Specific Antibody Patterns Research Articles

Impact of flavivirus vaccine-induced immunity on primary Zika virus antibody response in humans.

BackgroundZika virus has recently spread to South- and Central America, causing congenital birth defects and neurological complications. Many people at risk are flavivirus pre-immune due to prior infections with other flaviviruses (e.g. dengue virus) or flavivirus vaccinations. Since pre-existing cross-reactive immunity can potentially modulate antibody responses to Zika virus infection and may affect the outcome of disease, we analyzed fine-specificity as well as virus-neutralizing and infection-enhancing activities of antibodies induced by a primary Zika virus infection in flavivirus-naïve as well as yellow fever- and/or tick-borne encephalitis-vaccinated individuals.MethodologyAntibodies in sera from convalescent Zika patients with and without vaccine-induced immunity were assessed by ELISA with respect to Zika virus-specificity and flavivirus cross-reactivity. Functional analyses included virus neutralization and infection-enhancement. The contribution of IgM and cross-reactive antibodies to these properties was determined by depletion experiments.Principal findingsPre-existing flavivirus immunity had a strong influence on the antibody response in primary Zika virus infections, resulting in higher titers of broadly flavivirus cross-reactive antibodies and slightly lower levels of Zika virus-specific IgM. Antibody-dependent enhancement (ADE) of Zika virus was mediated by sub-neutralizing concentrations of specific IgG but not by cross-reactive antibodies. This effect was potently counteracted by the presence of neutralizing IgM. Broadly cross-reactive antibodies were able to both neutralize and enhance infection of dengue virus but not Zika virus, indicating a different exposure of conserved sequence elements in the two viruses.ConclusionsOur data point to an important role of flavivirus-specific IgM during the transient early stages of infection, by contributing substantially to neutralization and by counteracting ADE. In addition, our results highlight structural differences between strains of Zika and dengue viruses that are used for analyzing infection-enhancement by cross-reactive antibodies. These findings underscore the possible impact of specific antibody patterns on flavivirus disease and vaccination efficacy.

Analysis and Functional Consequences of Increased Fab-Sialylation of Intravenous Immunoglobulin (IVIG) after Lectin Fractionation

It has been proposed that the anti-inflammatory effects of intravenous immunoglobulin (IVIG) might be due to the small fraction of Fc-sialylated IgG. In this study we biochemically and functionally characterized sialic acid-enriched IgG obtained by Sambucus nigra agglutinin (SNA) lectin fractionation. Two main IgG fractions isolated by elution with lactose (E1) or acidified lactose (E2) were analyzed for total IgG, F(ab’)2 and Fc-specific sialic acid content, their pattern of specific antibodies and anti-inflammatory potential in a human in vitro inflammation system based on LPS- or PHA-stimulated whole blood. HPLC and LC-MS testing revealed an increase of sialylated IgG in E1 and more substantially in the E2 fraction. Significantly, the increased amount of sialic acid residues was primarily found in the Fab region whereas only a minor increase was observed in the Fc region. This indicates preferential binding of the Fab sialic acid to SNA. ELISA analyses of a representative range of pathogen and auto-antigens indicated a skewed antibody pattern of the sialylated IVIG fractions. Finally, the E2 fraction exerted a more profound anti-inflammatory effect compared to E1 or IVIG, evidenced by reduced CD54 expression on monocytes and reduced secretion of MCP-1 (CCL2); again these effects were Fab- but not Fc-dependent. Our results show that SNA fractionation of IVIG yields a minor fraction (approx. 10%) of highly sialylated IgG, wherein the sialic acid is mainly found in the Fab region. The tested anti-inflammatory activity was associated with Fab not Fc sialylation.

Pathogenicity and immunogenicity of Paracoccidioides brasiliensis isolates in the human disease and in an experimental murine model.

