Resistance to Pseudomonas aeruginosa septicemia in mice after transfer of immune spleen cells.

The resistance to P. aeruginosa septicemia was studied in mice after transfer of immune spleen cells from donors vaccinated with P. aeruginosa slime-extract. The protective capacity of these cells appeared in donors within 3 days after immunization and reached a maximum between day 4 and 6. Then it rapidly declined and disappeared on the 9th day after vaccination. This capacity of spleen cells from donors immunized several times with slime-extract was lasting longer than in the former group and decreased on day 9-11 after the last vaccination. However, the recipients were not protected against infection if the donor immune spleen cells were pretreated with anti-Thy 1.2 monoclonal antibodies. Moreover, it was found that the transfer of cells from vaccinated donors to nonimmune mice inoculated with P. aeruginosa enhanced a steady decrease of the number of viable organisms in the spleens of the recipients. The immunity conferred on the recipient mice was highly specific.