Characterization of the IgD binding site of encapsulated Haemophilus influenzae serotype b.

Summary, in English

Encapsulated Haemophilus influenzae is a causative agent of invasive disease, such as meningitis and septicemia. Several interactions exist between H. influenzae and the human host. H. influenzae has been reported to bind IgD in a nonimmune manner, but the responsible protein has not yet been identified. To define the binding site on IgD for H. influenzae, full-length IgD and four chimeric IgDs with interspersed TgG sequences and Ag specificity for dansyl chloride were expressed in stably transfected Chinese hamster ovary cells. The binding of recombinant IgD to a panel of encapsulated H. influenzae serotype b (Hib) and nontypeable strains were investigated using a whole cell ELISA and flow cytometry. IgD binding was detected in 50% of the encapsulated Hib strains examined, whereas nontypeable H. influenzae did not interact with IgD. Finally, mapping experiments using the chimeric IgD/IgG indicated that IgD C(H)1 aa 198-224 were involved in the interaction between IgD and H. influenzae. Thus, by using recombinant IgD and chimeras with defined Ag specificity, we have confirmed that Hib specifically binds IgD, and that this binding involves the IgD CHI region.

• Author: Martin Samuelsson; Teresia Hallström; Arne Forsgren; Kristian Riesbeck
• Department/s: Clinical Microbiology, Malmö
• Publishing year: 2007
• Language: English
• Pages: 6316-6319
• Publication/Series: Journal of Immunology
• Volume: 178
• Issue: 10
• Links: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=17475860&dopt=Abstract
• Document type: Journal article
• Publisher: American Association of Immunologists
• Topic: Immunology in the medical area
• Status: Published
• Research group: Clinical Microbiology, Malmö
• ISBN/ISSN/Other: ISSN: 1550-6606