Antibody-forming Cells Research Articles

Context-Dependent miR-21 Regulation of TLR7-Mediated Autoimmune and Foreign Antigen-Driven Antibody-Forming Cell and Germinal Center Responses.

MicroRNAs (miRNAs) are involved in healthy B cell responses and the loss of tolerance in systemic lupus erythematosus (SLE), although the role of many miRNAs remains poorly understood. Dampening miR-21 activity was previously shown to reduce splenomegaly and blood urea nitrogen levels in SLE-prone mice, but the detailed cellular responses and mechanism of action remains unexplored. In this study, using the TLR7 agonist, imiquimod-induced SLE model, we observed that loss of miR-21 in Sle1b mice prevented the formation of plasma cells and autoantibody-producing Ab-forming cells (AFCs) without a significant effect on the magnitude of the germinal center (GC) response. We further observed reduced dendritic cell and monocyte numbers in the spleens of miR-21-deficient Sle1b mice that were associated with reduced IFN, proinflammatory cytokines, and effector CD4+ T cell responses. RNA sequencing analysis on B cells from miR-21-deficient Sle1b mice revealed reduced activation and response to IFN, and cytokine and target array analysis revealed modulation of numerous miR-21 target genes in response to TLR7 activation and type I IFN stimulation. Our findings in the B6.Sle1bYaa (Sle1b Yaa) spontaneous model recapitulated the miR-21 role in TLR7-induced responses with an additional role in autoimmune GC and T follicular helper responses. Finally, immunization with T-dependent Ag revealed a role for miR-21 in foreign Ag-driven GC and Ab, but not AFC, responses. Our data suggest a potential multifaceted, context-dependent role for miR-21 in autoimmune and foreign Ag-driven AFC and GC responses. Further study is warranted to delineate the cell-intrinsic requirements and mechanisms of miR-21 during infection and SLE development.

Single-cell BCR and transcriptome analysis after influenza infection reveals spatiotemporal dynamics of antigen-specific B cells.

SummaryB cell responses are critical for antiviral immunity. However, a comprehensive picture of antigen-specific B cell differentiation, clonal proliferation, and dynamics in different organs after infection is lacking. Here, by combining single-cell RNA and B cell receptor (BCR) sequencing of antigen-specific cells in lymph nodes, spleen, and lungs after influenza infection in mice, we identify several germinal center (GC) B cell subpopulations and organ-specific differences that persist over the course of the response. We discover transcriptional differences between memory cells in lungs and lymphoid organs and organ-restricted clonal expansion. Remarkably, we find significant clonal overlap between GC-derived memory and plasma cells. By combining BCR-mutational analyses with monoclonal antibody (mAb) expression and affinity measurements, we find that memory B cells are highly diverse and can be selected from both low- and high-affinity precursors. By linking antigen recognition with transcriptional programming, clonal proliferation, and differentiation, these finding provide important advances in our understanding of antiviral immunity.

A single subcutaneous or intranasal immunization with adenovirus-based SARS-CoV-2 vaccine induces robust humoral and cellular immune responses in mice.

Optimal vaccines are needed for sustained suppression of SARS‐CoV‐2 and other novel coronaviruses. Here, we developed a recombinant type 5 adenovirus vector encoding the gene for the SARS‐CoV‐2 S1 subunit antigen (Ad5.SARS‐CoV‐2‐S1) for COVID‐19 immunization and evaluated its immunogenicity in mice. A single immunization with Ad5.SARS‐CoV‐2‐S1 via S.C. injection or I.N delivery induced robust antibody and cellular immune responses. Vaccination elicited significant S1‐specific IgG, IgG1, and IgG2a endpoint titers as early as 2 weeks, and the induced antibodies were long lasting. I.N. and S.C. administration of Ad5.SARS‐CoV‐2‐S1 produced S1‐specific GC B cells in cervical and axillary LNs, respectively. Moreover, I.N. and S.C. immunization evoked significantly greater antigen‐specific T‐cell responses compared to unimmunized control groups with indications that S.C. injection was more effective than I.N. delivery in eliciting cellular immune responses. Mice vaccinated by either route demonstrated significantly increased virus‐specific neutralization antibodies on weeks 8 and 12 compared to control groups, as well as BM antibody forming cells (AFC), indicative of long‐term immunity. Thus, this Ad5‐vectored SARS‐CoV‐2 vaccine candidate showed promising immunogenicity following delivery to mice by S.C. and I.N. routes of administration, supporting the further development of Ad‐based vaccines against COVID‐19 and other infectious diseases for sustainable global immunization programs.

