Immunoglobulin Class Research Articles

Factors predisposing to humoral autoimmunity against brain-antigens in health and disease: Analysis of 49 autoantibodies in over 7000 subjects

BackgroundCirculating autoantibodies (AB) against brain-antigens, often deemed pathological, receive increasing attention. We assessed predispositions and seroprevalence/characteristics of 49 AB in > 7000 individuals. MethodsExploratory cross-sectional cohort study, investigating deeply phenotyped neuropsychiatric patients and healthy individuals of GRAS Data Collection for presence/characteristics of 49 brain-directed serum-AB. Predispositions were evaluated through GWAS of NMDAR1-AB carriers, analyses of immune check-point genotypes, APOE4 status, neurotrauma. Chi-square, Fisher’s exact tests and logistic regression analyses were used. ResultsStudy of N = 7025 subjects (55.8 % male; 41 ± 16 years) revealed N = 1133 (16.13 %) carriers of any AB against 49 defined brain-antigens. Overall, age dependence of seroprevalence (OR = 1.018/year; 95 % CI [1.015–1.022]) emerged, but no disease association, neither general nor with neuropsychiatric subgroups. Males had higher AB seroprevalence (OR = 1.303; 95 % CI [1.144–1.486]). Immunoglobulin class (N for IgM:462; IgA:487; IgG:477) and titers were similar. Abundant were NMDAR1-AB (7.7 %). Low seroprevalence (1.25 %-0.02 %) was seen for most AB (e.g., amphiphysin, KCNA2, ARHGAP26, GFAP, CASPR2, MOG, Homer-3, KCNA1, GLRA1b, GAD65). Non-detectable were others. GWAS of NMDAR1-AB carriers revealed three genome-wide significant SNPs, two intergenic, one in TENM3, previously autoimmune disease-associated. Targeted analysis of immune check-point genotypes (CTLA4, PD1, PD-L1) uncovered effects on humoral anti-brain autoimmunity (OR = 1.55; 95 % CI [1.058–2.271]) and disease likelihood (OR = 1.43; 95 % CI [1.032–1.985]). APOE4 carriers (∼19 %) had lower seropositivity (OR = 0.766; 95 % CI [0.625–0.933]). Neurotrauma predisposed to NMDAR1-AB seroprevalence (IgM: OR = 1.599; 95 % CI [1.022–2.468]). ConclusionsHumoral autoimmunity against brain-antigens, frequent across health and disease, is predicted by age, gender, genetic predisposition, and brain injury. Seroprevalence, immunoglobulin class, or titers do not predict disease.

Immunoglobulins genes in Neoceratodus forsteri and Protopterus annectens explain the origin of the immunoglobulins of the animals that passed ashore

Sarcopterygian fishes are a taxon of bony fishes. They include lungfish and coelacanths (six species of lungfish and two species of coelacanths). Evolutionary adaptations arose with these fish, such as the appearance of lungs and paired lobed fins that help them move over the bottom of the sea. In the Devonian period, they came ashore, and tetrapods (amphibians, reptiles, and mammals) arose from them. Within immunology, they can teach us about the emergence of immunoglobulins D, A/X, and Y already present in amphibians. We have studied the genes of the immunoglobulins in the fish Sarcopterygii Neoceratodus forsteri and Protopterus annectens. In the first fish, we find that several loci for the constant chains of immunoglobulins are distributed across 4 chromosomes. We have found four genes for IgM, a gene for IgW and a gene for IgN. In the second, we find one locus with genes for IgN and IgM and another with one gene for IgW. With these sequences, together with those obtained in other publications, we have been able to study the possible evolution and emergence of immunoglobulin classes. We conclude that there are two evolutionary lineages, one focused on IgM and very conservative, and the other focused on IgW, which allows high variability. In the case of the animals that went to land, their IgD is formed only by domains whose origin is in the W lineage. IgA/X and IgY are unique since they arose from the recombination between the two evolutionary lineagess (M and W). In both IgA/X and IgY, the CH1 and CH2 domains come from domains whose origin is the W lineage, while their CH3 and CH4 derive from the M lineage.

