IgG Class Research Articles

Associations vulvar lichen sclerosus with autoimmune thyroid diseases.

Vulvar lichen sclerosus (VLS) is defined as a chronic inflammatory skin disease that most often involves lesions on the mucous membranes of the vulva with a tendency to progress to the anal skin. The etiopathogenesis of VLS remains unknown and is likely multifactorial. Data emphasize the role of immunological factors - more than 25% of VLS cases coexist with autoimmune diseases. The purpose of the present study was to determine the correlation of the prevalence of anti-thyroid antibodies - IgG class antibodies against thyroid peroxidase and IgG class antibodies against thyroglobulin in women with vulvar lichen sclerosus, and the appropriateness of screening tests for autoimmune thyroid diseases in women with vulvar lichen sclerosus. Fifty women with vulvar lichen sclerosus were enrolled in the study. The control group consisted of 41 healthy women. A detailed medical history was taken with all patients, followed by laboratory determinations - anti-thyroid antibodies - IgG class antibodies against thyroid peroxidase and IgG class antibodies against thyroglobulin. Antibodies to thyroid peroxidase were present in 12% of the study group with vulvar lichen sclerosus and 4.88% of the control group, and this difference was not statistically significant (p = 0.41). Anti-thyroglobulin antibodies were detected in 4% of the patients with vulvar lichen sclerosus and 4.88% of the control group, and this difference was not statistically significant either (p = 0.76). The study did not confirm the association of VLS with autoimmune thyroid diseases. Undoubtedly, based on the data available in the literature, further studies are needed to determine the mechanisms behind the association between vulvar lichen sclerosus and autoimmune thyroid diseases.

Human Herpesvirus-6B Infection and Alterations of Gut Microbiome in Patients with Fibromyalgia: A Pilot Study

Fibromyalgia (FM) is a chronic disorder characterized by widespread musculoskeletal pain often accompanied by fatigue, sleep disturbances, memory issues, and mood disorders. The exact cause of FM remains unknown, and diagnosis is typically based on a history of persistent widespread pain, as there are no objective biomarkers usable in diagnosis of this disorder available. The aim of this study was to identify measurable indicators specific to FM with potential as biomarkers. This study included 17 individuals diagnosed with FM and 24 apparently healthy persons. Using real-time polymerase chain reaction (qPCR), we detected the presence of human herpesvirus (HHV)-6A and B genomic sequences in DNA isolated from peripheral blood mononuclear cells (PBMCs) and buccal swabs. HHV-6-specific IgG and IgM class antibodies, along with proinflammatory cytokine levels, were measured using enzyme-linked immunosorbent assay (ELISA) and bead-based multiplex assays. Additionally, the gut microbiome was analyzed through next-generation sequencing. HHV-6B was more frequently detected in the PBMCs of FM patients. FM patients with a body mass index (BMI) of 30 or higher exhibited elevated cytokine levels compared to the control group with the same BMI range. Gut microbiome analysis revealed significant differences in both α-diversity and β-diversity between the FM and control groups, indicating a shift in species abundance in the FM group.

Using IMGT unique numbering for IG allotypes and Fc-engineered variants of effector properties and half-life of therapeutic antibodies.

Therapeutic monoclonal antibodies (mAb) are usually of the IgG1, IgG2, and IgG4 classes, and their heavy chains may be modified by amino acid (aa) changes involved in antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), complement-dependent cytotoxicity (CDC), and/or half-life. Allotypes and Fc-engineered variants are classified using IMGT/HGNC gene nomenclature (e.g., Homo sapiens IGHG1). Allotype names follow the WHO/IMGT nomenclature. IMGT-engineered variant names use the IMGT nomenclature (e.g., Homsap G1v1), which comprises species and gene name (both abbreviated) followed by the letter v (for variant) and a number. Both allotypes and engineered variants are defined by their aa changes and positions, based on the IMGT unique numbering for C domain, identified in sequence motifs, referred to as IMGT topological motifs, as their limits and length are standardized and correspond to a structural feature (e.g., strand or loop). One hundred twenty-six variants are displayed with their type, IMGT numbering, Eu-IMGT positions, motifs before and after changes, and their property and function (effector and half-life). Three motifs characterize effector variants, CH2 1.6-3, 23-BC-41, and the FG loop, whereas three different motifs characterize half-life variants, two on CH2 13-AB-18 and 89-96 with H93, and one on CH3 the FG loop with H115.

