KEY ACHIEVEMENTS IN GENE THERAPY DEVELOPMENT AND ITS PROMISING PROGRESS WITH GENE EDITING TOOLS (ZFN, TALEN, CRISPR/CAS9)

Gene therapy concept is based on introduction of the wild-type allele into a patient’s genome in order to reverse a specific mutation. It is designed to treat hereditary diseases as well as the other diseases occurring later in life. Gene therapy was first mentioned in the 1960s and 70s, whereupon a series of studies was carried out, and in 1990 the first successful gene therapy was conducted. Since then about 2 600 clinical trials based on this concept were completed or are in progress. The two biggest issues are introduction of an exogenous DNA to target tissue, and its controlled integration in the genome. Until recently, the exogenous DNA sequences were incorporated randomly in the patient’s genome. Even though most of these treatments gave positive results, there was always a possibility of insertional mutagenesis. Controlling the integration place has rapidly progressed with the development of gene editing tools: ZFN, TALEN and CRISPR/Cas9. Although they have been used in only several clinical studies, gene editing tools are a small step away from clinical usage. In this review, we will give historical overview of gene therapy development and describe recent tools that can be used in precision medicine

COMPARISON OF THREE METHODS FOR DETECTION OF ANTI-SARS-COV-2 ANTIBODIES

A novel positive-sense RNA virus named Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was identified in December 2019 in China. It is a systemic disease that includes severe respiratory distress, coronavirus disease 19 (Covid-19). The primary way of transmitting this virus is person-to-person contact via respiratory droplets, but it can also be transmitted by contaminated surfaces. Symptoms range from mild to severe, and the virus spreads quickly. On 11 March 2020 Covid-19 was declared a pandemic by the World Health Organization. The standard way to identify the presence of the virus is to detect its genome using real-time reverse transcriptase polymerase chain reaction (RT-PCR). It can be applied to respiratory tract samples such as nasopharyngeal swabs, sputum and bronchoalveolar lavage. In order to identify contact with the virus and immunological response of the individual, tests based on immunoassays were developed. Many of those tests were produced in short periods of time and they mostly differ on the sample that can be used (serum, plasma or whole blood), complexity and/or expense, and the class of the antibody they detect. The reliability of such tests is of high importance for epidemiological surveys as well as for the development of a vaccine. The aim of this study was to compare three commercially available immunoassay tests. Our results show that different serological tests have different sensitivity and specificity, and that the rapid option, which is the easiest to perform and has the lowest cost, provides the least reliable results

ANTENATAL DETECTION OF CHROMOSOMAL ABNORMALITIES COMBINING QF-PCR AND CYTOGENETIC ANALYSIS

Aim: To compare the diagnostic values and limitations of quantitative fluorescent polymerase chain reaction (QF-PCR) and conventional cytogenetic analysis in prenatal diagnosis of chromosomal abnormalities. Methods: A prospective study included simultaneous QF-PCR and cytogenetic analysis of 133 prenatal samples routinely obtained by amniocentesis or chorionic villus sampling (CVS). Additionally, QF-PCR analysis was performed on 14 tissue samples collected after termination of pregnancy (TOP) for which karyotyping could not be performed due to culture failure. Results: Among 133 analyzed prenatal samples, chromosomal abnormalities were diagnosed in 12 cases (9%), including 10 cases of numerical chromosomal aberrations and two cases with unbalanced structural rearrangements. Nine out of 12 chromosomal abnormalities were also detected with QF-PCR. However, all cases of major aneuploidies were successfully disclosed with QF-PCR, resulting in 100% detection rate for chromosomes 21, 18, 13, X and Y. Using a set of markers specific for chromosomes 21, 18 and 13, QF-PCR analysis of tissues collected after TOP revealed chromosomopathy in 21.4% of cases (two cases of trisomy 18 and one triploidy). A comparison of STR markers confirmed monozygosity in two monochorionic/diamniotic twin pregnancies. Conclusion: QF-PCR has been shown as a rapid and reliable method for prenatal diagnosis of the most common chromosomal aneuploidies, and as an adequate alternative to conventional karyotyping in cases where cytogenetic analysis is not possible due to failure of culturing process. However, conventional cytogenetics still presents a gold standard for the detection of structural aberrations and rare aneuploidies

BIOLOGICAL FEATURES OF SARS-CoV-2 AND CURRENT APPROACHES TO ANTIVIRAL THERAPY AND VACCINATION: A REVIEW

Since the first description of patients with pneumonia of unknown origin in Wuhan in December 2019, unprecedented efforts of the international scientific community led to the identification and molecular characterization of its etiological agent, e.g. SARS-CoV-2. The global pandemic of COVID-19 represents an outstanding challenge for the scientists and medical professionals worldwide. In this review, we discuss the most important aspects of SARS-CoV-2 biology and virology including antiviral and immunomodulatory treatment strategies as well as vaccine development