The state of individual components of humoral immunity of guinea pig blood in the dynamics of the formation of experimental periodontitis and immobilization stress and correction of their disorders by thiocetam

The research found a rapid increase in the level of immunoglobulin M, starting from the 3 rd day of the experiment in comparison with the control values, which clearly indicates its activation in particular, and stimulation of humoral immunity in general. In the later stages (on the 5 th and 15 th days) of the formation of experimental periodontitis (EP) and immobilization stress (IS), an increase of this indicator by 93.5% and 94.2% was found, respectively, against group I guinea pigs (p≤0, 05).Regarding the content of immunoglobulin G in the blood, the highest growth rates were recorded in the fourth group of guinea pigs with EP and IS (on the 15 th day), which indicates a direct dependence of the duration of damaging factors on the level of these indicators and the body's ability to the protective response. The results of the treatment showed the effect and the reduction of the activity of the studied classes of immunoglobulins. Thus, the use of thiocetam led to a significant decrease in the content of Ig M and G in the blood, respectively, by 33.8% (p1≤0.05) and 41.7% (p1≤0.05) in EP and IS compared with the group of animals were not exposed to this drug, which indicates the immunocorrective effect of this drug on the studied tests.

Infections and immune dysregulation in ataxia-telangiectasia children with hyper-IgM and non-hyper-IgM phenotypes: A single-center experience

Ataxia-telangiectasia (A-T) is a severe syndromic neurodegenerative inborn error of immunity characterized by DNA reparation defect, chromosomal instability, and hypersensitivity to ionizing radiation, thereby predisposing affected individuals to malignant transformation. While the leading disease symptomatology is associated with progressively debilitating cerebellar ataxia accompanied by central and peripheral nervous system dysfunctions, A-T is a multisystemic disorder manifesting with the heterogeneity of phenotypic features. These include airway and interstitial lung disease, chronic liver disease, endocrine abnormalities, and cutaneous and deep-organ granulomatosis. The impaired thymic T cell production, defective B cell development and antibody production, as well as bone marrow failure, contribute to a combined immunodeficiency predisposing to infectious complications, immune dysregulation, and organ-specific immunopathology, with the A-T hyper-IgM (HIGM) phenotype determining the more severe disease course. This study aimed to clarify the immunodeficiency and associated immune dysregulation as well as organ-specific immunopathology in children with A-T. We also sought to determine whether the hyper-IgM and non-hyper-IgM phenotypes play a discriminatory role and have prognostic significance in anticipating the clinical course and outcome of the disease. We retrospectively reviewed the medical records of twelve A-T patients, aged from two to eighteen years. The patients' infectious history, organ-specific symptomatology, and immunological workup including serum alpha-fetoprotein, immunoglobulin isotypes, IgG subclasses, and lymphocyte compartments were examined. For further comparative analysis, all the subjects were divided into two groups, HIGM A-T and non-HIGM A-T. The clinical evaluation of the study group showed that recurrent respiratory tract infections due to viral and bacterial pathogens and a chronic obstructive airway disease along with impaired humoral immunity, in particular complete IgA deficiency, were noted in all the A-T patients, with both HIGM and non-HIGM phenotypes. The most important features with the discriminatory role between groups, were autoimmune disorders, observable four times more frequently in HIGM than in non-HIGM A-T. Two patients with the HIGM A-T phenotype were deceased due to liver failure and chronic Epstein-Barr virus (EBV) infection. It may therefore be assumed that the HIGM form of A-T is associated with more profound T cell dysfunction, defective immunoglobulin class switching, chronic EBV expansion, and poorer prognosis.

