scholarly journals A Peptide-BasedPlasmodium falciparumCircumsporozoite Assay To Test for Serum Antibody Responses to Pre-Erythrocyte Malaria Vaccines

2011 ◽  
Vol 18 (5) ◽  
pp. 776-782 ◽  
Author(s):  
Stefan Kostense ◽  
Bregje Mommaas ◽  
Jenny Hendriks ◽  
Mariëlle Verhoeven ◽  
Mariska ter Haak ◽  
...  
Keyword(s):  
High Performance ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Repeat Region ◽  
Peptide Antigen ◽  
Content Type ◽  
Good Marker ◽  
Malaria Vaccines ◽  
Antibody Titers

ABSTRACTVarious pre-erythrocyte malaria vaccines are currently in clinical development, and among these is the adenovirus serotype 35-based circumsporozoite (CS) vaccine produced on PER.C6 cells. Although the immunological correlate of protection against malaria remains to be established, the CS antibody titer is a good marker for evaluation of candidate vaccines. Here we describe the validation of an anti-Plasmodium falciparumcircumsporozoite antibody enzyme-linked immunosorbent assay (ELISA) based on the binding of antibodies to a peptide antigen mimicking the CS repeat region. The interassay variability was determined to be below a coefficient of variation (CV) of 15%, and sensitivity was sufficient to detect low antibody titers in subjects from endemic regions. Antibody titers were in agreement with total antibody responses to the whole CS protein. Due to its simplicity and high performance, the ELISA is an easy and rapid method for assessment of pre-erythrocyte malaria vaccines based on CS.

scholarly journals Antibody Responses to Natural Rattlesnake Envenomation and a Rattlesnake Toxoid Vaccine in Horses

2013 ◽  
Vol 20 (5) ◽  
pp. 732-737 ◽  
Author(s):  
Lyndi L. Gilliam ◽  
Robert C. Carmichael ◽  
Todd C. Holbrook ◽  
Jennifer M. Taylor ◽  
Charlotte L. Ownby ◽  
...  
Keyword(s):  
Passive Transfer ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Vaccine Response ◽  
Crotalus Atrox ◽  
Content Type ◽  
The Third ◽  
Significant Difference ◽  
Rattlesnake Venom ◽  
Antibody Titers

ABSTRACTAntivenom antibody titers following administration of rattlesnake venom for antivenom production in horses are well documented; however, antivenom antibody titers following natural rattlesnake envenomation in horses are not. Antibody titers produced in response to the commercially available rattlesnake venom vaccine are also not published. Our study objectives were to measure antivenom antibody titers in rattlesnake-bitten horses and compare them to titers in horses vaccinated with the rattlesnake venom vaccine. Additionally, titers were compared in pregnant versus nonpregnant horses to assess the affect of pregnancy on vaccine response and were measured pre- and postsuckle in foals of vaccinated mares to detect passive transfer of vaccine immunoglobulins. Blood samples were collected from16 rattlesnake-bitten horses. Thirty-six horses (11 pregnant mares, 12 nonpregnant mares, 13 geldings) were vaccinated using aCrotalus atroxvenom toxoid vaccine. Blood was collected before administering each vaccination and 30 days following the third vaccination. Blood was collected from foals of vaccinated mares pre- and postsuckle. All serum was assayed for anti-Crotalus atroxvenom antibodies using an enzyme-linked immunosorbent assay (ELISA). Rattlesnake-bitten horses had higher (P= 0.001) titers than vaccinated horses. There was no significant difference between titers in vaccinated pregnant versus nonpregnant horses. One mare had a positive titer at foaling, and the foals had positive postsuckle titers. Antivenom antibody titer development was variable following natural envenomation and vaccination, and vaccine-induced titers were lower than natural envenomation titers. Further studies are required to determine if natural or vaccine antivenom antibody titers reduce the effects of envenomation.

scholarly journals Design and assessment of TRAP-CSP fusion antigens as effective malaria vaccines

