IgG Anti-tetanus Toxoid Research Articles

Seroprevalence of antibodies against diphtheria, tetanus, and pertussis across various age groups during the post-COVID-19 pandemic period in Chonburi Province, Thailand.

BackgroundLimited data exists regarding population immunity against diphtheria, tetanus, and pertussis in Thailand during the post-COVID-19 pandemic period. This study aimed to evaluate the age-specific seroprevalence of anti-diphtheria toxoid (anti-DT) IgG, anti-tetanus toxoid (anti-TT) IgG, and anti-pertussis toxin (anti-PT) IgG in individuals across diverse age groups in Chonburi province, Thailand following the COVID-19 pandemic. MethodsBetween October 2022 and January 2023, a total of 657 participants from Chonburi Province, Thailand, were included in this study. The participants were categorized into 9 age groups: < 5, 5-10, 11-20, 21-30, 31-40, 41-50, 51-60, 61-70, and > 70 years. Analysis of anti-DT, anti-TT, and anti-PT IgG levels was conducted using commercial ELISA kits (EUROIMMUN, Lübeck, Germany). ResultsOverall, 65.4% of the population had seroprotection against diphtheria (antibody level ≥0.1 IU/mL), while 95.1% had seroprotection against tetanus (antibody level ≥0.1 IU/mL). The 31-40 years age group exhibited the lowest seroprotection for diphtheria (48.9%), and the > 70 years age group had the lowest seroprotection for tetanus (73.3%). The < 5 years age group showed the highest seropositive rate and highest geometric mean titers for anti-PT IgG. On the contrary, the majority of individuals over 11 years of age displayed anti-PT IgG levels below 40 IU/mL. ConclusionsTo prevent diphtheria and pertussis outbreaks in Chonburi province, implementing catch-up vaccination is necessary. Targeted interventions should be deployed to enhance vaccination coverage among the susceptible population.

Dilution of humoral immunity: Results from a natural history study of healthy total knee arthroplasty patients.

The incidence of prosthetic joint infection (PJI) following elective primary total knee arthroplasty (TKA) is very low but serious risk remains. To identify unknown risk factors, we completed a natural history study of IgG specific forStaphylococcus aureus antigens previously phenotyped as protective (anti-Atl) and pathogenic (anti-Isd). Twenty-five male and 25 female optimized patients 50-85 years of age and BMI 24-39 undergoing primary TKA were prospectively enrolled. Blood sampling was performed preoperatively, postoperative Day 1, and at 2, 6, and 12 weeks, to assess serum cytokine, anti-staphylococcal IgG levels and anti-tetanus toxoid IgG measured via custom Luminex assay. Clinical, demographic, and PROMIS-10 data were collected with outcomes to 2 years postop. All participants completed the study and 2-year follow-up. No patients were readmitted or noted to develop a surgical site infection or serious adverse event, and patient-reported outcomes were improved. Serology revealed a highly significant decrease in six out of eight antibody titers against specific S. aureus antigens on Day 1 (p < 0.0001), five of which normalized to preoperative levels within 2 weeks. These changes were commensurate with a decrease and recovery of anti-tetanus toxoid titers, and a 20% drop in hemoglobin 13.8 ± 1.7 at preop to 11.1 ± 1.8 mg/dL on Day 1 (p < 0.0001). After TKA, a significant decrease in humoral immunity commensurate with blood loss and hemodilution was recorded. This decrease in circulating anti-staphylococcal antibodies in the early postop period may represent a periprosthetic joint infection risk factor for patients.

Immunogenicity of the pentavalent DTwP-HB-Hib vaccine (Shan-5) used in the Thai Expanded Program on Immunization compared to the hexavalent DTaP-HB-Hib-IPV and DTwP-HB-Hib (Quinvaxem) vaccines administered to infants at 2, 4, 6 months of age

