Search

A complex of trehalose-6, 6'-dimycolate (cord factor) and methylated bovine serum albumin was prepared, and its effect on the toxicity of cord factor in mice was studied. Either the active immunization with cord factor-methylated bovine serum albumin complex or the passive transfer of sera of rabbits vaccinated with the complex protected mice against the toxic action of cord factor. The antisera of mice and rabbits and gamma globulin fraction of rabbit antiserum demonstrated a precipitin reaction with an aqueous emulsion of cord factor. The reactivity of anticord factor was totally lost by treatment with 2-mercaptoethanol. The antigenic determinant group of cord factor was alpha-d-trehalose. Cord factor-anticord factor complex was devoid of activity to induce in vitro swelling and inhibition of respiratory and phosphorylative activity of mouse liver mitochondria. These results suggest that vaccination with cord factor-methylated bovine serum albumin complex induced the production of antibody to cord factor in mouse and rabbit serum which binds to cord factor and neutralizes its toxic activity either in vivo or in vitro.

The relationship between Inv phenotype and the amino acid residue at position 191 in kappa-type light polypeptide chains derived from the immunoglobulins of ten normal human sera was investigated. In each case, the amino acid present at position 191 correlated with the Inv phenotype of the individual. Kappa chains of seven Inv (-1,3) homozygotes had valine, while those of three Inv (1,3) heterozygotes had some chains with leucine and some with valine at this position. Genes encoding the Inv (1) and Inv (3) variants appear to be expressed equally in the heterozygous state, since approximately equal amounts of each gene product was recovered from heterozygotes. The correlation between Inv phenotype and the amino acid residue present at position 191 is identical to that previously established for kappa-type Bence-Jones proteins and myeloma protein light chains. These observations support the hypothesis that the valine-leucine interchange is encoded by two allelic forms of a single kappa-chain common region gene.