Development, production and characterization of SARS-CoV-2 virus-like particles (Coronaviridae: <i>Orthocoronavirinae: Betacoronavirus: Sarbecovirus</i>)

Introduction. The COVID-19 pandemic caused by SARS-CoV-2 has created serious health problems worldwide. The most effective way to prevent the occurrence of new epidemic outbreaks is vaccination. One of the modern and effective approaches to vaccine development is the use of virus-like particles (VLPs). The aim of the study is to develop a technology for production of VLP based on recombinant SARS-CoV-2 proteins (E, M, N and S) in insect cells. Materials and methods. Synthetic genes encoding coronavirus proteins E, M, N and S were used. VLP with various surface proteins of strains similar to the Wuhan virus, Delta, Alpha and Omicron were developed and cloned into the pFastBac plasmid. The proteins were synthesized in the baculovirus expression system and assembled into VLP in the portable Trichoplusia ni cell. The presence of insertion in the baculovirus genome was determined by PCR. ELISA and immunoblotting were used to study the antigenic activity of VLP. VLP purification was performed by ultracentrifugation using 20% sucrose. Morphology was assessed using electron microscopy and dynamic light scattering. Results. VLPs consisting of recombinant SARS-CoV-2 proteins (S, M, E and N) were obtained and characterized. The specific binding of antigenic determinants in synthesized VLPs with antibodies to SARS-CoV-2 proteins has been demonstrated. The immunogenic properties of VLPs have been studied. Conclusion. The production and purification of recombinant VLPs consisting of full-length SARS-CoV-2 proteins with a universal set of surface antigens have been developed and optimized. Self-assembling particles that mimic the coronavirus virion induce a specific immune response against SARS-CoV-2

Rapid Efficacy of Gemtuzumab Ozogamicin in Refractory AML Patients with Pulmonary and Kidney Failure

Objectives: To the best of our knowledge, data from Gemtuzumab ozogamicin in Acute Myeloid Leukemia (AML) patients with failure of organ functions and poor performance status are extremely lacking. Moreover, the fast recovery from organ failure, after Gemtuzumab ozogamicin administration, has never been reported. This study aimed to demonstrate the efficacy and rapid response of Gemtuzumab ozogamicin in refractory acute myeloid leukemia (AML) patients with pulmonary and kidney failure and poor performance status. Three refractory AML patients, with organ dysfunction, are described. One patient was pre-treated with intensive chemotherapy, and two other patients progressed during Azacitidine treatment. Two patients had respiratory failure grade 2 and one patient suffered from acute kidney insufficiency. Two patients were highly febrile with an elevated С-Reactive Protein (CRP) level. The WHO performance status of three was measured in all patients. Gemtuzumab ozogamicin administration was performed in three patients, followed by a further switch to Gemtuzumab ozogamicin + Azacitidine or &ldquo;7+3&rdquo; treatment. Results: Gemtuzumab ozogamicin administration resulted in abrupt fever cessation in two febrile patients simultaneously with a rapid decrease in CRP level and fast resolution of respiratory failure. Recovery of kidney function was noticed rapidly in patients with renal insufficiency. The WHO performance status was elevated in all three patients. No adverse grade II&ndash;III effects were noticed. Further treatment made two patients eligible for intensive chemotherapy, one patient underwent allogeneic stem cell transplantation, and the patient with kidney failure obtained complete remission. Conclusions: Gemtuzumab ozogamicin therapy appeared to be safe and highly efficacious in relapsed/refractory AML patients with organ dysfunction, like pulmonary or renal failure and poor performance status, and may contribute to rapid recovery from organ failures