Bacterial ligands in the rehabilitation of healthcare workers after COVID-19

Immune defense mechanisms in survivors of the COronaVIrus Disease-19 (COVID-19) and development of their rehabilitation during the pandemic both portray a great scientific and practical interest.The aim of the study was to explore effect of Immunovac-VP-4® (I-VP-4), a vaccine based on bacterial ligands, on the clinical and airway mucosal immunity parameters, along with systemic immune response in a group of medical workers in post-COVID period and in persons who did not develop the disease.Methods. 82 healthcare workers aged from 18 to 65 years were included in a prospective open controlled study. The participants were divided into 4 groups: groups 1 (n = 20) and 2 (n = 27) included those with a history of COVID-19, and groups 3 (n = 18) and 4 (n = 17) included those who did not have the disease. Volunteers in groups 1 and 3 received I-VP-4. Samples of oral fluid, induced sputum, nasopharyngeal and oropharyngeal mucosa scrapings, and venous blood were examined. The levels of total secretory immunoglobulin class A (sIgA) and immunoglobulin G (IgG) were determined by enzyme immunoassay. The phagocytic index (PI) of leukocytes was assessed by flow cytometry.Results. The group of patients who did not have COVID-19 and received IVP-4 (Group 3) showed a tendency to a smaller number of COVID-19 cases, as well as some reduction in days of incapacity for work due to the acute respiratory infections (ARI). The vaccine improved airway mucosal immunity parameters and innate immune response. sIgA increased in the induced sputum (p < 0.005) and unchanged in the oropharyngeal mucosa samples in Group 1. The PI of macrophages in oral fluid doubled (p < 0.05) in this group. At the same time, those parameters decreased in Group 2. In non-infected vaccinated patients (Group 3), a significant increase of PI of blood monocytes was found on the day 90 of the study (p < 0.05). Also, a four-fold increase of PI of macrophages in oral fluid in comparison with Group 4 (p < 0.05) was noted.Conclusion. I-VP-4 improved airway mucosal immunity mechanisms and the systemic immune response. The vaccine can be recommended for rehabilitation programs for COVID-19 survivors and for prevention of ARIs.

Detection of Epstein-Barr virus in systemic sclerosis patients: A molecular and serological based study.

This study aimed to evaluate an association between Epstein-Barr virus (EBV) and systemic sclerosis (SSc). One hundred and fifty (138 female, 12 male) consecutive adult SSc patients fulfilling the American College of Rheumatology (ACR)/ European League Against Rheumatism (EULAR) criteria were included in this cross-sectional study. Serological analysis by line blot for class immunoglobulin G (IgG) and IgM antibodies against EBV antigen (EBV capsid antigen [VCA] gp125, VCA p19, EBNA-1, p22, EA-D) and quantification of EBV DNA in whole blood by real-time polymerase chain reaction was performed. Class IgM antibodies against VCA gp125 (22.8% vs 0%, P < .0002), VCA p19 (55.7% vs 4.4%, P < .0001), EBNA1 (35.7% vs 0%, P < .0001), p22 (24.2% vs 0%, P < .0001), EA-D (14.2% vs 2.2%, P < .04), and class IgG antibodies against p22 (95.7% vs 82.2%, P < .02) and EA-D (54.2% vs 0%, P < .0001) reactivities were significantly higher in SSc patients than in controls. The past infection was significantly associated with the control group (42.8% vs 91%, P < .0001); and the viral reactivation was significantly associated with the SSc group (55.7% vs 4.4%, P < .0001). Only three (2%) out of 150 SSc patients were positive for EBV DNA, similar to the control group (2%) (P > .9). The study shows a strong serological association of EBV (reactivation stage) with SSc patients in the absence of viral DNA in the circulation, indicating the EBV reservoir or tropism presence elsewhere.

Autoantibodies elicited with SARS-CoV-2 infection are linked to alterations in double negative B cells.

Double negative (DN) B cells (CD27-IgD-) comprise a heterogenous population of DN1, DN2, and the recently described DN3 and DN4 subsets. In autoimmune disease, DN2 cells are reported to be precursors to autoreactive antibody secreting cells and expansion of DN2 cells is linked to elevated interferon levels. Severe SARS-CoV-2 infection is characterized by elevated systemic levels of pro-inflammatory cytokines and serum autoantibodies and expansion of the DN2 subset in severe SARS-CoV-2 infection has been reported. However, the activation status, functional capacity and contribution to virally-induced autoantibody production by DN subsets is not established. Here, we validate the finding that severe SARS-CoV-2 infection is associated with a reduction in the frequency of DN1 cells coinciding with an increase in the frequency of DN2 and DN3 cells. We further demonstrate that with severe viral infection DN subsets are at a heightened level of activation, display changes in immunoglobulin class isotype frequency and have functional BCR signaling. Increases in overall systemic inflammation (CRP), as well as specific pro-inflammatory cytokines (TNFα, IL-6, IFNγ, IL-1β), significantly correlate with the skewing of DN1, DN2 and DN3 subsets during severe SARS-CoV-2 infection. Importantly, the reduction in DN1 cell frequency and expansion of the DN3 population during severe infection significantly correlates with increased levels of serum autoantibodies. Thus, systemic inflammation during SARS-CoV-2 infection drives changes in Double Negative subset frequency, likely impacting their contribution to generation of autoreactive antibodies.

