Clustered regularly interspaced short palindromic repeats, a glimpse – impacts in molecular biology, trends and highlights

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is a novel molecular tool. In recent days, it has been highlighted a lot, as the Nobel prize was awarded for this sector in 2020, and also for its recent use in Covid-19 related diagnostics. Otherwise, it is an eminent gene-editing technique applied in diverse medical zones of therapeutics in genetic diseases, hematological diseases, infectious diseases, etc., research related to molecular biology, cancer, hereditary diseases, immune and inflammatory diseases, etc., diagnostics related to infectious diseases like viral hemorrhagic fevers, Covid-19, etc. In this review, its discovery, working mechanisms, challenges while handling the technique, recent advancements, applications, alternatives have been discussed. It is a cheaper, faster technique revolutionizing the medicinal field right now. However, their off-target effects and difficulties in delivery into the desired cells make CRISPR, not easily utilizable. We conclude that further robust research in this field may promise many interesting, useful results.

Clinic of infectious hemorrhagic diseases and fevers

Hemorrhagic fevers are found in various republics and regions of our country, and there is no doubt that the more doctors are aware of the clinical manifestations and methods of laboratory confirmation of this group of diseases, the more complete our ideas about the regions of their distribution will be. The literature on this issue is scattered and not always available to doctors in the periphery. That is why the publication of a monograph by E.A.

The prioritisation of zoonoses in the Republic of North Macedonia – Do we need one health approach

Zoonoses have a different impact on public health, determined by geographical and socio-economic factors, which requires their prioritization for prevention and control purposes to be performed at the national level. Prioritization of zoonoses is a mechanism used in policy-making, primarily in allocating available resources. Aim of the paper is to compare two different methods used for prioritization of zoonoses by Institute of public health (IPH) and Food and Veterinary Agency (FVA). Material and methods: IPH used a method prepared by the U.S. Centers for Disease Control and Prevention (CDC), - One Health Zoonotic Disease Prioritization (OHZDP) tool, adapted to national conditions (2019). FVA used a standardized semi-quantitative method based on the OIE Methodological Manual (List and Categorization of priority diseases in animals including and those transmitted to humans). A total of 21 zoonoses have been selected, based on their importance for the human and veterinary sector. These diseases are ranked according to the stated criteria of the two previously conducted prioritizations and their comparison is performed. Results: With the prioritization conducted by IPH and FVA the first 5 ranked zoonoses are: Hemorrhagic fevers with renal syndrome, Leishmaniasis, Tularemia, Brucellosis and Listeriosis. With the prioritization carried out by the FVA the first 5 ranked zoonoses are: Bovine brucellosis, Bovine tuberculosis, Salmonellosis, Avian influenza and West Nile fever. A Cumulative Annual Incidence is taken as a control parameter. Regarding this, the 5 first ranked zoonoses are Echinococcosis, Brucellosis, Lyme fever, Leishmaniasis and Tularemia. Conclusions: A comparative analysis of the separate lists of priorities for human and veterinary medicine shows that only a certain percentage overlap. Also, the presence of a number of zoonoses with endemic character, but also a more pronounced risk of new emergent diseases, determines the need to provide consensus on the methodology of prioritization of zoonoses, and its formalization and institutionalization, as a crucial step towards identification and prioritization of zoonoses that would be the subject of joint programs and interventions.

Immunophenotyping and transcriptional profiling of human plasmablasts in dengue.

Plasmablasts represent a specialized class of antibody secreting effector B cell population that transiently appear in blood circulation following infection or vaccination. The expansion of these cells generally tends to be massive in patients with systemic infections leading to viral hemorrhagic fevers such as dengue or ebola. To gain a detailed understanding of the human plasmablast responses beyond antibody expression, here we performed immunophenotyping and RNA seq analysis of the plasmablasts from dengue febrile children in India. We found that the plasmablasts expressed several adhesion molecules and chemokines or chemokine receptors that are involved in endothelial interactions or homing to inflamed tissues including skin, mucosa, and intestine; and upregulated expression of several cytokine genes that are involved in leukocyte extravasation and angiogenesis. These plasmablasts also upregulated expression of receptors for several B cell pro-survival cytokines that are known to be induced robustly in systemic viral infections such as dengue, some of which generally tend to be relatively higher in patients manifesting hemorrhage and/or shock compared to patients with mild febrile infection. These findings improve our understanding of human plasmablast responses during the acute febrile phase of systemic dengue infection. Importance Dengue is globally spreading, with over 100 million clinical cases annually, with symptoms ranging from mild self-limiting febrile illness to more severe and sometimes life-threatening dengue hemorrhagic fever or shock, especially among children. The pathophysiology of dengue is complex and remains poorly understood despite many advances indicating a key role for antibody dependent enhancement of infection. While serum antibodies have been extensively studied, the characteristics of the early cellular factories responsible for antibody production, i.e., plasmablasts, are only beginning to emerge. This study provides a comprehensive understanding of the transcriptional profiles of human plasmablasts from dengue patients.

