Expression Of Specific Antibodies Research Articles

Identification and characterization of the Cul t 1 as major allergen from biting midge Culicoides tainanus.

Midges are widely distributed globally. They can transmit numerous serious diseases as well as trigger an allergic reaction in the host. Their saliva contains a variety of proteins that act as sensitizers to stimulate the host's immune response, leading to IgE-mediated allergic symptoms. In the present study, we constructed a mouse sensitization model with the thorax extract of the Culicoides tainanus, and evaluated the sensitization model by behavior and specific antibody expression. SDS-PAGE/western blot was used to detect the binding proteins by IgE antibody in the thorax extract of the C. tainanus. The objective band was cut for mass spectrometry to preliminarily clarify the potential allergen. The pET21a-Cul t 1 recombinant expression vector was constructed and the target protein was purified by Ni affinity chromatography. The sensitizing effect of the sensitizer was verified in vitro and in vivo. Immunoblot analysis revealed that a 66 kDa protein (Cul t 1) from the chest extracts of C. tainanus could bind to serum IgE of sensitized mice. Cul t 1 was further identified by fragmentation, mass spectrometry and bioinformatics as maltase, an enzyme involved in sugar digestion. In vivo validation of the Cul t 1-mouse sensitization model showed that the scratching behavior of the Cul t 1 sensitized group was significantly higher than that of the control group according to behavioral evaluation. The results of HE staining of the skin of the injected area showed that Cul t 1 sensitized group was found to have a large number of inflammatory cell infiltration and increased fibrosis in the dermis. The ELISA detection of IgE showed that the Cul t 1 sensitized group was significantly elevated from the beginning of the 28th day onwards, and the expression level of IgE had a tendency to slow down with the prolongation of the sensitization time. The ELISA assay showed that the expression level of IgG1 increased significantly in the Cul t 1 group on day 42, while the results of the specific antibody IgG2a showed that there was no significant difference in both the Cul t 1 sensitized group and the control group. The results suggest that the immune response induced by Cul t 1 sensitized mice may be shifted toward a Th2 type immune response. In this study, we identified the sensitizer of the C. tainanus, named Cul t 1. We successfully constructed the recombinant expression vector pET21a-Cul t 1, purified the Cul t 1 sensitizer by affinity chromatography, and verified the sensitizing effect of Cul t 1 in mice. The results laid a practicable foundation for the subsequent immune therapy of midge bites and bite control.

Immune-related effects of compound astragalus polysaccharide and sulfated epimedium polysaccharide on newborn piglets

This study aimed to evaluate the immune effects of compound astragalus polysaccharide and sulfated epimedium polysaccharide (APS-sEPS) on the peripheral blood lymphocyte and intestinal mucosa in newborn piglets. A total of 40 newborn piglets were randomly divided into four groups during a 25-day experiment, including APS-sEPS, APS, sEPS and control group. The results showed that supplementation with APS-sEPS to newborn piglets remarkably increased the physiological parameters, especially the WBC. In peripheral blood, piglets that received APS-sEPS showed the highest proliferation of T lymphocytes, the percentage of CD3 + CD4+ and CD3 + CD8+ cells were the highest on days 15 and 25 (p < 0.05). The serum concentrations of IFN-γ on days 7 and 15, and IL-4, IL-10, sIgA on days 7, 15 and 25 in APS-sEPS group were significantly higher than those in the control group (p < 0.05). Furthermore, the villus length and the ratio of villus length to crypt depth in APS-sEPS group were both significantly increased compared to that of control group (p < 0.05). In the duodenum, jejunum and illume, the concentrations of IFN-γ, IL-10, total IgG and sIgA in APS-sEPS group were all significantly higher than that in control group (p < 0.05). In intestinal mucosa, APS-sEPS significantly increased the expression of NF-κB and IRF-3 mRNA in each section of small intestine of piglets. Nevertheless, in the illume segment, the effect of APS-sEPS was more significant than that of APS and sEPS (p < 0.05). The expression of TLR4 was more significant than that of control group in duodenum only. The results from the present research provide evidence that the suckling piglets administered with APS-sEPS supplement exhibited enhanced immune function of peripheral blood lymphocyte and expression of specific antibodies, and ameliorated intestinal morphological development and increased activities of humoral immune response in the small intestine, which would be related to the activation of the TLR4-NF-κB signaling pathway and IRF3.

Analysis of the Behaviour of Immunoglobulin G Antibodies in Children and Adults Convalescing From Severe Acute Respiratory Syndrome-Coronavirus-2 Infection.

