SUBCELLULAR-LOCALIZATION AND QUANTITATIVE-ANALYSIS OF TOXOPLASMA-GONDII TARGET ANTIGENS OF SPECIFIC IMMUNOGLOBULIN-G, IMMUNOGLOBULIN-M, IMMUNOGLOBULIN-A, AND IMMUNOGLOBULIN-E

The target antigens of specific immunoglobulins G, M, A, and E from pa tients with acquired acute toxoplasmosis were determined using immunoc ytochemistry. The relative repartition of these antigens in four cellu lar compartments of Toxoplasma (membrane complex, apical area, rhoptri es, and dense granules) was quantitatively evaluated. Rhoptry antigens mainly react positively with IgA. Membrane, submembrane area (membran e complex), and rhoptry antigens are immunodominant for IgA and IgM. A pical area antigens are recognized by IgM two times more than IgG and IgA. IgE recognized only rhoptry antigens. The localization of pathoge netically antigenic components and their identification by the immune system appeared to be of importance for selection of immunodominant or recombinant antigens. Such localization would improve laboratory diag nosis of serious congenital toxoplasmosis or in immunocompromised pati ents with toxoplasmic complications after cyst reactivation. (C) 1994 Wiley-Liss, Inc.