Expression of NKG2A inhibitory receptor on cytotoxic lymphocytes as an indicator of severity in Corona Virus Disease 2019 (COVID-19) patients.

NK group 2 member A (NKG2A) receptor transduces inhibitory signaling; suppressing NK and T-cell cytokine secretion and cytotoxic function. This study aimed to assess the expression of NKG2A inhibitory receptor on natural killer (NK) cells and CD8+ T lymphocytes in COVID-19 patients and correlate the results with disease severity defined according to the criteria established by the world health organization, in a trial to understand the immunological response towards COVID-19 infection. The study enrolled 30 COVID-19 patients classified into 2 groups that comprised 15 subjects each; moderate and severe based on clinical, radiological, and laboratory findings. Ten age and sex matched apparently healthy individuals were included in this study as a control group. About 1 ml EDTA anti-coagulated blood samples were collected for measuring expression of NKG2A/CD159a on CD56+ CD3- NK and CD3+CD8+ T cells by flow cytometry. Results revealed that COVID-19 patients had significantly lower NK and CD8+ T cell counts compared to healthy subjects. Severe cases had significantly lower CD8+ T counts compared to moderate ones. Percentages of NK and CD8+T cells expressing NKG2A receptor were significantly higher in cases compared to controls. Comparison between severe and moderate cases revealed that although the percentages of NK cells expressing NKG2A receptor were not significantly higher in severe cases, the mean fluorescence intensity was significantly higher. The percentages of CD8 +T cells expressing NKG2A receptor were significantly higher in severe cases with higher mean fluorescence intensity. In conclusion, our results indicate that elevated NKG2A expression on cytotoxic lymphocytes correlates with disease severity in COVID-19 patients, and may serve as a potential marker for prognosis. Additionally, the blockade of NKG2A should be investigated as means of enhancing NK cell and cytotoxic T cells antiviral immunity in patients with severe COVID-19 infection.

Green Approach to Overcome the Resistance Pattern of Candida spp. Using Biosynthesized Silver Nanoparticles Fabricated by Penicillium chrysogenum F9.

Candida species are the most common causative agents responsible for the majority of morbidity as well as mortality rates due to invasive fungal infections worldwide. In this study, a green approach was developed to control the pathogenic Candida spp. isolated from clinical samples, and prior data collections, ethics approval was obtained. Sixty candida isolates were obtained from the different device-associated infections and identified as Candida albicans, Candida tropicalis, Candida krusei, Candida parapsilosis, and Candida glabrata with prevalence rates 41.6, 38.3, 8.3, 6.6, and 5%, respectively. On the other hand, silver nanoparticles (Ag-NPs) were extra-cellular synthesized by biomass filtrate of previously identified Penicillium chrysogenum strain F9. The physico-chemical characterizations of biosynthesized Ag-NPs were assessed by using UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) patterns, transmission electron microscope (TEM), dynamic light scattering (DIS), and zeta potential (ζ) analysis. Data revealed successful synthesis of crystallographic spherical Ag-NPs with average size 18 to 60 nm at maximum absorption peak 415 nm. FT-IR analysis confirmed the presence of functional groups related to reduction, capping, and stabilizing Ag-NPs. The DLS analysis showed that NPs were homogenous and stable with poly-dispersity index (PDI) and ζ value 0.008 and - 21 mV, respectively. Susceptibility pattern analysis revealed that sixty Candida isolates (100%) were susceptible to Ag-NPs as compared to 25 isolates (41.6%), and 30 isolates (50%) were susceptible to fluconazole and amphotericin B, respectively. Interestingly, 30 Candida isolates (50%) were resistant to amphotericin B, which are more than those recorded for fluconazole (17 isolates with percent 28.3%), while 18 candida isolates (30%) were susceptible dose-dependent to fluconazole. The recorded minimum inhibitory concentration 50/90 (MIC50/90) was 62.5/125, 16/64, and 1/4 for Ag-NPs, fluconazole, and amphotericin B, respectively. However, green synthesized Ag-NPs can be used to overcome the resistance pattern of Candida spp., and recommended as an anti-candida agent.

Human Leukocyte Antigen-G (HLA-G) Expression in Precancerous and Cancerous Cervical Lesions: Association with Human Papilloma Virus Infection and Host Immune Response.