AFF3, a susceptibility factor for autoimmune diseases, is a molecular facilitator of immunoglobulin class switch recombination.

Immunoglobulin class switch recombination (CSR) plays critical roles in controlling infections and inflammatory tissue injuries. Here, we show that AFF3, a candidate gene for both rheumatoid arthritis and type 1 diabetes, is a molecular facilitator of CSR with an isotype preference. Aff3-deficient mice exhibit low serum levels of immunoglobulins, predominantly immunoglobulin G2c (IgG2c) followed by IgG1 and IgG3 but not IgM. Furthermore, Aff3-deficient mice show weak resistance to Plasmodium yoelii infection, confirming that Aff3 modulates immunity to this pathogen. Mechanistically, the AFF3 protein binds to the IgM and IgG1 switch regions via a C-terminal domain, and Aff3 deficiency reduces the binding of AID to the switch regions less efficiently. One AFF3 risk allele for rheumatoid arthritis is associated with high mRNA expression of AFF3, IGHG2, and IGHA2 in human B cells. These findings demonstrate that AFF3 directly regulates CSR by facilitating the recruitment of AID to the switch regions.

Determination of Anti-phage Antibodies in Calf Sera Following Application of Escherichia Coli and Mannheimia Haemolytica-specific Bacteriophages.

The widespread occurrence of drug-resistant bacteria has increased interest in alternatives to antibiotics for combatting bacterial infections, among which bacteriophages play an important role. The ability of phage proteins to induce an anti-phage immune response can significantly limit the effectiveness of treatment, which was the basis for the study described in this article. The aim of the study was to assess the effects of bacteriophages on the induction of an anti-phage humoral response in calves. The study was conducted using phage components of experimental preparations and sera from calves treated and not treated with phages. Levels of G, M and A immunoglobulins were analysed by ELISA. The assay plates were coated with whole Escherichia coli and Mannheimia haemolytica phages and selected phage proteins obtained in sodium dodecyl sulphate-polyacrylamide gel electrophoresis and two-dimensional electrophoresis. Neutralisation of phages by immunoglobulins was assessed by determining phage titres using double-layer plates. The results confirmed an increased anti-phage response affecting all immunoglobulin classes in the calf sera. The highest significant (P ≤ 0.05) level of antibodies was observed for IgG in the sera of calves receiving phages. The phage neutralisation test showed a significant differences (P ≤ 0.05) in the reduction of phage titres in comparison to untreated calves. Despite the induction of an anti-phage response, no significant negative effect on the antibacterial activity of phages was observed in vitro.

The content of immunoglobulins in the blood serum of mother cows with genital mycoplasmosis and calves born from them

The state of the immune system of newborn animals largely determines their further development, morbidity, and productive qualities. Various diseases of pregnant animals to a certain extent affect the body of the fetus, this is especially true if the disease is characterized by an erased clinical picture and it is difficult to diagnose it in a timely manner. One of these diseases is genital mycoplasmosis of cattle, which is widespread both in our country and abroad. Despite this, many aspects of the pathogenesis of genital mycoplasmosis remain poorly understood, especially the state of the immune system. A study was made of the content of immunoglobulin classes in healthy dry cows and cows with genital mycoplasmosis, as well as in calves born by them. The results showed a significant decrease in the level of immunoglobulins and a redistribution of their classes in cows with genital mycoplasmosis. Changes of a similar nature, but more pronounced, were also noted in calves born from these cows. Studies show that pregnant cows with genital mycoplasmosis develop an immunodeficiency state, characterized by a decrease in the total amount of immunoglobulins, a significant decrease in the level of Ig G and an increase in the concentration of Ig A. A similar immunodeficiency state was observed in calves obtained from these cows. The noted changes will be useful for the development of rational therapy for genital mycoplasmosis in cows.