The pandemic caused by SARS CoV-2 (COVID-19) has affected millions of people since 2020. There are clinical differences and in mortality between the adult and paediatric population. Recently, the immune response through the development of antibodies has gained relevance due to the risk of reinfection and vaccines' development.Objective: Was to compare the association of clinical history and the clinical presentation of the disease with the development of IgG antibodies against SARS-CoV-2 in paediatric and adult patients with a history of positive reverse transcriptase-polymerase chain reaction (RT-PCR) results.Methods: Cross-sectional observational study carried out in a Paediatric Hospital in Mexico City included patients under 18 years of age and health personnel with positive RT-PCR for COVID-19 comparing antibody expression. The development of specific IgG antibodies was measured, the presence of comorbidities, duration, and severity of symptoms was determined.Results: Sixty-one subjects (20 < 18 years and 41 > 18 years) were analysed. The median sample collection was 3 weeks. There were no differences in the expression of specific antibodies; no differences were shown according to the symptoms' severity. A positive correlation (r = 0.77) was demonstrated between the duration of symptoms and antibody levels.Conclusions: In conclusion, there is a clear association between the duration of the symptoms associated with SARS-CoV-2 infection and the IgG units generated in paediatric and adult patients convalescing from COVID-19.

Four Simple Biomimetic Mineralization Methods to Improve the Thermostability and Immunogenicity of Virus-like Particles as a Vaccine against Foot-and-Mouth Disease

The need for a cold chain system during storage and transport substantially increases the cost of vaccines. Virus-like particles (VLPs) are among the best countermeasures against foot and mouth disease virus (FMDV). However, VLPs are composed of pure proteins, and thus, are susceptible to heat. To address this problem, four simple biomimetic mineralization methods with the use of calcium phosphate were developed to improve heat tolerance via biomineralization. The results showed that biomineralization can significantly improve the heat resistance of VLPs. The biomineralized VLPs can be stored at low as 25 °C for eight days, and 37 °C for four days. Animal experiments showed that biomineralization had no effect on the immunogenicity of VLPs or the expression of specific antibodies (Abs) and neutralizing Abs. Even after heat treatment at 37 °C for four days, the biomineralized VLPs remained immunogenic and produced highly specific and neutralizing Abs with a high rate of protection. These results suggest that these biomineralization approaches can promote the thermal stability of VLPs against and significantly reduce dependence on cold storage and delivery systems.

Features of the immune status of middle and high school students in conditions of high blood content of a number of exogenous chemical impurities

Introduction. The quality of the habitat and increasing intensity of the educational load determine the negative changes of the health of schoolchildren, associated with a violation of immune mechanisms adaptation. Purpose. Study of features of the immune status of schoolchildren in the conditions of excessive hapten contamination by exogenous chemical factors. Materials and methods. Students who live in territories differing in the formation of excessive human-made chemical contamination (total 162 students) of senior and secondary education levels were examined. The analysis of contaminants in biological media utilizing gas chromatography method, high-performance liquid chromatography method, mass spectrometry method was performed. The state of cellular immunity was evaluated by the reaction of phagocytosis using formalinized ram erythrocytes and CD-immunogram parameters by flow cytometry. The state of humoral immunity identified with the production of serum immunoglobulins by radial immunodiffusion, as well as expression of specific antibodies to chemical factors by the method of allergosorbent testing. Results. We revealed an association of excess content of lead, nickel, formaldehyde, benzene, phenol in blood with deficiency phagocytic activity, imbalance of CD-subpopulations of immunocompetent cells characterized by the predominance of T lymphocytic activation (CD3+-lymphocytes), and a decrease in B-lymphocytes (CD19+-cells) both concerning the norm and to the group of schoolchildren with a permissible level of contaminating load. Secondary and senior students differed in imbalance of the immunoregulatory index CD4+/CD8+, and lower expression was revealed in high school students serum immunoglobulins IgM and IgA. In schoolchildren with excessive hapten contamination, there is a high level of sensitization to exogenous chemical factors according to the specific IgE antibodies to nickel, formaldehyde, and IgG to benzene, phenol, lead. Conclusion. The revealed imbalance of immune profile indices reflects the state of immunological health of schoolchildren, and the indices of cellular (immunoregulatory index CD4+/CD8+) and humoral (specific antihapten reagins) immunity, can be used as diagnostic for assessing the immune status in schoolchildren of secondary and senior levels of education in the conditions of excessive hapten contamination.