2019 ◽  
Author(s):  
Chafen Lu ◽  
Gaojie Song ◽  
Kristin Beale ◽  
Jiabin Yan ◽  
Emma Garst ◽  
...  
Keyword(s):  
Malaria Vaccine ◽  
Vaccine Development ◽  
Antibody Responses ◽  
Effective Vaccine ◽  
Repeat Region ◽  
Partial Protection ◽  
Adhesion Protein ◽  
Malaria Vaccines ◽  
Multi Stage ◽  
Antibody Titers

AbstractThe circumsporozoite protein (CSP) and thrombospondin-related adhesion protein (TRAP) are major targets for pre-erythrocytic malaria vaccine development. However, the most advanced CSP-based vaccine RTS,S provides only partial protection, highlighting the need for innovative approaches for vaccine design and development. Here we design and characterize TRAP-CSP fusion antigens, and evaluate their immunogenicity and protection against malaria infection. TRAP N-terminal folded domains were fused to CSP C-terminal fragments consisting of the C-terminal αTSR domain with or without the intervening repeat region. Homogenous, monomeric and properly folded fusion proteins were purified from mammalian transfectants. Notably, fusion improved expression of chimeras relative to the TRAP or CSP components alone. Immunization of BALB/c mice with the P. berghei TRAP-CSP fusion antigens formulated in AddaVax adjuvant elicited antigen-specific antibody responses. Remarkably, fusion antigens containing the CSP repeat region conferred complete sterile protection against P. berghei sporozoite challenge, and furthermore, mice that survived the challenge were completely protected from re-challenge 16 weeks after the first challenge. In contrast, fusion antigens lacking the CSP repeat region were less effective, indicating that the CSP repeat region provided enhanced protection, which correlated with higher antibody titers elicited by fusion antigens containing the CSP repeat region. In addition, we demonstrated that N-linked glycans had no significant effect on antibody elicitation or protection. Our results show that TRAP-CSP fusion antigens could be highly effective vaccine candidates. Our approach provides a platform for designing multi-antigen/multi-stage fusion antigens as next generation more effective malaria vaccines.

scholarly journals Dairy Heifers Naturally Exposed toFasciola hepaticaDevelop a Type 2 Immune Response and Concomitant Suppression of Leukocyte Proliferation

2017 ◽  
Vol 86 (1) ◽  
Author(s):  
John Graham-Brown ◽  
Catherine Hartley ◽  
Helen Clough ◽  
Aras Kadioglu ◽  
Matthew Baylis ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Peripheral Blood ◽  
Serum Antibody ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mixed Effect ◽  
Content Type ◽  
Grazing Season ◽  
Type 2 Immune Response

ABSTRACTFasciola hepaticais a parasitic trematode of global importance in livestock. Control strategies reliant on anthelmintics are unsustainable due to the emergence of drug resistance. Vaccines are under development, but efficacies are variable. Evidence from experimental infection suggests that vaccine efficacy may be affected by parasite-induced immunomodulation. Little is known about the immune response toF. hepaticafollowing natural exposure. Hence, we analyzed the immune responses over time in calves naturally exposed toF. hepaticainfection. Cohorts of replacement dairy heifer calves (n= 42) with no prior exposure toF. hepatica, on three commercial dairy farms, were sampled over the course of a grazing season. Exposure was determined through anF. hepatica-specific serum antibody enzyme-linked immunosorbent assay (ELISA) and fluke egg counts. Concurrent changes in peripheral blood leukocyte subpopulations, lymphocyte proliferation, and cytokine responses were measured. Relationships between fluke infection and immune responses were analyzed by using multivariable linear mixed-effect models. All calves from one farm showed evidence of exposure, while cohorts from the remaining two farms remained negative over the grazing season. A type 2 immune response was associated with exposure, with increased interleukin-4 (IL-4) production, IL-5 transcription, and eosinophilia. Suppression of parasite-specific peripheral blood mononuclear cell (PBMC) proliferation was evident, while decreased mitogen-stimulated gamma interferon (IFN-γ) production suggested immunomodulation, which was not restricted to parasite-specific responses. Our findings show that the global immune response is modulated toward a nonproliferative type 2 state following natural challenge withF. hepatica. This has implications in terms of the timing of the administration of vaccination programs and for host susceptibility to coinfecting pathogens.