The pathogenicity and immunogenicity of six recently isolated Paracoccidioides brasiliensis samples derived from patients presenting distinct and well defined clinical forms of paracoccidioidomycosis (PCM) were compared as to their virulence, tropism to different organs and ability to induce specific cellular and humoral immune response in susceptible (B10.A) inbred mice. Isolates Pb44 and Pb47 were obtained from acute cases, Pb50 from a chronic severe form, Pb45 from a chronic moderate case and both Pb56 and Pb57 from chronic mild forms of PCM. Pathogenicity and tropism of each fungal sample were evaluated by LD50% estimation, examination of gross lesions on various organs at 2, 4, 12 and 16 weeks post-infection, and by colony-forming unit (CFU) counts in the lungs at week 16 post-infection of mice. Fungal tropism in human PCM and in B10.A mice was always dissociated. A well defined relationship between virulence of the fungal sample and the clinical findings of the correspondent patient was not evident, although a tendency to higher LD50% and less intense paracoccidioidic lesions was observed in mice infected with Pb56 and Pb57. The specific DTH response patterns varied according to the infectant sample, but positive DTH reactions at the beginning of the infection and a tendency to anergy or low DTH responses at week 12 and/or week 16 post-infection were always observed. A correspondence between the DTH response in humans and in mice was noticeable only when the isolates from the most benign cases (Pb56 and Pb57) were considered. The specific antibody patterns in mice and in the correspondent patients were also not analogous. Collectively, these results indicate that an association between the fungal pathogenicity and immunogenicity in the human disease and in susceptible mice was discernible only when isolates obtained from very mild cases (Pb56 and Pb57) were considered.

Immunoepidemiology of Wuchereria bancrofti infection in two East African communities: Antibodies to the microfilarial sheath and their role in regulating host microfilaraemia

The response pattern of specific antibodies to the microfilarial sheath (sheath-Ab) of the mosquito-borne filarial parasite Wuchereria bancrofti was investigated in individuals from two East African communities with different levels of endemicity. Individuals from both communities presented a strong inverse relationship between positivity for sheath-Ab and being positive for microfilariae (mf) and circulating filarial antigens (CFA). The prevalence of sheath-Ab positivity was highest in young individuals, but peaked at a younger age in the high (1–14 years) than the low (15–19 years) endemicity community. IgG1, IgG2, IgG3 and IgE intensities to a crude adult filarial worm antigen were higher, and IgG4 intensities were lower, in sheath-Ab positive than in sheath-Ab negative individuals, probably reflecting the infection status of individuals. From the study it appears that individuals become sheath-Ab positive before mf and/or CFA can be detected in the peripheral blood, and only after later disappearance of sheath-Ab from the circulation can CFA and mf be diagnosed. In light of the findings, possible roles of the distinct sheath-Ab in the host–parasite relationship are discussed, and a hypothesis is proposed which suggests that sheath-Ab play an important role in the regulation of host microfilaraemia.

Protection by Natural Human Immunoglobulin M Antibody to Meningococcal Serogroup B Capsular Polysaccharide in the Infant Rat Protection Assay Is Independent of Complement-Mediated Bacterial Lysis

Neisseria meningitidis, an important cause of bacterial meningitis and septicemia worldwide, is associated with high mortality and serious sequelae. Natural immunity against meningococcal disease develops with age, but the specificity and functional activity of natural antibodies associated with protection are poorly understood. We addressed this question by using a selected subset of prevaccination sera (n = 26) with convergent or discrepant serum bactericidal activity (SBA) and infant rat protective activity (IRPA) against the serogroup B meningococcal strain 44/76-SL (B:15:P1.7,16) from Icelandic teenagers. The sera were analyzed by opsonophagocytic activity (OPA) assay, immunoblotting, immunoglobulin G (IgG) quantitation against live meningococcal cells by flow cytometry, and enzyme immunosorbent assay (EIA). High levels of SBA and OPA were reflected in distinct IgG binding to major outer membrane proteins and/or lipopolysaccharide in immunoblots. However, we could not detect any specific antibody patterns on blots that could explain IRPA. Only IgM antibody to group B capsular polysaccharide (B-PS), measured by EIA, correlated positively (r = 0.76, P < 0.001) with IRPA. Normal human sera (NHS; n = 20) from healthy Finnish children of different ages (7, 14, and 24 months and 10 years) supported this finding and showed an age-related increase in IRPA that coincided with the acquisition of B-PS specific IgM antibody. The protection was independent of complement-mediated bacterial lysis, as detected by the inability of NHS to augment SBA in the presence of human or infant rat complement and the equal protective activity of NHS in rat strains with fully functional or C6-deficient complement.

