Carboxymethyl cellulose, a nonimmunogenic hapten carrier with tolerogenic properties

This communication reports on the tolerogenic properties of carboxymethyl cellulose (CMC) as a nonimmunogenic carrier for 2.4 dinitrophenyl (DNP) and the benzylpenicilloyl determinant (BPO). Either normal or primed mice, given an optimal dose of 250 micrograms per animal of DNP CMC, when challenged with an immunogenic form of the hapten as early as 30 min or as late as 21 days thereafter were completely and specifically unresponsive to it. Experimental evidence suggests that this unresponsiveness is not due to suppressor cells. Furthermore, DNP CMC induces tolerance in vivo but fails to do so in vitro under conditions at which other tolerogenic carbohydrate hapten conjugates such as DNP-dextran do. This together with comparative studies of tolerance induction kinetics by DNP CMC and DNP-dextran in vivo led us to conclude that molecular properties other than the epitope density must be attributed to CMC's tolerogenic potential. CMC may also be used as a tolerogenic carrier for BPO with respect to IgE antibody production. Thus, normal or primed mice injected with the BPO CMC conjugate were found specifically unresponsive to a challenge with an immunogenic form of penicillin.