Publications by authors named "Nikola Ralchev"

Der p1 is one of the major allergens causing house dust mite (HDM) allergy. Pathological Der p1-specific B cells play a key role in allergic inflammation as producers of allergen-specific antibodies. Crosslinking the inhibitory FcγRIIb with the B cell receptor triggers a high-affinity suppressive signal in B cells.

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Systemic lupus erythematosus (SLE) is a complex autoimmune disease with a number of immunological aberrations in the mechanisms of innate and adaptive immune responses. Spontaneous and induced mouse models of the disease have contributed significantly to the advancement in lupus treatments. The involvement of humanized models, engrafted with lupus patients' immune cells, represented the possibility to study the development of SLE.

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SARS-CoV-2 caused the COVID-19 pandemic, which overwhelmed global healthcare systems. Over 776 million COVID-19 cases and more than 7 million deaths were reported by WHO in September 2024. COVID-19 vaccination is crucial for preventing infection and controlling the pandemic.

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Melanoma is one of the most common tumors worldwide, and new approaches and antitumor drugs for therapy are being investigated. Among the promising biomolecules of natural origin for antitumor research are gastropodan hemocyanins-highly immunogenic multimeric glycoproteins used as antitumor agents and components of therapeutic vaccines in human and mouse cancer models. A murine melanoma model established in C57BL/6 mice of the B16F10 cell line was used to study anticancer modified oxidized hemocyanins (Ox-Hcs) that were administered to experimental animals (100 μg/mouse) under different regimens: mild, intensive, and with sensitization.

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Article Synopsis
  • * Results showed these strains have strong antibacterial and antifungal properties, with unique abilities to inhibit various harmful fungi and significant antioxidant capacity.
  • * The research also indicates that one of the strains has potential effects on leukemia cell growth, paving the way for future development of targeted probiotics, while further safety studies are needed for validation.
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COVID-19, caused by the SARS-CoV-2 virus, has caused a global health crisis, necessitating a deeper understanding of its pathophysiology. In this study, we explored the immune and hematological dynamics in COVID-19 patients to gain insights into disease severity and prognosis. Our findings revealed distinct cytokine profiles in moderate and severe cases.

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Unlabelled: The development of antitumor drugs and therapy requires new approaches and molecules, and products of natural origin provide intriguing alternatives for antitumor research. Gastropodan hemocyanins-multimeric copper-containing glycoproteins have been used in therapeutic vaccines and antitumor agents in many cancer models.

Materials And Methods: We established a murine model of melanoma by challenging C57BL/6 mice with a B16F10 cell line for solid tumor formation in experimental animals.

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Der p 1 is one of the major allergenic molecules of Dermatophagoides pteronyssinus, causing house dust mite (HDM) allergy. The pathological B cells produce allergen-specific IgE antibodies that mediate the hypersensitivity reaction, therefore the selective elimination of these B cells is a legitimate therapeutic goal in allergy. Chimeric molecule Dp51-72 able to cross-link B cell inhibitory complement receptor type 1 and BCR on Der p 1-specific B cells was constructed.

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Hashimoto's thyroiditis is one of the most common endocrine disorders, affecting up to 20% of the adult population. No treatment or prevention exists except hormonal substitution for hypothyroidism. We hypothesize that it may be possible to selectively suppress anti-thyroglobulin (Tg) IgG antibody-producing B lymphocytes from HT patients by a chimeric protein molecule containing a monoclonal antibody specific for the human inhibitory receptor CR1, coupled to peptide epitopes derived from Tg protein.

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Objectives: Osteoarthritis (OA) is a chronic degenerative disorder of the joint characterized by cartilage breakdown and synovial inflammation. A number of different cells of innate and adaptive immunity contribute to joint pathology during OA inflammation. The interaction between the local synovial and systemic inflammatory cellular response and the structural changes in the joint is still unknown.

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Finding new effective compounds of natural origin for composing anti-tumor vaccines is one of the main goals of antitumor research. Promising anti-cancer agents are the gastropodan hemocyanins-multimeric copper-containing glycoproteins used so far for therapy of different tumors. The properties of hemocyanins isolated from the marine snail (RtH) and the terrestrial snail (HaH) upon their use as carrier-proteins in conjugated vaccines, containing ganglioside mimotope GD3P4 peptide, were studied in the developed murine melanoma model.

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Article Synopsis
  • - The study focuses on the Bcl-2 family proteins in metazoans, which play key roles in regulating apoptosis, particularly in the early evolutionary stages of these organisms, specifically analyzing four trBcl-2 homologs in a primitive metazoan.
  • - Among these homologs, trBcl-2L1 and trBcl-2L2 are found to be antiapoptotic, while trBcl-2L3 and trBcl-2L4 are proapoptotic, with trBax and trBak having specific roles in permeabilizing mitochondrial membranes and regulating antiapoptotic activities.
  • - The findings also reveal that the structure of trBcl-2L2
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