Role of MP-4 myelopeptide in regulation of antibody production and functional activity of macrophages under stress conditions

Myelopeptides are endogenous low-molecular weight peptides with immunoregulatory activity. Each of these myelopeptides has an individual sequence and plays a role in correction of immune system disorders. In our earlier studies, we have shown immunomodulatory effect of MP-3, MP-5, MP-6 myelopeptides upon functioning of peritoneal macrophages under the conditions of immobilization and cold stresses. The aim of this work was to investigate the effect of MP-4 myelopeptide upon antibody formation, production of reactive oxygen species, and absorptive activity of peritoneal macrophages in mice under the immobilization stress. Materials and methods. The in vivo experiments were carried out in 24 male Swiss mice weighing 17-22 g. Two-or six-hour immobilization stress was produced in the animals. MP-4 was injected intraperitoneally 30 min before the onset of stress, at a dose of 40 μg/kg. The animals were divided into 4 groups: 1, control; 2, stress; 3, stress + MP-4; 4, MP-4 injection. On day +5, cellularity and the number of antibody-forming cells (AOC) in spleen were assessed by the method of local hemolysis in an agarose gel according to Jerne. Production of reactive oxygen species by peritoneal cells was assessed using the luminol-dependent chemiluminescence (LZHL) reaction. The absorption capacity of peritoneal macrophages was assessed using a standard method using a BDFACSCalibur laser flow cytometer. Labeled St. aureus at a final concentration of 108 cells/ml were used as phagocytosis targets. Statistical analysis was performed using the unpaired Student's t-test. Results. It was found that two-hour immobilization stress did not affect the absorption activity of peritoneal leukocytes, whereas six-hour stress suppressed phagocytosis. Injection of MP-4 in stress-exposed animals did not lead to changes in phagocytic activity of peritoneal macrophages. MP-4 did not correct the stress-induced decrease in the number of antibody-forming cells from the spleen during six hours of immobilization, nor stress-induced increase in absolute amounts of AOC under the two-hour immobilization stress. In the group of animals receiving MP-4 and immobilized for two-hours, an increase in the number of nucleated cells was increased, as compared with the control group. Thus, in contrast to the previously studied myelopeptides, MP-4 did not show pronounced immunomodulatory effects upon these parameters.

Modulated in vitro lymphocytes in the treatment of alcoholism: Experimental study

IntroductionImmune cells are dysfunctional during long-term ethanol consumption and may contribute to the progression from healthy to problem drinking. Lymphocytes from mice with chronic ethanol exposure characterized by impaired functional activity, manifested in the combination of increased spontaneous proliferation against the background of low sensitivity to T- cell mitogens.ObjectivesWe first demonstrated that original compound meta-chloro-benzhydryl-urea (m-ch-BHU) in vitro restored long-term alcoholized mice lymphocytes activity through GABA(A) receptors. We also revealed the possibility of animal’s behavioral regulation by the transplantation of immune cells with definite functional characteristics, also modulated by psychoactive drugs. Based on the previous results we investigated effects of m-ch-BHU modulated lymphocytes transplantation in recipients with experimental alcoholism.MethodsMale (CBAxC57Bl/6)F1 mice with 6-month 10% ethanol exposure were undergoing the transplantation of syngeneic long-term alcoholized mice lymphocytes, pretreated in vitro with m-ch-BHU. Recipient’s ethanol consumption, nervous and immune systems functional activities were estimated.ResultsIt was shown that transplantation of lymphocytes with in vitro m-ch-BHU modulated functional activity caused in syngeneic recipients with chronic alcohol exposure essential ethanol consumption decrease and stimulation of motor and exploratory activities in the “open field” against the background of cytokines modulation in brain. The significant stimulation of humoral immune response, estimated by the relative number of antibody-forming spleen cells, and stimulation of DTH reaction were also detected in recipients after lymphocytes transplantation.ConclusionsResults demonstrated that transplantation of m-ch-BHU modulated lymphocytes caused positive psychoneuroimmunomodulating effect in animals with chronic alcohol exposure, so, it may be considered as a promising method in the treatment of alcoholismDisclosureNo significant relationships.

