scholarly journals A comparison of non-magnetic and magnetic beads for measuring IgG antibodies against Plasmodium vivax antigens in a multiplexed bead-based assay using Luminex technology (Bio-Plex 200 or MAGPIX)

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0238010
Author(s):  
Ramin Mazhari ◽  
Jessica Brewster ◽  
Rich Fong ◽  
Caitlin Bourke ◽  
Zoe S. J. Liu ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Magnetic Beads ◽  
Antibody Responses ◽  
Strongly Correlated ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Standard Curve ◽  
Luminex Technology ◽  
Specific Igg ◽  
Comparability Of Results

Multiplexed bead-based assays that use Luminex® xMAP® technology have become popular for measuring antibodies against proteins of interest in many fields, including malaria and more recently SARS-CoV-2/COVID-19. There are currently two formats that are widely used: non-magnetic beads or magnetic beads. Data are lacking regarding the comparability of results obtained using these two types of beads, and for assays run on different instruments. Whilst non-magnetic beads can only be run on flow-based instruments (such as the Luminex® 100/200™ or Bio-Plex® 200), magnetic beads can be run on both these and the newer MAGPIX® instruments. In this study we utilized a panel of purified recombinant Plasmodium vivax proteins and samples from malaria-endemic areas to measure P. vivax-specific IgG responses using different combinations of beads and instruments. We directly compared: i) non-magnetic versus magnetic beads run on a Bio-Plex® 200, ii) magnetic beads run on the Bio-Plex® 200 versus MAGPIX® and iii) non-magnetic beads run on a Bio-Plex® 200 versus magnetic beads run on the MAGPIX®. We also performed an external comparison of our optimized assay. We observed that IgG antibody responses, measured against our panel of P. vivax proteins, were moderately-strongly correlated in all three of our comparisons (pearson r>0.5 for 18/19 proteins), however higher amounts of protein were required for coupling to magnetic beads. Our external comparison indicated that results generated in different laboratories using the same coupled beads are also highly comparable (pearson r>0.7), particularly if a reference standard curve is used.

scholarly journals A comparison of non-magnetic and magnetic beads for measuring IgG antibodies against P. vivax antigens in a multiplexed bead-based assay using Luminex® technology (Bio-Plex® 200 or MAGPIX®)

2020 ◽  
Author(s):  
Ramin Mazhari ◽  
Jessica Brewster ◽  
Rich Fong ◽  
Caitlin Bourke ◽  
Zoe SJ Liu ◽  
...  
Keyword(s):  
Magnetic Beads ◽  
External Validation ◽  
Antibody Responses ◽  
Strongly Correlated ◽  
Reference Standard ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Standard Curve ◽  
Specific Igg ◽  
Comparability Of Results

AbstractMultiplexed bead-based assays that use Luminex xMAP® technology have become popular for measuring antibodies against proteins of interest in many fields, including malaria and more recently SARS-CoV-2/COVID-19. There are currently two formats that are widely used: non-magnetic beads or magnetic beads. Data is lacking regarding the comparability of results obtained using these two types of beads, and for assays run on different instruments. Whilst non-magnetic beads can only be run on flow-based instruments (such as the Luminex® 100/200™ or Bio-Plex® 200), magnetic beads can be run on both these and the newer MAGPIX® instruments. In this study we utilized a panel of purified recombinant Plasmodium vivax proteins and samples from malaria-endemic areas to measure P. vivax-specific IgG responses using different combinations of beads and instruments. We directly compared: i) non-magnetic versus magnetic beads run on a Bio-Plex® 200, ii) magnetic beads run on the Bio-Plex® 200 versus MAGPIX® and iii) non-magnetic beads run on a Bio-Plex® 200 versus magnetic beads run on the MAGPIX®. We also performed an external validation of our optimized assay. We observed that IgG antibody responses, measured against our panel of P. vivax proteins, were strongly correlated in all three of our comparisons, however higher amounts of protein were required for coupling to magnetic beads. Our external validation indicated that results generated in different laboratories using the same coupled beads are also highly comparable, particularly if a reference standard curve is used.

scholarly journals Antibody Responses to MAP 1B and Other Cowdria ruminantium Antigens Are Down Regulated in Cattle Challenged with Tick-Transmitted Heartwater

2001 ◽  
Vol 8 (2) ◽  
pp. 388-396 ◽  
Author(s):  
S. M. Semu ◽  
T. F. Peter ◽  
D. Mukwedeya ◽  
A. F. Barbet ◽  
F. Jongejan ◽  
...  
Keyword(s):  
Tick Infestation ◽  
Repeated Exposure ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Infected Cattle ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Cowdria Ruminantium ◽  
Infection Pressure ◽  
Specific Igg