Human leukocyte antigen-G (HLA-G) is a non-classical HLA-class Ib molecule with multiple immunoregulatory properties. Its main functions in physiological conditions are to abolish maternal immune cell activity against fetus and to establish immune tolerance at the maternal-fetal interface. Cervical tumor cells have been reported to express HLA-G which is one of the immunomodulatory molecules that is involved in every phase of cancer immunoediting. It has inhibitory functions against natural killer (NK) cells, T-lymphocytes, and antigen-presenting cells (APCs). The purpose of this study was to investigate the HLA-G expression in precancerous (squamous intraepithelial cervical lesion) and cancer cervix and determine HLA-G expression relation to HPV infection as well as host immune response. The study included 48 paraffin embedded cervical tissue sections [32 squamous intraepithelial lesion (SIL) {16 low grade lesions (LSIL) and 16 high grade lesions (HSIL)} and 16 cervical cancer tissue sections]. All tissue sections were examined for HLA-G expression by real time PCR and for host immune response by estimating the number of tumor infiltrating lymphocyte (TIL) and NK CD57+ cells. HLA-G expression increased progressively from precancerous and cancerous cervical lesions. There was an inverse relationship between HLA-G expression and estimated number of TILs and NK CD57+ cells. No significant statistical difference between HPV positive and HPV negative cervical lesions as regards HLA-G expression was detected. In conclusion, HLA-G is a potential biomarker for the diagnosis and prognosis of cervical cancer as there was a progressive increase in expression of HLA-G in precancerous and cancerous cervical lesion. It is functionally involved in tumor escape mechanisms as observed by inhibition of host immune response and more studies are needed to design strategies for blockade of HLA G expression or elimination of HLA G expressing cancer cells as this may be important to the efficacy of anticancer therapies.

Sugarcane bagasse lignin, and silica gel and magneto-silica as drug vehicles for development of innocuous methotrexate drug against rheumatoid arthritis disease in albino rats.

The present study clarifies co-therapy action of deliveries from their textural changes point of view. Methotrexate (MTX) was immobilized onto biodegradable lignin, silica gel and iron/silica nanocomposite. Loaded-MTX was i.p. injected into albino rats at doses of 0.25 and 0.5mg/kg/week for 2.5months, after which spleen, liver, testes and knee joint tissues were collected for tests. IFN-γ and IL-17A mRNA gene expressions in spleen in all biological samples were determined by RT-PCR. Physicochemical features of drug carriers were monitored by XRD, BET-PSD, SEM and TEM. Drug inflammatory-site targeting was found to be closely related to the physico-features of deliverers. The interlayered lignin of micro- and meso-pore channels directed MTX toward concealed infected cells in liver and testes tissues, while meso-structured silica flacks satisfied by gathering MTX around knee joints. The magneto-silica nanocomposite targeted MTX toward spleen tissue, which is considered as a lively factory for the production of electron rich compounds.

A study of innate and adaptive immune responses in beta-thalassemic patients with chronic hepatitis C virus infection.

Thalassemia major is an inherited disorder particularly common in people of Mediterranean, African, and Southeast Asian ancestry. Hepatitis C virus (HCV) is responsible for 80 - 90% of post transfusion hepatitis in beta-Thalassemic patients. Marked liver iron overload, which is often inevitable in patients on regular blood transfusion, and HCV infection have been shown to have a potentiating effect on hepatic fibrogenesis in thalassemic patients. This study aimed at investigating the impact of combined chronic hepatitis C and beta-Thalassemia on innate and adaptive immune responses. The study was conducted on 60 patients and 15 apparently healthy controls. Patients were dived into three groups: group 1: 35 patients with combined beta-thalassemia and chronic hepatitis C (CHC) (betaTH/CHC), group II: 15 beta-thalassemia patients without HCV infection (betaTH), group III: 10 patients with chronic hepatitis C infection (CHC). Assessment of the number of CD3+, CD4+, CD8+ T cells, NK cells, and NKT cells was done by flowcytometry. Human IFN-delta and IL-15 levels were estimated by Enzyme -Linked Immunosorbent Assay (ELISA). betaTH/CHC patients had significantly reduced numbers of conventional T lymphocytes, NK, NKT, CD4+, and CD8+ T cells when compared to betaTH patients. Serum IFN-gamma levels were significantly reduced in betaTH/CHC patients (2.57 pg/ml) in comparison to CHC patients (6.89pg/ml) and normal controls (4.73 pg/ml). A significant elevation of serum IL-15 levels in betaTH/CHC patients (38.04pg/ml) was found when compared to betaTH patients (16.22 pg/ml). Splenectomized patients showed reduced numbers of NK cells, NK T cells and lower CD4:CD8 ratio in comparison to non-splenectomized ones among betaTH/CHC patients. In conclusion our data show an obvious defective cellular innate immunity (NK & NKT cells) and cellular adaptive immunity (CD4+ T cells, CD8+ T cells, & INF-gamma) in (betaTH/CHC) patients, in comparison to (betaTH) patients. This observation suggests a potentiating effect of both CHC and beta-thalassemia on depression of innate and adaptive immune status in these patients

Role of IL-13 in the pathogenesis of bronchial asthma.

