35cS LOCAL TLSSLE REACTIVITY 



tuhc'K iilous aniiiKil itscll is so altered tliat it a((jiiires a sensitiz- 

 ing cajjacity. 



Ill most instaiues the reactivity to bacterial proteins in liypcr- 

 sensitixe animals cannot be neiitraHzed by spec ilic aiitiseia. Zins- 

 ser and ramiya Avcre unable to netitrali/e the tiibciciilin re- 

 action with the sera ol animals immnni/ed with either livino; C3r 

 dead tubercle bacilli. Zinsser and (irinnell (1927) attempted to 

 neutralize allerj^ic skin reactions jjroduced by aiitolyzed pneiimo- 

 cocci. The neutralizing antibodies were sujjplied by the sera and 

 peritoneal exudate oi sensitized animals and by sera of immunized 

 horses. They concluded that a certain definite but moderate 

 amount of neutralization could be accomj)lished but this never 

 resulted in complete neutralization and could ncjt be carried to 

 any significant degree of serimi diltition. The only successful ex- 

 ])eriments reported on complete neutralization of a presumed 

 bacterial allergic reaction have been those of Dochez and Sher- 

 man (1925) . These authors sensitized guinea pigs to a scarlatina 

 streptococcus and foinid that skin tests with the filtrate of the 

 organisms were positive (erythematous) abotit the eleventh day 

 after the last sensitizing injection. When skin tests were made 

 with the serum-neutralized toxin, the tests were negative. Dochez 

 and Stevens (1927) gave weekly intracutaneous injections of 

 Streptococcus scarlatiuae filtrate to two rabbits for twenty-seven 

 xveeks. Early in the course of inmiunization a skin reaction to the 

 unheatcd filtrate was demonstrable. This reaction was neutraliz- 

 able with specific antitoxin. Following a period of lc:)st skin reac- 

 tivity, cutaneous reactions were obtained finally xvith both the 

 heated and tinheated filtrates. These reactions were not neutraliz- 

 able. The interpretation was made that there existed tw^o anti- 

 genic sulostances in the filtrates of the hemolytic streptococci, one 

 corresponding to the toxin Avhich stimulates an early allergic 

 condition and which is completely netitralized by immune serum, 

 and the other consisting of proteins from the bacterial cell body 

 which recjuire a longer incubation period and the reactivity for 

 xvhich cannot be netitralized by specific antisera. 



Thtis far very iew successful results have been obtained in pas- 

 sive transfer of tuberculin sensitivity. Zinsser and Mueller (1925) 

 produced sensitivity to ttiberctilin in guinea pigs with the serum 

 of rabbits injected with living B. tuberculosis. The sensitization 

 appeared three to four days after the serum injection. They do 



