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MAbs 2024Integrins are cell surface receptors that mediate the interactions of cells with their surroundings and play essential roles in cell adhesion, migration, and...
Integrins are cell surface receptors that mediate the interactions of cells with their surroundings and play essential roles in cell adhesion, migration, and homeostasis. Eight of the 24 integrins bind to the tripeptide Arg-Gly-Asp (RGD) motif in their extracellular ligands, comprising the RGD-binding integrin subfamily. Despite similarity in recognizing the RGD motif and some redundancy, these integrins can selectively recognize RGD-containing ligands to fulfill specific functions in cellular processes. Antibodies against individual RGD-binding integrins are desirable for investigating their specific functions, and were selected here from a synthetic yeast-displayed Fab library. We discovered 11 antibodies that exhibit high specificity and affinity toward their target integrins, i.e. αVβ3, αVβ5, αVβ6, αVβ8, and α5β1. Of these, six are function-blocking antibodies and contain a ligand-mimetic R(G/L/T)D motif in their CDR3 sequences. We report antibody-binding specificity, kinetics, and binding affinity for purified integrin ectodomains, as well as intact integrins on the cell surface. We further used these antibodies to reveal binding preferences of the αV subunit for its 5 β-subunit partners: β6 = β8 > β3 > β1 = β5.
Topics: Humans; Saccharomyces cerevisiae; Integrin beta Chains; Integrin alphaV; Integrins; Peptide Library; Cell Surface Display Techniques; Protein Binding; Antibody Specificity
PubMed: 38889315
DOI: 10.1080/19420862.2024.2365891 -
PLoS Neglected Tropical Diseases Jun 2024The standard diagnosis of Ascaris lumbricoides and other soil-transmitted helminth (STH) infections relies on the detection of worm eggs by copromicroscopy. However,...
BACKGROUND
The standard diagnosis of Ascaris lumbricoides and other soil-transmitted helminth (STH) infections relies on the detection of worm eggs by copromicroscopy. However, this method is dependent on worm patency and shows only limited accuracy in low-intensity infection settings. We aimed to decipher the diagnostic accuracy of different antibodies using various Ascaris antigens in reference to copromicroscopy and quantitative PCR (qPCR), four months after national STH preventative chemotherapy among school children in western Kenya.
METHODOLOGY
STH infection status of 390 school children was evaluated via copromicroscopy (Kato-Katz and mini-FLOTAC) and qPCR. In parallel, Ascaris-specific antibody profiles against larval and adult worm lysates, and adult worm excretory-secretory (ES) products were determined by enzyme-linked immunosorbent assay. Antibody cross-reactivity was evaluated using the closely related zoonotic roundworm species Toxocara cati and Toxocara canis. The diagnostic accuracy of each antibody was evaluated using receiver operating curve analysis and the correspondent area under the curve (AUC).
PRINCIPAL FINDINGS
Ascaris was the predominant helminth infection with an overall prevalence of 14.9% (58/390). The sensitivity of mini-FLOTAC and Kato-Katz for Ascaris diagnosis reached only 53.5% and 63.8%, respectively compared to qPCR. Although being more sensitive, qPCR values correlated with microscopic egg counts (R = -0.71, P<0.001), in contrast to antibody levels. Strikingly, IgG antibodies recognizing the ES products of adult Ascaris worms reliably diagnosed active Ascaris infection as determined by qPCR and microscopy, with IgG1 displaying the highest accuracy (AUC = 0.83, 95% CI: 0.75-0.91).
CONCLUSION
IgG1 antibody responses against adult Ascaris-ES products hold a promising potential for complementing the standard fecal and molecular techniques employed for monitoring Ascaris infections. This is of particular importance in the context of deworming programs as the antibody diagnostic accuracy was independent of egg counts.
Topics: Ascariasis; Humans; Antibodies, Helminth; Animals; Child; Feces; Female; Male; Kenya; Sensitivity and Specificity; Adolescent; Microscopy; Multiplex Polymerase Chain Reaction; Real-Time Polymerase Chain Reaction; Ascaris lumbricoides; Antigens, Helminth; Enzyme-Linked Immunosorbent Assay; Ascaris; Endemic Diseases
PubMed: 38889190
DOI: 10.1371/journal.pntd.0012279 -
The Journal of Infectious Diseases Jun 2024Young children and older adults are susceptible for invasive pneumococcal disease (IPD) caused by Streptococcus pneumoniae. Pneumococcal protein-specific antibodies play...
