Katarzyna Zwolińska

The Infectious Etiology of Alzheimer’s Disease

Background: Inflammation is a part of the first line of defense of the body against invasive pathogens, and plays a crucial role in tissue regeneration and repair. A proper inflammatory response ensures the suitable resolution of inflammation and elimination of harmful stimuli, but when the inflammatory reactions are inappropriate it can lead to damage of the surrounding normal cells. The relationship between infections and Alzheimer’s Disease (AD) etiology, especially late-onset AD (LOAD) has been continuously debated over the past three decades. Methods: This review discusses whether infections could be a causative factor that promotes the progression of AD and summarizes recent investigations associating infectious agents and chronic inflammation with AD. Preventive and therapeutic approaches to AD in the context of an infectious etiology of the disease are also discussed. Results: Emerging evidence supports the hypothesis of the role of neurotropic viruses from the Herpesviridae family, especially Human herpesvirus 1 (HHV-1), Cytomegalovirus (CMV), and Human herpesvirus 2 (HHV-2), in AD neuropathology. Recent investigations also indicate the association between Hepatitis C virus (HCV) infection and dementia. Among bacteria special attention is focused on spirochetes family and on periodontal pathogens such as Porphyromonas gingivalis or Treponema denticola that could cause chronic periodontitis and possibly contribute to the clinical onset of AD. Conclusion: Chronic viral, bacterial and fungal infections might be causative factors for the inflammatory pathway in AD.

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.

The effects of killer cell immunoglobulin-like receptor (KIR) genes on susceptibility to HIV-1 infection in the Polish population

Killer cell immunoglobulin-like receptors (KIR) are the most polymorphic receptors of natural killer (NK) cells. Their activity diversifies the functions of NK cells in the antiviral immune response, so the presence of certain KIR may affect transmission of HIV-1. The aim of the study was to evaluate the influence of KIR genes on the susceptibility to HIV-1 infection in the Polish population depending on the route of exposure. We determined the frequencies of activating (2DS1, 2DS2, 2DS3, 2DS4f, 2DS4del, 2DS5, 3DS1) and inhibitory (2DL1, 2DL2, 2DL3, 2DL5, 3DL1) KIRs in HIV-1-positive patients (n = 459), individuals exposed to HIV-1 but uninfected (EU, n = 118) and in uninfected, healthy blood donors (BD, n = 98). Analysis was performed using stepwise logistic regression. Apart from KIRs, CCR5-∆32, and CCR2-64I, alleles were also analyzed, as we knew or suspected that these features could affect susceptibility to HIV infection. The regression confirmed the protective effect of CCR5-∆32 (OR = 0.25, p = 0.006) and CCR2-64I (OR = 0.59, p = 0.032) against HIV infection. Among KIR genes, 2DL3 was found to be a protective factor (OR = 0.30, p = 0.015). A similar effect was seen for 3DS1 but only in intravenous drug users (IDUs) (OR = 0.30, p = 0.019), not in sexually exposed people. 2DL5 was found to be a factor facilitating HIV infection (OR = 2.13, p = 0.013). A similar effect was observed for 2DL2 but only in females (OR = 2.15, p = 0.040), and 2DS1 in IDUs (OR = 3.03, p = 0.022). Our results suggest a beneficial role of KIR3DS1 and 2DL3 supporting resistance to HIV infection and a harmful effect of 2DS1, 2DL5, and 2DL2 genes promoting HIV acquisition.

Comparison of microbiological and physicochemical methods for enumeration of microorganisms.

Determination of the number of cultured bacteria is essential for scientific and industrial practice. A spread plate technique is the most common and accurate method for counting of microorganisms. However, time consuming incubation does not allow for a quick estimation of the number of bacteria in a growing culture. In the present study, the results of photometric measurements: direct optical density method (OD at 585 nm), UV absorbance at 260 and/or 280 nm of separated and lysed bacteria by sodium hydroxide and surfactant with the spread plate technique were compared. The linear regression model for bacterial strains Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli was used to compare these three methods. The UV measurement method enabled determination of the number of bacteria with similar precision. The procedure for solubilized bacteria UV measurement is robust, and is not influenced by dispersions in the original culture medium.

Frequency of human endogenous retroviral sequences (HERV) K113 and K115 in the Polish population, and their effect on HIV infection.

