Delipidated human casein was digested with trypsin and the enzymatic digest was fractionated on Sephadex G-50. The peptidic fractions were assayed for immunomodulating activity in two in vitro models. Fractions corresponding to molecular weights in the range of 2,000 +/- 600 were found to possess stimulating activity in these models.

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I57Rapidly growing liquid shake cultures of Monilinia fructigena secreted a polysaccharide which caused an increase in the viscosity of the nutrient liquor. Glucose/malt medium supported most rapid growth and greatest polysaccharide accumulation. Acetone precipitation and dialysis resulted in preparations which were essentially ash and nitrogen free. Gel chromatography indicated that the polysaccharide was polydisperse over the mol. wt range 80000 to 5000. Molecular size was positively correlated with viscosity and inversely correlated with aqueous solubility. Carbohydrate analyses by paper and gas-liquid chromatography indicated that glucose accounted for > 90 % of the sugar residues present. Mannose and galactose were also detected. Charged groups were absent. Periodate oxidation revealed that the main linkage was I + 4, with a low proportion of I + 2 linkages. The degree of branching varied between every fifth and every tenth residue. Linkages of I + 3 type were virtually absent. Interaction with concanavalin A indicated the presence of non-reducing terminal a-D-glucopyranosyl or a-D-mannopyranosyl residues.

Wax Dp, a peptido-glycolipid found in extracts of Mycobacterium tuberculosis var. hominis, was not found in extracts of three strains of still-grown M. tuberculosis var. bovis (BCG, Marmorek and Dupray). However, extracts from three other bovine strains (Behring, LA and BB) did yield waxes Dp, and these did not differ as to their molar ratios of alanine/glutamic acid/diaminopimelic acid from human waxes DP. All mycobacteria contain a chloroform-extractable, ether-soluble, acetone-insoluble glycolipid fraction called wax D (1, 4). Wax D fractions of human strains of Mycobacterium tuberculosis have important biological properties [Freund's adjuvant effect (3); induction of adjuvant arthritis (10)], whereas wax D fractions from