Three‐dimensional structure of the Fab fragment of a neutralizing antibody to human rhinovirus serotype 2

Abstract

The crystal structure of the antigen‐binding fragment of a monoclonal antibody (8F5) that neutralizes human rhinovirus serotype 2 has been determined by X‐ray diffraction studies. Antibody 8F5, obtained by immunization with native HRV2 virions, cross‐reacts with peptides of the viral capsid protein VP2, which contribute to the neutralizing immunogenic site B in this serotype. The structure was solved by the molecular replacement method and has been refined to an R‐factor of 18.9% at 2.8 Å resolution. The elbow angle, relating the variable and constant modules of the molecule is 127°, representing the smallest elbow angle observed so far in an Fab fragment. Furthermore, the charged residues of the epitope can be well accommodated in the antigen‐binding site. This is the first crystal structure reported for an antibody directed against an icosahedral virus.

Human Rhinovirus Type 2-Antibody Complexes Enter and Infect Cells via Fc-γ Receptor IIB1

“…These cells were maintained at a density between 10 5 and 10 6 viable cells/ml. HRV2, originally obtained from the ATCC, was propagated and labeled with 35 S-labeled cysteine/methionine (American Radiolabeled Chemicals, Inc., St. Louis, Mo.) as described previously (23).…”

“…35 S-labeled HRV2 (6 ϫ 10 4 cpm) was preincubated with or without MAbs (8F5, 40 g/ml; 3B10, 15 g/ml) for 1 h at RT in 500 l of MEM containing 10 mM EDTA under rotation and then cooled to 4°C. Subsequently, 5 ϫ 10 6 HeLa-FcRII suspension cells (following depletion of endogenous IgG) in 1 ml of MEM-10 mM EDTA were added and mixed, and the suspensions were divided into three aliquots (500 l each) and incubated for 1 h at 4°C.…”

“…Lysosomal degradation of MAb-complexed 35 S-labeled HRV2. 35 S-labeled HRV2 (3 ϫ 10 5 cpm) was preincubated with MAbs (8F5, 40 g/ml; 3B10, 15 g/ml) for 1 h at RT in 500 l of MEM containing 10 mM EDTA.…”

“…35 S-labeled HRV2 (3 ϫ 10 5 cpm) was preincubated with MAbs (8F5, 40 g/ml; 3B10, 15 g/ml) for 1 h at RT in 500 l of MEM containing 10 mM EDTA. These samples were then added to 10 7 suspension-grown HeLa-FcRII cells (depleted of endogenous IgG and suspended in 1 ml MEM, containing EDTA), mixed, and divided into three aliquots (500 l each) to be used for parallel determinations.…”

Crystallization and preliminary X-ray analysis of human rhinovirus serotype 2 (HRV2)

“…from virus and from antibody or receptor; Bella et al, 1998). The structure of at least one of the HRV2-neutralizing antibodies is available at atomic resolution (Tormo et al, 1992(Tormo et al, , 1994 and a model of the viral complex was built using the data of HRV1A. However, although closely related to HRV2, this serotype has substantially different neutralizing immunogens (Tormo et al, 1995), which prevents reliable predictions of the antibody±virus interface.…”