Botulinum toxin and botulism. A clinical case.

Botulism is an acute infectious disease caused by a neutrotoxin produced by the bacterium Clostridium botulinum and characterized by severe bulbar lesions. Botulism is characterized by the complexity of diagnosis and in adverse cases can lead to death. At the moment, in the complex therapy of botulism, the introduction of a mixture of antitoxic serums is mandatory. In addition to specific treatment, pathogenetic therapy is performed for all patients. Specific prophylaxis is carried out with polyanatoxin to a narrow group of people in contact with Clostridium botulinum or their toxins. However, neutralizing anti-botulinum antibodies may be detected in the blood serum of a number of individuals, which have a protective effect when encountering an infection. This article presents a clinical case of severe botulism in an adult patient with simultaneous absence of symptoms of the disease in family members.Botulinum toxin preparations have long been used in aesthetic medicine. It is worth noting that the botulinum toxin molecule has a high molecular weight and can cause an immune response with repeated injections, especially in areas rich in lymph nodes. Forming specific antibodies belong to the IgG class and may have neutralizing properties. In the above clinical case, the patient’s wife, during repeated injections of botulinum toxin, most likely, the formation of neutralizing antibodies occurred, which, in turn, protected the woman from the disease.

(Re-)Emergence of Oropouche Virus (OROV) Infections: Systematic Review and Meta-Analysis of Observational Studies.

Oropouche Virus (OROV; genus of Orthobunyavirus) is the causal agent of Oropouche Fever (OF). Due to the lack of specific signs and symptoms and the limited availability of diagnostic tests, the actual epidemiology of OROV infections and OF has been extensively disputed. In this systematic review with meta-analysis, a literature search was carried out in PubMed, Scopus, EMBASE, and MedRxiv in order to retrieve relevant articles on the documented occurrence of OROV infections. Pooled detection rates were then calculated for anti-OROV antibodies and virus detection (i.e., viral RNA detected by viral cultures and/or real-time polymerase chain reaction [RT-qPCR]). Where available, detection rates for other arboviruses (i.e., Dengue [DENV], Chikungunya [CHKV], and Zika Virus [ZIKV]) were calculated and compared to those for OROV. A total of 47 studies from South America and the Caribbean were retrieved. In individuals affected by febrile illness during OROV outbreaks, a documented prevalence of 0.45% (95% confidence interval [95%CI] 0.16 to 1.12) for virus isolation, 12.21% (95%CI 4.96 to 27.09) for seroprevalence (including both IgM and IgG class antibodies), and 12.45% (95%CI 3.28 to 37.39) for the detection of OROV-targeting IgM class antibodies were eventually documented. In the general population, seroprevalence was estimated to be 24.45% (95%CI 7.83 to 55.21) for IgG class antibodies. The OROV detection rate from the cerebrospinal fluids of suspected cases of viral encephalitis was estimated to be 2.40% (95%CI 1.17 to 5.03). The occurrence of OROV infections was consistently lower than that of DENV, CHKV, and ZIKV during outbreaks (Risk Ratio [RR] 24.82, 95%CI 21.12 to 29.16; RR 2.207, 95%CI 1.427 to 3.412; and RR 7.900, 95%CI 5.386 to 11.578, respectively) and in the general population (RR 23.614, 95%CI 20.584 to 27.129; RR 3.103, 95%CI 2.056 to 4.685; and RR 49.500, 95%CI 12.256 to 199.921, respectively). In conclusion, our study stresses the possibly high underestimation of OROV prevalence in the general population of South America, the potential global threat represented by this arbovirus infection, and the potential preventive role of a comprehensive "One Health approach".

Influenza virus antibodies inhibit antigen-specific de novo B cell responses in mice.