BackgroundThe pentavalent DTwP-HB-Hib (Shan-5) vaccine was first introduced into the Thailand Expanded Program on Immunization (EPI) in 2019. The Shan-5 vaccine is administered to infants at 2, 4, and 6 months of age, after initial vaccination with monovalent hepatitis B (HepB) and Bacillus Calmette-Guérin (BCG) vaccines at birth. This study compared the immunogenicity of the HepB, diphtheria, tetanus, and Bordetella pertussis antigens incorporated in the EPI Shan-5 vaccine versus the optional pentavalent (DTwP-HB-Hib) Quinvaxem and hexavalent (DTaP-HB-Hib-IPV) Infanrix-hexa vaccine. MethodsThree-dose Shan-5-vaccinated children were prospectively enrolled at the Regional Health Promotion Centre 5, Ratchaburi province, Thailand, between May 2020 and May 2021. Blood sampling was performed at months 7 and 18. The levels of HepB surface antibody (anti-HBs), anti-diphtheria toxoid (DT) IgG, anti-tetanus toxoid (TT) IgG, and anti-pertussis toxin (PT) IgG were evaluated using commercially available enzyme-linked immunoassays. ResultsAnti-HBs levels of ≥10 mIU/mL were achieved in 100 %, 99.2 %, and 99.2 % of infants in the Shan-5 EPI group, hexavalent group and Quinvaxem group one month after four dose immunization (at 0, 2, 4, 6 months of age), respectively. The geometric mean concentrations of the EPI Shan-5 and hexavalent groups were comparable but were higher than those of the Quinvaxem group. At one month after primary vaccination (month 7), infants in the Shan-5 EPI group had significantly higher levels of anti-DT IgG, anti-TT IgG, and anti-PT IgG than infants in the hexavalent and Quinvaxem groups. ConclusionsThe immunogenicity of the HepB surface antigen in the EPI Shan-5 vaccine was similar to that achieved by the hexavalent vaccine, but was higher than that achieved by the Quinvaxem vaccine. The Shan-5 vaccine is highly immunogenic and generates robust antibody responses after primary immunization.

MO283IMPACT OF VIS649, AN APRIL-NEUTRALIZING IGG2 MONOCLONAL ANTIBODY, ON TETANUS- AND DIPHTHERIA-TOXOID VACCINATION-ELICITED IMMUNE RESPONSES IN HEALTHY VOLUNTEERS: PHASE 1, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY

Abstract Background and Aims VIS649, a humanized immunoglobulin G (IgG2) monoclonal antibody that binds to and blocks the biological actions of a proliferation-inducing ligand (APRIL), is in clinical development as a potential treatment for immunoglobulin A (IgA) nephropathy (IgAN). In a Phase 1 study, VIS649 was associated with dose-dependent reductions in serum IgA, IgG and IgM, which were reversible and showed a dose-response effect with respect to time-to-recovery. The aim of the present analysis was to determine if VIS649 suppression of APRIL influences antibody responses to tetanus and diphtheria toxoid vaccination. Method This was a Phase 1, randomized, double-blind, placebo-controlled, single ascending dose study of VIS649 in healthy adult male and female volunteers (ClinicalTrials.gov identifier: NCT03719443). In one cohort within the study, participants were randomized in a 2:1 ratio to receive intravenous administration of VIS649 6.0 mg/kg or placebo, followed by a vaccine composed of tetanus and diphtheria toxoids (TENIVAC®, Sanofi Pasteur Limited), in order to evaluate the effect of VIS649 on recipients’ ability to generate a vaccine booster response (exploratory endpoint). Participants received intravenous administration of study drug on Day 1, were discharged from the institution on Day 2, received a single intramuscular dose of vaccine at the Week 4 visit, and were followed for 16 weeks in total on an outpatient basis. Blood samples were taken at regular intervals, and anti-tetanus toxoid and anti-diphtheria toxoid IgG, IgM and IgA quantitative ELISA assays were performed. Tetanus and diphtheria anti-toxoid IgG titers ≥0.1 IU/mL are generally considered to be protective. Results In the vaccination cohort, 15 participants were randomized and dosed with study drug or placebo, of whom 14 completed the study, and one participant who received VIS649 was lost to follow-up prior to receiving the vaccine. Both groups (placebo and VIS649) demonstrated increased tetanus anti-toxoid IgG titers following immunization, with a mean 7.9-fold increase in IU/mL at Week 6 for placebo recipients and a mean 6.4-fold increase in IU/mL for VIS649 recipients (Figure). At visits after Week 6, tetanus anti-toxoid IgG titers declined faster in the VIS649 group than in the placebo group (consistent with the reduction in total IgG associated with VIS649 administration) but remained above the protective threshold of 0.1 IU/mL for all participants throughout the study. Similar trends were observed for diphtheria anti-toxoid IgG titers, with a mean 5.5-fold increase in IU/mL at the Week 6 visit for placebo recipients and a mean 5.1-fold increase for VIS649 recipients (Figure). There was no evidence of tetanus- or diphtheria-toxoid elicited IgM responses in either the placebo or VIS649 groups, consistent with the recall nature of the vaccination. In a post hoc analysis, pre-existing serum tetanus/diphtheria anti-toxoid IgA titers fell between Day 1 and Week 4 in the VIS649 group, consistent with the overall suppression of total serum IgA, were boosted after vaccination in both groups, and declined faster in the VIS649 recipients thereafter. Conclusion VIS649 treatment did not interfere with participants’ ability to mount an antigen-specific serum IgG or IgA boost response to tetanus and diphtheria toxoid vaccination. There was no evidence of tetanus- or diphtheria-specific IgM responses in either the placebo or VIS649 groups, consistent with recall vaccination exposure. These data indicate that qualitative antibody responses are preserved during APRIL suppression.