Background The human genome contains about 8% of endogenous retroviral sequences originated from germ cell infections by exogenous retroviruses during evolution. Most of those sequences are inactive because of accumulation of mutations but some of them are still capable to be transcribed and translated. The latter are insertionally polymorphic HERV-K113 and HERV-K115. It has been suggested that their presence and expression was connected with several human diseases. It is also believed that they could interfere with the replication cycle of exogenous retroviruses, including HIV. Results Prevalence of endogenous retroviral sequences HERV-K113 and HERV-K115 was determined in the Polish population. The frequencies were found as 11.8% for HERV-K113 and 7.92% for HERV-K115. To verify the hypothesis that the presence of these HERVs sequences could affect susceptibility to HIV infection, comparison of a control group (HIV-negative, not exposed to HIV; n = 303) with HIV-positive patients (n = 470) and exposed but uninfected (EU) individuals (n = 121) was performed. Prevalence of HERV-K113 and HERV-K115 in the EU group was 8.26% and 5.71%, respectively. In the HIV(+) group we detected HERV-K113 sequences in 12.98% of the individuals and HERV-K115 sequences in 7.23% of the individuals. There were no statistically significant differences between groups studied. Conclusion The frequency of HERV-K113 and HERV-K115 sequences in Poland were found to be higher than usually shown for European populations. No relation between presence of the HERVs and HIV infection was detected.

Association between periodontal health status and cognitive abilities. The role of cytokine profile and systemic inflammation.

Background: Contemporary neurobiology, periodontal medicine, and immunology are now focusing on the relationship between chronic periodontitis and systemic diseases, which also include Alzheimer’s disease (AD). However a causative relationship between dementia and periodontitis has yet to be confirmed. Objective: The aim of the study was to determine whether periodontal health status and cognitive abilities are correlated with the relative changes in systemic measures of pro- and anti-inflammatory cytokines as a reflection of systemic inflammation. We hypothesized that poor periodontal health status may be associated with cognitive impairment and dementia via the exacerbation of systemic inflammation. Methods: Based on the periodontal and psychiatric examinations and the cytokine levels produced by unstimulated and LPS-stimulated PBL isolated from 128 participants, we have examined if the coexisting of these two clinically described conditions may have influence on the systemic inflammation. Mini-Mental State Examination (MMSE) and Bleeding on Probing (BoP) test results were combined into the one mathematical function U, which determines the severity of specific condition, called Cognitive and periodontal impairment state. Similarly, the levels of cytokines were combined into the one mathematical function V, whose value determines the level of Inflammatory state. The correlation between U and V was determined. Results: These results confirm that the presence of cognitive decline and the additional source of pro-inflammatory mediators, like periodontal health problems, aggravate the systemic inflammation. Conclusion: It is most likely that the comorbidity of these two disorders may deepen the cognitive impairment, and neurodegenerative lesions and advance to dementia and AD.

Inhibition of vesicular stomatitis virus replication in the course of HIV infection in patients with different stages of immunodeficiency.

The replication of vesicular stomatitis virus (VSV) in isolated human leukocytes has been used to measure the level of nonspecific antiviral immunity. However, during infection with some pathogens, the main effect observed is caused by interaction between the pathogen and VSV. This was also noted in advanced stages of HIV infection, when an inverse association between HIV viral load and VSV replication was found. The mutual effect was markedly stronger than the correlation between the VSV replication level and CD4(+) T-cell count. Since successful antiretroviral therapy is associated with a decrease in HIV viremia to undetectable levels, the effect of such therapy on VSV replication was expected and confirmed in this investigation. In fact, increased VSV titers were observed together with decreased HIV viral load, particularly in the case of efficient therapeutic schemes, for example those including lopinavir/ritonavir. The results showed that VSV replication capacity reflected the progression of HIV infection. Moreover, the presence of interferon in the plasma of AIDS patients was found to be only partially responsible for the inhibition of VSV replication. The results suggest a specific HIV-VSV interaction, whether direct or indirect. Thus the VSV replication assay may be applied in evaluating the stage of HIV infection.