Immunomodulating Properties of Humic Acids Extracted from Oligotrophic Sphagnum magellanicum Peat.

Humic acids extracted with sodium pyrophosphate from Oligotrophic Sphagnum magellanicum peat reduce mitogen-stimulated production of anti-inflammatory cytokine IL-10 by mouse peritoneal macrophages and do not affect the secretion of IL-4 by lymphocytes. The studied humic acid sample stimulates the production of proinflammatory cytokines IL-12, TNFα, IL-1β, and IFNγ by immunocompetent mouse cells and human mononuclear cells. Course administration of humic acids to mice enhances the humoral immunity, increasing the number of antibody-forming cells in the spleen and the titer of antibodies in the blood serum after immunization with sheep red blood cells.

A T-dependent antibody response evaluation in CD-1 mice after an acute whole-body inhalation exposure to nickel (II) chloride hexahydrate

Nickel (Ni) in ambient air may vary regionally with contributions from both natural processes and anthropogenic activities. Exposure to Ni compounds in ambient air above a certain level is associated with acute adverse effects, such as upper respiratory tract irritation, pneumonitis, and chronic adverse effects, such as respiratory cancer. Inhalation reference exposure standards are enacted in different jurisdictions to minimize exposures to ambient Ni above levels that can elicit adverse effects. This paper reports a guideline-/GLP-compliant study designed for setting inhalation exposure standards to protect from immunological effects associated with acute exposure to Ni. Female CD-1 mice were exposed via whole-body inhalation to aerosolized nickel chloride hexahydrate for 24-hr at nominal (vs. mean analyzed) concentrations of 20 (16), 50 (44) and 100 (81) µg Ni/m3. Host T-cell antibody immunological responses to intravenously-injected sheep red blood cells were then measured ex vivo in an Antibody-Forming Cell (AFC) assay. Exposure to the Ni substance significantly decreased spleen cell levels by 33%, but this was within biological variability for outbred mice. No concurrent decreases in spleen, thymus, or body weights were noted. No immunosuppression was observed with the Ni substance in the context of Total Spleen Activity [IgM AFC/spleen (× 103)] and Specific Activity [IgM AFC/spleen cells (× 106)]. Significant concentration-independent increases in Total Spleen Activity and Specific Activity seen with the nickel chloride hexahydrate were normal and within biological variability for outbred mice. In contrast, cyclophosphamide (positive control) significantly decreased spleen cell numbers, spleen and thymus weights, and abolished Specific Activity and Total Spleen Activity. Based on results here, an NOAEC of 81 µg Ni/m3 for immunosuppressive effects from inhaled nickel chloride hexahydrate was identified. It is hoped this value can be used to derive a reference standard for human exposure to ambient Ni.

STAT4 Is Largely Dispensable for Systemic Lupus Erythematosus-like Autoimmune- and Foreign Antigen-Driven Antibody-Forming Cell, Germinal Center, and Follicular Th Cell Responses.