Serologic Testing with ANCA, ASCA, and Anti-OmpC in Children and Young Adults with Crohn's Disease and Ulcerative Colitis: Diagnostic Value and Correlation with Disease Phenotype

Serologic testing is increasingly being utilized to evaluate children with suspected inflammatory bowel disease (IBD). The aim of this paper was to evaluate the sensitivity and specificity of a currently available panel involving four antibodies: deoxyribonuclease (DNase)-sensitive perinuclear antineutrophil cytoplasmic antibody (DNase-sensitive pANCA), IgA and IgG antibodies to Saccharomyces cerevisiae (IgA and IgG ASCA), and antibody to Escherichia coli outer membrane porin (anti-OmpC). We also wished to determine whether antibody levels correlated with disease activity, and whether a specific antibody pattern correlated with location and outcome of disease in children. We studied sera from 81 children with Crohn's disease (CD), 54 with ulcerative colitis (UC), and 63 controls. Clinical data, disease activity, and disease diagnosis were gathered at the time of serum sampling, and charts were re-reviewed at time of the study to determine long-term outcome. Enzyme-linked immunosorbent assay was utilized to determine titers of antibodies to ASCA, DNase-sensitive pANCA, and anti-OmpC; the presence of perinuclear staining for ANCA was confirmed by immunofluorescence. We identified ASCA antibodies in 44% of CD patients, 0% of UC patients, and 1 control patient. DNase-sensitive pANCA antibodies were found in 70% of patients with UC, 18% of CD patients (predominantly Crohn's colitis), and 3% of controls. Anti-OmpC as an isolated assay had low sensitivity for both CD (24%) and UC (11%), and displayed a 5% false-positive rate. However, anti-OmpC did identify a small number of IBD patients not detected by the other assays. If any one or more of the four antibodies was positive, the overall sensitivity of the four antibody panel was 65% for CD and 76% for UC, with a specificity of 94%. Patients who were ASCA-positive were more likely to have disease of the ileum or ileum and right colon than patients who were ASCA-negative (58%vs 18%, p < 0.001). Patients with ASCA-positive were also more likely to require ileocecal resection (36%vs 13%, p < 0.05). A currently available commercial antibody panel has good sensitivity and excellent specificity for CD and UC. The ASCA antibodies, while highly specific for CD, identify predominantly the subset of children with disease of the ileum and ascending colon who may be at increased risk of surgery.

Characterization of a Sarcocystis neurona isolate from a Missouri horse with equine protozoal myeloencephalitis

Little information is available about antigenic variation of Sarcocystis neurona isolated from horses with equine protozoal myeloencephalitis, nor is there much information available on the specific antibody pattern to S. neurona antigens of horses from different geographic regions where S. neurona isolates have been obtained. This communication reports on the characterization of a new S. neurona isolate, SN-MU1. The isolate was obtained from a 3-year old Thoroughbred that had asymmetrical neurological signs and localized skeletal muscle atrophy. This S. neurona isolate is similar to other S. neurona isolates by molecular analysis of the internal transcribed spacer (ITS-1) region and a random-amplified polymorphic DNA marker, but is phenotypically distinct from the other S. neurona isolates examined. Evaluation of the antibodies from the affected horse and immunohistochemical results suggested that antigenic variation of S. neurona can result in variable antibody–antigen reactivity observed in the S. neurona immunoblot test.

Antibody response of patients with Helicobacter pylori-related gastric adenocarcinoma: significance of anti-cagA antibodies.

The aim of this study was to search for a specific antibody pattern in sera from patients suffering from Helicobacter pylori-related gastric adenocarcinoma (GAC). The serological response of 22 patients suffering from GAC, 31 patients with gastroduodenal ulcer, and 39 asymptomatic subjects was analyzed using immunoblotting performed with three H. pylori strains: strain ATCC 43579; strain B110, isolated from a patient with ulcers; and strain B225, isolated from a patient with GAC. In addition, the latex agglutination test Pyloriset Dry was used to analyze ambiguous sera. H. pylori seropositivity was 75% in the GAC group, 61.3% in the ulcer group, and 56.4% in the asymptomatic group. Anti-CagA antibodies were found more often in the GAC group (48.8%) and in the ulcer group (47.3%) than in the asymptomatic group (21.2%). These percentages depended on the strain used as an antigen: in the GAC group, the anti-CagA frequencies were 93.3, 40, and 13.3% with strains B225, B110, and ATCC 43579, respectively. Thus the presence of anti-CagA antibodies was increased in patients suffering from H. pylori-related GAC, in particular when the CagA antigen was from a GAC strain. These data suggest the existence of a CagA protein specifically expressed by H. pylori strains isolated from GAC patients.

