Mortality in individuals treated with COVID-19 convalescent plasma varies with the geographic provenance of donors

Successful therapeutics and vaccines for coronavirus disease 2019 (COVID-19) have harnessed the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Evidence that SARS-CoV-2 exists as locally evolving variants suggests that immunological differences may impact the effectiveness of antibody-based treatments such as convalescent plasma and vaccines. Considering that near-sourced convalescent plasma likely reflects the antigenic composition of local viral strains, we hypothesize that convalescent plasma has a higher efficacy, as defined by death within 30 days of transfusion, when the convalescent plasma donor and treated patient were in close geographic proximity. Results of a series of modeling techniques applied to approximately 28,000 patients from the Expanded Access to Convalescent Plasma program (ClinicalTrials.gov number: NCT04338360) support this hypothesis. This work has implications for the interpretation of clinical studies, the ability to develop effective COVID-19 treatments, and, potentially, for the effectiveness of COVID-19 vaccines as additional locally-evolving variants continue to emerge.

Mortality in individuals treated with COVID-19 convalescent plasma varies with the geographic provenance of donors

Successful therapeutics and vaccines for coronavirus disease 2019 (COVID-19) have harnessed the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Evidence that SARS-CoV-2 exists as locally evolving variants suggests that immunological differences may impact the effectiveness of antibody-based treatments such as convalescent plasma and vaccines. Considering that near-sourced convalescent plasma is likely to reflect the antigenic composition of local viral strains, we hypothesized that convalescent plasma has a higher efficacy, as defined by death within 30 days of transfusion, when the convalescent plasma donor and treated patient were in close geographic proximity. Results of a series of modeling techniques applied to a national registry of hospitalized COVID-19 patients supported this hypothesis. These findings have implications for the interpretation of clinical studies, the ability to develop effective COVID-19 treatments, and, potentially, for the effectiveness of COVID-19 vaccines as additional locally-evolving variants continue to emerge.

Determining the degree of kinship of sarlik yaks bred in the mountainous regions of the Kabardino-Balkarian Republic by blood groups

The formation of immunogenetics as a science was the result of numerous studies on the study of blood groups and other polymorphic systems, the results of which are successfully applied both in animal husbandry and in animal breeding. Modern biotechnological methods used to analyze blood groups enable us to determine the true origin of animals. To determine the correctness of the breeding processes occurring in the breed, the antigenic composition of blood groups, which are also used to study the reliability of origin, needs to be studied. The results obtained make it possible to analyze genetic similarity, determine the level of polymorphism and the nature of structural changes in the result of breeding work. Also, by analyzing the distribution of the frequency of occurrence of antigens, it is possible to determine the genetic distances and genetic similarity of breeds and lines among themselves [1].

Structural peculiarities of biopolymers produced by diazotrophic endobiont Herbaspirillum spp.

Diazotrophic endobionts Herbaspirillum spp. were studied in respect to the structural peculiarities of the lipopolysaccharides (LPS), O-specific polysaccharides (OPS) structure, antigenic composition and genetics.

Investigation of the relationship of latent tuberculosis infection with the development of myeloid and lymphoblastic leukemia

Annotation. The relationship between tuberculosis infection and hemoblastosis has attracted the attention of physicians and has been the basis for a wide variety of assumptions. In the second half of the XIX century, there was expressed an opinion about the unique nature of these pathologies. They explained this phenomenon as the immunochemical affinity of specific tumor and mycobacterial antigens, but not as a result of the persistence of mycobacterium tuberculosis (MBT). The aim of the study was to investigate the association of latent tuberculosis infection and oncogenesis, in particular with leukemias. From transplantable human myeloblasts with acute myeloid leukemia (Kasumi-1) and T-lymphocytes with T-lymphoblastic leukemia (Jurkat), including 0.22 μm filtrate of their lysates were isolated from mycobacterium tuberculosis (MBT) with deficient cell wall (CWD). During primary microscopy, the MBT was found mainly in the form of coccoid. The isolated coccoid Kasumi and Jurkat had close antigen affinity and shared antigens with typical MBT. After prolonged incubation with the growth promoter, not only CWD MBT was isolated from all lysates and filtrates, but isolates with identical morphology and antigenic composition were obtained. This strongly suggested that the MBT and their modified forms could be associated with various types of leukemia. Moreover, the affinity of FLK-BLV isolates with blood of people with latent tuberculosis infection, cattle tuberculosis, CWD forms M. bovis and M. tuberculosis was determined, confirming the role of tuberculosis infection in the development of various forms of the disease depending on the host genome, as well as the features of the adaptive reactions of the infectious agent. In particular, after destruction by ultrasound and filtration through Amicon Ultracel® 100 K and Millex® GP 0.22 μm, their filtrates gave an increase in the number of CWD MBT with acid-resistant elements and had the same antigenic composition, including the original isolates. The long-term incubation of the test material in the growth promoter and numerous transplants on the adapted MyCel DW medium played a major role in the allocation of CWD.

The Impact of the Antigenic Composition of Chimeric Proteins on Their Immunoprotective Activity against Chronic Toxoplasmosis in Mice

Toxoplasmosis may pose a serious threat for individuals with weakened or undeveloped immune systems. However, to date, there is no specific immunoprophylaxis for humans. Thus, the aim of this study was to evaluate the immunogenicity of three trivalent—SAG2-GRA1-ROP1L (SGR), SAG1L-MIC1-MAG1 (SMM), and GRA1-GRA2-GRA6 (GGG)—and two tetravalent—SAG2-GRA1-ROP1-GRA2 (SGRG) and SAG1-MIC1-MAG1-GRA2 (SMMG)—chimeric T. gondii proteins, as well as their protective potential against chronic toxoplasmosis in laboratory mice. All three trivalent recombinant proteins possessed immunogenic properties, as defined by specific humoral and cellular responses in vaccinated mice characterized by the synthesis of specific IgG (IgG1/IgG2a) antibodies in vivo and the release of Th1/Th2 cytokines by stimulated splenocytes in vitro. Immunization with all three recombinant proteins provided partial protection against toxoplasmosis, although the protective capacity strongly depended on the individual antigenic composition of each preparation. The antigens providing the highest (86%) and lowest (45%) protection, SGR and SMM, respectively, were supplemented with GRA2 antigen fragment, to form the tetravalent chimeric proteins SGRG and SMMG. Further study revealed that the tetravalent preparations exhibited high immunogenic potential; however, the addition of another antigen to the recombinant protein structure had distinct effects on the protection generated, compared to that of the trivalent counterparts, depending on the antigen tested.

Use of antigenic composition to differentiate among Rhizoctonia solani isolates from flax

Rhizoctonia solani is an plant pathogenic fungus with a wide host range and worldwide distribution. Double diffusion technique was used to differentiate among Rhizoctonia solani isolates from flax. In this technique, antisera of isolate 23 (AG-2) and isolate 24 (AG-4) reacted against antigens of 24 isolates belonging to AG-2 and Ag-4. The antiserum of isolate 23 (AG-2) was insensitive to differentiate among the isolates of AG-2, while it was highly sensitive to differentiate among some isolates of AG-4. The antiserum of isolate 24 (AG-4) was highly sensitive as a serotaxonomic tool to differentiate among AG-2 and AG-4, while it was of limited value in differentiating among isolates of within each AG.