Non specific immunity to diphtheria and tetanus toxins not induced

Abstract

Guinea pigs were injected subcutaneously with a number of antigens with the expectation that non specific as well as specific immunity would be induced. The non specific immunity was looked for by testing the guinea pigs'resistance to diphtheria and tetanus toxins and to several pathogenic organisms.

Suspensions of pure proteins (casein, edestin) and dead organisms (B. coli, B. pyocyaneus) were the antigens used. They were prepared as follows: a 1.000 gm. portion of pure dry protein was suspended in 20 cc. of 0.5 per cent acid sodium phosphate solution. The suspensions contained in sterile weighing bottle were incubated, tested for sterility, and when found free from contaminating organisms were diluted with 0.8 per cent sodium chloride. The calculated volume of protein suspension was then injected. Acid sodium phosphate solution was used for suspending the antigens in order to avoid disintegration or autolysis of protein with attendant formation of toxic products as suggested by Thomson. 1

Cultures of B. coli and B. pyocyaneus were grown 18 to 24 hours on 1 per cent dextrose 3 per cent agar slants without peptone. Peptone was omitted because Hitchens 2 found that organisms grown on peptone agar are much more toxic than those grown on peptone free media. The growths were suspended in a solution containing 0.5 per cent phenol, 0.5 per cent chloroform and 0.5 per cent acid sodium phosphate.

No attempt was made at bacterial counts. An approximate idea of the number of organisms injected was obtained from the data of Wilson and Dickson. 3 According to these investigators one milligram of dry B. coli contains 6.5 billions; one milligram of dry B. pyocyaneus, 3.5 billions of organisms.

The diphtheria and tetanus toxins and antitoxins used were the standard preparations furnished by the Hygienic Laboratory, Washington, D. C. One minimal lethal dose of Diphtheria Toxin No. 266 for 500-600 gm. guinea pigs was 0.015 cc. injected subcutaneously. One minimal lethal dose of Tetanus Toxin No. F 3 for 350 gm. guinea pigs was 0.0075 mg. subcutaneously.