ABSTRACT Serological diagnosis of heartwater or Cowdria ruminantium infection has been hampered by severe cross-reactions with antibody responses to related ehrlichial agents. A MAP 1B indirect enzyme-linked immunosorbent assay that has an improved specificity and sensitivity for detection of immunoglobulin G (IgG) antibodies has been developed to overcome this constraint (A. H. M. van Vliet, B. A. M. Van der Zeijst, E. Camus, S. M. Mahan, D. Martinez, and F. Jongejan, J. Clin. Microbiol. 33:2405–2410, 1995). When sera were tested from cattle in areas of endemic heartwater infection in Zimbabwe, only 33% of the samples tested positive in this assay despite a high infection pressure (S. M. Mahan, S. M. Samu, T. F. Peter, and F. Jongejan, Ann. N.Y. Acad. Sci 849:85–87, 1998). To determine underlying causes for this observation, the kinetics of MAP 1B-specific IgG antibodies in cattle after tick-transmitted C. ruminantium infection and following recovery were investigated. Sera collected weekly over a period of 52 weeks from 37 cattle, which were naturally or experimentally infected with C. ruminantium via Amblyomma hebraeum ticks, were analyzed. MAP 1B-specific IgG antibody responses developed with similar kinetics in both field- and laboratory-infected cattle. IgG levels peaked at 4 to 9 weeks after tick infestation and declined to baseline levels between 14 and 33 weeks, despite repeated exposure to infected ticks and the establishment of a carrier state as demonstrated by PCR and xenodiagnosis. Some of the serum samples from laboratory, and field-infected cattle were also analyzed by immunoblotting and an indirect fluorescent-antibody test (IFAT) to determine whether this observed seroreversion was specific to the MAP 1B antigen. Reciprocal IFAT and immunoblot MAP 1-specific antibody titres peaked at 5 to 9 weeks after tick infestation but also declined between 30 and 45 weeks. This suggests that MAP 1B-specific IgG antibody responses and antibody responses to other C. ruminantium antigens are down regulated in cattle despite repeated exposure to C. ruminantium via ticks. Significantly, serological responses to the MAP 1B antigen may not be a reliable indicator of C. ruminantium exposure in cattle in areas of endemic heartwater infection.

scholarly journals Detection of Genotype-Specific Antibody Responses to Glycoproteins B and H in Primary and Non-Primary Human Cytomegalovirus Infections by Peptide-Based ELISA

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 399
Author(s):  
Federica Zavaglio ◽  
Loretta Fiorina ◽  
Nicolás M. Suárez ◽  
Chiara Fornara ◽  
Marica De Cicco ◽  
...  
Keyword(s):  
Human Cytomegalovirus ◽  
Primary Infection ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Background Strain ◽  
Specific Igg ◽  
Cytomegalovirus Infections ◽  
Specific Igg Antibodies

Background: Strain-specific antibodies to human cytomegalovirus (HCMV) glycoproteins B and H (gB and gH) have been proposed as a potential diagnostic tool for identifying reinfection. We investigated genotype-specific IgG antibody responses in parallel with defining the gB and gH genotypes of the infecting viral strains. Methods: Subjects with primary (n = 20) or non-primary (n = 25) HCMV infection were studied. The seven gB (gB1-7) and two gH (gH1-2) genotypes were determined by real-time PCR and whole viral genome sequencing, and genotype-specific IgG antibodies were measured by a peptide-based enzyme-linked immunosorbent assay (ELISA). Results: Among subjects with primary infection, 73% (n = 8) infected by gB1-HCMV and 63% (n = 5) infected by gB2/3-HCMV had genotype-specific IgG antibodies to gB (gB2 and gB3 are similar in the region tested). Peptides from the rarer gB4-gB7 genotypes had nonspecific antibody responses. All subjects infected by gH1-HCMV and 86% (n = 6) infected by gH2-HCMV developed genotype-specific responses. Among women with non-primary infection, gB and gH genotype-specific IgG antibodies were detected in 40% (n = 10) and 80% (n = 20) of subjects, respectively. Conclusions: Peptide-based ELISA is capable of detecting primary genotype-specific IgG responses to HCMV gB and gH, and could be adopted for identifying reinfections. However, about half of the subjects did not have genotype-specific IgG antibodies to gB.