Seroprevalence of antibodies against diphtheria, tetanus, and pertussis among healthy Thai adolescents

ObjectiveTo determine the seroprevalence of antibodies against of diphtheria, tetanus, and pertussis among Thai adolescents. MethodsA cross-sectional study was conducted among Thai adolescents aged 11–20 years who had completed five doses of diphtheria, tetanus, and pertussis (DTP)-containing vaccine during childhood, either diphtheria toxoid, tetanus toxoid, whole-cell pertussis (DTwP) or diphtheria toxoid, tetanus toxoid, acellular pertussis (DTaP) vaccine. Protective antibodies against diphtheria, tetanus, and pertussis were defined as anti-diphtheria toxoid IgG ≥0.1 IU/ml, anti-tetanus toxoid IgG ≥0.1 IU/ml, and anti-Bordetella pertussis toxin IgG ≥5 IU/ml, respectively. ResultsOf 220 adolescents (median age 16 years), 45% had received a tetanus toxoid, reduced diphtheria toxoid (Td) booster vaccine during adolescence, and none (0%) had received a tetanus toxoid, reduced diphtheria toxoid, acellular pertussis (Tdap) booster vaccine. Overall, 50%, 99%, and 57% of adolescents demonstrated protective antibodies against diphtheria, tetanus, and pertussis, respectively. The geometric mean concentrations (GMCs) of antibodies against diphtheria (p = 0.06) and tetanus (p < 0.001) were higher among adolescents who had received Td vaccine. Nevertheless, the antibody levels against both diseases waned over time, regardless of Td booster vaccination. Likewise, pertussis antibody levels gradually declined after the fifth childhood dose of DTwP/DTaP vaccine. ConclusionsApproximately half of these healthy Thai adolescents had not maintained protective antibodies against diphtheria and pertussis. A booster vaccination with diphtheria toxoid and/or acellular pertussis-containing vaccines is a crucial strategy to prevent such diseases in this population.

The anti-carbamylated protein antibody response is of overall low avidity despite extensive isotype switching.

To better understand the contribution of autoantibodies in RA and the biology of their responses, we evaluated the avidity of the anti-carbamylated protein (anti-CarP) antibody response. The avidity of anti-CarP antibody, ACPA and anti-tetanus toxoid IgG were determined using elution assays. Anti-CarP IgG avidity was measured in sera of 107 RA patients, 15 paired SF and serum samples and 8 serially sampled sera before and after disease onset. The avidity of anti-CarP IgG is low compared with the avidity of anti-tetanus toxoid IgG present in the same sera. Likewise, although less pronounced, anti-CarP also displayed a lower avidity as compared with the avidity of ACPA IgG. No difference in anti-CarP IgG avidity is observed between ACPA positive or ACPA negative patients. Anti-CarP IgG avidity is higher in anti-CarP IgM-negative compared with IgM-positive individuals. Furthermore, the anti-CarP avidity in serum is higher than in SF. Using samples of individuals that over time developed RA we observed no anti-CarP avidity maturation in the years before disease onset. In contrast to ACPA avidity, the anti-CarP avidity is not associated with severity of joint destruction. The anti-CarP response is of overall low avidity, even lower than the ACPA IgG avidity, and does not show apparent avidity maturation before or around disease onset. Overall, isotype switch and avidity maturation seem to be uncoupled as isotype switch occurs without avidity maturation, pointing towards a commonality in the regulation of both autoantibody responses as opposed to the pathways governing recall responses.

