INCIDENCE OF RAT-SOLUBLE PLACENTAL FACTORS ON IGE AND IGG(2A) SYNTHESIS

PROBLEM: The in vive effect of soluble factors present in placental cu lture supernatants (PCSs) on the synthesis of rat immunoglobulin E (Ig E) and IgG(2a) isotypes was investigated. METHOD OF STUDY: Batches of Wistar SPF rats immunized with a 10-mu g dose of ovalbumin and AI(OH)( 3) were used: group I, consisted of virgin rats; group II, virgin fema les injected simultaneously with PCSs; and group III, pregnant females . As controls, nonimmunized batches were included. Serum samples were collected at days 0 (basal) and 10 after antigen challenge, determinin g levels of total and specific antiovalbumin of both IgE and IgG(2a) b y enzyme-linked immunoadsorbent assay (ELISA). RESULTS: In vive and at least at the doses administered, PCSs exert an inhibitory effect on t he synthesis of specific and total anti-ovalbumin IgE during the cours e of immune response to such challenge. However, PCSs did not modify s erum values of total and specific IgG(2a). CONCLUSIONS: These results suggest that PCSs exert selective influence on the synthesis of divers e immunoglobulin isotypes during immune response, through the balance of cytokines synthesized by placental cells.