Study of Antibody Levels in Children with Purulent Otitis Media

1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 117-120 ◽  
Author(s):  
P. Branefors ◽  
T. Dahlberg ◽  
O. Nylén
Keyword(s):  
Otitis Media ◽  
Serum Antibody ◽  
Acute Otitis Media ◽  
High Serum ◽  
Haemophilus Influenzae Type ◽  
Enzyme Linked Immunosorbent Assay ◽  
Polysaccharide Antigens ◽  
Antibody Titers ◽  
Iga Antibody ◽  
Antibody Levels

A series of episodes of acute otitis media were studied with reference to the bacterial findings in the nasopharynx and the specific antibody response in a group of children nine months to ten years of age, with previous frequent episodes of acute otitis media, Serum IgG, IgM and IgA antibody levels against five polysaccharide antigens, namely Haemophilus influenzae type b and Streptococcus pneumoniae types 3, 6, 19 and 23, were studied by means of an enzyme-linked immunosorbent assay. The selection of polysaccharide antigens was based on isolation frequency. The sera to be tested were tenfold serially diluted. An extinction of 0.2 over the base was taken as the end-point titer and expressed as in-log10. The results showed that most children including those under three years of age showed increasing homologous antibody titers at an infection, or had already initially very high antibody titers, especially of the IgG class. The titers reached levels of 104 to 105. In some cases, however, it could be shown that high serum antibody titers did not give protection against a new infection with the same serological type of bacteria. It was also demonstrated that most children, regardless of age, had IgG and IgM titers against the heterologous antigens. In some cases the levels were quite high (103 to 104). However, the IgA antibody levels were lower and in a considerable number of samples antibodies were not even detectable.

scholarly journals Rapid Detection of Serum Antibody by Dual-Path Platform VetTB Assay in White-Tailed Deer Infected with Mycobacterium bovis

2013 ◽  
Vol 20 (6) ◽  
pp. 907-911 ◽  
Author(s):  
Konstantin P. Lyashchenko ◽  
Rena Greenwald ◽  
Javan Esfandiari ◽  
Daniel J. O'Brien ◽  
Stephen M. Schmitt ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Mycobacterium Bovis ◽  
Skin Testing ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Antibody Detection ◽  
Serum Samples ◽  
Content Type ◽  
In The Wild ◽  
Free Ranging

ABSTRACTBovine tuberculosis (TB) in cervids remains a significant problem affecting farmed herds and wild populations. Traditional skin testing has serious limitations in certain species, whereas emerging serological assays showed promising diagnostic performance. The recently developed immunochromatographic dual-path platform (DPP) VetTB assay has two antigen bands, T1 (MPB83 protein) and T2 (CFP10/ESAT-6 fusion protein), for antibody detection. We evaluated the diagnostic accuracy of this test by using serum samples collected from groups of white-tailed deer experimentally inoculated withMycobacterium bovis,M. aviumsubsp.paratuberculosis, orM. bovisBCG Pasteur. In addition, we used serum samples from farmed white-tailed deer in herds with no history of TB, as well as from free-ranging white-tailed deer culled during field surveillance studies performed in Michigan known to have bovine TB in the wild deer population. The DPP VetTB assay detected antibody responses in 58.1% of experimentally infected animals within 8 to 16 weeks postinoculation and in 71.9% of naturally infected deer, resulting in an estimated test sensitivity of 65.1% and a specificity of 97.8%. The higher seroreactivity found in deer with naturally acquiredM. bovisinfection was associated with an increased frequency of antibody responses to the ESAT-6 and CFP10 proteins, resulting in a greater contribution of these antigens, in addition to MPB83, to the detection of seropositive animals, compared with experimentalM. bovisinfection. Deer experimentally inoculated with eitherM. aviumsubsp.paratuberculosisorM. bovisBCG Pasteur did not produce cross-reactive antibodies that could be detected by the DPP VetTB assay. The present findings demonstrate the relatively high diagnostic accuracy of the DPP VetTB test for white-tailed deer, especially in the detection of naturally infected animals.

