Elevated Levels Of Specific Antibodies Research Articles

Multi-epitope vaccine expressed in Leishmania tarentolae confers protective immunity to Toxoplasma gondii in BALB/c mice

Current study deals with a novel multi-epitope vaccine designed in silico and its confirmation experiments for potential efficacy in BALB/c mice. Major histocompatibility complex (MHC)-binding and B-cell binding epitopes of five Toxoplasma antigens (SAG1, ROP16, GRA12, MIC4 and M2AP) were predicted. Selected epitopes were fused together using SAPGTP linker, and antigenicity, allergenicity, physico-chemical features, secondary and tertiary structures and validations were all performed via bioinformatics servers. Then, vaccine construct was cloned into pLEXSY-neo 2.1 vector. After Leishmania tarentolae transfection, live recombinant and wild parasites were subcutaneously injected into 6–8 week female BALB/c mice and immune responses were measured. Results showed that the peptide possessed 282 amino acid residues with average molecular weight of 28.06 kDa. About 90% of the peptide residues were incorporated in favored and allowed regions of the Ramachandran plot. Vaccinated mice showed remarkably elevated levels of specific antibodies (P < 0.05) with predominance of IgG2a production. Also, a Th1 immune response with production of IFN-γ and relatively increased survival rate against intraperitoneal challenge with RH strain was demonstrated in immunized mice than control groups (P < 0.05). Also, very low levels of IL-4 were demonstrated, which showed statistically significant association with controls (P < 0.05). The findings clarified that multi-epitope vaccine expressed in Leishmania tarentolae induced significant immune responses against acute toxoplasmosis.

Rheumatoid arthritis is caused by aProteusurinary tract infection

Genetic, molecular and biological studies indicate that rheumatoid arthritis (RA), a severe arthritic disorder affecting approximately 1% of the population in developed countries, is caused by an upper urinary tract infection by the microbe, Proteus mirabilis. Elevated levels of specific antibodies against Proteus bacteria have been reported from 16 different countries. The pathogenetic mechanism involves six stages triggered by cross-reactive autoantibodies evoked by Proteus infection. The causative amino acid sequences of Proteus namely, ESRRAL and IRRET, contain arginine doublets which can be acted upon by peptidyl arginine deiminase thereby explaining the early appearance of anti-citrullinated protein antibodies in patients with RA. Consequently, RA patients should be treated early with anti-Proteus antibiotics as well as biological agents to avoid irreversible joint damages.

Role of scuticociliate proteinases in infection success in turbot, Psetta maxima (L.)

Scuticociliatosis caused by Philasterides dicentrarchi is one of the most severe diseases of farmed turbot, Psetta maxima (L.). Immunized fish showed elevated levels of specific antibodies (Ab), which caused the destruction of parasites through the activation of complement by the alternative and classical pathways. By using affinity chromatography on bacitracin-sepharose columns, we demonstrated the existence of high levels of parasite proteinases in the serum and, to a lesser extent, in the ascitic fluid of experimentally infected fish, and the absence of such proteinases in the serum of uninfected fish. Serum from uninfected fish displayed haemolytic activity against sheep red blood cells. However, incubation of this serum with parasite proteinases led to a decrease in serum haemolytic activity, suggesting that proteinases are able to destroy fish complement. Proteinases isolated from serum or ascitic fluid of infected fish were also able to degrade turbot Ab. Preincubation of turbot serum containing specific Ab for P.dicentrarchi with the proteinases led to a significant decrease in the killing activity of the serum. The results confirm that P.dicentrarchi proteinases in serum from infected fish may provide a mechanism for circumventing normal host immunity by inactivating the Ab and complement factors required for complement activation.