Genome-wide association studies identified variants in the transcription factor STAT4 gene and several other genes in the STAT4 signaling pathway, such as IL12A, IL12B, JAK2, and TYK2, which are associated with an increased risk of developing systemic lupus erythematosus (SLE) and other autoimmune diseases. Consistent with the genome-wide association studies data, STAT4 was shown to play an important role in autoimmune responses and autoimmunity development in SLE mouse models. Despite such important role for STAT4 in SLE development in mice and humans, little is known whether and how STAT4 may regulate extrafollicular Ab-forming cell (AFC) and follicular germinal center (GC) responses, two major pathways of autoreactive B cell development and autoantibody production. To our surprise, we found STAT4 to be largely dispensable for promoting autoimmune AFC and GC responses in various autoimmune- and SLE-prone mouse models, which strongly correlated with autoantibody production, and immune complex deposition and immune cell infiltration in the kidney. We further observed that STAT4 deficiency had no effects on AFC, GC, and Ag-specific Ab responses during protein Ag immunization or influenza virus infection. Additionally, CD4+ effector and follicular Th cell responses in autoimmune- and SLE-prone mice and protein Ag-immunized and influenza virus-infected mice were intact in the absence of STAT4. Together, our data demonstrate a largely dispensable role for STAT4 in AFC, GC, and Ab responses in SLE mouse models and in certain foreign Ag-driven responses.

Effects of an environmentally relevant PCB-mixture on immune function, clinical chemistry, and thyroid hormone levels in adult female B6C3F1 mice

ABSTRACT Polychlorinated biphenyls (PCBs) have been assessed for immunotoxicity; however, humans and wildlife are exposed to multiple PCBs environmentally. Therefore, the aim of this study was to examine the effects of a complex 37 PCB congener mixture identified in blubber specific to dolphins residing in the estuarine waters of Charleston, South Carolina. Immunotoxicity was determined in adult female B6C3F1 mice by assessing lymphocyte proliferation, splenic and thymic immunophenotypes, and IgM production. Mice were exposed via oral gavage to the PCB-mixture (0, 1.8, 3.6, 7.1, or 14.3 mg/kg/day) for 28 days to yield a targeted total administered dose (TAD) 0, 50, 100, 200, or 400 mg/kg. Significant increased liver weight occurred at the highest treatment. IgM production was suppressed compared to control for all treatments. Numbers of thymic CD4+/CD8+, CD4-/CD8-, and CD4+/CD8- cells were not altered, but numbers of thymic CD4-/CD8+ cells were significantly increased in the highest treatment. Lymphocyte proliferation was not markedly affected by any treatment. The numbers of splenic CD4/CD8 T-cells or MHCII+ cells were not significantly changed. Humoral immunity using the plaque-forming cell assay for determining the specific IgM antibody-forming cell response appeared to be the most sensitive endpoint affected. As the lowest concentration tested resulted in decreased IgM production and total and free thyroxine (T4) serum levels a NOAEL was not identified. The calculated ED50 for suppression of IgM production was 2.4 mg/kg/day.

Immunoprotective therapy for suppression of humoral immune response induced by hypoxia and toxemia

The possibility of using preparations limiting toxemia and hypoxia, in particular inhibitors of proteoletic enzymes and antihypoxants, as preparations having immunoprotective activity is considered. Under the conditions of the experimental model of severe mechanical injury on mice-hybrids of the first generation F1 (CBAC57BL6), the immunoprotective activity of such antihypoxants as amtisol and a derivative of 1, 2, 4-triazino-5, 6 indole, as well as a counterkal, a drug limiting toxemia and a cationoacceptor preparation of dimexide, administered to immunized erythythermal It has been shown that in the body of mice receiving antihypoxants, contrical and dimexide accumulate significantly more antibody-forming cells compared to their number in animals of the control group. Thus, amtisol, a derivative of 1, 2, 4-triazino-5, 6 indole, contrical and dimexide can be considered not only as preparations for pathogenetic therapy of trauma, but also as immunoprotectors drugs that indirectly limit the formation of post-traumatic immunodeficiency and the risk of infection in an immunocompromised host. The risk of infectious complications and the generalization of the inflammatory process in patients after severe mechanical injury is more than 50%. Prevention of infectious complications of traumatic disease should be comprehensive and aimed at correcting the function of the immune system.