BACKGROUND
Young children and older adults are susceptible for invasive pneumococcal disease (IPD) caused by Streptococcus pneumoniae. Pneumococcal protein-specific antibodies play a protective role against IPD; however, not much is known about the pace of acquisition, maturation, and maintenance of these antibodies throughout life.
METHODS
Immunoglobulin G (IgG) and IgA levels, avidity, and/or specificity to the pneumococcal proteome in serum and saliva from healthy young children, adults, and older adults, with known carriage status, were measured by enzyme-linked immunosorbent assay (ELISA) and 2-dimensional western blotting against ΔcpsTIGR4.
RESULTS
Eleven-month-old children, the youngest age group tested, had the lowest pneumococcal proteome-specific IgG and IgA levels and avidity in serum and saliva, followed by 24-month-old children and were further elevated in adult groups. Among adult groups, the parents had the highest serum and saliva IgG and IgA antibody levels. In children, antibody levels and avidity correlated with daycare attendance and presence of siblings, posing as proxy for exposure and immunization. Immunodominance patterns slightly varied throughout life.
CONCLUSIONS
Humoral immunity against the pneumococcal proteome is acquired through multiple episodes of pneumococcal exposure. Low-level and low-avidity antiproteome antibody profiles in young children may contribute to their IPD susceptibility, while in overall antiproteome antibody-proficient older adults other factors likely play a role.
PubMed: 38888894
DOI: 10.1093/infdis/jiae255 -
Journal of Medical Virology Jun 2024Human immunodeficiency virus (HIV) infection is still a global public health issue, and the development of an effective prophylactic vaccine inducing potent neutralizing...
Human immunodeficiency virus (HIV) infection is still a global public health issue, and the development of an effective prophylactic vaccine inducing potent neutralizing antibodies remains a significant challenge. This study aims to explore the inflammation-related proteins associated with the neutralizing antibodies induced by the DNA/rTV vaccine. In this study, we employed the Olink chip to analyze the inflammation-related proteins in plasma in healthy individuals receiving HIV candidate vaccine (DNA priming and recombinant vaccinia virus rTV boosting) and compared the differences between neutralizing antibody-positive (nab + ) and -negative(nab-) groups. We identified 25 differentially expressed factors and conducted enrichment and correlation analysis on them. Our results revealed that significant expression differences in artemin (ARTN) and C-C motif chemokine ligand 23 (CCL23) between nab+ and -nab- groups. Notably, the expression of CCL23 was negatively corelated to the ID of neutralizing antibodies and the intensity of the CD4 T cell responses. This study enriches our understanding of the immune picture induced by the DNA/rTV vaccine, and provides insights for future HIV vaccine development.
Topics: Humans; Antibodies, Neutralizing; Vaccinia virus; HIV Antibodies; HIV-1; Adult; Proteomics; AIDS Vaccines; Male; HIV Infections; Vaccines, DNA; Female; Healthy Volunteers; Vaccines, Synthetic; Plasma; Young Adult
PubMed: 38888113
DOI: 10.1002/jmv.29749 -
RMD Open Jun 2024The objective of this study is to evaluate whether anti-neutrophil cytoplasmic antibody (ANCA) seropositivity and antigen specificity at diagnosis have predictive...
OBJECTIVES
The objective of this study is to evaluate whether anti-neutrophil cytoplasmic antibody (ANCA) seropositivity and antigen specificity at diagnosis have predictive utility in paediatric-onset small vessel vasculitis.
METHODS
Children and adolescents with small vessel vasculitis (n=406) stratified according to the absence (n=41) or presence of ANCA for myeloperoxidase (MPO) (n=129) and proteinase-3 (PR3) (n=236) were compared for overall and kidney-specific disease activity at diagnosis and outcomes between 1 and 2 years using retrospective clinical data from the ARChiVe/Paediatric Vasculitis Initiative registry to fit generalised linear models.
RESULTS
Overall disease activity at diagnosis was higher in PR3-ANCA and MPO-ANCA-seropositive individuals compared with ANCA-negative vasculitis. By 1 year, there were no significant differences, based on ANCA positivity or specificity, in the likelihood of achieving inactive disease (~68%), experiencing improvement (≥87%) or acquiring damage (~58%). Similarly, and in contrast to adult-onset ANCA-associated vasculitis, there were no significant differences in the likelihood of having a relapse (~11%) between 1 and 2 years after diagnosis. Relative to PR3-ANCA, MPO-ANCA seropositivity was associated with a higher likelihood of kidney involvement (OR 2.4, 95% CI 1.3 to 4.7, p=0.008) and severe kidney dysfunction (Kidney Disease Improving Global Outcomes (KDIGO) stages 4-5; OR 6.04, 95% CI 2.77 to 13.57, p<0.001) at onset. Nonetheless, MPO-ANCA seropositive individuals were more likely to demonstrate improvement in kidney function (improved KDIGO category) within 1 year of diagnosis than PR3-ANCA seropositive individuals with similarly severe kidney disease at onset (p<0.001).