Clinical values of multiple Epstein-Barr virus (EBV) serological biomarkers detected by xMAP technology

BackgroundSerological examination of Epstein-Barr virus (EBV) antibodies has been performed for screening nasopharyngeal carcinoma (NPC) and other EBV-associated diseases.MethodsBy using xMAP technology, we examined immunoglobulin (Ig) A antibodies against Epstein-Barr virus (EBV) VCA-gp125, p18 and IgA/IgG against EA-D, EBNA1 and gp78 in populations with distinct diseases, or with different genetic or geographic background. Sera from Cantonese NPC patients (n = 547) and healthy controls (n = 542), 90 members of high-risk NPC families and 52 non-endemic healthy individuals were tested. Thirty-five of NPC patients were recruited to observe the kinetics of EBV antibody levels during and after treatment. Patients with other EBV-associated diseases were collected, including 16 with infectious mononucleosis, 28 with nasal NK/T cell lymphoma and 14 with Hodgkin's disease.ResultsBoth the sensitivity and specificity of each marker for NPC diagnosis ranged 61–84%, but if combined, they could reach to 84.5% and 92.4%, respectively. Almost half of NPC patients displayed decreased EBV immunoactivities shortly after therapy and tumor recurrence was accompanied with high EBV antibody reactivates. Neither the unaffected members from high-risk NPC families nor non-endemic healthy population showed statistically different EBV antibody levels compared with endemic controls. Moreover, elevated levels of specific antibodies were observed in other EBV-associated diseases, but all were lower than those in NPC.ConclusionCombined EBV serological biomarkers could improve the diagnostic values for NPC. Diverse EBV serological spectrums presented in populations with different EBV-associated diseases, but NPC patients have the highest EBV activity.

Risk factors for immunologically mediated disease in workers with respiratory symptoms when exposed to hexahydrophthalic anhydride

Occupational immunologic lung diseases caused by exposures to substances such as hexahydrophthalic anhydride are significant health problems. It would be useful to identify risk factors, other than exposure, for occupational immunologic lung diseases such as occupational asthma. Our objective was to identify risk factors for development of immunologically mediated disease in workers with respiratory symptoms associated with exposure to hexahydrophthalic anhydride. A medical and immunologic survey study was conducted of 33 employees with respiratory symptoms associated with hexahydrophthalic anhydride exposure. Of the 33 employees with respiratory symptoms, 20 had no immunologically mediated disease. Seven had both immunoglobulin E-mediated and immunoglobulin G-mediated disease, 5 had immunoglobulin E-mediated disease only, and 1 had immunoglobulin G-mediated disease only. Although larger samples would have rendered atopy a statistically significant risk factor (assuming effect replication), the associated effect strength represents less than a 16% improvement versus chance, which is indicative of marginal clinical significance. However, as expected, elevated levels of specific antibodies were statistically and clinically significant risk factors. Development of one type of immunologically mediated disease was highly predictive of development of the other type. In hexahydrophthalic anhydride-exposed employees with respiratory symptoms, development of immunologically mediated respiratory disease is most closely associated with presence of specific immunoglobulin E or immunoglobulin G antibodies. Neither race, age, smoking status, atopy, nor exposure levels emerged as significant risk factors in this symptomatic study population.

Prevalence of antibodies toBorrelia burgdorferi in forestry workers and blood donors from the same region in Switzerland

Sera from 259 forestry workers and 100 blood donors in the Canton of Solothurn, Switzerland, were tested for IgG antibodies to Borrelia burgdorferi in two EIAs using as antigen either sonic extract of whole organisms or purified flagella. Applying a 95% specific cut-off value based on results in the sera of 100 blood donors, 86 (33%) and 91 (35%) of the forestry workers respectively showed an elevated specific IgG level in the two EIAs. None of the 259 forestry workers had clinical signs of active infection at the time blood was taken, and only nine could recall experiencing erythema-migrans-like skin lesions within the last ten years. Thus, asymptomatic infections must be frequent. Elevated specific antibody levels increased significantly with the age of the forestry workers (p less than 0.0001) and the duration of occupational exposure to ticks (p = 0.0001). Thus serological results in individuals with high exposure to ticks must be interpreted with caution in view of the high a priori prevalence of antibodies to Borrelia burgdorferi in such persons. The prevalence of antibody to the Borrelia burgdorferi flagellum in a control population not selected for tick exposure, in this case blood donors, seems to be independent of geographical origin.

Seroprevalence of toxocariasis in a hospital based sample in Ireland.

THIS study provides, for the first time, an estimate of the prevalence of Toxocara infection in Irish children. Sera from 302 children aged two to five years attending a Dublin paediatric hospital in 1983 were examined for toxocaral antibodies. Fifty-seven (19%) of the children had significantly elevated specific antibody levels in the diagnostic range suggestive of current or past infection.