Iwona Mozer-Lisewska

NK Cells Prevalence, Subsets and Function in Viral Hepatitis C

Innate immunity appears to play an important role in the pathogenesis of viral hepatitis C. Among various cell subsets of this immunity natural killer (NK) cells raised particular interest. These cells are abundant in liver, possess significant cytotoxic potential and show links with adaptive immunity. They play important role, particularly in the acute phase of viral infections, including hepatitis C. They exhibit various types of receptors, either inhibitory or activating, that are able to react with distinct ligands on infected cells. Homozygosity of some receptors, namely KIR2DL3 reacting with recipient HLA-C1 antigens is a herald of good prognosis in hepatitis C virus (HCV) infection. In the early stage of the latter, both the prevalence and the cytotoxicity of NK cells are increased. Their inhibitory receptors are down regulated whereas activating ones are up regulated. Interferon-γ secreted by NK56+bright NK cells has a direct cytotoxic effect on infected hepatocytes. In contrast, in the chronic phase of HCV liver disease both, the prevalence and function of NK cells are impaired. Nevertheless, their cytotoxicity contributes to liver injury. Cells show change in the polarization profile from NK1 to NK2, manifested by secretion of immunosuppressive cytokines. Some HCV peptides are inhibitory for NK cells leading to the reduction of their antiviral activity. The unwanted effects of HCV peptides can be at least partly reversed by the antiviral therapy.

Significance of toll-like receptors expression in tumor growth and spreading: a short review.

Toll-like receptors (TLRs) are considered now as crucial sensors of innate immunity. Their role in the recognition of pathogens and the initiation of adaptive immune responses against them is well known. However, in last years TLRs have been identified on several tumor cells, including human malignancies. Their expression in cancer was found to be twofold: either promoting or inhibiting tumor progression. It was also demonstrated that several TLRs agonists, either natural or synthetic ones, may have beneficial effect on tumor-mediated disease, leading to potentiation of immune response to tumor-associated antigens. TLR-agonist linked tumor immunotherapy is still in nascent state, but growing rapidly, also in the area of common human malignancies. To date, the most promising and the most frequently studied interaction in tumor immunotherapy trials seems to be TLR9 and its synthetic agonists.

TLR receptors in laryngeal carcinoma - immunophenotypic, molecular and functional studies.

Toll-like receptors (TLRs) have been shown to play crucial role in the recognition of unicellular pathogens. We have shown the expression of three TLRs on tumor cells of human laryngeal carcinoma by means of immunohistochemistry. In the current study we searched presence of TLR1-10 on protein and molecular level in larynx carcinoma cell lines and the impact of respective TLR ligands on TLR expression. Larynx carcinoma cell lines have been used. Cell were subjected to immunocytochemistry. RNA isolated from the cells was tested by RT-PCR. Cells were cultured in the presence of respective TLR ligands. Cells than were harvested and subjected to flow cytometry, using anti TLR1-10 Moabs. The cells were evaluated of membrane and cytoplasmic cell staining. TLR reactivity varied in individual cell lines. RT-PCR allowed to show mRNA for all TLRs tested. After short-term cell culture each cell line exhibited distinct pattern of expression of TLRs following interaction with respective ligand. Cytoplasmic TLR staining had usually higher MFI value than membrane one, but after culture with ligand it became reversed. TLRs 7 and 9 showed highest expression in the majority of tumor cells tested. In conclusion, larynx carcinoma cell lines exhibit rather universal expression of TLRs, both on protein and molecular level. Culture of TLR expressing tumor cells with ligands points out for potential reactivity of tumor cells with TLR agonists, what may have therapeutic implications.

