BACTERIAL ANTIGENS AND SPECIFICITY 361 



cose and galactose, suffice to orientate protein specificity when 

 the corresponding giucosides of the two sugars are coupled to the 

 same protein. 



4. The unconjugated giucosides, although themselves not pre- 

 cipitable in immune serum, inliibit the reaction between the 

 homologous sugar-]U'()tein and ils specifie antil)ody. The inhil)i1ion 

 test is specific. 



5. The sugar derivatives unattached to protein exhibit the prop- 

 erties of carl)ohydrate haptens ; they are nonantigenie but spe- 

 cifically reactive, as shown l)y inliibition tests. 



Following this work, Avery and Goebel (1931) coupled the nitro- 

 gen-free polysaccharide of Type III pneumococci onto horse serum 

 globulin after preparing p-amino and p-nitromonol)enzyl ethers 

 of the specifie polysaccharide. They produced active immunity 

 and type-specific antibodies in rabbits for Type III pneumococ- 

 cus by injecting the polj^saceharide horse serum globulin anti- 

 genic complex. They were also able to protect mice specifically 

 by immunization with the same. 



Hotchkiss and Goebel (1937) and Goebel (1938, 1939) have 

 extended the work on synthetic conjugated antigens. The former 

 synthesized azoproteins containing glucuronic acid and galac- 

 turonic acid respectively. The galacturonic acid azoprotein gave 

 positive precipitin reactions with Type I anti-pneumococcus 

 serum. In 1939 Goebel produced an antigen containing cello- 

 biuronic acid that produced active immunity in rabbits to virulent 

 T3'pe III pneumococci. Serum from these immunized ra])bits 

 conferred passive immunity to mice for Types II, III, and VIII 

 pneumococci. The serum also gave positive Neufeld quellung re- 

 actions. 



Friedlander's Bacillus. — In 1925 Heidelberger, Goebel and 

 Avery became interested in the capsular substance of a strain of 

 the Friedlander's bacillus. Earlier (1921) Toenniessen had iso- 

 lated from the capsular substance of a strain of this organism, a 

 snow-white nonreducing substance that was a polysaccharide sub- 

 stantially free of nitrogen. Upon hydrolysis it yielded reducing 

 sugars. Toenniessen found that these yielded an osazone which 

 he regarded as that of galactose. His work was confirmed by 

 Kramar (1922). The substance was not studied immunologically 