Catalytic activity of serum and immunoglobulins of classes G and A in patients with breast cancer

The objective of this study was to investigate DNase, various types of proteolytic and oxidoreductase serum and abzyme activities, as well as the serum contents of free DNA in patients with breast tumors in accordance with the clinical, pathological and immunohistochemical characteristics of the tumors. It was found that catalytic antibodies isolated from blood serum of patients with breast oncopathology exhibit proteolytic, DNase and oxidoreductase activity, which varies depending on the course of the disease. It is worth noting that catalytic activity of IgAs (per unit of Ig concentration) can be 1-2 orders of magnitude higher than the analogous activity of IgGs. It was found that DNase, proteolytic (cathepsin G, cathepsin B) serum enzymatic activities and cathepsin G-like activity of IgG and IgA differ in patients with malignant and benign breast tumors and in healthy individuals. These parameters depend on the advance of the tumor process, histological and immunohistochemical characteristics of the tumor, as well as on the probability of tumor progression. In particular, the progression of the tumor process is accompanied by an increase of the activity of serum DNase and cathepsin B, decline of the concentration of patients` serum DNA, being also followed by marked changes of the nuclease, proteolytic and oxidoreductase activity of IgG and IgA.

P821: LATE ONSET AND/OR LONG LASTING NEUTROPENIA IN CHILDHOOD: CLINICAL AND HEMATOLOGICAL CHARACTERISTICS AND OUTCOMES

Background: In contrast with primary autoimmune neutropenia of infants and pre-school children, characterized by the presence of anti-polymorphonuclear antibodies (anti-PNN), benign course and spontaneous resolution at age 3-5 years, late onset (LO) and/or long lasting (LL) neutropenia of childhood is vaguely described. Aims: To address characteristics and outcomes in a cohort of children with LO/LL diagnosed and followed by our Department. Methods: Cross-sectional study of patients aged 0-16 years with LO (age >5 years, in accordance with Fioredda et al, 2020) or LL (duration >3 years) neutropenia (1.5 G/L) +/- leukopenia (Z-score ≤2 according to age and gender); with a first visit or continued follow-up in our Department of Pediatric Hematology-Oncology (T.A.O.) during the period 2015-2020. Patients with severe congenital neutropenia (SCN) were excluded. Detection of anti-PNN using GAT and GIFT was centralized. Results: From 1972 to 2021, 534 cases of neutropenia/leukopenia were recorded (5, 40, 82, 134, 273 during 1970-1979, 1980-1989, 1990-1999, 2000-2009, 2010-2021, respectively); 152 were included in the cross-sectional study. Sixty-one (40%) had no LO/LL (age<5 years, resolution within≤3 years), 77 (51%0 had LO and 14 (9%) had LL. Male/female ratio was 47% vs 52% vs 28% in no LO/LL vs LO vs LL, respectively (P=0.27), median age 1 vs 11.1 vs 3.1 years (P<10-4), median neutrophil count 0.5 vs 1.2 vs 0.6 G/L (P<10-4), and with concomitant leukopenia in 27% vs 53% vs 36% (P=0.009) or lymphopenia in 3% vs 10% vs 7% of cases (P=0.27). Anti-PNN were detected in 83% vs 42% vs 60% of patients no LO/LL vs LO vs LL, respectively (P=0.12). Familial neutropenia was observed in three pairs of siblings/cousins with LL, possible ethnic neutropenia in 7 patients, probable genetic predisposition to cancer in 4 patients LO/LL and a congenital metabolic syndrome in one patient LL. Infection, mostly cutaneous, occurred in 17% vs 24% vs 66% no LO/LL vs. LO vs. LL (P=0.02). Bone marrow examination was performed in 8 patients (4 LO, 4 LL) and showed mild hypoplasia in 2 (LO). Mild peripheral blood lymphocytic subsets abnormalities were observed in ¼ of the patients, particularly in LO, and mild reduction of serum immunoglobulin class levels in ¼ of the patients, without difference between no LO/LL and LO. Genetic typing performed in 9% of patients LO/LL (targeted pediatric MDS panel N=2, primary immunodeficiency N=2, SCN N=1, whole-exome sequencing N=2) showed a heterozygous TACI mutation in one patient with LL and frequent infections of moderate severity. In total, MDS, immunodeficiency and autoimmunity was noted in 1%, 5% and 4% of patients LO and immunodeficiency in 14% of patients LL. One patient LL developed B-cell precursor ALL. One patient LO with Evans syndrome received eltrombopag, without response, and MMF with response. All patients are alive. Neutropenia resolved spontaneously in 54% of patients. Two-year probability of unresolved neutropenia was 26% vs 78% vs 100% in patients no LO/LL, LO and LL, respectively (P<10-4). Summary/Conclusion: LO/LL neutropenia might be associated with bone marrow failure syndromes, immunodeficiency or autoimmunity. Long-term follow-up and investigations are needed in children with LO/LL neutropenia. Genetic typing in specialized reference networks, like EuNet-INNOCHRON or EWOG, might identify diagnostic subgroups of clinical relevance.

