The cell wall as the antigenic site for antibodies stimulating ingestion (MSF) and inhibition (BIF) of Brucella in macrophages from normal and immune animals.

Following extraction with hot trichloracetic acid and digestion with trypsin, deoxyribonuclease and ribonuclease, cell wall residues of strain Rev I contained an antigenic moiety capable of removing antibodies responsible for stimulation of ingestion, inhibition of Brucella growth by macrophages, and agglutination of Brucella. The preparation was dermonecrotic for both normal and immune rabbits and, when injected in oil, stimulated antibody production. The peptidoglycan-containing structure was degraded by egg-white lysozyme and enzymes from normal and immune macrophages with an accompanying loss of dermonecrotic and serumabsorbing capacity.