Novel Triazole Hybrids of Betulin: Synthesis and Biological Activity Profile

Betulin derivatives containing a 1,2,3-triazole ring possess a wide spectrum of biological activities, including antiviral, anticancer, and antibacterial activity. A series of novel triazoles were prepared by the 1,3-dipolar cycloaddition reaction between the alkyne derivatives of betulin and organic azides. The chemical structures of the obtained compounds were defined by 1H and 13C NMR, IR, and high-resolution mass spectrometry (HR-MS) analysis. The target triazoles were screened for their antiviral activity against DNA and RNA viruses. The cytotoxic activity of the obtained compounds 5a–k and 6a–h was determined using five human cancer cell lines (T47D, MCF-7, SNB-19, Colo-829, and C-32) by a WST-1 assay. The bistriazole 6b displayed a promising IC50 value (0.05 μM) against the human ductal carcinoma T47D (500-fold higher potency than cisplatin). The microdilution method was applied for an evaluation of the antimicrobial activity of all of the compounds. The triazole 5e containing a 3′-deoxythymidine-5′-yl moiety exhibited antibacterial activity against two gram-negative bacteria vz. Klebsiella pneumoniae and Escherichia coli (minimal inhibitory concentration (MIC) range of 0.95–1.95 μM).

VSV based virotherapy in ovarian cancer: the past, the present and …future?

The standard approach to treating patients with advanced epithelial ovarian cancer (EOC) after primary debulking surgery remains taxane and platinum-based chemotherapy. Despite treatment with this strategy, the vast majority of patients relapse and develop drug-resistant metastatic disease that may be driven by cancer stem cells (CSCs) or cancer initiating cells (CICs). Oncolytic viruses circumvent typical drug-resistance mechanisms, therefore they may provide a safe and effective alternative treatment for chemotherapy-resistant CSCs/CICs. Among oncolytic viruses vesicular stomatitis virus (VSV) has demonstrated oncolysis and preferential replication in cancer cells. In this review, we summarize the recent findings regarding existing knowledge on biology of the ovarian cancer and the role of ovarian CSCs (OCSCs) in tumor dissemination and chemoresistance. In addition we also present an overview of recent advances in ovarian cancer therapies with oncolytic viruses (OV). We focus particularly on key genetic or immune response pathways involved in tumorigenesis in ovarian cancer which facilitate oncolytic activity of vesicular stomatitis virus (VSV). We highlight the prospects of targeting OCSCs with VSV. The importance of testing an emerging ovarian cancer animal models and ovarian cancer cell culture conditions influencing oncolytic efficacy of VSV is also addressed.

The role genes encoding of killer cell immunoglobulin-like receptors (KIRs) and their ligands in susceptibility to and progression of HIV infection.

NK cells are a part of the innate antiviral response. Their activity is regulated by signals from the surface receptors. Some of them, known as killer cell immunoglobulin-like receptors (KIRs), determine the quality and intensity of the immunological response, together with their ligands (HLA class I). KIR genes are very polymorphic, and this is reflected in the NK activity modulation. The stimulation of NK cells, especially in the early stages of the infection, can reduce the transmission of HIV or slow down the progression of infection. The varied KIR/HLA repertoire is a limiting factor for the risk of HIV infection and disease progression. Such diversity enables optimal regulation of NK cells and maintenance of the balance between activation to eliminate infected cells and inhibition. The control of NK cell activity via KIR3DL1/3DS1 and HLA-Bw4 (especially Bw4-80I) seems to be very important in the HIV context. With a few exceptions, it leads to a reduction of susceptibility to HIV infection and better viremia control, and slows down depletion of CD4+ T cells. Incompatibility of sexual partners for KIRs and HLA may oblige NK cells from the exposed partner to reject incoming cells from the HIV-positive partner. The presence of the inhibitory KIR, in the absence of its ligand, results in a lower threshold of NK cell activation, which reduces the chance of infection. The presence of an inhibitory receptor with a low affinity to the ligand (KIR2DL3+HLA-C1) is associated with lower susceptibility, and the effective NK cell inhibition (KIR2DL2+HLA-C1) results in increased susceptibility to HIV infection. The advantage of activating KIRs, especially in the presence of their ligands, is associated with higher cytolytic abilities, and thus reduced risk of HIV infection. If the virus is not eliminated in an early stage of infection, massive activation of NK is unfavorable due to the excessive stimulation of the immune system.