scholarly journals 405. Serum Antibody Responses Against Carbapenem-Resistant Klebsiella pneumoniae in Infected Patients

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S206-S206
Author(s):  
Kasturi Banerjee ◽  
Michael Motley ◽  
Elizabeth Diago-Navarro ◽  
Bettina C Fries
Keyword(s):  
Therapeutic Potential ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Size Exclusion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Affinity Column ◽  
Carbapenem Resistant ◽  
Potential Vaccine ◽  
Clade 1 ◽  
Humoral Responses

Abstract Background Capsular polysaccharide (CPS) of Carbapenem-resistant K. pneumoniae ST258 (CR-Kp) is a potential vaccine target. CPS of these isolates generally falls within 2 homology groups named clade 1 and clade 2. We and others have made antibodies (Abs) that act against clade2 CR-Kp but failed to make therapeutic Abs against clade1 CR-Kp. Previous studies had shown that studying patient’s antibody responses could help in identifying suitable candidates for developing immunotherapies. Thus, we sought to identify potential vaccine candidates by investigating the humoral response CPS in CR-Kp-infected patients. Methods 24 CR-Kp isolates and corresponding serums were collected from inpatients at Stony Brook Hospital. CPS was isolated and purified by size-exclusion column chromatography from CR-Kp strains 34 (clade 2), 36 (clade 1), and 38 (clade-Other). Anti-CPS Abs in patient’s serum were detected by enzyme-linked immunosorbent assay (ELISA) and bulk Abs from positive serum were purified using an affinity column. These Abs were tested for activity against CR-Kp by serum bactericidal and agglutination assays. Results 50% of clade2 CR-Kp-infected patients had humoral responses against CPS34. 77% of clade 1-infected patients sera cross-reacted wtih CPS34, but none of them developed Abs against CPS36. Interestingly, 90% of clade1 and 60% of clade 2-infected patients, respectively, showed Abs binding to CPS38. Thus, we selectively purified Anti-CPS Abs from two clade-Other-infected patients and observed that they were cross-reactive with all three CPS. Further, these Anti-CPS Abs agglutinated all tested CR-Kp isolates (34, 36, and 38) when compared with control human IgG (P < 0.005). Additionally, these Anti-CPS Abs promoted killing of clade2 bacteria and inhibited the growth of clade1 bacteria in Ab-mediated serum bactericidal assay. These data elucidate that humoral responses developed in clade-Other CR-Kp-infected patients have therapeutic potential. Conclusion With the unavailability of effective antimicrobials for CR-Kp, approaches like developing novel anti-CPS vaccine could serve as an alternate therapy. Our data suggest that developing immunotherapies targeting CPS38 could potentially provide protection across both clade1 and clade2 bacteria in clinical settings. Disclosures All authors: No reported disclosures.

scholarly journals Serodiagnostic Potential of Mycobacterium avium MAV2054 and MAV5183 Proteins

2012 ◽  
Vol 20 (2) ◽  
pp. 295-301 ◽  
Author(s):  
A-Rum Shin ◽  
Kil-Soo Lee ◽  
Kang In Lee ◽  
Tae Sun Shim ◽  
Won-Jung Koh ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Characteristic Curve ◽  
Receiver Operator Characteristic Curve ◽  
Curve Analysis ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Good Discrimination ◽  
Content Type ◽  
Pulmonary Tb ◽  
Latent Tb

