scholarly journals A high-affinity antibody against the CSP N-terminal domain lacks Plasmodium falciparum inhibitory activity

2020 ◽  
Author(s):  
Elaine Thai ◽  
Giulia Costa ◽  
Anna Weyrich ◽  
Rajagopal Murugan ◽  
David Oyen ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Plasmodium Falciparum ◽  
Antibody Response ◽  
Health Concern ◽  
Binding Motif ◽  
Specific Monoclonal Antibody ◽  
High Affinity ◽  
Terminal Domain ◽  
Immunogen Design

AbstractMalaria is a global health concern and research efforts are ongoing to develop a superior vaccine to RTS,S/AS01. To guide immunogen design, we seek a comprehensive understanding of the protective humoral response against Plasmodium falciparum circumsporozoite protein (PfCSP). In contrast to the well-studied responses to the repeat region and the C-terminus, the antibody response against the N-terminal domain of PfCSP (N-CSP) remains obscure. Here, we characterized the molecular recognition and functional efficacy of the N-CSP-specific monoclonal antibody 5D5. The crystal structure at 1.85 Å resolution revealed that 5D5 binds an α-helical epitope in N-CSP with high affinity through extensive shape and charge complementarity, and the unusual utilization of an N-linked glycan. Nevertheless, functional studies indicated low 5D5 binding to live Pf sporozoites, and lack of sporozoite inhibition in vitro and in mosquitoes. Overall, our data on low recognition and inhibition of sporozoites do not support the inclusion of the 5D5 epitope into the next generation of CSP-based vaccines.Summary StatementThe Plasmodium falciparum sporozoite surface protein, PfCSP, is an attractive vaccine target, but the antibody response against the CSP N-terminal domain has remained understudied. Here, to guide immunogen design, Thai et al. provide insights into the binding motif and functional efficacy of the N-terminal domain-specific monoclonal antibody, 5D5.

scholarly journals A high-affinity antibody against the CSP N-terminal domain lacks Plasmodium falciparum inhibitory activity

2020 ◽  
Vol 217 (11) ◽  
Author(s):  
Elaine Thai ◽  
Giulia Costa ◽  
Anna Weyrich ◽  
Rajagopal Murugan ◽  
David Oyen ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Humoral Response ◽  
Health Concern ◽  
Functional Studies ◽  
High Affinity ◽  
Terminal Domain ◽  
C Terminus ◽  
Immunogen Design

Malaria is a global health concern, and research efforts are ongoing to develop a superior vaccine to RTS,S/AS01. To guide immunogen design, we seek a comprehensive understanding of the protective humoral response against Plasmodium falciparum (Pf) circumsporozoite protein (PfCSP). In contrast to the well-studied responses to the repeat region and the C-terminus, the antibody response against the N-terminal domain of PfCSP (N-CSP) remains obscure. Here, we characterized the molecular recognition and functional efficacy of the N-CSP–specific monoclonal antibody 5D5. The crystal structure at 1.85-Å resolution revealed that 5D5 binds an α-helical epitope in N-CSP with high affinity through extensive shape and charge complementarity and the unusual utilization of an antibody N-linked glycan. Nevertheless, functional studies indicated low 5D5 binding to live Pf sporozoites and lack of sporozoite inhibition in vitro and in vivo. Overall, our data do not support the inclusion of the 5D5 N-CSP epitope into the next generation of CSP-based vaccines.

scholarly journals Monoclonal antibody AHN-1 inhibits phagocytosis by human neutrophils

Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 333-339
Author(s):  
KM Skubitz ◽  
DJ Weisdorf ◽  
PK Peterson
Keyword(s):  
Monoclonal Antibody ◽  
Lysosomal Enzyme ◽  
Surface Proteins ◽  
Superoxide Production ◽  
Human Neutrophils ◽  
Enzyme Release ◽  
Specific Monoclonal Antibody ◽  
Normal Human ◽  
Major Surface

The granulocyte-specific monoclonal antibody, AHN-1, immunoprecipitates two major surface-iodinated proteins of 105,000 and 145,000 to 150,000 daltons from normal human neutrophils. In this study, the effect of AHN- 1 on a number of neutrophil functions was evaluated in vitro. Both complement- and antibody-mediated phagocytosis were inhibited when human neutrophils were pretreated with AHN-1 and opsonized bacteria were used as targets. The inhibition of phagocytosis was specific, in that lysosomal enzyme release and chemotaxis were not altered by treatment with AHN-1. AHN-1 did inhibit superoxide production by neutrophils in response to particulate stimuli, but not in response to the soluble stimulus, 12-O-tetradecanoylphorbol-13-acetate. The data indicate that one or both of these surface proteins may be important in the process of phagocytosis. AHN-1 should be useful in isolating and further characterizing the nature of these molecules.

scholarly journals Cross-reactive antibody response to mRNA SARS-CoV-2 vaccine after recent COVID-19-specific monoclonal antibody therapy

2021 ◽  
Author(s):  
Stacey Schultz-Cherry ◽  
Maureen A McGargill ◽  
Paul G Thomas ◽  
Jeremie H Estepp ◽  
Aditya H Gaur ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Immune Responses ◽  
Antibody Response ◽  
Antibody Therapy ◽  
Antibody Responses ◽  
Monoclonal Antibody Therapy ◽  
Receptor Binding Domain ◽  
Specific Monoclonal Antibody ◽  
Vaccine Failure ◽  
Reactive Antibody

Abstract Efficacy of COVID-19 vaccines administered after COVID-19-specific monoclonal antibody is unknown, and ‘antibody interference’ might hinder immune responses leading to vaccine failure. In an IRB-approved prospective study, we found that an individual who received mRNA COVID-19 vaccination <40 days after COVID-19-specific monoclonal antibody therapy for symptomatic COVID-19 had similar post-vaccine antibody responses to SARS-CoV-2 receptor binding domain (RBD), for four important SARS-CoV-2 variants (B.1, B.1.1.7, B.1.351 and P.1), as other participants who were also vaccinated following COVID-19. Vaccination against COVID-19 shortly after COVID-19-specific monoclonal antibody can boost and expand antibody protection, questioning the need to delay vaccination in this setting.

scholarly journals A single domain of yeast poly(A)-binding protein is necessary and sufficient for RNA binding and cell viability.

