK cells from the CD26 positive fraction of cord blood mononuclear cells.

Cord blood mononuclear cells were cultured for 21 days using different combinations of stem cell factors (SCF), Flt3 ligand (FL), IL-2, IL- 7, and IL-15. The harvested cells were then analyzed by flowcytometry every week for 21 days.

T cell differentiation from CD26 subset of cord blood mononuclear cells increased by using IL-2 and IL-7. Our data showed that IL-2 and IL-7 significantly affected the generation of B cells from CD26+ cord blood mononuclear cells. On the other hand, NK (NKp46+) derived CD26+ cells increased by IL-15 and IL-2.

Taking all into account, we conclude that B, T, and NK cells can differentiate from the CD26+ subset of mononuclear cord blood cells by using key regulatory cytokines.