Detection of Anti-tetanus Toxoid Monoclonal Antibody by Using Modified Polycarbonate Surface

In recent years, CD surface modification methods are employed for immunoassay techniques that is called BioCD technology. In this research, first polycarbonate surface was activated with UV ozone and a hydrophilic surface was obtained. Contact angle measurements and atomic force microscopy technique confirmed the hydrophilic property of surface. After that, tetanus toxoid was immobilized on modified CD surface then specific monoclonal antibody, gold nanoparticles conjugated antibody, silver salt, and hydroquinone were added on modified CD surface. So a sandwiches complex as tetanus toxoid, tetanus toxoid monoclonal antibody, and gold nanoparticles conjugated antibody was obtained on CD surface. ATR result showed the immobilization of tetanus toxoid on modified CD surface. Localized surface plasmon resonance (LSPR) and DLS results confirmed the complex formation. Silver salt and hydroquinone were added for signal amplification. Detection limit of anti-tetanus toxoid IgG monoclonal antibody was obtained 0.005 IU/ml by LSPR and DLS techniques. The presented method increases the assay’s sensitivity. BioCD-based immunoassay for detection of anti-tetanus toxoid IgG monoclonal antibody could be applicable in development and fabrication of biomedical devices.

OC-009 Withdrawal of anti-tnf following sustained remission for inflammatory bowel disease: a systematic review and meta-analysis

<h3>Summary</h3> HIV-Exposed Uninfected (HEU) infants are a rapidly expanding population in sub-Saharan Africa and are highly susceptible to disease caused by encapsulated bacteria in the first year of life. The mechanism of this increased risk is still poorly understood. We therefore investigated if HIV exposure dysregulates HEU infant immunity and if this is amplified by human herpes virus infection (HHV). Here, we compared monocyte enzymatic function, innate and adaptive immune cell phenotype, and vaccine-induced antibody responses between HEU and HUU infants. We demonstrate altered monocyte phagosomal function and B cell subset homeostasis, and lower vaccine-induced anti-<i>Haemophilus influenzae type b</i> (<i>Hib)</i> and anti-Tetanus Toxoid (TT) IgG titers in HEU compared to HUU infants. There was no difference in the prevalence of HHV infection between HEU and HUU infants. Our findings suggest that even in the era of antiretroviral therapy (ART)-mediated viral suppression, HIV exposure dysregulates monocyte and B cell function during a vulnerable period of immune maturation in infancy. This may contribute to the high rates of invasive bacterial disease and pneumonia in HEU infants.

Tetanus and diphtheria immunity among term and preterm infant-mother pairs in Turkey, a country where maternal and neonatal tetanus have recently been eliminated.

The aim of our study was to investigate the anti-tetanus and anti-diphtheria antibody titres and the placental transfer of these antibodies in a group of vaccinated and unvaccinated mothers and their term or preterm offsprings. Anti-tetanus and anti-diphtheria toxoid IgG antibodies were measured quantitatively by ELISA in 91 infant-mother pairs. Protective concentrations of anti-tetanus and anti-diphtheria were found in 58.3 and 50% of mothers in the unvaccinated group and 94.5 and 85.5% of the mothers in the vaccinated group. Protective concentrations were found in 63.9 and 50% of cord samples, respectively, in the unvaccinated group and in 96.4 and 85.5% of cord samples, respectively, in the vaccinated group (p = 0.0001). There were no differences in the maternal and cord geometric mean concentrations (GMCs) of anti-toxoid antibodies between those who received two doses or one dose of Td. The GMCs of maternal and cord anti-tetanus and anti-diphtheria were statistically similar between preterm and term groups. Placental transfer ratios (TR) for anti-tetanus and anti-diphtheria were 175 and 150%, respectively, in the preterm group and 213 and 178%, respectively, in the term group. There was a strong correlation between maternal and cord anti-toxoid antibody levels. Maternal vaccination was the only predictor of having protective concentrations of anti-toxoid antibodies in cord blood. Vaccinating pregnant women with at least one dose of Td would confer protection for both the term and preterm infant-mother pairs. Therefore, health personnel caring for pregnant women have the responsibility to emphasize the importance of Td vaccination to avoid missed immunization opportunities.

Evaluation of the safety and immunogenicity in United Kingdom laboratory workers of a combined Haemophilus influenzae type b and meningococcal capsular group C conjugate vaccine.