1987 ◽  
Vol 7 (9) ◽  
pp. 3268-3276 ◽  
Author(s):  
A B Sachs ◽  
R W Davis ◽  
R D Kornberg
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Association Constant ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
High Affinity ◽  
Terminal Domain ◽  
Necessary And Sufficient

The poly(A)-binding protein (PAB) gene of Saccharomyces cerevisiae is essential for cell growth. A 66-amino acid polypeptide containing half of a repeated N-terminal domain can replace the entire protein in vivo. Neither an octapeptide sequence conserved among eucaryotic RNA-binding proteins nor the C-terminal domain of PAB is required for function in vivo. A single N-terminal domain is nearly identical to the entire protein in the number of high-affinity sites for poly(A) binding in vitro (one site with an association constant of approximately 2 X 10(7) M-1) and in the size of the binding site (12 A residues). Multiple N-terminal domains afford a mechanism of PAB transfer between poly(A) strands.

scholarly journals Yeast PIAS-type Ull1/Siz1 Is Composed of SUMO Ligase and Regulatory Domains

2005 ◽  
Vol 280 (43) ◽  
pp. 35822-35828 ◽  
Author(s):  
Yoshimitsu Takahashi ◽  
Yoshiko Kikuchi
Keyword(s):  
Neck Region ◽  
Binding Motif ◽  
Conjugation System ◽  
Regulatory Domains ◽  
Terminal Domain ◽  
Sumo Ligase ◽  
Lysine Residues ◽  
Protein Instability ◽  
Two Hybrid

SUMO (small ubiquitin-like modifier)/Smt3 (suppressor of mif two) is a member of the ubiquitin-related protein family and is known to conjugate with many proteins. In the sumoylation pathway, SUMO/Smt3 is transferred to substrate lysine residues through the thioester cascade of E1 (activating enzyme) and E2 (conjugating enzyme), and E3 (SUMO ligase) functions as an adaptor between E2 and each substrate. Yeast Ull1 (ubiquitin-like protein ligase 1)/Siz1, a PIAS (protein inhibitor of activated STAT)-type SUMO ligase, modifies both cytoplasmic and nuclear proteins. In this paper, we performed a domain analysis of Ull1/Siz1 by constructing various deletion mutants. A novel conserved N-terminal domain, called PINIT, as well as the RING-like domain (SP-RING) were required for the SUMO ligase activity in the in vitro conjugation system and for interaction with Smt3 in an in vitro binding assay. The most distal N-terminal region, which contains a putative DNA-binding SAF-A/B, Acinus, and PIAS (SAP) motif, was not required for the ligase activity but was involved in nuclear localization. A strong SUMO-binding motif was identified, which interacted with Smt3 in the two-hybrid system but was not necessary for the ligase activity. The most distal C-terminal domain was important for stable localization at the bud neck region and thereby for the substrate recognition of septins. Furthermore, the C-terminal half conferred protein instability on Ull1/Siz1. Taken together, we conclude that the SP-RING and PINIT of Ull1/Siz1 are core domains of the SUMO ligase, and the other domains are regulatory for protein stability and subcellular localization.

Invasion of erythrocytes in vitro by Plasmodium falciparum can be inhibited by monoclonal antibody directed against an S antigen

1985 ◽  
Vol 7 (6) ◽  
pp. 587-593 ◽  
Author(s):  
A. SAUL ◽  
J. COOPER ◽  
L. INGRAM ◽  
R. F. ANDERS ◽  
G. V. BROWN
Keyword(s):  
Monoclonal Antibody ◽  
Plasmodium Falciparum

A new anti-idiotype antibody capable of binding rituximab on the surface of lymphoma cells

Blood ◽  
2004 ◽  
Vol 104 (8) ◽  
pp. 2540-2542 ◽  
Author(s):  
Mark S. Cragg ◽  
Mike B. Bayne ◽  
Alison L. Tutt ◽  
Ruth R. French ◽  
Stephen Beers ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Surface ◽  
Immunoglobulin G ◽  
Human Immunoglobulin ◽  
Lymphoma Cells ◽  
Fine Specificity ◽  
High Affinity ◽  
Anti Cd20

Abstract The chimeric anti-CD20 monoclonal antibody (mAb), rituximab, is an established part of the management of many non-Hodgkin lymphomas. The in vivo action of rituximab remains elusive, and this partially reflects a lack of highly specific reagents to detect rituximab binding at the cell surface. Here we report a new high-affinity mAb (MB2A4) with fine specificity for the idiotype of rituximab. It is able to detect rituximab in vitro, in the presence of high levels of human immunoglobulin G (IgG), in the serum of patients receiving rituximab therapy, and, surprisingly, when rituximab is bound to CD20 on the cell surface. We propose that the anti–idiotype (Id) binds to rituximab molecules bound univalently at the cell surface, facilitated by the relatively high off-rate of rituximab. This reagent provides new insights into the binding of rituximab at the cell surface and demonstrates a mode of binding that could be exploited for the surface detection of other mAbs with clinical and biologic applications.

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