Telomerase Expression Related with Poor Immune Response to HCV Core Antigen in Egyptian HCV Patients' PBMCs

Background

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver.

Aim

This study aimed to assess serum human telomerase enzyme (hTERT) levels and their relation to the progression of liver disease. Also, it aimed to assess the effect of hepatitis C virus (HCV) core protein on memory T-cells in HCV patients with or without HCC and the correlation between memory cell phenotype and the progression of the disease in the same patients.

Methods

HTERT level in serum was assessed through relative quantitative RT-PCR. Flow cytometric analysis was used to assess T-cell responsiveness (as IFN- γ secretion) before and after stimulation with HCV core protein and the memory CD8+ cell phenotype using several differentiation markers.

Results

HTERT was found to be increased in a stepwise manner upon comparing its level in controls, chronic hepatitis patients, cirrhotic patients, and HCC patients. T-cells showed a similar manner of stepwise decrease in response (decreased IFN- γ secretion) in HCC patients compared to HCV patients without HCC and controls. Also, late differentiated memory cells (CD8+, CD27-, CD28-, CD45RA+, and CCR7-) were depleted in HCC patients compared to HCV patients without HCC.

Conclusion

These results suggest a negative correlation between hTERT and IFN- γ secretion by T-cells in HCV patients and that this relationship, along with the depletion of late differentiated memory cells, could help the progression of liver disease to HCC.

Assessment of Interferon Gamma-Induced Protein 10 mRNA Release Assay for Detection of Latent Tuberculosis Infection in Egyptian Pediatric Household Contacts

OBJECTIVES

Current diagnostic tests for tuberculosis (TB) in children living in low-endemic countries are limited by low specificity and the inability of the current tests to differentiate between active TB and latent TB infection (LTBI). This study aimed to evaluate the blood IP-10 mRNA expression level to detect LTBI in Egyptian pediatric household contacts (PHC).

METHODS

TB-specific IP-10 and IFN-γ mRNA levels were assessed by real-time quantitative PCR (RT-qPCR) in 72 Egyptian PHC of active pulmonary TB cases. All study participants were also assessed by Tuberculin Skin Test (TST) and Quantiferon gold in tube (QFN-GIT) assay.

RESULTS

IP-10 and IFN-γ mRNA expression levels were significantly higher in PHC with active TB or LTBI than TB negative (p < 0.0001). The level of IP-10 mRNA expression was significantly higher in PHC with active TB than LTBI (p = 0.0008). In contrast, there was no significant differences in the IFN-γ mRNA expression between PHC with active TB compared to LTBI (p = 0.49). The sensitivity and specificity of the IP-10 RT-qPCR were 94.2% and 95.2%, respectively, in PHC with active TB compared to 85.7% and 81.8% in PHC with LTBI. The negative and positive predictive values and accuracy of IP-10 RT-qPCR for distinguishing active TB from LTBI were 85.2%, 58.3%, and 72.6% respectively.

CONCLUSION

Blood IP-10 mRNA expression level may be a potential diagnostic marker to help distinguish active TB from LTBI in PHC.

Assessment of Human Papillomavirus Infection and Risk Factors in Egyptian Women With Breast Cancer

Numerous risk factors for breast cancer (BC) have been identified. High-risk human papilloma virus (HR-HPV) is the etiological agent of cervical cancer and in some cases of head and neck cancer, specifically oropharyngeal cancer, but the role of HR-HPV in evoking neoplasia in BC is still unclear. In this study, all women above the age of 18 visiting the oncology clinic at Al-Azhar university hospital and Ain Shams specialized hospital between the period of February 2017 and March 2018 were invited to participate. We determined the prevalence of HR-HPV genotypes 16, 18, and 31 in breast tissue samples from 72 women with treatment-naïve BC and 15 women with benign breast lesions (BBL) by quantitative real-time PCR (qRT-PCR) and primer sets targeting the E6 and E7 regions. High-risk human papilloma virus DNA was detected in 16 of 72 (22.2%) BC cases (viral load range = 0.3-237.8 copies/uL) and 0 of 15 women with BBL. High-risk human papilloma virus was detected in 14 of 16 (87.5%), 2 of 16 (12.5%), and 0 of 16 (0%) for genotypes 16, 18, and 31, respectively. Forty-three age-matched healthy Egyptian women were enrolled as controls for assessment of local risk factors that can be used to initiate a strategy of BC prevention in Egypt. Assessment of the risk factors demonstrated that low education level, passive smoking, lack of physical activity, family history of cancer, and use of oral contraception were significant risk factors for BC. In conclusion, our results lead us to postulate that HR-HPV infection may be implicated in the development of some types of BC in Egyptian women. In addition, identification of local risk factors can support practical prevention strategies for BC in Egypt.