ABSTRACTTheMycobacterium avium-M. intracellularecomplex (MAC) causes a pulmonary disease (PD) similar to tuberculosis (TB). Diagnosis of MAC-PD is complicated and time-consuming. In this study, the serodiagnostic potential of the newly identified MAV2054 and MAV5183 proteins was evaluated in subjects with MAC-PD, pulmonary TB, or latent TB and in noninfected healthy controls (HC), together with HspX and the 38-kDa antigen, well-known serodiagnosticM. tuberculosisantigens. All four antigens evoked significantly higher IgG responses in MAC-PD and active TB than in latent TB and HC subjects. Among the antigens, MAV2054 elicited the highest antibody responses in pulmonary TB and MAC-PD patients. IgG titers against MAV2054 and MAV5183 were significantly higher in MAC-PD than in pulmonary TB subjects. In addition, the levels of IgG against all antigens in theM. intracellulareand fibrocavitary forms were higher than those in theM. aviumand nodular bronchiectatic forms, respectively. Based on sensitivity and receiver operator characteristic curve analysis, the best candidates for detection of MAC-PD and pulmonary TB were MAV2054 and the 38-kDa antigen, respectively. In total, 76.0% of MAC-PD and 65.0% of active TB patients were reactive to at least two antigens. In contrast, only 2.8% of HC subjects were reactive with two or more antigens. Our findings suggest that an enzyme-linked immunosorbent assay (ELISA) using the four antigens would be valuable for screening for mycobacterial lung disease, including MAC-PD and pulmonary TB, although it does not provide good discrimination of the disease-causing pathogens.

scholarly journals Antibodies to Borrelia burgdorferi OspA, OspC, OspF, and C6 Antigens as Markers for Early and Late Infection in Dogs

2012 ◽  
Vol 19 (4) ◽  
pp. 527-535 ◽  
Author(s):  
Bettina Wagner ◽  
Heather Freer ◽  
Alicia Rollins ◽  
David Garcia-Tapia ◽  
Hollis N. Erb ◽  
...  
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
The United States ◽  
Sensu Stricto ◽  
Antibody Responses ◽  
Surface Proteins ◽  
Early Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Content Type ◽  
Antibody Levels

ABSTRACTLyme disease in the United States is caused byBorrelia burgdorferisensu stricto, which is transmitted to mammals by infected ticks.Borreliaspirochetes differentially express immunogenic outer surface proteins (Osp). Our aim was to evaluate antibody responses to Osp antigens to aid the diagnosis of early infection and the management of Lyme disease. We analyzed antibody responses during the first 3 months after the experimental infection of dogs using a novel multiplex assay. Results were compared to those obtained with two commercial assays detecting C6 antigen. Multiplex analysis identified antibodies to OspC and C6 as early as 3 weeks postinfection (p.i.) and those to OspF by 5 weeks p.i. Antibodies to C6 and OspF increased throughout the study, while antibodies to OspC peaked between 7 and 11 weeks p.i. and declined thereafter. A short-term antibody response to OspA was observed in 3/8 experimentally infected dogs on day 21 p.i. Quant C6 enzyme-linked immunosorbent assay (ELISA) results matched multiplex results during the first 7 weeks p.i.; however, antibody levels subsequently declined by up to 29%. Immune responses then were analyzed in sera from 125 client-owned dogs and revealed high agreement between antibodies to OspF and C6 as robust markers for infection. Results from canine patient sera supported that OspC is an early infection marker and antibodies to OspC decline over time. The onset and decline of antibody responses toB. burgdorferiOsp antigens and C6 reflect their differential expression during infection. They provide valuable tools to determine the stage of infection, treatment outcomes, and vaccination status in dogs.

scholarly journals Analysis of Human Serum Immunoglobulin G against O-Acetyl-Positive and O-Acetyl-Negative Serogroup W135 Meningococcal Capsular Polysaccharide