Hepatitis C virus load and expression of a unique subset of cellular genes in circulating lymphoid cells differentiate non‐responders from responders to pegylated interferon alpha–ribavirin treatment

Based on investigations of liver biopsy material, certain cellular genes have been implicated as correlates of success or failure to interferon alpha–ribavirin (IFN/RBV) therapy against hepatitis C. The current study aimed at determining whether expression of host genes thought to be relevant to HCV replication in the liver would be correlated with HCV infection status in peripheral blood mononuclear cells (PBMCs) and also with patient responsiveness to IFN/RBV treatment. Therefore, PBMCs from patients with chronic hepatitis C responding (n = 35) or not (n = 49) to IFN/RBV and from healthy controls (n = 15) were evaluated for HCV RNA load and cellular gene expression. Non‐responders had 3‐ to 10‐fold higher basal levels of interleukin (IL)‐8, IFN‐stimulated gene 15 (ISG15), 2′,5′‐oligoadenylate synthetase (OAS), and Toll‐like receptors (TLR)‐4, ‐5, and ‐7 compared to responders. Non‐responders with similar post‐treatment follow‐ups as responders persistently expressed 6‐ to 20‐fold greater levels of IL‐8, ISG15, and OAS after therapy. Higher expression of IFN‐α, IFN‐γ, and IFN‐λ was found in PBMCs of individuals achieving sustained virological response, either before or after therapy. Pre‐treatment HCV RNA loads in PBMCs of non‐responders were significantly higher (P = 0.016) than those of responders. In conclusion, the data indicate that immune cells of responders and non‐responders to IFN/RBV therapy exhibited significantly different virological and host gene expression profiles. Elevated baseline HCV loads and TLR‐4, ‐5, and ‐7 levels, and persistently high levels of IL‐8, ISG15, and OAS were correlated with IFN non‐responsiveness. The results warrant further investigations on the utilization of PBMCs for predicting success or failure to IFN‐based therapies. J. Med. Virol. 85:441–448, 2013.

The incidence and significance of pattern-recognition receptors in chronic viral hepatitis types B and C in man.

Chronic viral hepatitis B and C are among the most common and devastating liver diseases worldwide. Immune response plays a crucial role in the course of both diseases. In spite of the importance of the adaptive arm of the immune response, there is a growing role of innate immunity, the earliest confronted with viral attack. Pattern-recognition receptors (PRRs) and, in particular, Toll-like receptors (TLRs) are molecules which are able not only to recognize foreign invaders, but also quickly mount an antiviral defense. Activation of PRRs has been demonstrated in both hepatitis types, i.e. in situ in the liver and on while blood cells. Both viruses, HCV and HBV, are able to subvert the PRR-mediated antiviral response by means of various proteins and enzymes. HCV acts via the non-structural proteins NS2 and NS3/4A, while HBV HBeAg is inversely correlated with TLR activity. Viral counterattack is particularly directed toward dendritic cells, those creating the link with the adaptive immune response. Apart from TLRs, other PRRs such as RIG-1 and MDA-5 are also able to recognize viral infection and participate in the activation of type I interferon synthesis. TLRs manifest gene polymorphism, which was shown to affect several consequences associated with chronic viral hepatitis such as liver cirrhosis and the outcome of liver allotransplantation. There have been numerous attempts to take advantage of the existence and activity of PRRs for the patients’ benefit. Several authors examined the role of TLR synthetic agonists as inducers of TLR activation. In hepatitis C the most promising agonists appear to be TLR3, 7, and 9 for potential antiviral therapy. PRRs may also act as potent adjuvants in HBV vaccines. Their baseline mRNA levels may have predictive value in the course of antiviral therapy.

Seroprevalence of anti-HEV IgG in 182 Polish patients.

INTRODUCTION Hepatitis E virus (HEV) infection is an emergent disease in developed countries. HEV seroprevalence in such areas significantly exceeds values expected when one considers infection with this virus only as a problem restricted to classical endemic regions. To date, no related data are available in Poland. In this study we aimed to obtain HEV seroprevalence data and compare them with similar data for hepatitis A virus (HAV) in Polish patients. MATERIAL/METHODS From February 1st, 2013, to October 15th, 2013, we performed anti-HEV IgG (anti-HEV) tests (EIAgen HEV IgG Kit; Adaltis, Milano, Italy) in 182 patients (101 men and 81 women; 61 patients were HIV-positive) of one center in Poland, aged 19-85 (47.2 ± 14.2 years). RESULTS We found a 15.9% seropositivity rate for anti-HEV (16.3% of the study population with an unequivocal test result) and 38.5% for anti-HAV. In 6 cases (3.4%), anti-HEV-positive persons had never travelled abroad. In contrast to HAV seroprevalence data, there was no significant difference in HEV seroprevalence between young adults (18-40 years) and older patients (p<0.0001 and p=0.0967, respectively). Anti-HEV were found in 21.3% of HIV-infected individuals. CONCLUSIONS HEV infection may occur in Poland. Anti-HAV seropositivity among Polish patients is significantly higher than anti-HEV. In contrast to HAV, HEV seroprevalence is similar in younger and older patients. The clinical course of HEV infection in Polish citizens seems to be largely asymptomatic. Polish HIV patients may be more commonly exposed to HEV than similar individuals from other countries.