The composition of peripheral immunocompetent cell subpopulations and cytokine content in the brain structures of mutant Disc1-Q31L mice.

The DISC1 (disrupted in sсhizophrenia 1) gene is associated with brain dysfunctions, which are involved in a variety of mental disorders, such as schizophrenia, depression and bipolar disorder. This is the first study to examine the immune parameters in Disc1-Q31L mice with a point mutation in the second exon of the DISC1 gene compared to mice of the C57BL/6NCrl strain (WT, wild type). A flow cytometry assay has shown that intact Disc1- Q31L mice differ from the WT strain by an increase in the percentage of CD3+ T cells, CD3+CD4+ Т helper cells and CD3+CD4+CD25+ T regulatory cells and a decrease in CD3+CD8+ T cytotoxic/suppressor cells in the peripheral blood. A multiplex analysis revealed differences in the content of cytokines in the brain structures of Disc1-Q31L mice compared to WT mice. The content of pro-inflammatory cytokines was increased in the frontal cortex (IL-6, IL- 17 and IFNγ) and striatum (IFNγ), and decreased in the hippocampus and hypothalamus. At the same time, the levels of IL-1β were decreased in all structures being examined. In addition, the content of anti-inflammatory cytokines IL-4 was increased in the frontal cortex, while IL-10 amount was decreased in the hippocampus. Immune response to sheep red blood cells analyzed by the number of antibody-forming cells in the spleen was higher in Disc1-Q31L mice at the peak of the reaction than in WT mice. Thus, Disc1-Q31L mice are characterized by changes in the pattern of cytokines in the brain structures, an amplification of the peripheral T-cell link with an increase in the content of the subpopulations of CD3+CD4+ T helpers and CD3+CD4+CD25+ T regulatory cells, as well as elevated immune reactivity to antigen in the spleen.

Natural organic matter does not diminish the mammalian bioavailability of 2,3,7,8-tetrachlorodibenzo-p-dioxin

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a toxic and persistent organic pollutant found in soils and sediments. It has been linked to several adverse health outcomes in humans and wildlife, including suppression of the immune system. TCDD is strongly sorbed to soils/sediments due to its extremely low water solubility. Presently, the bioavailability of soil/sediment-sorbed TCDD to mammals is not completely understood. Our previous studies demonstrated that TCDD adsorbed to representative inorganic geosorbents (i.e. porous silica and smectite clay) exhibited the same bioavailability to mice as TCDD dissolved in corn oil, whereas sequestration by activated carbons eliminated TCDD bioavailability. In this study, we evaluated the effects of amorphous natural organic matter (NOM), primarily in the form of aquatic humic and fulvic acids, on the mouse bioavailability of TCDD. An aqueous suspension of TCDD mixed with NOM was administered to mice via oral gavage. The relative bioavailability of TCDD was assessed by two sensitive aryl hydrocarbon receptor-mediated responses in mice: 1) hepatic induction of cyp1A1 mRNA; and 2) suppression of immunoglobulin M (IgM) antibody-forming cell (AFC) response which is an indicator of immunotoxicity. Hepatic induction of cyp1A1 mRNA and suppression of IgM AFC induced by TCDD were similar in the NOM-sorbed form and dissolved in corn oil, revealing no loss of bioavailability when associated with NOM. Hence, NOM-associated TCDD is as capable of suppressing humoral immunity in mice as TCDD dissolved in corn oil, indicating that NOM-sorbed TCDD is likely to fully retain its bioavailability to mammals and, by inference, humans.

Bim establishes the B-cell repertoire from early to late in the immune response.