BackgroundAlthough a combined Haemophilus influenzae type b (Hib)/meningococcal capsular group C (MenC) conjugate vaccine with a tetanus toxoid carrier protein (Hib/MenC-TT) is not licensed for use in those above 2 years of age due to lack of data on safety and efficacy, certain patient groups at high risk of MenC and/or Hib disease are recommended to receive it. Laboratory workers working with Hib and/or MenC cultures may be at a potentially increased risk of acquiring infectious diseases and vaccination is therefore an important safety consideration. We undertook a clinical trial to investigate the safety and immunogenicity of Hib/MenC-TT vaccine in this cohort.MethodsA total of 33 subjects were recruited to the trial, all of whom were vaccinated. Serology was completed on samples taken at baseline and four weeks following vaccination to determine MenC specific IgG, MenC serum bactericidal antibody (SBA), anti-Hib polyribosylribitol phosphate (PRP) IgG and anti-tetanus toxoid IgG responses.ResultsAt baseline, high proportions of subjects had protective antibody concentrations against MenC, Hib and tetanus due to previous vaccination and/or natural exposure. Vaccination induced > 3, 10 and 220 fold increases in geometric mean concentrations for MenC SBA, anti-tetanus toxoid IgG and anti-Hib PRP IgG, respectively. Following vaccination, 97% of subjects had putative protective SBA titres ≥ 8, 100% had short term protective anti-Hib PRP IgG concentrations ≥ 0.15 μg/mL and 97% had protective anti-tetanus toxoid concentrations ≥ 0.1 IU/mL. No safety concerns were reported with minor local reactions being reported by 21% of subjects.ConclusionsImmunological responses determined in this trial are likely a combination of primary and secondary responses due to previous vaccination and natural exposure. Subjects were a representative cross-section of laboratory workers, enabling us to conclude that a single dose of Hib/MenC-TT was safe and immunogenic in healthy adults providing the evidence that this vaccine may be used for providing protection in an occupational setting.

A triple positive staining to capture B cells expressing anti-tetanus toxoid IgG in human blood

Event Abstract Back to Event A triple positive staining to capture B cells expressing anti-tetanus toxoid IgG in human blood Eduardo Aliprandini1, Wagner Quintilio2, Jorge Kalil3, 4, Silvia B. Boscardin5 and Ana M. Moro1, 4* 1 Laboratório de Biofármacos em Células Animais, Instituto Butantan, Brazil 2 Controle de Qualidade, Instituto Butantan, Brazil 3 Instituto Butantan, Brazil 4 INCT/iii - Instituto de Investigação em Imunologia, Brazil 5 Departamento de Parasitologia, ICB/USP, Brazil Aiming to sort B cells expressing anti-tetanus toxoid IgG from human blood that could be used for heavy and light chain amplification and cloning, this work started by the preliminary detection of such cells in 10 mL of human peripheral blood. After informed consent, blood was drawn from six volunteers and the mononuclear cells (PBMC) were stained using anti CD19-FITC, anti IgG-APC, and streptavidin-PerCP-Cy5.5, following analysis by flow cytometry. Tetanus toxoid (TT) conjugated to biotin (TT-bio) was included or not in the mixture. Five donors were selected based on their high anti-TT antibody titers: 12.0, 16.1, 13.3, 13.0 and 12.2 UI/mL; a sixth donor did not receive tetanus booster immunization after infant vaccination (titer 1.2 UI/mL). Despite the fact that all donors presented protective anti-TT antibody titers (>0,1 UI/mL), neither donor (1) or (6) showed detectable anti-TT producing B-lymphocytes in the blood. The other 4 donors presented variable responses, expressed as anti-TT B lymphocytes/10^6 PBMC as 16.13, 36.18, 11.15 and 2.82. The frequency of anti-TT lymphocytes did not correlate with frequency of total lymphocytes in PBMC, which varied between 35 to 62%. The individual variability of the immunological response denotes the importance of testing several donors, even with a small volume of blood. The possibility of detection of the desired cells by the above mentioned triple staining protocol prompted us to draw a large volume of blood from the donors in order to start the sorting protocols. Acknowledgements Financial support: CAPES, FAPESP, CNPq. Keywords: antibody, Tetanus Toxoid, B lymphocytes, Flow Cytometry, immune repertoire Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Adaptive Immunity Citation: Aliprandini E, Quintilio W, Kalil J, Boscardin SB and Moro AM (2013). A triple positive staining to capture B cells expressing anti-tetanus toxoid IgG in human blood. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00567 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 May 2013; Published Online: 22 Aug 2013. * Correspondence: Dr. Ana M Moro, Laboratório de Biofármacos em Células Animais, Instituto Butantan, São Paulo, Brazil, anamoro@butantan.gov.br Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Eduardo Aliprandini Wagner Quintilio Jorge Kalil Silvia B Boscardin Ana M Moro Google Eduardo Aliprandini Wagner Quintilio Jorge Kalil Silvia B Boscardin Ana M Moro Google Scholar Eduardo Aliprandini Wagner Quintilio Jorge Kalil Silvia B Boscardin Ana M Moro PubMed Eduardo Aliprandini Wagner Quintilio Jorge Kalil Silvia B Boscardin Ana M Moro Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