乙型肝炎相关性肝衰竭患者HBV DNA低水平复制及特异性抗体表达的临床意义

Objective To investigate the influential factors and clinical significance of low- level hepatitis B virus ( HBV) DNA replication and specific antibody expression in patients with HBV- related liver failure. Methods A retrospective analysis was performed on the medical records of 391 patients with HBV- related liver failure and 394 patients with chronic hepatitis B ( CHB) hospitalized in the Tianjin Second People's Hospital from June 2008 to December 2013. The HBV DNA level was compared between patients with HBV- related liver failure and those with CHB, and the influential factors were analyzed. According to the expression of HBV serum markers ( HBV- Ms) , patients with liver failure were divided into specific antibody- positive group ( positive for anti- HBs, anti- HBe or anti- HBc) and specific antibody- negative group ( negative for anti- HBs, anti- HBe or anti- HBc) . The changes in HBV DNA level and survival were compared between the two groups. Between- group comparison was made by independent- samples t test or Mann- Whitney rank sum test, and comparison of enumeration data was made by chi- square test. Results The patients with HBV- related liver failure had a significantly lower HBV DNA level than the CHB patients ( Z =- 16. 469, P < 0. 05) . The levels of HBV DNA in HBeAg- positive and- negative patients with liver failure were significantly lower than those in patients with CHB ( Z1=- 11. 665, P < 0. 05; Z2=- 12. 853, P < 0. 05) . Of the391 patients with HBV- related liver failure, 29 ( 7. 42%) were specific antibody- positive, and 25 ( 86. 21%) of them died; 362 ( 92. 58%) were specific antibody-negative, and 157 ( 43.37%) of them died. There was a significant difference in mortality between the specific antibody- positive and specific antibody- negative groups ( P < 0. 05) . The specific antibody- positive group had a significantly lower HBV DNA level than the specific antibody- negative group ( Z =- 3. 594, P < 0. 05) . For either group, the HBV DNA level was significantly lower in HBeAg- negative patients than in HBeAg- positive patients ( Z = 7. 427 or 7. 513, P < 0. 05) . Conclusion HBV M expression and the body's immune status play a role in the progression of HBV- related liver failure. HBV DNA replication is at a low level in the immune clearance phase. Being positive for anti- HBs, anti- HBe, and anti- HBc suggest a super immune response to HBV, leading to rapid progression of disease and high mortality.

Human scFv SIgA expressed on Lactococcus lactis as a vector for the treatment of mucosal disease

The gastrointestinal tract is a complex niche and the main port of entry of many pathogens that trigger a wide range of diseases like inflammatory bowel disease (IBD) and colon cancer. Antibodies are effective for treating such diseases, but a system capable of local delivery at the site of the pathology, thus avoiding systemic side effects, is not yet available. Here we report a novel recombinant scFvSIgA1 protein produced by Lactococcus lactis, anchored to the bacterial membrane, which retains its full immuno-recognizing potential. This scFv fragment employed was specific for a colon cancer epitope, epithelial glycoprotein protein-2 (EGP-2). Accordingly L. lactis expressing this chimeric protein was capable of binding cells expressing this epitope. Expression of specific antibodies on bacteria may allow local delivery of anticancer agents produced by such bacteria in conjunction with the antibody and provides a new avenue in the quest for targeted drug delivery.

W07.174 Atheroprotective immunization with MDA-modified APO B-100 peptide sequences is associated with activation of TH2 specific antibody expression

W07.174 Atheroprotective immunization with MDA-modified APO B-100 peptide sequences is associated with activation of TH2 specific antibody expression

W07.174 Atheroprotective immunization with MDA-modified APO B-100 peptide sequences is associated with activation of TH2 specific antibody expression

W07.174 Atheroprotective immunization with MDA-modified APO B-100 peptide sequences is associated with activation of TH2 specific antibody expression

Early induction and augmentation of parasitic antigen-specific antibody-producing B lymphocytes in the non-Peyer's patch region of the small intestine.

In this study, B lymphocytes from the small intestine of immunized rats were examined for their expression of specific antibodies against Trichinella spiralis (TS) antigen. The isotypes of the antigen-specific antibodies on B cells were examined via immunofluorescence microscopy. Monoclonal mouse anti-rat IgE, IgG1, IgG2a, IgG2b, IgG2c, IgA and IgM primary antibodies in conjunction with FITC-conjugated goat anti-mouse Ig secondary antibody and XRITC-conjugated 9D4 T. spiralis antigen were used to study the dynamics of the appearance of activated B lymphocytes in the small intestine, Peyer's patch, both the germinal center (PP-GC) and the non-germinal center (PP-NGC), the mesenteric lymph node (MLN), and the spleen. The results demonstrate that activated B cells are elicited by TS in the non-Peyer's patch region of the small intestine to express all isotypes of antibodies against TS antigen. IgG- and IgE-producing cells (Ab-PC) began proliferation only 1 and 2 days after infection, respectively. The strongest response was mounted by the IgE-PC in the lamina propria of the intestine. The response by IgA-PC generated was not only significantly delayed and also much weaker than that of the IgE- and IgG-PC. Peyer's patches failed to be a significant contributor in this immune response. Although this antigen-specific immune response was produced in the MLN and the spleen, it was weaker than that of the small intestine. The study indicates the potential ability of an immunized host to generate an early, yet effective, humoral immunity against T. spiralis in the non-Peyer's patch region of the small intestine."

Parameters affecting heterogeneity of mouse anti-hapten antibody.

Plate acrylamide gel isoelectric focusing was used to assess the heterogeneity of anti-hapten antibody raised in various inbred mouse strains. Parameters including dose, timing of injection and hapten-carrier combinations were varied. It was found that the heterogeneity of antibody production against a given immunogen is characteristic of the mouse strain. All mice within a strain appear to possess the same genetic potentlal for specific antibody production. However, each mouse may differ in its capacity to express this potential. Manipulation of parameters affecting antibody production allows the investigator to control the phenotypic expression of specific antibody.