Antibodies specific for the antigenic domain 1 of glycoprotein B (gpUL55) of human cytomegalovirus bind to different substructures
Abstract
Glycoprotein B (gB, gpUL55) is a major antigen for the induction of neutralizing antibodies against human cytomegalovirus, making it an attractive antigen for active and passive immunoprophylaxis. The immunodominant region on gB is the antigenic domain 1 (AD-1), a complex structure which requires a minimal linear amino acid sequence of more than 75 amino acids (aa 552-635) for antibody binding. We have analyzed the fine specificity of neutralizing and nonneutralizing AD-1-binding monoclonal antibodies. Point mutations were introduced into AD-1 and mutants were expressed as bacterial fusion proteins. The antigens were analyzed in immunoblots using a panel of 13 human and murine monoclonal antibodies. Complete loss of binding of all antibodies was observed with mutations at cysteine residues 573 and 610 as well as with a combinatorial exchange of prolines at position 577 and 613. The remaining mutations had different effects on antibody binding. Six individual recognition patterns were observed, indicating various antigenic substructures on AD-1. Changing the Fc portions of 3 murine monoclonal antibodies to human IgG1 showed that neutralization of AD-1-binding immunoglobulins is exerted by different mechanisms. Dependent on the r...Continue Reading
Citations
HCMV glycoprotein B subunit vaccine efficacy mediated by nonneutralizing antibody effector functions
Related Concepts
Related Feeds
Antibody Specificity
Antibodies produced by B cells are highly specific for antigen as a result of random gene recombination and somatic hypermutation and affinity maturation. As the main effector of the humoral immune system, antibodies can neutralize foreign cells. Find the latest research on antibody specificity here.