Impact of prepartum administration of a vaccine against infectious calf diarrhea on nonspecific colostral immunoglobulin concentrations of dairy cows.

Passive transfer of colostral immunoglobulins from the cow to the calf is essential for calf health. The objective of this study was to determine if prepartum administration of a vaccine stimulates increased concentrations of colostral immunoglobulins of dairy cows beyond what is explained by vaccine-specific immunoglobulins. A prospective cohort study was conducted on a spring-calving commercial dairy farm that had a policy of only vaccinating cows with even ear tag numbers with a calf diarrhea vaccine, whereas cows with odd ear tag numbers were left unvaccinated. Cows in the vaccinated group (even ear tag numbers, n = 204) received a sensitizer and booster vaccination with a vaccine against bovine rotavirus (serotypes G6 and G10), bovine coronavirus, and E. coli having the K99 pili adherence factor. A sensitizer was given because the study vaccine was different from the vaccine previously used. Cows in the control group (odd ear tag numbers, n = 194) received a 2-mL subcutaneous sterile saline solution. Both groups received two treatments at a 3-wk interval, completing the treatments approximately 2 wk prior to the planned start of calving. During the calving period, technicians separated calves from cows immediately after parturition and prior to suckling, and cows were completely milked out within 6 h of parturition. Vaccine-specific, total, and nonvaccine-specific (total minus vaccine-specific) concentrations of immunoglobulin classes A, G1, G2a, and M (IgA, IgG1, IgG2a, and IgM, respectively) were quantified by mass spectrometry for 20 colostrum samples from each treatment group. Predicted mean non-vaccine-specific colostral IgM concentrations were 8.76 (95% CI = 7.18-10.67) and 5.78 (95% CI = 4.74-7.05) mg/mL for vaccinated and control cows, respectively (P = 0.005). Predicted mean non-vaccine-specific colostral IgG1 concentrations were 106.08 (95% CI = 92.07-120.08) and 95.30 (95% CI = 81.30-109.31) mg/mL among vaccinated and control cows, respectively; however, these means were not significantly different (P = 0.278). It is thus possible that the vaccine, in addition to specifically managing infectious calf diarrhea, may also have non-specific benefits by improving colostrum quality through increased non-vaccine-specific colostrum IgM concentrations. Further research is necessary to determine the mechanism for these preliminary findings, whether the effect may occur in other immunoglobulin classes, and what impacts it may have on calf health outcomes.

Non-neuronal Cholinergic Muscarinic Acetylcholine Receptors in the Regulation of Immune Function

Immune cells such as T and B cells, monocytes and macrophages all express most of the cholinergic components of the nervous system, including acetylcholine (ACh), choline acetyltransferase (ChAT), high affinity choline transporter, muscarinic and nicotinic ACh receptors (mAChRs and nAChRs, respectively), and acetylcholinesterase (AChE). Because of its efficient cleavage by AChE, ACh synthesized and released from immune cells acts only locally in an autocrine and/or paracrine fashion at mAChRs and nAChRs on themselves and other immune cells located in close proximity, leading to modification of immune function. Immune cells generally express all five mAChR subtypes (M1-M5) and neuron type nAChR subunits α2-α7, α9, α10, β2-β4. The expression pattern and levels of mAChR subtypes and nAChR subunits vary depending on the tissue involved and its immunological status. Immunological activation of T cells via T-cell receptor-mediated pathways and cell adhesion molecules upregulates ChAT expression, which facilitates the synthesis and release of ACh. At present, α7 nAChRs expressed in macrophages are receiving much attention because they play a central role in anti-inflammatory cholinergic pathways. However, it now appears that through modification of cytokine synthesis, Gq/11-coupled mAChRs play a prominent role in regulation of T cell proliferation and differentiation and B cell immunoglobulin class switching. It is anticipated that greater understanding of Gq/11-coupled mAChRs on immune cells will provide an opportunity to develop new and effective treatments for immunological disorders.