Specific antibody patterns in a senegalese population recently exposed to Schistosoma mansoni

Specific antibody patterns in a senegalese population recently exposed to Schistosoma mansoni

Specific antibody patterns in a senegalese population recently exposed to Schistosoma mansoni

Specific antibody patterns in a senegalese population recently exposed to Schistosoma mansoni

Epstein Barr virus specific antibody patterns in lung transplant recipients with post transplant lymphoproliferative disease

Epstein Barr virus specific antibody patterns in lung transplant recipients with post transplant lymphoproliferative disease

Epstein Barr virus specific antibody patterns in lung transplant recipients with post transplant lymphoproliferative disease

Epstein Barr virus specific antibody patterns in lung transplant recipients with post transplant lymphoproliferative disease

Specific Antibody Patterns of Wistar Rats Inoculated with Third Stage Larvae of Anisakis simplex

Levels of excretory-secretory (ES)-specific antibody were measured in Wistar rats inoculated with 1, 5, or 20 third stage larvae (L3) of Anisakis simplex. Primary inoculation induced ES-specific IgM and IgG titers, paralleling inoculum size. Secondary inoculations resulted in an IgM and IgG titer augmentation in 1 or 5 larvae-inoculated animals to levels comparable to those of animals inoculated with 20 larvae, but titers in high inoculum animals did not increase upon secondary inoculation. Primary inoculation induced low ES-specific IgE antibody titers. However, secondary inoculation produced a different pattern than with IgM or IgG titers. Instead of titers equivalent to animals receiving more larvae, rats receiving 1 larva developed higher IgE titers than rats receiving larger inoculums. IgE titers of single larvae-inoculated rats peaked at 3-5 days after secondary inoculation but disappeared by day 14. The time course of IgE production is therefore consistent with duration of the infection. As the natural infection typically involves few larvae, monitoring ES-specific IgE may be a useful diagnostic tool for human intestinal anisakiasis.

Development of specific antibody patterns and clinical symptoms following Ockelbo virus infection.

Sixteen patients with symptoms typical for Ockelbo disease (rash, arthralgia, fever) were enrolled in a 2 1/2 year study, during which clinical symptoms were recorded and ELISA was employed to study specific IgM, IgG and IgG subclass development. Initially, all patients presented with rash and arthralgia, and five patients still suffered from joint symptoms at the end of the study period. Ockelbo virus specific IgM was detected during the first week post onset in 6 patients and in 15 patients by day 14. One patient failed to develop specific IgM and was later diagnosed with a human parvovirus B19 infection. All patients were IgM-negative 2 1/2 years post onset. Seroconversions or significant titer rises for specific total IgG were seen in 15 patients. IgG titers generally peaked within one year but in two patients maximum titers were seen 2 1/2 years post onset. Development of IgG1 followed that of total IgG, while IgG3, after an initial increase in all Ockelbo disease patients, remained at peak levels for one year in four patients, three of whom still had detectable IgG3 at the end of the study period. Ockelbo virus specific IgG2 or IgG4 was not detected in any of the patients.

A specific T-cell receptor genotype preference in the immune response to a synthetic Plasmodium falciparum malaria vaccine

In recent studies with 63 and 122 volunteers vaccinated with the SPf 66 synthetic malaria vaccine, specific antibody patterns were classified as high or low responders. Using the Polymerase Chain Reaction (PCR), a specific and selective preference was shown for the V beta arrangement of the T-cell receptor in the high responder group involving the V beta-8 gene. The low responder group showed the rearrangement of a different set of genes, and a particular association with V beta-10.

Immunoblot analysis of antibody binding to polypeptides of Borrelia burgdorferi in children with different clinical manifestations of Lyme disease.

We analyzed by means of immunoblot technique the patterns of antibodies binding to polypeptides of Borrelia burgdorferi B31 in the sera of 21 children with different stages of Lyme disease. All sera but one recognized the flagellar protein 41 kD and all but two the 83-kD protein. The number of proteins recognized rose from clinical stage I to stage III. The polypeptides of the mol wt 55 and 31 kD were exclusively bound by IgM and the proteins 66, 58, 39, and 36 kD exclusively by IgG. Based on the number of proteins visualized by single sera, IgM was the predominant isotype in stages I and II peaking in stage II, whereas in stage III IgG predominated. Considering the number of proteins recognized and the corresponding antibody isotype, a serologic differentiation between the three stages of the disease is feasible: within stage I and within stage III patients with different clinical signs had distinct antibody patterns. No clearcut pattern could be discriminated in stage II for patients with different settings. Immunoblotting yields a possible distinction between active infection and serological scar by the detection of specific antibody patterns.