Antibody responses to fluke cysteine proteinases in Paragonimus- and Fasciola-infected rats

1998 ◽  
Vol 72 (3) ◽  
pp. 187-191 ◽  
Author(s):  
T. Ikeda
Keyword(s):  
Cross Reactivity ◽  
Antibody Responses ◽  
Cysteine Proteinases ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Capture Elisa ◽  
Igm Antibody ◽  
Specific Igg ◽  
Secretory Products ◽  
Specific Igg Antibodies

AbstractIgG and IgM antibody responses to fluke cysteine proteinases in Paragonimus ohirai- and Fasciola sp.-infected rats were followed by means of cystatin capture ELISA using fluke excretory-secretory products for 10 weeks after infection. The specific IgG antibodies were detectable at week 2 postinfection in all P. ohirai-infected and some Fasciola-infected rats. Levels of specific IgG antibodies increased rapidly between week 2 and 6, and slightly thereafter, in both infected groups. From week 3, specific IgG antibody levels were higher in Fasciola-infected than P. ohirai-infected rats. Sera from infected rats did not react with heterologous cysteine proteinases throughout the infection periods. In both infected groups, the kinetic patterns of specific IgM antibody responses were similar to those of specific IgG antibody responses although the ELISA levels of the IgM antibody responses were much lower. In abnormal infections with P. ohirai metacercariae x-irradiated at 2 krad, the specific IgG antibodies were detectable at week 2 postinfection with similar ELISA values to normal P. ohirai infection, but thereafter increased little. In infections with P. westermani, for which the rat is not a suitable host, even stunted worms induced a comparable specific IgG antibody response, although the response was lower than in normal infections with P. ohirai. These results indicate that cystatin capture ELISA can distinguish clearly between Paragonimus and Fasciola infections which show immunodiagnostic cross-reactivity and is useful even in the early stages of the infection and in the infection of unsuitable hosts.

scholarly journals Antibodies to Protein but Not Glycolipid Structures Are Important for Host Defense againstMycoplasma pneumoniae

2018 ◽  
Vol 87 (2) ◽  
Author(s):  
Patrick M. Meyer Sauteur ◽  
Adrianus C. J. M. de Bruijn ◽  
Catarina Graça ◽  
Anne P. Tio-Gillen ◽  
Silvia C. Estevão ◽  
...  
Keyword(s):  
Neurological Disorders ◽  
Antibody Formation ◽  
Antibody Responses ◽  
Igg Antibodies ◽  
Wild Type ◽  
Content Type ◽  
Bruton Tyrosine Kinase ◽  
Specific Igg ◽  
Deficient Mice ◽  
Specific Igg Antibodies

ABSTRACTAntibody responses toMycoplasma pneumoniaecorrelate with pulmonaryM. pneumoniaeclearance. However,M. pneumoniae-specific IgG antibodies can cross-react with the myelin glycolipid galactocerebroside (GalC) and cause neurological disorders. We assessed whether antiglycolipid antibody formation is part of the physiological immune response toM. pneumoniae. We show that antibodies againstM. pneumoniaeproteins and glycolipids arise in serum ofM. pneumoniae-infected children and mice. Although antibodies toM. pneumoniaeglycolipids were mainly IgG, anti-GalC antibodies were only IgM. B-1a cells, shown to aid in protection against pathogen-derived glycolipids, are lacking in Bruton tyrosine kinase (Btk)-deficient mice.M. pneumoniae-infected Btk-deficient mice developedM. pneumoniae-specific IgG responses toM. pneumoniaeproteins but not toM. pneumoniaeglycolipids, including GalC. The equal recovery fromM. pneumoniaeinfection in Btk-deficient and wild-type mice suggests that pulmonaryM. pneumoniaeclearance is predominantly mediated by IgG reactive withM. pneumoniaeproteins and thatM. pneumoniaeglycolipid-specific IgG or IgM is not essential. These data will guide the development ofM. pneumoniae-targeting vaccines that avoid the induction of neurotoxic antibodies.

scholarly journals Polymorphisms in B Cell Co-Stimulatory Genes Are Associated with IgG Antibody Responses against Blood–Stage Proteins of Plasmodium vivax

PLoS ONE ◽  
2016 ◽  
Vol 11 (2) ◽  
pp. e0149581 ◽  
Author(s):  
Gustavo C. Cassiano ◽  
Adriana A. C. Furini ◽  
Marcela P. Capobianco ◽  
Luciane M. Storti-Melo ◽  
Maristela G. Cunha ◽  
...  
Keyword(s):  
B Cell ◽  
Plasmodium Vivax ◽  
Antibody Responses ◽  
Blood Stage ◽  
Igg Antibody

scholarly journals Evaluation of CpG-ODN-Adjuvanted Toxoplasma gondii Virus-Like Particle Vaccine upon One, Two, and Three Immunizations

Pharmaceutics ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 989
Author(s):  
Hae-Ji Kang ◽  
Ki-Back Chu ◽  
Min-Ju Kim ◽  
Hyunwoo Park ◽  
Hui Jin ◽  
...  
Keyword(s):  
B Cells ◽  
Toxoplasma Gondii ◽  
Protective Immunity ◽  
Protective Efficacy ◽  
Antibody Responses ◽  
Strongly Correlated ◽  
Cpg Odn ◽  
Virus Like Particle ◽  
Iga Antibody ◽  
Specific Igg

