Apoptosis and immunophenotyping of peripheral blood lymphocytes in Iranian COVID-19 patients: Clinical and laboratory characteristics.

A novel member of human coronavirus, named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has been recently recognized in China and rapidly spread worldwide. Studies showed the decreasing of peripheral blood lymphocytes in a majority of patients. In this study, we have reported the clinical features, laboratory characteristics, the frequency of peripheral blood lymphocyte subpopulations, and their apoptosis pattern in Iranian coronavirus infectious disease (COVID-19) patients. Demographic and clinical data of 61 hospitalized confirmed cases with COVID-19 at Imam Khomeini Hospital were collected and analyzed. Peripheral blood mononuclear cells were isolated from all samples and the apoptosis pattern was evaluated using Annexin V/propidium iodide method. The frequency of lymphocyte subsets, including T-CD4+ , T-CD8+ , NK, B cells, and monocytes, was measured in all patients and 31 controls by flow cytometry. Our findings demonstrated that the percentage of lymphocytes, CD4+ , and CD8+ T cells were decreased in COVID-19 patients compared with the control group. Regarding the clinical severity, the number of lymphocytes, CD4+ , CD8+ T cells, and NK cells were also decreased in severe cases when compared with mild cases. Finally, our data have also indicated the increase in apoptosis of mononuclear cells from COVID-19 patients which was more remarkable in severe clinical cases. The frequency of immune cells is a useful indicator for prediction of severity and prognosis of COVID-19 patients. These results could help to explain the immunopathogenesis of SARS-CoV-2 and introducing novel biomarkers, therapeutic strategies, and vaccine candidates.

Evaluation of Innate Lymphoid Cells (ILCs) Population in the Mouse Model of Colorectal Cancer.

BACKGROUND: Innate Lymphoid Cells (ILCs) promote tissue homeostasis, contribute to the immune defense mechanisms, and play important roles in the initiation of immune responses and chronic inflammation. OBJECTIVE: To understand the roles of innate lymphoid cells in the pathophysiology of colorectal cancer (CRC) in the mouse model. METHODS: CRC was induced using azoxymethane (AOM) and dextran sulfate sodium (DSS) in Balb/c mice (the chemically induced group=18 mice), or orthotopic injection of CT-26 cell line into the colon of another set of Balb/c mice (the orthotopic group=14mice). Normal saline was injected into 18 mice, as the sham group. After 80 days, the chemically induced group was divided into two subgroups, dysplasia (8 mice) and reparative change (10 mice), based on pathological examinations. The frequencies of ILC1, 2, and 3 were then measured in colon tissues using flow cytometry by four markers including an anti-mouse lineage cocktail (FITC anti-mCD3/FITC anti-mGr-1/FITC anti-mCD11b/ FITC anti-mCD45R (B220)/FITC anti-mTer-119), PE/Cy7 anti-mouse CD45, PE anti-mouse CD117 (c-kit), and APC anti-mouse IL-33 Rα (ST2). RESULTS: The total ILC population was significantly higher in the chemically induced reparative change compared with the sham group. ILC1 percentage in the chemically induced reparative change was significantly higher compared to those in the other three groups (Sham, chemically induced dysplasia and orthotopic dysplasia). The orthotopic dysplasia group showed more ILC3 percentage than the other groups. CONCLUSION: ILC1 and ILC3 subgroups increased significantly in reparative and dysplastic experimental CRC respectively. Thus ILC1 may have an inhibitory effect on tumor growth whereas ILC3 promotes tumor progression.

Ninety-six-hour starved peripheral blood mononuclear cell supernatant inhibited LA7 breast cancer stem cells induced tumor via reduction in angiogenesis and alternations in Gch1 and Spr expressions.