Specific antibody patterns over a two-year period after rubella immunization with RA 27/3 live attenuated vaccine

Screening for rubella antibodies was carried out on 1557 schoolgirls aged 9–20. Of seronegative subjects 70% (442/631) were immunized with RA 27/3 rubella vaccine and some of the vaccinees underwent a serological and clinical follow-up over a two year period. Adverse reactions occurred in 27% of vaccinees, usually 1–2 weeks after immunization; late reactions were never observed. The vaccine-induced seroconversion rate evaluated at 4–5 weeks after immunization was 99.7%. Both one and two years after immunization the seropositivity rate of vaccinees was 100%. The maximum geometric mean antibody titre (GMT) was observed at 4–5 weeks after vaccination and a significant GMT decrease was evident on both the following annual controls. Specific antibody patterns in vaccinees were highly variable and in a small number of subjects a remarkable antibody titre decrease was noticed.

Monitoring of antibodies in patients on immunotherapy with insect venoms by immunoblotting.

A rapid nitrocellulose immunoblotting procedure based upon electrophoretic transfer has been used to monitor patient specific IgE and IgG antibodies before and after specific Hymenoptera insect venom therapy. The patients followed a conventional schedule for immunotherapy with Pharmalgen bee and yellow jacket venoms. The allergenic profiles of the patients before and after treatment were qualitatively similar in many patients, but some showed decreased IgE binding after treatment. On the other hand, there was a significant increase in specific IgG antibodies directed towards phospholipase and hyaluronidase in the bee-venom-treated patients and towards antigen 5, phospholipase and hyaluronidase in the patients treated with yellow jacket venom. The immunoblotting is very useful for a rapid evaluation of patient specific antibody patterns without the prior isolation of allergens.

Heterogeneity of acetylcholine receptor antibodies in patients with myasthenia gravis

Antibodies against the nicotinic acetylcholine receptor in sera of 21 myasthenia gravis patients were checked for their ability to block or split binding of alpha-bungarotoxin to the human acetylcholine receptor. Affinity-purified acetylcholine receptors from human skeletal muscle were used in parallel in the common precipitation assay and an inhibition assay. Cross-reactivity of acetylcholine receptor antibodies was analyzed with receptor preparation from different species (calf, rat, Torpedo c. and Electrophorus e.), purified identically to high specific activity. An antibody pattern was set up for each patient and related to the clinical state of the disease. alpha-Bungarotoxin-inhibiting antibodies were demonstrable in 74% of myasthenia gravis patients, alpha-bgt displacing antibodies were found in 39% of the investigated sera. Broad cross-reactivity with acetylcholine receptors from other mammalian muscle was evident (calf 75%, rat 90%) only very few sera reacted with acetylcholine receptors from electric fish (Torpedo c. 14%, Electrophorus e. 38%). Antibody concentrations determined by using xenoantigens were much lower than those obtained by human acetylcholine receptor. The lack of a clear-cut correlation between the amount of serum antibodies and the clinical state of myasthenia gravis can be explained by the established antibody-heterogeneity, shown by a constant antibody pattern characteristic for each patient. However, between this specific antibody pattern and the state of the disease no correlation could be established either.

Fluorescent Antibody Responses to Chlamydial Infection in Patients with Lymphogranuloma Venereum and Urethritis

Abstract Indirect immunofluorescence (the micro IF test) was used to study trachomainclusion conjunctivitis and lymphogranuloma venereum (LGV) serum antibody patterns in a venereal disease clinic population. Antibodies undifferentiated as to immunoglobulin class, but probably IgG, were detected in 80% of the study participants and titers were particularly high in LGV patients. Two kinds of antibody were observed. One was broadly reactive to all test antigens, and one was specifically directed toward strains of a particular antigenic type. Although most sera were broadly reactive, 40% also showed some type specificity. Specific antibody patterns in persons from whom chlamydiae were isolated usually corresponded to the immunotypes of isolates, and LGV reaction patterns were particularly associated with LGV patients. IgM antibodies were observed in 20% of the study participants. These were usually type specific and perhaps indicated current infection. The sensitive micro IF test is considered useful in the epidemiologic study of chlamydial infections of genital origin and can provide information about the nature of infecting strains.