Asthma is a chronic inflammatory disease of the lung. Although it is multifactorial in origin, the inflammatory process is believed to be a result of inappropriate immune responses to common aeroallergens in genetically susceptible individuals. As such, it has been reported that Th2 cytokines play a pivotal role in the pathogenesis of disease. The aim of this study was to evaluate the role of IL-13 in the pathogenesis of bronchial asthma. The study was carried out on 71 subjects out of which 54 were asthmatic patients and 17 were normal controls. Patients with bronchial asthma were further classified according to the National Asthma Education and Prevention Program (NAEPP) into 4 groups: intermittent, mild persistent, moderate persistent and severe persistent. IL-13 serum levels were estimated in patients and controls by ELISA. Asthmatic patients showed a statistical significant elevation of serum IL-13 levels (mean = 78.5 +/- 64.5 pg/ml) as compared to controls (mean = 51.8 +/- 24.9 pg/ml). When patients with different degrees of severity were compared, a significant increase in serum IL-13 was found in patients with intermittent asthma (mean = 106 +/- 105 pg/ml) as compared to those with mild (mean = 63.6 +/- 14.7 pg/ml) and severe persistent asthma (mean = 64.9 +/- 29.1 pg/ml). Only patients with intermittent asthma showed a highly significant increase in serum IL-13 than controls. No statistically significant difference was found between patients not on steroids, patients on inhaled steroids and those on systemic steroids. A statistically significant increase in IL-13 serum levels was observed in patients not on steroids compared to normal controls. A significant increase in blood eosinophil counts was found in patients during acute asthmatic attacks as compared to those who were stable. In conclusion, IL-13 is a key cytokine with critical role in the immunopathogenesis of bronchial asthma. Steroids can downregulate IL-13, but inhaled steroids alone might not be able to abolish the airway remodeling process in asthmatics. Although patients with intermittent asthma are asymptomatic in between exacerbations, inflammation and remodeling are ongoing in their lungs.

A possible pathogenic role of CD4+CD25+ T-regulatory cells in psoriasis.

Psoriasis is a chronic autoimmune inflammatory disease of the skin with strong genetic and environmental risk factors. T lymphocytes are thought to be central in its pathogenesis. CD4+CD25+ T regulatory (T reg) cells suppress inflammatory responses triggered by T effector cells. Interleukin-10 (IL-10) is an important anti-inflammatory and immunosuppressive cytokine with major impact on regulatory mechanisms in the skin. This study aimed at determining the role of CD4+CD25+ T reg cells and IL-10 in the pathogenesis of psoriasis and evaluating the effect of ultraviolet type A or B phototherapy (PUVA or NB-UVB) on both of them. The study was conducted on 20 patients suffering from severe psoriasis and 11 apparently healthy volunteers who served as controls. Clinical evaluation of disease severity was expressed by means of the Psoriasis Area and Severity Index (PASI) score. Assessment of the frequency of CD4+CD25+ T reg cells and IL-10 mRNA gene expression in peripheral blood mononuclear cells (PBMCs) was done by flowcytometry and reverse transcriptase-polymerase chain reaction (RT-PCR) respectively. No statistical difference was found between numbers of CD4+CD25+ T reg cells in peripheral blood of psoriasis patients and controls. However, IL-10 mRNA gene expression in PBMCs of untreated psoriatic patients showed significantly decreased levels in comparison to controls. There was no statistically significant difference in T reg cell numbers before and after phototherapy despite the marked clinical improvement of psoriatic patients as assessed by PASI score. On the other hand IL-10 mRNA gene expression increased markedly after successful ultraviolet therapy. In conclusion, the percent of T reg cells are apparently normal in peripheral blood of psoriasis patients. Studies that assess the suppressive function of T reg cells in psoriatic skinare recommended. IL-10 seems to play a crucial role in mediating UV-induced immunosuppression and could be used as a prognostic marker in follow up of psoriatic patients.

Active cytomegalovirus infection in patients with atopic dermatitis.

Atopic dermatitis (AD) is a complex immunologic skin disorder that is expressed when genetically predisposed individuals are exposed to certain environmental stimuli. Inspite of the high prevalence of cytomegalovirus (CMV) infection and its potent immunomodulatory activities, the relation of CMV to AD is still poorly understood and is still to be clarified. The aim of the present study was to evaluate the frequency of active CMV infection in patients with AD and its possible etiologic role in the pathogenesis of the disease. Also, we tried to find if a relation between active CMV infection and disease severity exists. The present study was carried on 31 patients with AD with various degrees of disease severity. Ten apparently healthy subjects were enrolled in the study as a control group. Anti CMV IgG antibodies were estimated by quantitative enzyme immunoassay to discriminate between recent CMV infection and CMV reactivation. Active CMV infection was diagnosed by using nested PCR to detect CMV DNA in the sera of the studied subjects. The detection rate of CMV genome was higher in patients with AD in comparison to the control group. Cytomegalovirus genome was detected in the sera of 52% (16/31) of patients with AD (87.5% of them were seropositive for anti-CMV IgG antibodies). On the other hand no CMV DNA was detected in any of the serum samples of the control subjects. The difference was statistically significant. No significant relation was found between active CMV infection and disease severity. Also, no significant statistical difference was found between the two studied groups as regards the prevalence of latent CMV infection. In addition, no significant difference was detected between anti-CMV IgG antibody levels in all seropositive subjects. Our results denote that active subclinical CMV infection is more frequent in patients with AD and may have possible immunomodulatory role in the etiopathogenesis of AD but it is not related to disease severity.