Introduction: The microenvironment of solid tumors such as breast cancer is heterogeneous and complex, containing different types of cell, namely, cancer stem cells and immune cells. We previously reported the immunoregulatory behavior of the human immune cell in a solid tumor microenvironment-like culture under serum starvation stress for 96 h. Here, we examined the effect of this culture-derived solution on breast cancer development in rats. Method: Ninety-six-hour starved PBMCs supernatant (96 h-SPS) was collected after culturing human PBMCs for 96 h under serum starvation condition. Breast cancer stem cells, LA7 cell line, was used for in vitro study by analyzing gene expression status and performing cytotoxicity, proliferation, scratch wound healing assays, followed by in vivo tumor induction in three groups of mature female Sprague Dawley rats. Animals were treated with 96 h-SPS or RPMI and normal saline as control, n = 6 for each group. After biochemical analysis of iron, lactate, and pH levels in the dissected tumors, Ki67 antigen expression, angiogenesis, and necrosis evaluation were carried out. Metabolic-related gene expression was assessed using RT-qPCR. Moreover, 96 h-SPS composition was discovered by Nano-LC-ESI-MS/MS. Results: 96 h-SPS solution reduced the LA7 cell viability, proliferation, and migration and Gch1 and Spr genes expression in vitro (p< 0.05), whereas stemness gene Oct4 was upregulated (p< 0.01). The intracellular lactate was significantly decreased in the 96 h-SPS treated group (p = 0.007). In this group, Gch1 and Spr were significantly downregulated (p< 0.05), whereas the Sox2 and Oct4 expression was not changed significantly. The number of vessels and mitosis (Ki67+ cells) in the 96 h-SPS-treated group was significantly reduced (p = 0.024). The increased rate of necrosis in this group was statistically significant (p = 0.04). Last, proteomics analysis revealed candidate effectors' components of 96 h-SPS solution. Conclusion: 96 h-SPS solution may help to prevent cancer stem cell mediated tumor development. This phenomenon could be mediated through direct cytotoxic effects, inhibition of cell proliferation and migration in association with reduction in Gch1 and Spr genes expression, angiogenesis and mitosis rate, and necrosis augmentation. The preliminary data obtained from the present study need to be investigated on a larger scale and can be used as a pilot for further studies on the biology of cancer development.

CD8+ T-cells Co-expressing PD-1 and TIGIT Are Highly Frequent in Chronic Lymphocytic Leukemia.

The role of immune checkpoint receptors in T-cell exhaustion has been demonstrated in several cancers. We investigated the co-expression of TIGIT/PD-1 and LAG-3/PD-1 cells in patients with chronic lymphocytic leukemia (CLL). The frequencies of TIGIT+PD-1+CD8+and LAG-3+PD-1+CD8+cells and relative mRNA expression of LSECtin and CD155 were examined in PBMCs from 33 CLL patients and 20 controls. The percentage of TIGIT+PD-1+CD8+cells was significantly higher in CLL patients than in control subjects, with the preference in advanced stage patients. However, LAG-3+PD-1+CD8+cell percentage was significantly lower in CLL patients than in the control subjects and no significant difference were found between the early and advanced stages of the disease. An increase in the mRNA expression level of LSECtin, but not that of CD155, was observed in CLL patients compared to the control subjects. Collectively, a higher co-expression of PD-1 and TIGIT on CD8+ T-cells in CLL compared to control subjects suggests an important role of TIGIT in T-cell exhaustion in CLL patients especially those with advanced disease.

CD4+ T Cells are Exhausted and Show Functional Defects in Chronic Lymphocytic Leukemia.

BACKGROUND: Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the western world. This health problem is caused due to the accumulation of mature B-lymphocytes in the peripheral blood and bone marrow. In the course of cancer, CD4+ T cells become "exhausted" and characterized with poor effector functions and the expression of multiple inhibitory receptors. OBJECTIVE: To investigate the frequency and functional properties of exhausted CD4+ T lymphocytes in patients with CLL. METHODS: Peripheral blood mononuclear cells were obtained from 25 untreated CLL patients and 15 healthy volunteers. CLL patients were clinically classified according to the Rai staging system. The frequency of CD4+/Tim-3+/PD-1+ cells was obtained by flow cytometry. To evaluate cell proliferation and cytokine production, CD4+ T cells were isolated and stimulated with phytohemagglutinin and PMA/ionomycin. Concentrations of IL-2, IFN-γ, TNF-α, and IL-10 were measured in the culture supernatants of stimulated cells by the ELISA technique. RESULTS: The percentage of CD4+/Tim-3+/PD-1+ cells was significantly higher in CLL patients than that of healthy controls. CD4+ T cells from CLL patients showed lower proliferative responses, a lower production of IL-2, IFN-γ, and TNF-α, and a higher production of IL-10, compared to healthy controls. CD4+ T cells from CLL patients in advanced clinical stages showed more exhaustion features than those of early stages. CONCLUSION: Given that the exhaustion phase of T cells can be reversible, targeted blocking of immune inhibitory molecules could be a promising tool to restore the host immune responses against leukemic cells in CLL.