Frequency of CD4+ regulatory T cells, CD8+ T cells, and human papilloma virus infection in Egyptian Women with breast cancer

Several subsets of regulatory CD4+ T cells (CD4+ Tregs) have been described in peripheral blood and tumor microenvironment of breast cancer (BC) patients and may play a role in the progression of BC. High-risk human papilloma virus (HR-HPV) has a causal role in cervical, head, and neck tumors but the role of HR-HPV in evoking neoplasia in BC is still unclear. In this study we assessed the prevalence of CD4+CD25+ FOXP3+ regulatory T cells (CD4+Tregs) and CD3+ CD8+ T cells by flow cytometry in peripheral blood from a total of 55 Egyptian women, including 20 treatment-naïve BC, 15 with breast benign lesions (BBL), and 20 healthy volunteers (HV). HR-HPV genotypes type 16, 18, and 31 were investigated in breast tissue from all BC and BBL patients using Real-Time PCR. HR-HPV was detected in 4/20 (20%) and 0/15 (0%) BC and BBL patients respectively. The frequency of CD4+ Tregs was significantly higher in BC compared to BBL and HV, (P < 0.001). In addition, we observed a significantly higher frequency of CD3+ CD8+ T cells in peripheral blood of patients with late stage III BC compared to early stage I and II BC (P = 0.011). However, there was no significant association between the ratio of CD8+ T cell to CD4+ Tregs frequencies and the expression of Estrogen Receptor (ER), Progesterone Receptor (PR), and Human Epidermal Growth Factor Receptor 2 (HER2). These results lead us to postulate that the association between the frequency of CD4+ Tregs and CD8+ T cells in the peripheral blood may be a prognostic or predictive parameter in Egyptian women with BC. In addition, HR-HPV infection may be implicated in the development of some types of BC in Egyptian women.

Evaluation of immunodiagnostic potential of ESAT-6 synthetic peptides mixture in Egyptian pulmonary tuberculosis patients

Identification of M. tuberculosis ESAT-6 proteins has enhanced research for developing new specific and reliable in vitro diagnostic tests for pulmonary tuberculosis. The aim of this study was to assess the diagnostic potential of ESAT-6 synthetic overlapping peptides mixture (Pepmix) for diagnosis of pulmonary M. tuberculosis infection in Egypt. IFN-gammaand IL-17 production was assessed in whole-blood culture assay after overnight stimulation with M. tuberculosis crude culture filtrate (CF), purified 38 kDa antigen, and ESAT-6 Pepmix. Concentration of IFN-gamma and IL-17 was evaluated in the culture supernatant by ELISA. Patients with active pulmonary TB patients (n = 37), Tuberculin Skin Test (TST) positive healthy subjects (n = 16) and TST negative healthy subjects (n = 16) were included. Results indicated that IFN-gammaproduction following stimulation with crude CF, and 38 kDa purified antigen was not significantly different between patients and TST+ healthy controls. In contrast, Pepmix clearly distinguished between patients and TST+ healthy subjects with sensitivity of 70.3 % and specificity 96.9 %. The concentration of secreted IL-17 was significantly lower than IFN-gamma, and no statistically significant difference was found between groups. It is concluded that IFN-gamma assay using ESAT-6 Pepmix, as antigenic stimulus, has the potential to rapidly diagnose pulmonary TB infection.

Human natural killer T cells (NKT), NK and T cells in pulmonary tuberculosis: potential indicators for disease activity and prognosis

One third of the world's population is infected with Mycobacterium tuberculosis (MTB). However, active disease can develop only in a small percentage, when the immunity is weakened. The acquired immune response to MTB is primarily mediated by T cells. Natural killer (NK) cells play a central role in innate immunity to microbial pathogens. Human NKT cells have characteristics of both T and NK cells and also exhibit antimycobacterial activity. This work aimed to enumerate T, NK and NKT cells in active pulmonary TB compared with healthy controls and to study the correlation between these cells with different factors affecting prognosis of pulmonary TB as disease severity, complications or associated diseases, antitubrculosis chemotherapy, and age & gender. Of the 22 active tuberculosis patients examined, 17 were recent cases and 5 recurrent. Healthy controls were divided into 14 individuals with detectable reaction to purified protein derivative (PPD+) and 14 individuals without detectable reaction to PPD-. The percentages of T, NK and NKT cells in erythrocyte-lysed whole blood samples were determined using flowcytometry. The percentage of NKT cells was significantly higher among the recently diagnosed MTB cases as compared with both PPD+ (P < 0.01) and PPD- (P < 0.01) healthy controls, while no significant difference could be found in the percentages of T or NK cells among these groups. However, comparing recurrent cases with recently diagnosed cases showed a significant difference only in the percentage of T cells (P < 0.01). There was also a significant difference in the percentage of T cells according to severity of disease (P < 0.01) and in the association of diabetes mellitus (P < 0.01). Age, gender and treatment with antituberculosis chemotherapy had no effect on the percentages of T, NK or NKT cells. It is concluded that T and NKT cells play an important role in immunity against TB. In active pulmonary tuberculosis, increased T cell count points to severity of the disease, while their reduced count predicts bad prognosis. Human NKT cell count is a marker of disease activity. Enumeration of these cells in peripheral blood can be used as a non-invasive prognostic indicator for patients with active pulmonary TB.