Successful vaccines against specific pathogens often require multiple immunizations and adjuvant usage. Yet, assessing the protective efficacy of different immunization regimens with adjuvanted Toxoplasma gondii vaccines remains elusive. In this study, we investigated the vaccine efficacy induced by CpG-ODN-adjuvanted T. gondii virus-like particles (VLPs) after challenge infection with T. gondii (ME49) in mice (BALB/c) upon one, two, and three immunizations. Immunization with adjuvanted T. gondii VLPs induced higher levels of T. gondii-specific IgG and/or IgA antibody responses, germinal center (GC) B cells, total B cells, and CD4+ and CD8+ T cells compared with unadjuvanted VLPs. Increasing the number of immunizations was strongly correlated with enhanced protective immunity against T. gondii in mice, with the highest protection being demonstrated in mice thrice-immunized with either adjuvanted T. gondii VLPs or VLPs alone. Notably, lesser bodyweight reductions and cerebral cyst counts were observed in mice receiving multiple immunizations with the adjuvanted VLPs, thereby confirming the effectiveness of adjuvanted boost immunizations. These results demonstrated that multiple immunizations with T. gondii VLPs is an effective approach, and the CpG-ODN can be developed as an effective adjuvant for T. gondii VLP vaccines.

scholarly journals Occurrence of COVID-19 Symptoms During SARS-CoV-2 Infection Defines Waning of Humoral Immunity

2021 ◽  
Vol 12 ◽  
Author(s):  
Jun Wu ◽  
Bo-Yun Liang ◽  
Yao-Hui Fang ◽  
Hua Wang ◽  
Xiao-Li Yang ◽  
...  
Keyword(s):  
Humoral Immunity ◽  
Antibody Responses ◽  
Surveillance Program ◽  
Igg Antibodies ◽  
Immunization Programs ◽  
Specific Igg ◽  
Asymptomatic Infections ◽  
Asymptomatic Individuals ◽  
Specific Igg Antibodies

Approximately half of the SARS-CoV-2 infections occur without apparent symptoms, raising questions regarding long-term humoral immunity in asymptomatic individuals. Plasma levels of immunoglobulin G (IgG) and M (IgM) against the viral spike or nucleoprotein were determined for 25,091 individuals enrolled in a surveillance program in Wuhan, China. We compared 405 asymptomatic individuals who mounted a detectable antibody response with 459 symptomatic COVID-19 patients. The well-defined duration of the SARS-CoV-2 endemic in Wuhan allowed a side-by-side comparison of antibody responses following symptomatic and asymptomatic infections without subsequent antigen re-exposure. IgM responses rapidly declined in both groups. However, both the prevalence and durability of IgG responses and neutralizing capacities correlated positively with symptoms. Regardless of sex, age, and body weight, asymptomatic individuals lost their SARS-CoV-2-specific IgG antibodies more often and rapidly than symptomatic patients did. These findings have important implications for immunity and favour immunization programs including individuals after asymptomatic infections.

scholarly journals Modified Vaccinia Ankara Based SARS-CoV-2 Vaccine Expressing Full-Length Spike Induces Strong Neutralizing Antibody Response

2020 ◽  
Author(s):  
Nanda Kishore Routhu ◽  
Sailaja Gangadhara ◽  
Narayanaiah Cheedarla ◽  
Ayalnesh Shiferaw ◽  
Sheikh Abdul Rahman ◽  
...  
Keyword(s):  
Antibody Response ◽  
Room Temperature ◽  
Vaccine Candidate ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Full Length ◽  
Spike Protein ◽  
Strongly Correlated ◽  
Igg Antibodies ◽  
Potential Vaccine

AbstractThere is a great need for the development of vaccines for preventing SARS-CoV-2 infection and mitigating the COVID-19 pandemic. Here, we developed two modified vaccinia Ankara (MVA) based vaccines which express either a membrane anchored full-length spike protein (MVA/S) stabilized in a prefusion state or the S1 region of the spike (MVA/S1) which forms trimers and is secreted. Both immunogens contained the receptor-binding domain (RBD) which is a known target of antibody-mediated neutralization. Following immunizations with MVA/S or MVA/S1, both spike protein recombinants induced strong IgG antibodies to purified full-length SARS-CoV-2 spike protein. The MVA/S induced a robust antibody response to purified RBD, S1 and S2 whereas MVA/S1 induced an antibody response to the S1 region outside of the RBD region. Both vaccines induced an antibody response in the lung and that was associated with induction of bronchus-associated lymphoid tissue. MVA/S but not MVA/S1 vaccinated mice generated robust neutralizing antibody responses against SARS-CoV-2 that strongly correlated with RBD antibody binding titers. Mechanistically, S1 binding to ACE-2 was strong but reduced following prolonged pre-incubation at room temperature suggesting confirmation changes in RBD with time. These results demonstrate MVA/S is a potential vaccine candidate against SARS-CoV-2 infection.

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