Antibody responses to influenza vaccines tend to be focused on epitopes encountered during prior influenza exposures, with little production of de novo responses to novel epitopes. To examine the contribution of circulating antibodies to this phenomenon, we passively transferred a hemagglutinin (HA)-specific monoclonal antibody (mAb) into mice before immunizing with whole inactivated virions. The HA mAb inhibited de novo HA-specific antibodies, plasmablasts, germinal center B cells, and memory B cells, while responses to a second antigen in the vaccine, neuraminidase (NA), were uninhibited. The HA mAb potently inhibited de novo antibody responses against epitopes near the HA mAb binding site. The HA mAb also promoted IgG1 class switching, an effect that, unlike the inhibition of HA responses, relied on signaling through Fc-gamma receptors. These studies suggest that circulating antibodies inhibit de novo B cell responses in an antigen-specific manner, which likely contributes to differences in antibody specificities elicited during primary and secondary influenza virus exposures.IMPORTANCEMost humans are exposed to influenza viruses in childhood and then subsequently exposed to antigenically drifted influenza variants later in life. It is unclear if antibodies elicited by earlier influenza virus exposures impact immunity against new influenza virus strains. Here, we used a mouse model to investigate how an anti-hemagglutinin (HA) monoclonal antibody (mAb) affects de novo B cell and antibody responses to the protein targeted by the monoclonal antibody (HA) and a second protein not targeted by the monoclonal antibody [neuraminidase (NA)]. Collectively, our studies suggest that circulating anti-influenza virus antibodies can potently modulate the magnitude and specificity of antibody responses elicited by secondary influenza virus exposures.

Repeated COVID-19 mRNA vaccination results in IgG4 class switching and decreased NK cell activation by S1-specific antibodies in older adults

BackgroundPrevious research has shown that repeated COVID-19 mRNA vaccination leads to a marked increase of SARS-CoV-2 spike-specific serum antibodies of the IgG4 subclass, indicating far-reaching immunoglobulin class switching after booster immunization. Considering that repeated vaccination has been recommended especially for older adults, the aim of this study was to investigate IgG subclass responses in the ageing population and assess their relation with Fc-mediated antibody effector functionality.ResultsSpike S1-specific IgG subclass concentrations (expressed in arbitrary units per mL), antibody-dependent NK cell activation, complement deposition and monocyte phagocytosis were quantified in serum from older adults (n = 38–50, 65–83 years) at one month post-second, -third and -fifth vaccination. Subclass distribution in serum was compared to that in younger adults (n = 64, 18–47 years) at one month post-second and -third vaccination.Compared to younger individuals, older adults showed increased levels of IgG2 and IgG4 at one month post-third vaccination (possibly related to factors other than age) and a further increase following a fifth dose. The capacity of specific serum antibodies to mediate NK cell activation and complement deposition relative to S1-specific total IgG concentrations decreased upon repeated vaccination. This decrease associated with an increased IgG4/IgG1 ratio.ConclusionsIn conclusion, these findings show that, like younger individuals, older adults produce antibodies with reduced functional capacity upon repeated COVID-19 mRNA vaccination. Additional research is needed to better understand the mechanisms underlying these responses and their potential implications for vaccine effectiveness. Such knowledge is vital for the future design of optimal vaccination strategies in the ageing population.

ценка риска формирования у детей вторичного иммунодефицита в условиях контаминации биосред алюминием и полиморфизма гена клеточной гибели FAS rs1159120 и антигенраспознающего гена толл-подобного рецептора TLR4 rs1927911

