IMMUNE-RESPONSE AGAINST 2 EPITOPES ON SAME THYMUS-INDEPENDENT POLYSACCHARIDE CARRIER .1. ROLE OF EPITOPE DENSITY IN CARRIER-DEPENDENT IMMUNITY AND TOLERANCE

  • 1 January 1977
    • journal article
    • research article
    • Vol. 33  (1) , 59-68
Abstract
Immunogenicity and tolerogenicity of 2 epitopes (.alpha. 1-6 and FITC [fluorescein isothiocyanate]) on the same dextran B 512 carrier were investigated. Both epitopes were thymus-independent, immunogenic and tolerogenic. The marked dose differences between the 2 epitopes with regard to tolerance induction were apparently a consequence of the affinity and the heterogeneity of the responding [mouse] B [bone marrow-derived] cells and the epitope density employed for detecting the PFC [plaque-forming cells] in a predictable way. The .alpha. 1-6 response, in contrast to the anti-FITC response, was homogeneous and of low affinity and the number of precursor B cells was low. Different mouse strains were high-, low- or non-responders to .alpha. 1-6, but all the strains tested responded to the FITC epitope coupled to dextran. Dextran and FITC-dextran were polyclonal B cell activators in the strains tested, irrespective of their ability to respond to the .alpha. 1-6 epitope. Epitope density and MW of the immunogen and Ig[immunoglobulin] receptor affinity for the epitope on the B cells are variables which markedly influence the binding of the immunogen to the specific B cells, and therefore affect the delivery of the nonspecific triggering signal.