Transmitted HIV drug resistance in antiretroviral-treatment-naive patients from Poland differs by transmission category and subtype

OBJECTIVES The surveillance of HIV-transmitted drug resistance mutations (t-DRMs), including temporal trends across subtypes and exposure groups, remains a priority in the current management of the epidemic worldwide. METHODS A cross-sectional analysis of 833 treatment-naive patients from 9 of 17 Polish HIV treatment centres. Partial pol sequences were used to analyse drug resistance with a general time reversible (GTR)-based maximum likelihood algorithm used for cluster/pair identification. Mutation frequencies and temporal trends were investigated. RESULTS t-DRMs were observed in 9% of cases (5.8% for NRTI, 1.2% NNRTI and 2.0% PI mutations) and were more common among heterosexually infected (HET) individuals (13.4%) compared with MSM (8.3%, P = 0.03) or injection drug users (IDUs; 2.9%, P = 0.001) and in MSM compared with IDUs (P = 0.046). t-DRMs were more frequent in cases infected with the non-B variant (21.6%) compared with subtype B (6.6%, P < 0.001). With subtype B a higher mutation frequency was found in MSM compared with non-MSM cases (8.3% versus 1.8% for IDU + HET, P = 0.038), while non-B variants were associated with heterosexual exposure (30.4% for HET versus 4.8% for MSM, P = 0.019; versus 0 for IDU, P = 0.016). Trends in t-DRM frequencies were stable over time except for a decrease in NNRTI t-DRMs among MSM (P = 0.0662) and an NRTI t-DRM decrease in HET individuals (P = 0.077). With subtype B a higher frequency of sequence pairs/clusters in MSM (50.4%) was found compared with HET (P < 0.001) and IDUs (P = 0.015). CONCLUSIONS Despite stable trends over time, patterns of t-DRMs differed notably between transmission categories and subtypes: subtype B was associated with MSM transmission and clustering while in non-B clades t-DRMs were more common and were associated with heterosexual infections.

Contribution of genes for killer cell immunoglobulin-like receptors (KIR) to the susceptibility to chronic hepatitis C virus infection and to viremia.

BACKGROUND Natural killer (NK) cells are an important element of innate immunity against viruses, although their numbers decrease in the liver during chronic HCV infection. NK cells express a large panel of inhibitory and activating receptors. The most polymorphic of these are killer cell immunoglobulin-like receptors (KIRs) which are encoded by multiple genes that may be present or absent in given individuals depending on their genotype. This variability results in differential susceptibility to viral infections and diseases, including HCV infection and its consequences. AIMS AND METHODS The aim of this study was to test whether chronical infection with HCV and the viremia levels are associated with any KIR gene in the Polish population. We typed 301 chronically HCV-infected patients and 425 non-infected healthy individuals for the presence or absence of KIR genes and their ligands, HLA-C C1 and C2 groups as well as HLA-B and HLA-A Bw4-positive alleles. RESULTS We found that males, but not females, possessing KIR2DS2 and KIR2DL2 genes had a 1.7 higher probability to become chronically HCV-infected than males negative for these genes (p=0.0213). In accord with this, centromeric B region, containing KIR2DS2 and KIR2DL2 genes, was also associated with chronic HCV infection in males. In addition, patients of both genders possessing KIR2DS3 but not KIR2DS5 gene exhibited, on average, 2.6 lower level of viremia than HCV-infected individuals with other genotypes (p=0.00282). This was evident in those infected at a young age. KIR2DS3-positive patients also had lower mean levels of bilirubin than KIR2DS3-negative ones (p=0.02862). CONCLUSION Our results suggest a contribution of the KIR2DS2 and KIR2DL2 genes (cenB haplotype) to the susceptibility to chronic HCV infection, and an association of the KIR2DS3 gene in the absence of KIR2DS5 with low viremia levels.

p21/Wafl/Cipl cellular expression in chronic long-lasting hepatitis C: correlation with HCV proteins (C, NS3, NS5A), other cell-cycle related proteins and selected clinical data.