Secondary immunodeficiency remains an incompletely understood medical problem, and despite a significant number of international and scientific studies, there is no complete picture of the causes and consequences of this pathology. Metal cations have been proven to participate in the formation of acquired immunodeficiency. In particular, aluminum properties as an immune suppressor have been established and its targets in the body have been identified in case aluminum was present in biological media. However, no evaluations have been accomplished so far as regards the role of specific point genetic changes, that is, polymorphisms in the genes of immune system compartments that determine the risk of negative effects caused by contamination with metal cations, including aluminum. It is quite relevant to search and substantiate immunogenetic markers to create an indicator system for diagnostics and prevention of secondary immunodeficiency states in children associated with aluminum contamination in biological media. We examined 97 preschool children exposed to elevated levels of airborne aluminum (in an area influenced by a metallurgic production). The study groups were divided depending on either presence or absence of secondary immunodeficiency as immune system pathology (common variable immunodeficiency D83). Several markers of the immune system were evaluated: aluminum-specific IgG, CD3+, CD4+, CD8+, CD127-, CD95+, CD284+, and phagocytic activity; we also evaluated polymorphism of TLR4 A8595G (rs1927911) and FAS C14405T (rs1159120) genes of innate and acquired immunity. According to the results obtained by examining biological media composition, children with secondary immunodeficiency had 1.8 times higher aluminum levels in urine (0.0095 ± 0.0014 vs. 0.0054 ± 0.0009 mg/dm3, reference range < 0.0075 mg/dm3) as opposed to their conditionally healthy peers. We established an authentic inverse dependence between the expression level of the main CD clusters (CD3+: r = -0.38; CD4+: r = -0.39; CD8+: r = -0.26) as well as indicators of phagocytic activity (r = -0.22–0.23) and the level of aluminum contamination in biological media (urine). Expression of T-mature lymphocyte clusters was found to be inhibited by 1.3–3.1 times (including T-helper, effector T-lymphocytes, NK-killers, regulatory lymphocytes) and we also detected some changes in expression of specific immunoglobulin of IgG class to aluminum. All this results in an unacceptable level of relative risk (RR = 1.23–1.63) of developing secondary immunodeficiency against increased frequency of allele C and genotype CC of FAS gene (rs1159120) by 1.2 and 1.5 times respectively, as well as minor allele G of TLR4 gene (rs1927911) by 1.8 times relative to the comparison group (OR = 4.05; CI: 1.41–11.59; p = 0.006; RR = 1.23; CI: 1.02–1.48) and (OR = 2.01; CI: 1.04–3.91; p = 0.037; RR = 1.64; CI:1.46–1.94). Toll-dependent and FAS-dependent mechanism of this risk is associated with aluminum contamination. It is recommended to use a combination of immune and genetic markers as indicator ones when evaluating the immune system state, in order to prevent the risk (RR = 1.23–1.63) of secondary immunodeficiency associated with aluminum contamination in biological media.

Assessing risks of secondary immunodeficiency in children with aluminum contamination in biological media and polymorphism of the cell death gene FAS rs1159120 and the antigen-recognizing gene of the toll-like receptor TLR4 rs1927911

Secondary immunodeficiency remains an incompletely understood medical problem, and despite a significant number of international and scientific studies, there is no complete picture of the causes and consequences of this pathology. Metal cations have been proven to participate in the formation of acquired immunodeficiency. In particular, aluminum properties as an immune suppressor have been established and its targets in the body have been identified in case aluminum was present in biological media. However, no evaluations have been accomplished so far as regards the role of specific point genetic changes, that is, polymorphisms in the genes of immune system compartments that determine the risk of negative effects caused by contamination with metal cations, including aluminum. It is quite relevant to search and substantiate immunogenetic markers to create an indicator system for diagnostics and prevention of secondary immunodeficiency states in children associated with aluminum contamination in biological media. We examined 97 preschool children exposed to elevated levels of airborne aluminum (in an area influenced by a metallurgic production). The study groups were divided depending on either presence or absence of secondary immunodeficiency as immune system pathology (common variable immunodeficiency D83). Several markers of the immune system were evaluated: aluminum-specific IgG, CD3+, CD4+, CD8+, CD127-, CD95+, CD284+, and phagocytic activity; we also evaluated polymorphism of TLR4 A8595G (rs1927911) and FAS C14405T (rs1159120) genes of innate and acquired immunity. According to the results obtained by examining biological media composition, children with secondary immunodeficiency had 1.8 times higher aluminum levels in urine (0.0095 ± 0.0014 vs. 0.0054 ± 0.0009 mg/dm3, reference range < 0.0075 mg/dm3) as opposed to their conditionally healthy peers. We established an authentic inverse dependence between the expression level of the main CD clusters (CD3+: r = -0.38; CD4+: r = -0.39; CD8+: r = -0.26) as well as indicators of phagocytic activity (r = -0.22–0.23) and the level of aluminum contamination in biological media (urine). Expression of T-mature lymphocyte clusters was found to be inhibited by 1.3–3.1 times (including T-helper, effector T-lymphocytes, NK-killers, regulatory lymphocytes) and we also detected some changes in expression of specific immunoglobulin of IgG class to aluminum. All this results in an unacceptable level of relative risk (RR = 1.23–1.63) of developing secondary immunodeficiency against increased frequency of allele C and genotype CC of FAS gene (rs1159120) by 1.2 and 1.5 times respectively, as well as minor allele G of TLR4 gene (rs1927911) by 1.8 times relative to the comparison group (OR = 4.05; CI: 1.41–11.59; p = 0.006; RR = 1.23; CI: 1.02–1.48) and (OR = 2.01; CI: 1.04–3.91; p = 0.037; RR = 1.64; CI:1.46–1.94). Toll-dependent and FAS-dependent mechanism of this risk is associated with aluminum contamination. It is recommended to use a combination of immune and genetic markers as indicator ones when evaluating the immune system state, in order to prevent the risk (RR = 1.23–1.63) of secondary immunodeficiency associated with aluminum contamination in biological media.