CONCLUSIONS
The results of this study suggest important paediatric-specific differences in the predictive value of ANCA compared with adult patients that should be considered when making treatment decisions in this population.
Topics: Humans; Antibodies, Antineutrophil Cytoplasmic; Male; Female; Child; Adolescent; Peroxidase; Myeloblastin; Retrospective Studies; Kidney Diseases; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Biomarkers; Child, Preschool; Prognosis; Predictive Value of Tests
PubMed: 38886004
DOI: 10.1136/rmdopen-2024-004315 -
JCI Insight Jun 2024Antibody-mediated depletion studies have demonstrated that CD8+ T cells are required for effective immune control of SIV. However, this approach is confounded by several...
Antibody-mediated depletion studies have demonstrated that CD8+ T cells are required for effective immune control of SIV. However, this approach is confounded by several factors, including reactive CD4+ T cell proliferation, and further provides no specificity information. We circumvented these limitations by selectively depleting CD8+ T cells specific for the Gag epitope CTPYDINQM (CM9) via the administration of immunotoxin-conjugated tetrameric complexes of CM9/Mamu-A*01. Immunotoxin administration effectively depleted circulating but not tissuelocalized CM9-specific CD8+ T cells, akin to the bulk depletion pattern observed with antibodies directed against CD8. However, we found no evidence to indicate that circulating CM9-specific CD8+ T cells suppressed viral replication in Mamu-A*01+ rhesus macaques during acute or chronic progressive infection with a pathogenic strain of SIV. This observation extended to macaques with established infection during and after continuous antiretroviral therapy. In contrast, natural controller macaques experienced dramatic increases in plasma viremia after immunotoxin administration, highlighting the importance of CD8+ T cell-mediated immunity against CM9. Collectively, these data showed that CM9-specific CD8+ T cells were necessary but not sufficient for robust immune control of SIV in a nonhuman primate model and, more generally, validated an approach that could inform the design of next-generation vaccines against HIV-1.
PubMed: 38885329
DOI: 10.1172/jci.insight.174168 -
Molecular Therapy. Methods & Clinical... Jun 2024Over 4% of the global population is estimated to live with autoimmune disease, necessitating immunosuppressive treatment that is often chronic, not curative, and carries...
Over 4% of the global population is estimated to live with autoimmune disease, necessitating immunosuppressive treatment that is often chronic, not curative, and carries associated risks. B cells have emerged as key players in disease pathogenesis, as evidenced by partial responsiveness to B cell depletion by antibody-based therapies. However, these treatments often have transient effects due to incomplete depletion of tissue-resident B cells. Chimeric antigen receptor (CAR) T cells targeting B cells have demonstrated efficacy in refractory systemic lupus erythematosus. To this end, we developed an anti-CD19 CAR T cell product candidate, CABA-201, containing a clinically evaluated fully human CD19 binder (IC78) with a 4-1BB costimulatory domain and CD3 zeta stimulation domain for treatment refractory autoimmune disease. Here, we demonstrate specific cytotoxic activity of CABA-201 against CD19 Nalm6 cells with no off-target effects on primary human cells. Novel examination of CABA-201 generated from primary T cells from multiple patients with autoimmune disease displayed robust CAR surface expression and effective elimination of the intended target autologous CD19 B cells . Together, these findings support the tolerability and activity of CABA-201 for clinical development in patients with autoimmune disease.
PubMed: 38883975
DOI: 10.1016/j.omtm.2024.101267 -
Journal of Pregnancy 2024There is insufficient evidence to assess the risk of the production of clinically important alloimmune irregular red blood cell (RBC) antibodies in first-time pregnant... (Comparative Study)
Comparative Study
Comparison of the Detection Rate and Specificity of Irregular Red Blood Cell Antibodies Between First-Time Pregnant Women and Women With a History of Multiple Pregnancies Among 18,010 Chinese Women.