In T cell-dependent antibody responses, some of the activated B cells differentiate along extrafollicular pathways into low-affinity memory and plasma cells, whereas others are involved in subsequent germinal center (GC) formation in follicular pathways, in which somatic hypermutation and affinity maturation occur. The present study demonstrated that Bim, a proapoptotic BH3-only member of the Bcl-2 family, contributes to the establishment of the B-cell repertoire from early to late stages of immune responses to T cell-dependent antigens. Extrafollicular plasma cells grew in the spleen during the early immune response, but their numbers rapidly declined with the appearance of GC-derived progeny in wild-type mice. By contrast, conditional Bim deficiency in B cells resulted in expansion of extrafollicular IgG1+ antibody-forming cells (AFCs) and this expansion was sustained during the late response, which hampered the formation of GC-derived high-affinity plasma cells in the spleen. Approximately 10% of AFCs in mutant mice contained mutated VH genes; thus, Bim deficiency appears not to impede the selection of high-affinity AFC precursor cells. These results suggest that Bim contributes to the replacement of low-affinity antibody by high-affinity antibody as the immune response progresses.

Immune Activity of Polysaccharide Fractions Isolated from Korean Red Ginseng

Korean red ginseng (KRG)’s pharmacological efficacy and popular immunomodulatory effects have already been proven in many studies; however, the component of KRG that is effective in immune activity has not been studied before. Therefore, this study extracted and separated KRG for an immune activity comparison. In the water fraction obtained by extracting KRG powder with water, a red ginseng neutral polysaccharide (RGNP) fraction and a red ginseng acidic polysaccharide (RGAP) fraction were obtained. Each fraction was orally administered for 10 days to mice with reduced immunity, and the number of IgM antibody-forming cells (AFCs) in splenocytes was measured to compare the immune activity of the water fractions. The results showed that the RGAP fraction has the greatest number of AFCs. To set the optimal dose of the RGAP fraction, which had the highest immune activity, the AFCs, macrophage activity, and splenocyte subtype in the mice were analyzed. As a result, the number of AFCs was significantly increased in the RGAP fraction compared to RGNP. The intraperitoneal macrophage phagocytosis activity and the number of T cells, B cells, and macrophages in the spleen increased significantly. It can, therefore, be confirmed that immune activity increases by a fraction containing higher RGAP content, and we hypothesize that RGAP activates immune activity.

The impact of the Chimaphila umbellata (L.) W.P. C.Barton extract on the immune response in animals

With the water-alcohol extraction method was obtained liquid extract from Chimaphila umbellata (L.)W.P.C. Barton. Experimental studies on the azathioprine immunosuppression model showed a pronounced opposition to the development of a secondary immunodeficiency state under the influence of 14-day course use of a dealcoholized extract of the aerial part of Chimaphila umbellata (L.)W. P.C.Barton. The results of the humoral state assessment and cellular link of the immune response in F1 line laboratory mice (C57B1 / 6 × CBA) indicate that the plant extracts: 1. Restores the immune status by the delayed-type hypersensitivity reaction to 85.6%, with 100% in the intact control and 69.9 in the control - azathioprine. 2. Influences the number of antibody-forming cells, significantly increasing their absolute value by 2.36, and the relative - by 1.84 times in comparison with control-azathioprine. The immunocorrecting activity of umbellata wintergreen Chimaphila umbellata (L.) W. P. C.Barton extract is consistent with previously obtained results on the study of antipyretic, analgesic, antimicrobial, and wound healing anti-inflammatory effects.

Plasmacytoid Dendritic Cells and Type I Interferon Promote Extrafollicular B Cell Responses to Extracellular Self-DNA

Class-switched antibodies to double-stranded DNA (dsDNA) are prevalent and pathogenic in systemic lupus erythematosus (SLE), yet mechanisms of their development remain poorly understood. Humans and mice lacking secreted DNase DNASE1L3 develop rapid anti-dsDNA antibody responses and SLE-like disease. We report that anti-DNA responses in Dnase1l3-/- mice require CD40L-mediated Tcell help, but proceed independently of germinal center formation via short-lived antibody-forming cells (AFCs) localized to extrafollicular regions. Type I interferon (IFN-I) signaling and IFN-I-producing plasmacytoid dendritic cells (pDCs) facilitate the differentiation of DNA-reactive AFCs invivo and invitro and are required for downstream manifestations of autoimmunity. Moreover, the endosomal DNA sensor TLR9 promotes anti-dsDNA responses and SLE-like disease in Dnase1l3-/- mice redundantly with another nucleic acid-sensing receptor, TLR7. These results establish extrafollicular B cell differentiation into short-lived AFCs as a key mechanism of anti-DNA autoreactivity and reveal a major contribution of pDCs, endosomal Toll-like receptors (TLRs), and IFN-I to this pathway.