Studies indicate that proteins of hepatitis C virus (HCV) disturb expression of cell-cycle-related proteins. A disturbed cell-cycle control is a hepatocellular carcinoma (HCC) risk factor in patients with HCV-related liver damage. The present study aimed to analyse the cellular expression of p21/Wafl/Cipl (p21) in long-lasting chronic hepatitis C (CH-C), its correlation with the key oncogenic HCV proteins (C, NS3, NS5A), other cell-cycle-related proteins (PCNA, Ki-67, cyclin D1, p53) and selected clinical data. Archival liver biopsies, obtained from patients with CH-C, normal livers, and hepatocellular carcinoma (HCC) specimens were analysed by immunocytochemistry and ImmunoMax technique. In CH-C overexpression of p21 protein was demonstrated. Positive correlations of p21 protein expression in CH-C involved age of the patients, grading, and liver steatosis. Moreover, expression of p21 correlated significantly with expression of p53 protein, of D1 cyclin and Ki-67. Although Ki-67 antigen was related to p21 expression, only Ki-67 expression proved to be directly related to liver staging. Expression of the NS3 protein, which prevailed in CH-C patients, manifested correlation with p21 expression, and that of cyclin D1. In presence of preserved potential for regeneration, overexpression of p21 indicates inhibition of cell cycle in hepatocytes, which probably plays a protective role for the chronically damaged cells. Out of the three HCV proteins only NS3 seems to affect control of p21 protein expression in in vivo infection. Nevertheless, the studies indicate that neither expression of p21 protein nor that of viral NS3 protein can serve as a marker of progression of CH-C to HCC in vivo.

The insulin-like growth factor-1 and expression of its binding protein‑3 in chronic hepatitis C and hepatocellular carcinoma

The role of growth factors produced by the liver, including insulin-like growth factor-1 (IGF-1) and its main binding protein, IGF binding protein-3 (IGFBP-3), in hepatitis C virus (HCV)-associated carcinogenesis has only partially been recognized and there is not much data available on the local expression of IGF-1 and IGFBP-3 in chronic hepatitis C (CH‑C). Therefore, the aim of the present study was to evaluate the IGF‑1 and IGFBP‑3 serum levels and tissue expression in liver biopsies of CH‑C patients (n=37) and hepatocellular carcinoma (HCC) samples (n=61) as related to age- and gender-matched control serum samples (n=15) and healthy liver samples (n=10). Serum concentrations of IGF-1 (S-IGF-1) and IGFBP‑3 (S-IGFBP‑3) were measured by the ELISA method. Tissue expression of proteins was detected using ABC immunocytochemistry and evaluated applying a spatial visualization technique. Concentrations of S-IGF-1 and hepatic expression of IGF-1 (H-IGF-1) proved to be lower in CH-C compared to the controls. No significant differences were detected in the concentration of S-IGFBP-3 between the studied groups but the S-IGF-1/IGFBP-3 ratio in the CH-C group was significantly lower compared to the control. H-IGFBP-3 was higher in CH-C compared to those in the control and HCC. In HCC, lower expression of H-IGF-1 was detected compared to the control and a higher H-IGF-1/IGFBP-3 ratio compared to CH-C. A negative correlation was detected between S-IGF-1 and S-IGF-1/IGFBP-3 ratio, on the one hand, and age, grading and concentration of α-fetoprotein (AFP) on the other, while H-IGFBP-3 was negatively correlated with BMI in the CH‑C group. In patients with CH‑C, the H‑IGF‑1/IGFBP‑3 ratio was higher compared to that of the S‑IGF‑1/IGFBP‑3 ratio. The studies documented a disturbed H‑IGF‑1 and H‑IGFBP‑3 in CH‑C, which may be of significance in carcinogenesis. Examination of serum concentration and tissue expression of the two proteins and, first of all, estimation of the IGF‑1/IGFBP‑3 ratio may provide additional (to the estimation of IGF‑1 and AFP) non-invasive markers in HCV‑related liver injury.