There is insufficient evidence to assess the risk of the production of clinically important alloimmune irregular red blood cell (RBC) antibodies in first-time pregnant women. Using the microcolumn gel antiglobulin method, 18,010 Chinese women with a history of pregnancy and pregnant women were screened for irregular RBC antibodies, and for those with positive test results, antibody specificity was determined. The detection rate and specificity of irregular RBC antibodies in women with a history of multiple pregnancies (two or more) and first-time pregnant women were determined. In addition to 25 patients who passively acquired anti-D antibodies via an intravenous anti-D immunoglobulin injection, irregular RBC antibodies were detected in 121 (0.67%) of the 18,010 women. Irregular RBC antibodies were detected in 93 (0.71%) of the 13,027 women with a history of multiple pregnancies, and antibody specificity was distributed mainly in the Rh, MNSs, Lewis, and Kidd blood group systems; irregular RBC antibodies were detected in 28 (0.56%) of the 4983 first-time pregnant women, and the antibody specificity was distributed mainly in the MNSs, Rh, and Lewis blood group systems. The difference in the percentage of patients with irregular RBC antibodies between the two groups was insignificant ( = 1.248, > 0.05). Of the 121 women with irregular RBC antibodies, nine had anti-Mur antibodies, and one had anti-Di antibodies; these antibodies are clinically important but easily missed because the antigenic profile of the reagent RBCs that are commonly used in antibody screens does not include the antigens that are recognized by these antibodies. Irregular RBC antibody detection is clinically important for both pregnant women with a history of multiple pregnancies and first-time pregnant women. Mur and Di should be included in the antigenic profile of reagent RBCs that are used for performing antibody screens in the Chinese population.
Topics: Humans; Female; Pregnancy; Erythrocytes; China; Adult; Pregnancy, Multiple; Isoantibodies; Rho(D) Immune Globulin; Sensitivity and Specificity; Antibody Specificity; MNSs Blood-Group System; Asian People; Kidd Blood-Group System; East Asian People
PubMed: 38883212
DOI: 10.1155/2024/5539776 -
Microbes and Infection Jun 2024Antibody-dependent enhancement (ADE) of dengue virus (DENV) infection is one of the mechanisms contributing to increased severity during heterotypic, secondary...
Antibody-dependent enhancement (ADE) of dengue virus (DENV) infection is one of the mechanisms contributing to increased severity during heterotypic, secondary infection. The complement protein C1q has been shown to reduce the magnitude of ADE in vitro. Therefore, we investigated the mechanisms of C1q modulation of ADE, focusing on processes of viral entry. Using a model of ADE of DENV-1 infection in human myeloid cell lines in the presence of monoclonal antibodies, 4G2 and 2H2, we found that C1q produced nearly a 40-fold reduction of ADE of DENV-1 in K562 cells, but had no effect in U937 cells. In K562 cells, C1q reduced adsorption of DENV-1/4G2 and exerted a dual inhibitory effect on adsorption and internalization of DENV-1/2H2. Distinct endocytic pathways in the presence of antibody corresponded to conditions where C1q produced a differential action. Also, C1q did not affect the intrinsic cell response mediated by FcγR in human myeloid cells. The modulation of ADE of DENV-1 by C1q is dependent on the FcγR expressed on immune cells and the specificity of the antibody comprising the immune complex. Understanding protective and pathogenic mechanisms in the humoral response to DENV infections is crucial for the successful design of antivirals and vaccines.
PubMed: 38880233
DOI: 10.1016/j.micinf.2024.105378 -
Virology Jun 2024The hemagglutinin-esterase-fusion (HEF) protein binds 9-O-acetylated sialic acids-containing glycans on the cell surface and drives influenza D virus (IDV) entry. The...
The hemagglutinin-esterase-fusion (HEF) protein binds 9-O-acetylated sialic acids-containing glycans on the cell surface and drives influenza D virus (IDV) entry. The HEF is a primary determinant of the exceptional thermal and acid stability observed in IDV infection biology. Here, we expressed and purified the receptor binding domain (RBD) of the IDV HEF protein in Escherichia coli and characterized its receptor binding and antigenic properties. The data from these experiments indicate that (i) the RBD can bind with specificity to turkey red blood cells (RBC), and its binding can be specifically inhibited by IDV antibody; (ii) the RBD efficiently binds to the cell surface of MDCK cells expressing the receptor of IDV; and (iii) anti-RBD antibodies are capable of blocking RBD attachment to MDCK cells as well as of inhibiting the virus from agglutinating RBCs. These observations support the utility of this RBD in future receptor and entry studies of IDV.
PubMed: 38880069
DOI: 10.1016/j.virol.2024.110138