UVB light exposure promotes IgE autoantibody production and skin autoreactivity in mice that express a lupus-associated isoform of Foxp3

Abstract Foxp3 activity is required for the maintenance of self-tolerance, but humans encode an additional exon 2-deficient splice variant isoform of FOXP3 with no known function. To determine how exon 2 of FOXP3 contributes to Treg activity, we generated mice that express exon 2-deficient FoxP3 (called B6.FoxP3ΔExon2). B6.FoxP3ΔExon2 mice develop mild autoimmunity (splenomegaly, autoantibodies and kidney nephritis) with significantly elevated titers of skin-reactive IgE. We also observed skin-reactive IgE antibodies in SLE patients with active photosensitivity, so we challenged B6 and B6.FoxP3ΔExon2 mouse skin with ultraviolet B (UVB) light to determine if UVB damage can induce skin-reactive IgE production. When compared to B6 controls, B6.FoxP3ΔExon2 mice developed greater skin inflammation with increased infiltration of Tregs (CD4+Foxp3+), effector T cells (CD4+CD44+Foxp3−) and IgE+ plasma cells (B220lowCD138+Blimp1+) at the site of UVB damage. B6.FoxP3ΔExon2 mice also had higher numbers of IgE+ antibody-forming cells, IL4-producing T cells (CD4+CD44+Foxp3−) and IgE-producing B cells, but lower numbers of CTLA4+ Tregs in draining lymph nodes from UVB-treated skin. Finally, UVB-treated B6.FoxP3ΔExon2 mice also had worsened kidney disease, phenocopying multi-systemic flares that occur in SLE patients with photosensitivity. Collectively, we found that exon 2 of the Foxp3 gene is required to control UVB-induced cutaneous inflammation though the regulation of type 2 immune activation and skin-reactive IgE. Thus, our findings suggest that photosensitivity reactions in SLE patients may be mediated by altered Foxp3 activity and skin-reactive IgE that could be therapeutically targeted to control systemic autoimmune flares.

Serine phosphorylation of the STAT1 transactivation domain promotes autoreactive B cell and systemic autoimmunity development

Abstract Although STAT1 tyrosine-701 phosphorylation (STAT1-pY701) is indispensable for STAT1 function, the requirement for STAT1 serine-727 phosphorylation (STAT1-pS727) during autoimmune and anti-pathogen responses remains unclear. Here we report that STAT1-pS727 promotes autoimmune antibody-forming cell (AFC) and germinal center (GC) responses, driving systemic lupus erythematosus (SLE) development. STAT1-pS727, however, is not required for GC and antibody responses to foreign-antigens including pathogens or gut microbiota. STAT1-pS727 plays an important B cell-intrinsic role in driving autoimmunity. Transcriptomic analysis of B cells from TLR7-accelerated SLE-prone mice reveals STAT1-pS727-mediated gene regulation of cellular pathways known to be involved in autoimmune GC and AFC responses. Mechanistically, TLR7 activation in B cells induces STAT1-pS727 and during autoimmune responses TLR7 signaling converges with IFNγ-STAT1 signaling in B cells by recruiting STAT1 into the MyD88 signaling complex. Together, we identify previously unappreciated differential regulation of autoimmune and anti-pathogen responses by STAT1-pS727, and implicate STAT1-pS727 as a therapeutic target for SLE.

