Immunological paralysis against type 8 and immunity against type 3 Diplococcus pneumoniae induced by the soluble specific substance of type 8.

Brooke, Marcus S. (Massachusetts Institute of Technology, Cambridge). Immunological paralysis against type VIII and immunity against type III Diplococcus pneumoniae induced by the soluble specific substance of type VIII. J. Bacteriol. 90:1296-1303. 1965.-Mice injected with relatively large quantities of the soluble specific substance of type VIII Diplococcus pneumoniae (SVIII) are, on the basis of challenge experiments, paralyzed against type VIII but immune against type III D. pneumoniae. Their sera contain antibodies which react with sheep cells coated with SIII. Unfortunately, it was not possible to develop an in vitro test with SVIII. When the SVIII was treated with a specific SVIII depolymerase before injection into mice, the sera still contained antibodies against SIII and some protection was afforded these mice against type III but not against type VIII challenge. When the SVIII was treated with a specific SIII depolymerase, antibodies were not detectable and the mice were not protected against type III or type VIII challenge. On the basis of these results it is suggested that either the SVIII strain is a hybrid forming both SVIII and SIII molecules or that part of the SVIII chain is altered to consist of repeating units of cellobiuronic acid rather than alternating units of cellobiuronic acid and the disaccharide galactose-glucose. The quantity of SIII in some preparations of SVIII is calculated to be of the order of 0.01%. It is not clear whether all type VIII strains at all times possess the capacity to elicit antibodies which react specifically against SIII, or if this is the property of only some strains and some preparations of these strains.