PURIFICATION AND PARTIAL CHARACTERIZATION OF A PRODUCT FROM YERSINIA-PSEUDOTUBERCULOSIS WITH THE ABILITY TO ACTIVATE HUMAN T-CELLS

We tried to purify a substance exhibiting mitogenicity for human perip heral blood lymphocytes from Yersinia pseudotuberculosis isolated from patients with Y. pseudotuberculosis infection manifesting acute and s ystemic clinical symptoms. The supernatant of a suspension of the bact eria disrupted by sonication was serially chromatographed on DEAE-Seph arose fast-flow, Sephacryl S-100 HR, and TSK-gel G2000SW high-pressure liquid chromatography columns. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that the purified mitogenically active substance migrated as a single band corresponding to a molecula r mass of 21 kDa. We designated the purified substance Y. pseudotuberc ulosis-derived mitogen (YPM). YPM stimulated human peripheral T cells to proliferate and produce interleukin-2 at 0.1 ng/ml or more. YPM-ind uced T-cell activation required the expression of HLA class II molecul es on accessory cells.