ABSTRACT
The Antigen L is made of the 10 p.100 TCA precipitable proteins that remained after 2 p.100 TCA proteins precipitation of a live BCG culture filtrate. It is 6 times more active in guinea pigs sensitized by living BCG than by inactivated BCG. The reference tuberculin (BR6) is the fraction retained by DEAE-Cellulose chromatography of the purified TP tuberculin described elsewhere (2). The kinetic study of BR6 using guinea pigs sensitized by live or inactivated BCG showed that between the 2nd and 4th month, BR6 had the same activity in both cases in respect to the diameter of the erythema reactions. Therefore, BR6 may serve as reference for the Antigen L between the 2nd and 4th month of sensitization.
Subject(s)
Antigens, Bacterial/standards , Mycobacterium/immunology , Nontuberculous Mycobacteria/immunology , Animals , Antigens, Bacterial/administration & dosage , Antigens, Bacterial/analysis , Guinea Pigs , Hypersensitivity, Delayed , Indicators and Reagents , Mycobacterium bovis/immunology , Quality ControlABSTRACT
The tuberculins are made of mixtures of antigens. Certain elements are common to all tuberculins, others are particular to each one. Bovine and human tuberculins are widely different. This is the reason why the activities of a bovine tuberculin using a human tuberculin standard will be in a ratio of 1 to 5 according to whether the guinea-pigs were sensitized with human or bovine mycobacteria. Also, the activities measured for a given tuberculin might be different if the mycobacteria used in sensitization were inactivated or not, depending on the amount of Antigen L in the tuberculin or in the standard. Because BCG is well defined and used worldwide we propose that a new standard be prepared from BCG cultures, and that the animals be sensitized by live BCG. Two new units are proposed: Bovine Clinical Unit (B.C.U.) and Human Clinical Unit (H.C.U.).
Subject(s)
Tuberculin/standards , Animals , Antigens, Bacterial/immunology , Cattle , Evaluation Studies as Topic , Guinea Pigs , Humans , Mycobacterium/immunology , Mycobacterium bovis/immunology , Quality ControlABSTRACT
The preparation of antigen L using culture filtrates of live BCG is described. The procedure consisted essentially of precipitating this filtrate with 10% trichloroacetic acid in the presence of N-butyl alcohol 4% final concentration. The precipitate was chromatographed on carboxy-methyl-trisacryl-M and then on DEAE-trisacryl-M; in both cases, maximal biological activity (delayed-type hypersensitivity) was found in the void volume. The product thus obtained was chromatographed on a molecular sieve so as to eliminate poorly active fractions. The final product was 30-fold more active on guinea-pigs sensitized with live BCG than on those sensitized with inactivated BCG.
Subject(s)
Antigens, Bacterial/isolation & purification , Tuberculin/immunology , Animals , Antigens, Bacterial/immunology , Chromatography, DEAE-Cellulose , Chromatography, Gel , Chromatography, Ion Exchange , Electrophoresis, Polyacrylamide Gel , Guinea Pigs , Isoelectric FocusingABSTRACT
This report described the occurrence of an antigen in the tubercle bacilli. The antigen, designated antigen L, was mainly active in delayed hypersensitivity reaction in Guinea Pigs sensitized with living bacilli such as the B.C.G. strain. It was found in cultures filtrates of bovine strains as well as the human strains of tubercle bacilli.