An unexpected IgE anti-receptor binding domain response following natural infection and different types of SARS-CoV-2 vaccines

Humoral response to SARS-CoV-2 has been studied, predominantly the classical IgG and its subclasses. Although IgE antibodies are typically specific to allergens or parasites, a few reports describe their production in response to SARS-CoV-2 and other viruses. Here, we investigated IgE specific to receptor binding domain (RBD) of SARS-CoV-2 in a Brazilian cohort following natural infection and vaccination. Samples from 59 volunteers were assessed after infection (COVID-19), primary immunization with vectored (ChAdOx1) or inactivated (CoronaVac) vaccines, and booster immunization with mRNA (BNT162b2) vaccine. Natural COVID-19 induced IgE, but vaccination increased its levels. Subjects vaccinated with two doses of ChAdOx1 exhibited a more robust response than those immunized with two doses of CoronaVac; however, after boosting with BNT162b2, all groups presented similar IgE levels. IgE showed intermediate-to-high avidity, especially after the booster vaccine. We also found IgG4 antibodies, mainly after the booster, and they moderately correlated with IgE. ELISA results were confirmed by control assays, using IgG depletion by protein G and lack of reactivity with heterologous antigen. In our cohort, no clinical data could be associated with the IgE response. We advocate for further research on IgE and its role in viral immunity, extending beyond allergies and parasitic infections.

Comparison of in-house enzyme-linked immunosorbent assay (ELISA) and six commercial ELISAs for Detection of antibodies to Bordetella pertussis

Enzyme-linked immunosorbent assays (ELISA) are currently the method of choice for the serodiagnosis of pertussis and play a key role in the diagnosis of pertussis in adolescents and adults, as well as in epidemiological studies. In the present study, the in-house developed indirect ELISA was comparatively evaluated with six commercial kits from various manufacturers. Antipertussis antibodies were measured in 40 serum samples from patients with clinical symptoms of respiratory tract infection, in two WHO standards, and in seven human ECDC control sera. IgA and IgG antibodies were detected at a diagnostically significant level by different ELISA kits of 5.0% to 27.0% and 12.0% to 70.0% of patients' sera, appropriately. The analysis of results carried out with six commercial kits showed only 17.5% consistent results in class IgG (either clearly positive or negative). The average percentage of errors in the level of antibodies determined in the control samples, reference serum samples, differed quite significantly and ranged from 9.5% to 35.4% depending on the kit. This poor correlation of the results obtained on various serological tests intended for the serodiagnosis of pertussis may cause very serious diagnostic problems, especially when examining a serum sample obtained once during the course of the disease.

Identification of specific IgG class antibodies to certain flaviviruses in the population of the Republic of Guinea

One of the most common arboviruses in the world are representatives of the genus Orthoflavivirus (family Flaviviridae). On the territory of the Republic of Guinea, the circulation of such representatives of this family as the yellow fever virus (YFV), West Nile virus (WNV) and dengue virus (DENV) has been confirmed. The aim of the study was to determine the level of specific IgG class antibodies to YFV, DENV and WNV in residents of various landscape– geographical zones of the Republic of Guinea by the ELISA method. Materials and methods. For the study, a panel of 1559 blood serums from practically healthy people was compiled, which were collected in all landscape and geographical zones of the Republic of Guinea. The detection of specific IgG class antibodies to DENV and WNV was carried out with commercial diagnostic drugs, and for YFV — with an experimental ELISA test system based on an analogue of the third domain of protein E obtained at the State Research Center for Virology and Biotechnology “Vector” of Rospotrebnadzor. Results. When testing blood sera in 28.5% (95% CI: 26.3–30.7) of cases, IgG antibodies to YFV, to DENV — in 11.8%, (95% CI: 10.3–13.5) and to WNV — in 27.0% (95% CI: 24.8–29.3) were detected. Antibodies to three viruses simultaneously (YFV, DENV and WNV) were detected in 30 cases, to YFV and DENV — 14, YFV and WNV — 44, DENV and WNV — 56. Conclusion. The detection of antibodies to WNV and DENV confirms the fact of the continued circulation of these pathogens in the territory of the Republic of Guinea, which poses a health risk to the local population. A detailed study of the molecular genetic and antigenic properties of flaviviruses circulating in this area will allow the development of more specific diagnostic tools.