A study of the role of IL-12 in pulmonary tuberculosis using the whole blood flowcytometry technique

Pulmonary tuberculosis remains a major health problem. It is caused by Mycobacterium tuberculosis, which elicits a T-cell dependent immune response, initiated by monocytes through a large number of cytokines of which interleukin-12 is thought to play a critical role in initiation and regulation of T-helper (Th-1) like responses. To better understand the role of IL-12 in pulmonary tuberculosis patients, intracellular IL-12 in peripheral blood-derived monocytes was examined by flowcytometery. The percentage of monocytes producing IL-12 was measured after invitro stimulation of heparinized whole blood with mycobacterial protein antigens (culture filtrate). Of the 22 active tuberculosis patients, 17 were recent cases and 5 recurrent cases. Healthy controls were 14 individuals with detectable reaction to purified protein derivative (PPD+) and 14 without detectable reaction to PPD. The role of different factors affecting disease outcome such as treatment, age, gender, smoking, severity of disease and presence of other complications on the percentage of monocytes producing IL-12 was studied. Recurrent TB patients had a higher number of monocytes producing IL-12 in unstimulated cultures compared to other groups (P < 0.001). However, after in vitro stimulation there was a significant decrease in the number of monocytes producing IL-12 in recurrent TB patients as compared to recently diagnosed TB patients and healthy PPD+ individuals (P < 0.001). Antituberculosis chemotherapy was the only factor that had significant effect on the percentage of monocytes producing IL-12 (p < 0.05) while other studied factors did not show significant effect (p > 0.05). It is concluded that IL-12 plays a prominent regulatory role in tuberculosis.

HCV-specific CD27- CD28- memory T cells are depleted in hepatitis C virus and Schistosoma mansoni co-infection

Factors that influence the generation and maintenance of memory CD8+ T cells are not fully understood. The homeostasis of memory T cells is highly dynamic and tightly regulated by various stimuli, including cytokines and antigen-major histocompatibility complex ligands. We characterized the hepatitis C virus (HCV)-specific CD8+ T-cell responses in a cohort of HCV-infected individuals with or without Schistosoma mansoni co-infection from Egypt. We observed a significantly decreased CD27- CD28- (late differentiated) memory T-cell population in the HCV co-infected individuals compared to those with HCV infection alone. In contrast, there was no significant difference in the CD27+ CD28+ (early differentiated) memory T cells between the two groups. Analysis of human cytomegalovirus-specific CD8+ T-cell responses in the same individuals failed to reveal a similar pattern of altered memory T-cell differentiation. Thus, S. mansoni co-infection targets a specific subset of memory CD8+ T cells in HCV infection.

Interferon gamma assay for diagnosis of childhood tuberculosis

We measured interferon-gamma (IFN-gamma) in supernatant of peripheral blood mononuclear cell (PBMC) cultures stimulated with mycobacterial antigens. The study included ten children with newly diagnosed active pulmonary tuberculosis (TB), ten with inactive TB and 8 healthy controls. IFN-gamma was quantified by ELISA. Antigen stimulated PBMCs produced IFN-gamma at significantly higher levels than the background levels of nonstimulated cultures. Following specific antigen stimulation in vitro with TB bacilli, the PBMCs from patients with active and inactive TB produced significantly higher levels of IFN-gamma (433.15+/-119.80 and 420.64+/-131.52 respectively) than controls (241.2+/-119.74), (P< 0.001). However, no significant difference was found between active and inactive TB patients. In conclusion, estimation of specific IFN-gamma production by PBMC may be a useful immunological tool for diagnosis of childhood tuberculosis.

Serum antibodies to group A streptococcal extracellular and cell-associated antigens in Egyptians with post-streptococcal diseases

We investigated serum antibodies to a comprehensive array of group A streptococcal antigens and superantigens in Egyptian subjects. Antibodies to Streptococcus pyogenes cell-associated proteins and to proteins released by rapidly dividing S. pyogenes were compared in four patient groups with different post-streptococcal diseases and in healthy controls. Enzyme-linked immunosorbent assays showed that total Ig and IgG to extracellular antigens were significantly higher in patients with acute rheumatic fever (ARF) compared to healthy controls, but no differences were found in either total Ig or IgG titres to cell-associated proteins between any of the groups. Western blotting showed that multiple extracellular and cell-associated antigens, covering a wide range of molecular masses, were recognised by all sera, including healthy controls. No evidence was obtained for putative dominant antigens associated with any disease group, although a low molecular mass cell-associated protein (approximately 4 kDa) was clearly recognised by two-thirds of subjects irrespective of disease status. These findings demonstrate that raised serum Ig and IgG titres to extracellular, but not cell-associated, S. pyogenes antigens are a feature of ARF in this population, and suggest that multiple S. pyogenes antigens contribute to this response.