A Conformational Change of C Fragment of Tetanus Neurotoxin Reduces Its Ganglioside-Binding Activity but Does Not Destroy Its Immunogenicity

The C fragment of tetanus neurotoxin (TeNT-Hc) with different conformations was observed due to the four cysteine residues within it which could form different intramolecular disulfide bonds. In this study, we prepared and compared three types of monomeric TeNT-Hc with different conformational components: free sulfhydryls (50 kDa), bound sulfhydryls (44 kDa), and a mixture of the two conformational proteins (half 50 kDa and half 44 kDa). TeNT-Hc with bound sulfhydryls reduced its binding activity to ganglioside G(T1b) and neuronal PC-12 cells compared to what was seen for TeNT-Hc with free sulfhydryls. However, there was no significant difference among their immunogenicities in mice, including induction of antitetanus toxoid IgG titers, antibody types, and protective capacities against tetanus neurotoxin challenge. Our results showed that the conformational changes of TeNT-Hc resulting from disulfide bond formation reduced its ganglioside-binding activity but did not destroy its immunogenicity, and the protein still retained continuous B cell and T cell epitopes; that is, the presence of the ganglioside-binding site within TeNT-Hc may be not essential for the induction of a fully protective antitetanus response. TeNT-Hc with bound sulfhydryls may be developed into an ideal human vaccine with a lower potential for side effects.

Oral Immunization with Recombinant Salmonella Induces Mucosal IgA Antibodies in CD4-Deficient Mice

It is well established that CD4+ T cells are major contributors to the induction and regulation of antigen-specific antibody responses in both mucosal and systemic compartments. However, our previous studies have demonstrated that oral immunization of CD4-/- mice with soluble protein plus cholera toxin as adjuvant elicited antigen-specific IgA antibody responses in the gastrointestinal tract. In this study, we investigated whether oral delivery of live bacteria could elicit mucosal immunity in CD4-/- mice. Oral immunization with recombinant Salmonella expressing fragment C of tetanus toxin resulted in serum IgG and IgA anti-tetanus toxoid antibody responses. Furthermore, CD4-/- mice are capable of eliciting secretory IgA antibodies in the intestinal tract. Antibody-forming cell analysis confirmed the antibody titers by revealing significant numbers of tetanus toxoid-specific IgG- and IgA-forming cells in the spleen and IgA-forming cells in intestinal lamina propria. In addition, significant delayed-type hypersensitivity responses were detected in CD4-/- mice given rSalmonella-Tox C. These results suggest that antigen-specific mucosal as well as systemic antibody responses can be induced in the absence of CD4+ T cells after oral immunization with Salmonella.

Evaluation of the immunogenicity and safety of an indigenously developed DTwP-Hib tetravalent combination vaccine (Shan 4) with EasyFourTM in Indian infants administered per EPI schedule

The study was planned to assess and compared immunogenicity and safety of an indigenous DTPw-Hib combination vaccine (Shan 4) with EasyFour, the available DTwP-Hib vaccine in India. Overall 210 healthy infants, six to eight weeks of age were randomized to receive three doses of either Shan 4 or EasyFour at 6, 10 and 14 weeks of age. Antibodies were analyzed prior to and four to six weeks post third vaccine dose. Solicited and unsolicited local and systemic events in the follow up period after each dose were recorded. Post vaccination 100% of the infants in Shan 4 and EasyFour groups had seroprotective concentrations of Anti PRP-T IgG antibodies, IgG anti-diphtheria toxoid antibodies and IgG anti-tetanus toxoid antibodies. Following third dose of vaccination 86.99% subjects in the Shan 4 group and 73.85% subjects in the EasyFour group seroconverted for anti-pertussis antibody titres. Two Serious Adverse Events (SAEs) were reported during the course of the study, all unrelated to the respective vaccine administered. Most commonly reported adverse events in both the groups were pain at injection site, mild fever (< 103° F) and minor swelling at injection site. The study proved that Shan 4 was safe and immunogenic compared to the available licensed vaccine.