Lassa Fever Virus Binds Matriglycan—A Polymer of Alternating Xylose and Glucuronate—On α-Dystroglycan

Lassa fever virus (LASV) can cause life-threatening hemorrhagic fevers for which there are currently no vaccines or targeted treatments. The late Prof. Stefan Kunz, along with others, showed that the high-affinity host receptor for LASV, and other Old World and clade-C New World mammarenaviruses, is matriglycan—a linear repeating disaccharide of alternating xylose and glucuronic acid that is polymerized uniquely on α-dystroglycan by like-acetylglucosaminyltransferase-1 (LARGE1). Although α-dystroglycan is ubiquitously expressed, LASV preferentially infects vascular endothelia and professional phagocytic cells, which suggests that viral entry requires additional cell-specific factors. In this review, we highlight the work of Stefan Kunz detailing the molecular mechanism of LASV binding and discuss the requirements of receptors, such as tyrosine kinases, for internalization through apoptotic mimicry.

Viral-induced inflammatory coagulation disorders: Preparing for another epidemic

A number of viral infectious diseases have emerged or reemerged from wildlife vectors that have generated serious threats to global health. Increased international traveling and commerce increase the risk of transmission of viral or other infectious diseases. In addition, recent climate changes accelerate the potential spread of domestic disease. The Coronavirus disease 2019 (COVID-19) pandemic is an important example of the worldwide spread, and the current epidemic will unlikely be the last. Viral hemorrhagic fevers, such as Dengue and Lassa fevers, may also have the potential to spread worldwide with a significant impact on public health with unpredictable timing. Based on the important lessons learned from COVID-19, it would be prudent to prepare for future pandemics of life-threatening viral diseases. Among the various threats, this review focuses on the coagulopathy of acute viral infections since hypercoagulability has been a major challenge in COVID-19, but represents a different presentation compared to viral hemorrhagic fever. However, both thrombosis and hemorrhage are understood as the result of thromboinflammation due to viral infections, and the role of anticoagulation is important to consider.

Antibody-based inhibition of pathogenic New World Hemorrhagic Fever mammarenaviruses by steric occlusion of the human transferrin receptor 1 apical domain

Pathogenic Clade B New World mammarenaviruses (NWM) can cause Argentine, Venezuelan, Brazilian, and Bolivian hemorrhagic fevers. Sequence variability among NWM glycoproteins (GP) poses a challenge to the development of broadly neutralizing therapeutics against the entire clade of viruses. However, blockade of their shared binding site on the apical domain of human Transferrin Receptor 1 (hTfR1/CD71) presents an opportunity for the development of effective and broadly neutralizing therapeutics. Here we demonstrate that the murine monoclonal antibody OKT9, which targets the apical domain of hTfR1, can sterically block cellular entry by viral particles presenting Clade B NWM glycoproteins (GP1-GP2). OKT9 blockade is also effective against viral particles pseudotyped with glycoproteins of a recently identified pathogenic Sabia-like virus. With nanomolar affinity for hTfR1, the OKT9 antigen binding fragment (OKT9-Fab) sterically blocks Clade B NWM-GP1s and reduces infectivity of an attenuated strain of Junin virus. Binding of OKT9 to the hTfR1 ectodomain in its soluble, dimeric state produces stable assemblies that are observable by negative stain electron microscopy. A model of the OKT9-sTfR1 complex, informed by the known crystallographic structure of sTfR1 and a newly determined structure of the OKT9 antigen binding fragment (Fab) suggests that OKT9 and the Machupo virus GP1 share a binding site on the hTfR1 apical domain. The structural basis for this interaction presents a framework for the design and development of high-affinity, broadly acting agents targeting Clade B NWMs. Importance Pathogenic Clade B NWMs cause grave infectious diseases: the South American hemorrhagic fevers. Their etiological agents are Junin (JUNV), Guanarito (GTOV), Sabiá (SABV), Machupo (MACV), Chapare (CHAV), and a new Sabiá-like (SABV-L) virus recently identified in Brazil. These are priority A pathogens due to their high infectivity and mortality, their potential of person-to-person transmission, and the limited availability of effective therapeutics and vaccines to curb their effects. While low homology between surface glycoproteins of NWMs foils efforts to develop broadly neutralizing therapies targeting NWMs, this work provides structural evidence that OKT9, a monoclonal antibody targeting a single NWM glycoprotein binding site on hTfR1, can efficiently prevent their entry into cells.

Differential Laboratory Diagnosis of Acute Fever in Guinea: Preparedness for the Threat of Hemorrhagic Fevers

Acute febrile illnesses occur frequently in Guinea. Acute fever itself is not a unique, hallmark indication (pathognomonic sign) of any one illness or disease. In the infectious disease context, fever’s underlying cause can be a wide range of viral or bacterial pathogens, including the Ebola virus. In this study, molecular and serological methods were used to analyze samples from patients hospitalized with acute febrile illness in various regions of Guinea. This analysis was undertaken with the goal of accomplishing differential diagnosis (determination of causative pathogen) in such cases. As a result, a number of pathogens, both viral and bacterial, were identified in Guinea as causative agents behind acute febrile illness. In approximately 60% of the studied samples, however, a definitive determination could not be made.