2005 ◽  
Vol 12 (5) ◽  
pp. 586-592 ◽  
Author(s):  
Peter C. Giardina ◽  
Emma Longworth ◽  
Renee E. Evans-Johnson ◽  
Michaelene L. Bessette ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Immunoglobulin G ◽  
Capsular Polysaccharide ◽  
Solid Phase ◽  
Geometric Mean ◽  
Serum Antibody ◽  
Fluid Phase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Titers ◽  
The Impact

ABSTRACT The capsular polysaccharide of Neisseria meningitidis serogroup W135 is expressed in both O-acetyl-positive (OA+) and O-acetyl-negative (OA−) forms. This study investigates the impact of OA status (OA+ versus OA−) on serological measurements of anti-W135 immunoglobulin G (IgG) antibodies in immunized adults. W135-specific serum antibody assignments were made for 28 postimmunization sera from adults by enzyme-linked immunosorbent assay using the meningococcal standard reference serum CDC1992. The established IgG concentration in micrograms per milliliter ([IgG]μg/ml) for CDC1992 against OA+ antigen (16.2 μg/ml) was used as a reference to assign a concentration of 10.13 μg/ml IgG against OA− antigen by cross-standardization. Overall, the IgG assignments for these sera were higher against OA+ antigen (geometric mean concentration [GMC] = 7.16 μg/ml) than against OA− antigen (GMC = 2.84 μg/ml). However, seven sera showed higher specific [IgG]μg/ml values against the OA+ antigen than against the OA− antigen. These sera were also distinguished by the inability of fluid-phase OA− antigen to compete for antibody binding to OA+ solid-phase antigen. Although there was no overall difference in functional activity measured by complement-mediated serum bactericidal assay (SBA) against OA+ and OA− target bacteria (geometric mean titers of 9,642 and 9,045, respectively), three serum specimens showed a large difference in SBA antibody titers against OA+ versus OA− W135 target bacteria, which may reflect different epitope specificities for these sera. Our data indicate that, for some sera, the agreement in anti-OA+ versus anti-OA− W135 IgG assignments is serum specific and does not reflect the functional (killing) activity in vitro.

scholarly journals Protective Immune Responses to the 42-Kilodalton (kDa) Region of Plasmodium yoelii Merozoite Surface Protein 1 Are Induced by the C-Terminal 19-kDa Region but Not by the Adjacent 33-kDa Region

2002 ◽  
Vol 70 (2) ◽  
pp. 820-825 ◽  
Author(s):  
Niklas Ahlborg ◽  
Irene T. Ling ◽  
Wendy Howard ◽  
Anthony A. Holder ◽  
Eleanor M. Riley
Keyword(s):  
Gene Segment ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Plasmodium Yoelii ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Merozoite Surface Protein 1 ◽  
Antibody Titers ◽  
Processing Product

ABSTRACT Vaccination of mice with the 42-kDa region of Plasmodium yoelii merozoite surface protein 1 (MSP142) or its 19-kDa C-terminal processing product (MSP119) can elicit protective antibody responses in mice. To investigate if the 33-kDa N-terminal fragment (MSP133) of MSP142 also induces protection, the gene segment encoding MSP133 was expressed as a glutathione S-transferase (GST) fusion protein. C57BL/6 and BALB/c mice were immunized with GST-MSP133 and subsequently challenged with the lethal P. yoelii YM blood stage parasite. GST-MSP133 failed to induce protection, and all mice developed patent parasitemia at a level similar to that in naive or control (GST-immunized) mice; mice immunized with GST-MSP119 were protected, as has been shown previously. Specific prechallenge immunoglobulin G (IgG) antibody responses to MSP1 were analyzed by enzyme-linked immunosorbent assay and immunofluorescence. Despite being unprotected, several mice immunized with MSP133 had antibody titers (of all IgG subclasses) that were comparable to or higher than those in mice that were protected following immunization with MSP119. The finding that P. yoelii MSP133 elicits strong but nonprotective antibody responses may have implications for the design of vaccines for humans based on Plasmodium falciparum or Plasmodium vivax MSP142.

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