9NAQ

Cryo-EM structure of 110_C4 Fab in complex with CIDRa1.7 PfEMP1

9NAQ の概要

• エントリーDOI: 10.2210/pdb9naq/pdb
• EMDBエントリー: 49201
• 分子名称: 110_C4 Fab heavy chain, 110_C4 Fab light chain, Erythrocyte membrane protein 1 (3 entities in total)
• 機能のキーワード: serum antibody, cryo-em, monoclonal antibody, pfemp1, malaria, immune system
• 由来する生物種: Homo sapiens; 詳細
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 163476.92

構造登録者

Raghavan, S.S.R.,Ward, A.B. (登録日: 2025-02-12, 公開日: 2025-08-27)

主引用文献

Turner, L.,Nunez de Villavicencio Diaz, T.,Raghavan, S.S.R.,Kana, I.H.,Lyimo, E.,Reitzel, C.,Wang, C.W.,Berube, E.,Jensen, R.W.,Loeffler, J.R.,Fernandez-Quintero, M.L.,Theander, T.G.,Lusingu, J.P.A.,Le Bihan, T.,Han, X.,Minja, D.T.R.,Ward, A.B.,Ma, B.,Lavstsen, T.
Identification of broadly inhibitory anti-PfEMP1 antibodies by mass spectrometry sequencing of plasma IgG from a malaria-exposed child.
Proc.Natl.Acad.Sci.USA, 122:e2508744122-e2508744122, 2025

PubMed Abstract: pathology is driven by the accumulation of parasite-infected erythrocytes in blood capillaries. This sequestration process is mediated by the parasite's erythrocyte membrane protein 1 (PfEMP1) adhesins, which bind select endothelial cell receptors. A subset of PfEMP1 binding human endothelial protein C receptor (EPCR) through their cysteine-rich interdomain region alpha 1 (CIDRα1) domains drives the pathogenesis to severe malaria. Despite high sequence diversity among CIDRα1 domains, individuals living in malaria-endemic regions become immune to severe disease in part through acquisition of antibodies inhibiting the PfEMP1-EPCR interaction. Here, we demonstrate an approach to identify pathogen-specific human monoclonal antibodies from plasma, combining mass spectrometry analysis of antigen-purified polyclonal plasma IgG and Ig transcript sequencing. We identified a clonal family of broadly reactive and EPCR binding-inhibitory human monoclonal antibodies against CIDRα1. The antibodies, isolated from a 9-y-old child, exhibited potent inhibition of EPCR binding broadly across CIDRα1 domains as well as binding of infected erythrocytes to EPCR. Structural analysis of one antibody variant complexed with CIDRα1 revealed a shared epitope of the clonal antibody family overlapping the EPCR binding site and the epitopes of two previously identified monoclonal antibodies, C7 and C74, with similar functional patterns. However, although C7, C74, and 110-3 antibodies all depend on the same few residues conserved in CIDRα1 to retain EPCR binding, the 110-3 antibodies contact additional variable residues, reducing their breadth of reactivity across the CIDRα1 family. These data bolster the hypothesis that broadly inhibitory antibodies against severe malaria-associated PfEMP1 target similar epitopes and are commonly developed in malaria-exposed individuals.

PubMed: 40833410
DOI: 10.1073/pnas.2508744122

実験手法

ELECTRON MICROSCOPY (3.4 Å)