The CH1 domain influences the expression and antigen sensing of the HIV-specific CH31 IgM-BCR and IgG-BCR

How different classes of the B cell antigen receptor (BCR) sense viral antigens used in vaccination protocols is poorly understood. Here, we study antigen binding and sensing of human Ramos B cells expressing a BCR of either the IgM or IgG1 class with specificity for the CD4-binding-site of the envelope (Env) protein of the HIV-1. Both BCRs carry an identical antigen binding site derived from the broad neutralizing antibody (bnAb) CH31. We find a five times higher expression of the IgG1-BCR in comparison to the IgM-BCR on the surface of transfected Ramos B cells. The two BCR classes also differ from each other in their interaction with cognate HIV Env antigens in that the IgG1-BCR and IgM-BCR bind preferentially to polyvalent and monovalent antigens, respectively. By generating an IgM/IgG1 chimeric BCR, we found that the class-specific BCR expression and antigen-sensing behavior can be transferred with the CH1γ domain from the IgG1-BCR to the IgM-BCR. Thus, the class of CH1 domain has an impact on BCR assembly and expression as well as on antigen sensing.

T cell independent antibody responses with class switch and memory using peptides anchored on liposomes

Vaccines generally require T lymphocytes for B-cell activation and immunoglobulin class switching in response to peptide or protein antigens. In the absence of T cells, limited IgG class switch takes place, germinal centers are short-lived, and the B cells lack memory. Here, immunization of mice with liposomes containing 15mer peptides and monophosphoryl lipid A (MPLA) as adjuvant, induced T-cell independent (TI) IgG class switch within three days, as well as germinal center formation. The antibody responses were long-lived, strictly dependent on Toll-like receptor 4 (TLR4) signaling, partly dependent on Bruton’s tyrosine kinase (BTK) signal transmission, and independent of signaling through T-cell receptors, MHC class II and inflammasome. The antibody response showed characteristics of both TI type 1 and TI type 2. All IgG subclasses could be boosted months after primary immunization, and the biological function of the secreted antibodies was demonstrated in murine models of allergic anaphylaxis and of bacterial infection. Moreover, antibody responses after immunization with peptide- and MPLA-loaded liposomes could be triggered in neonatal mice and in mice receiving immune-suppressants. This study demonstrates T-cell independent endogenous B-cell memory and recall responses in vivo using a peptide antigen. The stimulation of these antibody responses required a correct and dense assembly and administration of peptide and adjuvant on the surface of liposomes. In the future, TI vaccines may prove beneficial in pathological conditions in which T-cell immunity is compromised through disease or medicines or when rapid, antibody-mediated immune protection is needed.

Diagnostic Significance Vasoendothelial Growth Factor Depending on the Severity and Duration of Atopic Dermatitis, as Well as Taking into Account the Presence of Markers of Herpes Virus Infection

Currently, the problem of diagnosis and treatment of diseases associated with disorders of the angiogenesis process, as well as regenerative processes, is acute. Factors regulating the processes of angiogenesis in allergic diseases, including atopic dermatitis, play a key role in maintaining chronic inflammation and can have a significant impact on the course of the disease. Materials and methods: The study is analytical cross-sectional and presented by a comprehensive examination of 140 patients with AtD aged 2 to 12 years (median age 4.2 years), divided into 2 groups: 70 children with an established diagnosis of AtD; 70 children with atopic dermatitis infected with herpes simplex virus (AtD+HVI). The control group consisted of 70 somatically healthy children. A special laboratory examination included the determination of specific IgM and/or IgG class antibodies to herpes simplex virus type 1-2 antigens by enzyme immunoassay (ELISA); determination of the DNA of the studied herpesviruses in blood samples by polymerase chain reaction; determination of vascular endothelial growth factor A (VEGF-A) in the blood plasma of patients by ELISA. The results of our own research: A statistically significant (p <0.001) increase in the level of vascular endothelial growth factor A in blood serum was found in children with AtD compared with the control group. Against the background of infection with the herpes simplex virus, an increase in the level of vascular endothelial growth factor A in blood serum was revealed compared with patients with atopic dermatitis (p < 0.001). There was also a statistically significant increase in serum VEGF-A levels in patients with AtD (p < 0.001) and AtD+HVI (p < 0.001) with an increase in the severity of AtD. This was confirmed by the results of a correlation analysis that revealed the relationship between the level of VEGF-A and the severity of clinical symptoms of the disease.The addition of herpesvirus infection to AtD worsens the clinical symptoms of this disease.