State of cellular and humoral systemic immunity in women of reproductive age under the development of proliferative processes in the endometry of the uterus and breast glands

The immune system plays an important role in the pathogenesis of endometrial hyperplasia (EH) and benign breast tumors, as in the body of women this system interacts closely with the reproductive system. Due to the fact that the transformation of endometrial cells and mammary glands is controlled by the immune system, it is important to study the redistribution of components of cellular and humoral immune components in women with combined pathology.&#x0D; The aim of the study was to study the state of cellular and humoral parts of the immune system in women of reproductive age, patients with endometrial hyperplasia and benign breast tumors.&#x0D; Materials and methods. Studies of the state of the immune cell were performed in peripheral blood to determine the subpopulation composition of blood lymphocytes using monoclonal antibodies to antigens CD3 + (total number of T lymphocytes), CD4 + (T-helpers), CD8 + (T-suppressors), CD16 + (NK cells), CD19 + (B-lymphocytes). Indicators of humoral immunity - immunoglobulins (Ig) of classes A, M and G were determined using monospecific sera against these immunoglobulins.&#x0D; Results of the research. There was a decrease in the mean values of T-lymphocytes, T-suppressors, T-helpers and B-lymphocytes with a simultaneous increase in NK cells in the peripheral blood in patients with GE and mastopathy compared with the control group. There was a decrease in the immunoregulatory index - the ratio of CD4 + / CD8 +. An increase in the content of Ig G and a decrease in the levels of Ig M and Ig A in the groups of patients with GE and in the combination of GE and mastopathy in comparison with healthy women is shown.&#x0D; Conclusions. Immunological homeostasis, which is characterized by changes in cellular and humoral immunity at the systemic level, is involved in the violation of reproductive function in women with hormonal imbalance, which leads to the development of GE and mastopathy

Absolute Quantitation of Serum Antibody Reactivity Using the Richards Growth Model for Antigen Microspot Titration.

In spite of its pivotal role in the characterization of humoral immunity, there is no accepted method for the absolute quantitation of antigen-specific serum antibodies. We devised a novel method to quantify polyclonal antibody reactivity, which exploits protein microspot assays and employs a novel analytical approach. Microarrays with a density series of disease-specific antigens were treated with different serum dilutions and developed for IgG and IgA binding. By fitting the binding data of both dilution series to a product of two generalized logistic functions, we obtained estimates of antibody reactivity of two immunoglobulin classes simultaneously. These estimates are the antigen concentrations required for reaching the inflection point of thermodynamic activity coefficient of antibodies and the limiting activity coefficient of antigen. By providing universal chemical units, this approach may improve the standardization of serological testing, the quality control of antibodies and the quantitative mapping of the antibody–antigen interaction space.

Multimericity Amplifies the Synergy of BCR and TLR4 for B Cell Activation and Antibody Class Switching.

Sustained signaling through the B cell antigen receptor (BCR) is thought to occur only when antigen(s) crosslink or disperse multiple BCR units, such as by multimeric antigens found on the surfaces of viruses or bacteria. B cell-intrinsic Toll-like receptor (TLR) signaling synergizes with the BCR to induce and shape antibody production, hallmarked by immunoglobulin (Ig) class switch recombination (CSR) of constant heavy chains from IgM/IgD to IgG, IgA or IgE isotypes, and somatic hypermutation (SHM) of variable heavy and light chains. Full B cell differentiation is essential for protective immunity, where class switched high affinity antibodies neutralize present pathogens, memory B cells are held in reserve for future encounters, and activated B cells also serve as semi-professional APCs for T cells. But the rules that fine-tune B cell differentiation remain partially understood, despite their being essential for naturally acquired immunity and for guiding vaccine development. To address this in part, we have developed a cell culture system using splenic B cells from naive mice stimulated with several biotinylated ligands and antibodies crosslinked by streptavidin reagents. In particular, biotinylated lipopolysaccharide (LPS), a Toll-like receptor 4 (TLR4) agonist, and biotinylated anti-IgM were pre-assembled (multimerized) using streptavidin, or immobilized on nanoparticles coated with streptavidin, and used to active B cells in this precisely controlled, high throughput assay. Using B cell proliferation and Ig class switching as metrics for successful B cell activation, we show that the stimuli are both synergistic and dose-dependent. Crucially, the multimerized immunoconjugates are most active over a narrow concentration range. These data suggest that multimericity is an essential requirement for B cell BCR/TLRs ligands, and clarify basic rules for B cell activation. Such studies highlight the importance in determining the choice of single vs multimeric formats of antigen and PAMP agonists during vaccine design and development.

