Evidence for a compartmentalized B cell response as characterized by IgG epitope specificity in human ocular toxoplasmosis.
Infectious agents in the eye induce both a local and a systemic humoral immune response. Previously, differences in Ag recognition were observed between systemic and ocular derived IgG of patients with ocular toxoplasmosis. This finding implied a nonrandom distribution of IgG-producing B cells in the inflamed eye. In the present study, we compared the intraocular and systemic B cell responses of patients with ocular toxoplasmosis to a single Toxoplasma gondii Ag. Two series of C-terminally deleted recombinant T. gondii GRA-2 proteins were constructed to delineate IgG B cell epitopes of paired ocular and serum samples. Differences in epitope region recognition between the ocular and systemic compartment were detected in 9 of 13 patients. The difference in distribution of GRA-2 epitopes between paired samples is indicative of a local GRA-2 specific B cell population functionally different from the systemic GRA-2-specific B cell population. Our results suggest a selective activation of a subset of B cells locally in nonlymphoid tissue.
Klaren
V N
VN
Department of Molecular Immunology, The Netherlands Ophthalmic Research Institute, Amsterdam, The Netherlands. v.klaren@ioi.knaw.nl
Peek
R
R
D000293:Adolescent; D000328:Adult; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D000953:Antigens, Protozoan / Q000032:analysis / Q000276:immunology; D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D018604:Epitope Mapping / Q000379:methods; D018985:Epitopes, B-Lymphocyte / Q000032:analysis / Q000276:immunology*; D005260:Female; D006801:Humans; D016056:Immunodominant Epitopes / Q000032:analysis / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000032:analysis / Q000276:immunology; D015800:Protozoan Proteins / Q000032:analysis / Q000276:immunology; D014126:Toxoplasmosis, Ocular / Q000276:immunology*
D000953:Antigens, Protozoan; D018985:Epitopes, B-Lymphocyte; C106990:Gra2 protein, Toxoplasma gondii; D016056:Immunodominant Epitopes; D007074:Immunoglobulin G; D010446:Peptide Fragments; D015800:Protozoan Proteins