In vivo tracking of ex vivo generated 89 Zr-oxine labeled plasma cells by PET in a non-human primate model.

B cells are an attractive platform for engineering to produce protein-based biologics absent in genetic disorders, and potentially for the treatment of metabolic diseases and cancer. As part of pre-clinical development of B cell medicines, we demonstrate a method to collect, ex vivo expand, differentiate, radioactively label, and track adoptively transferred non-human primate (NHP) B cells. These cells underwent 10- to 15-fold expansion, initiated IgG class switching, and differentiated into antibody secreting cells. Zirconium-89-oxine labeled cells were infused into autologous donors without any preconditioning and tracked by PET/CT imaging. Within 24 hours of infusion, 20% of the initial dose homed to the bone marrow and spleen and distributed stably and equally between the two. Interestingly, approximately half of the dose homed to the liver. Image analysis of the bone marrow demonstrated inhomogeneous distribution of the cells. The subjects experienced no clinically significant side effects or laboratory abnormalities. A second infusion of B cells into one of the subjects resulted in an almost identical distribution of cells, suggesting a non-limiting engraftment niche and feasibility of repeated infusions. This work supports the NHP as a valuable model to assess the potential of B cell medicines as potential treatment for human diseases.

Development and Evaluation of Monoclonal Antibodies against CBPP Antigen with the End Goal of Developing an ELISA Kit.

Contagious bovine pleuropneumonia (CBPP) is an infectious and contagious bacterial respiratory disease that affects cattle with significant economic losses to the African animal industry. The use of ELISA kits based on monoclonal antibodies (mAbs) will aid in quick and precise diagnosis of CBPP, contributing to disease control and prevention in cattle. Thus, this research aims to develop and evaluate monoclonal antibodies against CBPP (T1/44) antigen for use in ELISA kits for CBPP diagnosis. Hybridoma technology was used to develop monoclonal antibodies that recognize and bind to the CBPP (T1/44) antigen. The antibody-secreting hybridomas were produced after immunizing mice with purified CBPP antigens. The hybridomas were screened for high sensitivity, specificity, and liking to the antigen. The selected mAbs were assessed for sensitivity and specificity against CBPP antigen using different immunoassays, dot-blot, ELISA, and mouse mAb isotyping. The monoclonal antibodies were profoundly specific, with a higher hindrance to CBPP antigen (<0.50 OD) while lacking cross-reactivity to other antigens. The monoclonal antibodies could distinguish CBPP antigen at low concentrations, showing their high sensitivity (>80% PI). The isotyped mAbs of intrigued appeared to have a place in the IgG class. These identified monoclonal antibodies can be utilized to develop an ELISA kit for CBPP diagnosis, which would give a fast, precise, and cost-effective strategy for screening and checking CBPP in cattle herds.