Antibody Light Chains: Key to Increased Monoclonal Antibody Yields in Expi293 Cells?

When constructing isogenic recombinant IgM–IgG pairs, we discovered that μ heavy chains strongly prefer partnering with λ light chains for optimal IgM expression in transiently cotransfected Expi293 cells. When μ chains were paired with κ light chains, IgM yields were low but increased by logs—up to 20,000 X—by using λ chains instead. Switching light chains did not alter epitope specificity. For dimeric IgA2, optimal expression involved pairing with λ chains, whereas light-chain preference varied for other immunoglobulin classes. In summary, recombinant IgM production can be drastically increased by using λ chains, an important finding in the use of IgM for mucosal immunoprophylaxis.

Choice of therapy for psoriasis: inhibition of IL-23 p19 – data from clinical studies and real practice

The article presents the results of clinical studies and real practice of the effectiveness and safety of the use of a new genetically engineered biological drug Risankizumab. Skyrizi (risankizumab) is an innovative drug, it is a humanized monoclonal antibody – immunoglobulin class G1 (IgG1) – which specifcally inhibits the cytokine IL-23 by binding to its subunit p19. It is believed that cytokine IL-23, involved in inflammatory processes, is associated with a number of chronic immune-mediated diseases, including psoriasis. According to direct comparative randomized clinical trials, risankizumab is superior in effectiveness in the short term and, most importantly, in the long term most genetically engineered biologic drugs, including TNF-α inhibitors, secukinumab, ustekinumab. In the ultIMMa-1 and ultIMMa-2 studies, sPGA 0/1 and PASI 90 (p &lt; 0.001) were achieved after 16 weeks of treatment with Skyrizi. After 16 weeks of treatment in both studies, the majority of patients achieved sPGA 0/1 (88% and 84%, respectively), and PASI 90 in both studies reached 75% of patients receiving Skyrizi. According to the LIMMitless open extended study, after completion of ultIMMa-1 and –2 (based on LOCF analysis), the proportion of patients receiving Skyrizi up to 2.5 years (136 weeks) withholding PASI 90 and PASI 100 was 87% and 63%, respectively. One of the potential advantages of IL-23 inhibitors is also the long-term maintenance of the achieved effect after treatment cessation. During patient management in the course of randomized controlled trials of phase 3, data were obtained on the high safety of the drug and the absence of signifcant risks in relation to serious infections, cardiovascular events, malignant neoplasms. The drug is effective in case of insuffcient response to adalimumab, ustekinumab, secukinumab. The article presents two clinical cases of the use of risankizumab in patients of different ages with severe psoriasis, with ineffciency or intolerance to systemic therapy, as well as in connection with the eluding effect of previously conducted treatment methods. PASI 90/100 was achieved in all patients. No adverse events were observed.

Switch Tandem Repeats Influence the Choice of the Alternative End-Joining Pathway in Immunoglobulin Class Switch Recombination.

Immunoglobulin class switch recombination (CSR) plays an important role in humoral imm\\une responses by changing the effector functions of antibodies. CSR occurs between highly repetitive switch (S) sequences located upstream of immunoglobulin constant gene exons. Switch sequences differ in size, the nature of their repeats, and the density of the motifs targeted by the activation-induced cytidine deaminase (AID), the enzyme that initiates CSR. CSR involves double-strand breaks (DSBs) at the universal Sµ donor region and one of the acceptor S regions. The DSBs ends are fused by the classical non-homologous end-joining (C-NHEJ) and the alternative-NHEJ (A-NHEJ) pathways. Of the two pathways, the A-NHEJ displays a bias towards longer junctional micro-homologies (MHs). The Sµ region displays features that distinguish it from other S regions, but the molecular basis of Sµ specificity is ill-understood. We used a mouse line in which the downstream Sγ3 region was put under the control of the Eµ enhancer, which regulates Sµ, and analyzed its recombination activity by CSR-HTGTS. Here, we show that provision of Eµ enhancer to Sγ3 is sufficient to confer the recombinational features of Sµ to Sγ3, including efficient AID recruitment, enhanced internal deletions and robust donor function in CSR. Moreover, junctions involving Sγ3 display a bias for longer MH irrespective of sequence homology with switch acceptor sites. The data suggest that the propensity for increased MH usage is an intrinsic property of Sγ3 sequence, and that the tandem repeats of the donor site influence the choice of the A-NHEJ.