Pharmacological assessment of immunotropic activity of new gel metabiotic on cellular and humoral immunity in experimentally modeled thermal skin burns

Thermal skin burns were experimentally modeled in laboratory animals revealed immunotropic effects of new gel metabiotic consisting of complex biological active substances produced by Bacillus subtilis B-3679 strain as part of three gel transcutaneous bases: tizol, eftiderm and organosilicon glycerohydrogel on cellular and humoral immunity. The aim of the study was to evaluate immunotropic activity of a new gel metabiotic on cellular and humoral immunity in experimentally modeled thermal skin burns in 60 white laboratory Wistar rats, weighed 180-220 g, for metabiotic consisting of a complex biologically active substances produced by Bacillus subtilis B-3679 strain containng the three gel transcutaneous bases: tizol, ephtiderm and organosilicon glycerohydrogel (KTGG). Registered, standardized antimicrobial and wound-healing ointment levosin was used as a control. The experimental data obtained confirm the effectiveness of using the drugs studied for treatment of first and second degree thermal burns revealed by faster decreased area of affected area compared to experimental animals treated with levosin. While evaluating therapeutic effectiveness of experimental samples of metabiotic-based gel preparations, their influence on various parameters of cellular and humoral immunity in modeled thermal skin burn was examined. We assessed phagocytic activity of blood neutrophils and peritoneal macrophages, quantified T and B lymphocytes, as well as antibody-forming cells and immunoglobulins of various classes. It was found that in experimental animals reproducing models of traumatic skin injuries, there is an increase in the level of all the studied parameters of humoral immunity. Concentration of immunoglobulin M, circulating immune complexes and immunoglobulin E, as well as various cytokines, increased larger. The level of α-interferon and the receptor antagonist interleukin-1 was elevated. Thus, the study of the humoral status of experimental animals that received test metabiotic-based gel preparations in modeled thermal skin burns, allows to conclude that they significantly influenced various arms both cellular and humoral immunity. More marked effects were observed for metabiotic-based drugs containing tizol and KTGG. In general, based on the experimental data we can conclude that the relatively high therapeutic effectiveness of examined drugs in the treatment of thermal skin burn wounds in experimental animals, use of which provided earlier removal of necrotic masses, accelerated regeneration processes, and prevented development of secondary wound infection in burns.

Effect of carpesium abrotanoides petroleum ether fraction on phagocytic function of macrophages and antibody forming cell in mice

Objective To study the effects of carpesium abrotanoides petroleum ether fraction on phagocytic function of macrophages and antibody forming cell in mice. Methods The extract carpesium abrotanoides petroleum ether fraction, forty five mice were divided into the control group and low and high dose groups of carpesium abrotanoides petroleum ether fraction by random number table method, 15 mices in each group. The low-dose and high-dose groups of carpesium abrotanoides petroleum ether fraction were given 50 mg/kg and 100 mg/kg respectively by gavage for 10 days. The spleen weight, growth index, the phagocytosis of macrophages and the number of antibody-forming cells in peritoneal macrophages of mice were detected by chicken erythrocyte phagocytosis test and hemolytic plaque test. Results Compared with the control group, the spleen weight (192.4 ± 11.49 mg, 204.6 ± 10.59 mg vs. 117.6 ± 10.89 mg), the growth index (6.04 ± 0.54, 6.06 ± 0.40 vs. 3.89 ± 0.14), antibody forming (1 216.4 ± 94.1, 1 548.8 ± 86.4 vs.361.0 ± 11.7), phagocytosis percentage of macrophages (58.60% ± 2.60%, 72.0% ± 3.08% vs. 35.49% ± 1.64%), and Phagocytosis index (2.01 ± 0.10, 2.69 ± 0.15 vs. 0.37 ± 0.06) of the groups of low doses and high doses of Carpesium abrotanoides Petroleum ether fraction significantly increased (P<0.05). Conclusions The low doses and high doses of Carpesium abrotanoides Petroleum ether fraction can enhance the mice's specific and nonspecific immune function,and protect the immune system of mice. Key words: Carpesium abrotanoides; Macrophages; Immune function; Mice