Effect of Immunity to SARS-CoV-2 Virus on Blood Cellular Composition

Relevance. The new coronavirus infection (COVID-19) is still a public health problem and a threat to socio-economic well-being. Most studies have focused predominantly on humoral immunity, and there are no data on the cellular composition of blood in dynamics. Aim. To study the dynamics of changes in blood cellular composition depending on the type of immunity formed (natural, hybrid, breakthrough, postvaccinal) to SARS-CoV-2 virus. Materials and Methods. A total of 130 volunteers participated in the study. Immunophenotyping of peripheral blood leukocytes using flow cytometry was performed. The presence of specific IgG antibodies to N-protein SARS-CoV-2, total IgA and cytokines (IL-4, IL-10, IFN-γ, TNF-α) was assessed in serum by ELISA. Results and Discussion. A statistically significant increase in BL was recorded in volunteers with hybrid immunity 1 month (14,0% (12,3–16,4%)) after vaccination compared to healthy volunteers (9,1% (6,4–10,2%), p = 0,0007) and people with primary COVID-19 infection (10,2% (8,3–12,1%), p = 0,0134). In volunteers with natural and hybrid immunity, as well as in revaccinated people, an increase in B1-cells (CD3-CD19+CD5+CD27-) was observed during 3–9 months of observation. It is shown that the increase of B-lymphocytes with «switched» class of synthesized antibodies was detected in people with breakthrough immunity. Increased levels of T-lymphocytes expressing HLA-DR were recorded in all individuals during 6–9 months of follow-up. Volunteers with breakthrough immunity showed a significant increase in the positivity index when assessing the presence of specific IgG class antibodies to the coronavirus N-protein compared with volunteers with natural and hybrid immunity. Conclusions. Vaccination promotes protective immunity sufficient for timely activation of memory T- and B-cells in breakthrough immunity and maintenance of immunologic efficacy in hybrid immunity against COVID-19. The results help to assess the strain of innate and adaptive immunity in novel coronavirus infection and to fill gaps in the understanding of immunopathogenesis in COVID-19.

Seroprevalence and risk factors of Toxoplasma gondii in goats (Capra hircus) in the state of Espírito Santo, Southeast Brazil

Toxoplasma gondii is described as a potential cause of abortion in goats and as a threat to public health. To estimate the prevalence of goats infected by T. gondii, in different cities in the Espírito Santo State, and to identify possible risk factors for infection a serological study was conducted. A total of 146 goat serum samples from the cities of Cariacica, Serra and Vila Velha were analyzed. The presence of IgG Class Immunoglobulins was serologically evaluated by Immunofluorescence antibody test (IFAT) and by Enzyme-linked Immunosorbent Assay (ELISA). The seroprevalence of anti-T. gondii was 46.6% (68/146) in both techniques and the same samples got the same results in both techniques. Among the analyzed sera, 70.6% (48/68) exhibited high-avidity IgG antibodies, and 29.4% (20/68) exhibited low-avidity IgG antibodies, suggesting that the infection was chronic in the infected animals. Female sex, age group over two years old, water from the public supply system, storage of food and supplies in an open and unprotected place, and the presence of a domestic cat on the property were identified as risk factors for T. gondii infection in goats. The state of Espirito Santo has a high frequency of infected goats, and this is the first research on caprine toxoplasmosis seroepidemiology in that region.

Immune Response after Anti-SARS-CoV-2 mRNA Vaccination in Relation to Cellular Immunity, Vitamin D and Comorbidities in Hemodialysis Patients.

In the global threat of SARS-CoV-2, individuals undergoing maintenance dialysis represent a vulnerable population with an increased risk of severe COVID-19 outcomes. Therefore, immunization against SARS-CoV-2 is an essential component of healthcare strategy for these patients. Existing data indicate that they tend to exhibit a reduced immune response to vaccines compared to the general population. Our study aimed to assess both humoral and cellular immune responses following two doses of an anti-SARS-CoV-2 mRNA vaccine, an ability to maintain adequate antibody titers over time, and potential relations with vitamin D, comorbidities and other factors in hemodialysis patients based on a single center experience. A total of 41/45 patients (91.1%) responded to the second dose of the anti-SARS-CoV-2 mRNA vaccine. The titer of anti-SARS-CoV-2 IgG class antibodies and levels of T cells three to four weeks after vaccination were lower in dialysis patients than in healthy controls. Antibodies titer in dialysis patients had a positive correlation with B lymphocytes and was related to cardiovascular diseases. The level of CD4+ cells had a negative correlation with hemodialysis vintage, as did the vitamin D level with post-vaccination seroconversion and decline in anti-SARS-CoV-2 antibodies titer during six months after vaccination. Hemodialysis patients had decreased amounts of CD4+ and CD8+ cells and lower levels of anti-SARS-CoV-2 antibodies than healthy controls. Therefore, chronic hemodialysis could lead to diminished cellular immunity and humoral immune response to the anti-SARS-CoV-2 mRNA vaccination and reduced protection from COVID-19. Comorbidity in cardiovascular diseases was associated with a lower level of specific anti-SARS-CoV-2 antibody titer. Vitamin D may be important in maintaining stable levels of anti-SARS-CoV-2 antibodies, while the duration of dialysis treatment could be one of the factors decreasing anti-SARS-CoV-2 antibody titer and determining lower CD4+ cell counts.