Functional T-Cell Deficiency in Adolescents Who Experience Serogroup C Meningococcal Disease despite Receiving the Meningococcal Serogroup C Conjugate Vaccine

Some individuals have experienced meningococcal disease despite receiving the meningococcal serogroup C conjugate (MCC) vaccine in adolescence. We sought to determine whether this is due to subclinical functional B- or T-cell immunodeficiency. Of 53 vaccine failures identified by enhanced surveillance of England and Wales from 1999 to 2004, 15 received MCC vaccine in adolescence, 9 of whom were recruited 2 to 6 years following convalescence from meningococcal disease. Their peripheral blood mononuclear cells (PBMCs) were incubated with polyclonal activators designed to mimic T-cell-independent B-cell stimulation by bacterial polysaccharides and the T-cell stimulation provided by the protein component of the conjugate vaccine. Subsequent proliferation and activation of T and B lymphocytes were measured, along with T-cell help to B cells. Compared to age-, sex-, geographically, and ethnicity-matched controls, CD4 T-cell proliferation rates in response to both anti-CD3 (T-cell receptor [TCR]) stimulation and anti-CD3 in the presence of B cells activated through anti-IgD conjugated to dextran (alpha-delta-dex) were lower in PBMCs derived from vaccine failures (P = 0.044 and P = 0.029, respectively). There was reduced CD4 cell activation of the patient cells compared to controls following stimulation by CD3 (P = 0.048). B-cell activation during incubation of PBMCs with the T-cell stimuli, anti-CD3 (P = 0.044), or anti-CD3 plus anti-CD28 (P = 0.018) was relatively impaired in patients. Anti-tetanus toxoid IgG concentrations were lower in the vaccine failure group (P = 0.0385). There was a relative defect of T-cell responsiveness to T-cell-dependent antigen stimulation in MCC vaccine failures, which was manifested in reduced T-cell help to B cells.

Tetanus toxoid-loaded transfersomes for topical immunization

Topical immunization is a novel immunization strategy by which antigens and adjuvants are applied topically to intact skin to induce potent antibody and cell-mediated responses. Among various approaches for topical immunization, the vesicular approach is gaining wide attention. Proteineous antigen alone or in combination with conventional bioactive carriers could not penetrate through the intact skin. Hence, specially designed, deformable lipid vesicles called transfersomes were used in this study for the non-invasive delivery of tetanus toxoid (TT). Transfersomes were prepared and characterized for shape, size, entrapment efficiency and deformability index. Fluorescence microscopy was used to investigate the mechanism of vesicle penetration through the skin. The immune stimulating activity of these vesicles was studied by measuring the serum anti-tetanus toxoid IgG titre following topical immunization. The immune response was compared with the same dose of alum adsorbed tetanus toxoid (AATT) given intramuscularly, topically administered plain tetanus toxoid solution, and a physical mixture of tetanus toxoid and transfersomes again given topically. The results indicated that the optimal transfersomal formulation had a soya phosphatidylcholine and sodium deoxycholate ratio of 85:15%, w/w. This formulation showed maximum entrapment efficiency (87.34 +/- 3.81%) and deformability index (121.5 +/- 4.21). An in-vivo study revealed that topically administered tetanus toxoid-loaded transfersomes, after secondary immunization, elicited an immune response (anti-TT-IgG) comparable with that produced by intramuscular AATT. Fluorescence microscopy revealed the penetration of transfersomes through the skin to deliver the antigen to the immunocompetent Langerhans cells.

Antibody Response to Polysaccharide Conjugate Vaccines after Nonmyeloablative Allogeneic Stem Cell Transplantation

After allogeneic stem cell transplantation with reduced-intensity conditioning regimens (allo-RIST) patients are susceptible to bacterial and viral infections for a period that may last several years. The efficacy of the recommended vaccination schedules, in terms of induction of a protective antibody response, is unknown. In this study, the reconstitution of humoral immunity after allo-RIST is determined by measuring the vaccination-induced antibody response against Streptococcus pneumoniae, Haemophilus influenzae type b (Hib), and tetanus toxoid (TT) 1 year posttransplantation. Patients who underwent allo-RIST were vaccinated according to a schedule starting at 12 months following transplantation with conjugated vaccines against S. pneumoniae, Hib, and TT. Of twenty-six patients both pre- and postvaccination sera were available. Patients were required to be off immunosuppression at the time of vaccination, and, therefore, 9 of the 26 patients did not start vaccination at 12 months post-stem cell transplantation but rather at a median range of 15 (12-36 months) posttransplantation. Except for pneumococcal serotype 6B, more than 73% of the patients developed antibody levels >or=0.35 microg/mL for all pneumococcal serotypes included in the vaccine. For Hib and TT, protective antibody levels were found in 77% and 96% of the patients, respectively. Vaccination of patients at a median of 15 months post-allo-RIST leads to significant rise in concentrations of pneumococcal, Hib, and TT antibodies in the majority of patients.

