MECHANISM OF ANTIBODY FORMATION 69 



proximately eight-fold higher than those in the corresponding sera on 

 the basis of nitrogen contents. The absence of antibody titer in the 

 final washings of the lymphoid cells showed that the antibody titer in 

 the extracts was derived from the cells and not from adherent lymph. 

 Salivary gland or muscle tissue, containing reticulum cells, macro- 

 phages, or fibroblasts, from the same immunized mice which had 

 yielded antibody-containing lymphoid cells, showed no extractable ag- 

 glutinins or hemolysins. Also lymphoid cell extracts from non- 

 immunized mice were negative when tested for antibodies. Though 

 these results seem to offer support to the theory that lymph nodes or 

 lymphocytes might be the sites of antibody formation, these investiga- 

 tors stated that sites of antibody production and concentration other 

 than lymph nodes may exist, e.g., bone marrow, spleen, liver, and other 

 organs containing high proportions of reticulo-endothelial cells. These, 

 however, were not examined. On the basis of the above results, though 

 overwhelmingly favorable for the lymphatic system as the site for 

 production of antibody, they were not inclined to conclude that 

 lymphocytes necessarily are concerned with antibody formation. 



Another study in this direction was reported by Kass (1945). Start- 

 ing with a premise of questionable validity that if antibody is synthe- 

 sized in lymphocytes, normal serum gamma-globulin should also be 

 present, he prepared rabbit antisera to highly purified (electro- 

 phoretically 98 to 100 per cent pure) human gamma-globulin. These 

 sera reacted specifically with extracts from human mesenteric lymph 

 nodes obtained within one hour after death of a patient. Extracts 

 of washed slices of human liver failed to react with the antiserum. This 

 finding was interpreted to show the presence of gamma-globulin in 

 lymphocytes and thereby the synthesis of antibody gamma-globulin 

 within the same cell was assumed. 



A few years previous to the publications of Ehrich and Harris, Harris, 

 et al., and Kass (cited above), Burnet, et al. (1938, 1941) reported 

 the results of comparative studies pertaining to this question. Burnet 

 and Lush (1938), immunizing mice with a virulent strain of influenza 

 virus, found that antibody production occurred in the lymph node. 

 Studying the spread of herpes virus and the formation of antibody in 

 rabbits, they found that two out of five rabbits showed significant 

 amounts of antibody in the lymph node at six and seven days after 

 injection, while the results with another rabbit were weakly positive. 