Precursor frequencies for DNA-specific B lymphocytes in patients with systemic lupus erythematosus (SLE).

Precursor frequencies for anti-DNA-secreting B cells were estimated in six healthy donors and 18 SLE patients with active and inactive disease. Precursors for IgG anti-dsDNA-secreting B cells were exclusively detected in SLE patients (73% of active patients and one inactive patient, 0.01-0.99% of IgG-producing B cells). These frequencies were in the same order of magnitude as frequencies of precursors for IgG anti-tetanus toxoid, which were detectable in three healthy volunteers after booster vaccination (0.07-0.8% of IgG-producing B cells), but not before (< 0.01%). Precursors for IgG anti-ss-DNA secreting B cells were observed in 33% of healthy donors and in 78% of SLE patients (0.01-0.32% of IgG-producing B cells). Only patient-derived IgG anti-DNA clones cross-reacted with (33%) or were monoreactive to dsDNA (12%). Precursors for IgM anti-DNA-secreting B cells were observed in healthy donors and SLE patients in comparable frequencies and with similar reactivities with ssDNA and dsDNA. Segregation analyses and sorting experiments showed that > 94% of clones secreting IgG anti-DNA were derived from in vivo sIgG+ B cells. sIgM+ B cells were induced to switch in vitro; however, only twice were cultures containing IgM and IgG anti-DNA antibodies observed under clonal conditions. In conclusion, our results indicate that precursor B cells for IgG anti-dsDNA in SLE patients are similarly selected and expanded as are precursor B cells specific for foreign antigens such as tetanus toxoid.

T and B cell responses following immunization with tetanus toxoid in IgA nephropathy.

The B and T cell responses were investigated in IgA nephropathy before and after immunization with tetanus toxoid (TT). Both IgA and IgG anti-tetanus toxoid antibodies were elicited, but the IgA antibodies were significantly greater in patients (92.6 +/- 11.7 ELISA units) than in the controls (49.2 +/- 7.5 ELISA units). This was associated with a significantly greater proportion of IgA+ B cells in patients than controls before immunization. However, a significant increase in the proportion of IgA1 binding CD4 and CD8 cells was also found. The proportion of CD3 cells with gamma delta T cell receptors (CD3+TCR gamma delta +), was significantly greater before immunization in the IgA nephropathy patients (37.0% +/- 2.4), compared with controls (10.0% +/- 2.3; P less than 0.001). Immunization with TT further enhanced the CD3+TCR gamma delta + cells in patients to 45.8% +/- 7.2 compared with controls (16.3% +/- 4.5), with a corresponding decrease in CD3+TCR alpha beta + cells in the patients (P less than 0.001). CD3+TCR gamma delta + cells are upregulated by common microbial antigens and clinical exacerbations of IgA nephropathy are frequently associated with mucosal infections and a rise in serum IgA concentration. The increased TCR gamma delta expression may be responsible for the enhanced IgA antibody response in IgA nephropathy. The increase in IgA antibodies may than exert a controlling effect by binding to augmenting T cells and thereby inhibiting their function.

Étude de quatre trousses de titrage des anticorps antitétaniques pour la sélection des plasmas destinés au fractionnement (LFB)

Antitetanus antibodies titration is carried out by French National Blood Services (FNBSs) with the aim of seeking donors whose title of antibodies are greater or equal to 8 IU/ml. Different kits are used: ELISA antitetanus toxoid IgG (The Binding Site), ELISAT (Diagast), tetanus toxoid IgG ELISA (Diamed), ELISA IgG tetanus (Ingen). As the results obtained using these different reagents show some discrepancies with the control results carried out by the Laboratoire Français des Biotechnologies (LFB), it appeared necessary to harmonize the selection practices. With this intention a study of the different kits was initiated. Method Different samples were used during this evaluation: (1) the Reference Control (RC) used by the FNBS; (2) a serum sample of high title; (3) a range of dilution of national standard. The following tests were carried out: (1) robustness with the evaluation of the contamination and the board effect; (2) linearity and repeatability (eight deposits of each standard, RC and points of national standard dilutions); (3) reproducibility; (4) homogeneity. After automatic dilution of the samples, the plates were then processed according to the protocol of the manufacturer. Results The study gives the CV in percentage of repeatability and reproducibility, the values of the standards provided as well as the biais compared to the RC and the uncertainty of measurements. Conclusion This study gave the possibility to rank each kit compared to RC and to specify the variations which surround each result. This variation can explain the discrepancy of conformity of plasma when title is close to the threshold of selection.