STIMULATION OF MONOCYTE PRODUCTION BY AN ENDOGENOUS MEDIATOR INDUCED BY A COMPONENT FROM LISTERIA-MONOCYTOGENES

  • 1 January 1982
    • journal article
    • research article
    • Vol. 46  (2) , 343-351
Abstract
A monocytosis-producing activity is present in a saline-extractable material (SE) from L. monocytogenes. The mechanism of stimulation of monocyte production by SE was studied. Serum obtained from mice at appropriate times after injection of SE induced monocytosis in normal recipients. The monocytosis-inducing activity present in serum differed from SE with respect to timing of the monocytosis, fractionation pattern on a Sephadex G-200 column and thermolability. The minimum dose of SE capable of producing a monocytosis was 100 .mu.g. Antibody to SE capable of detecting SE at a concentraction of .gtoreq. 5 .mu.g/ml failed to detect SE in samples of active serum. Therefore it seemed highly unlikely that activity in serum was due to the presence of trace amounts of SE. The activity present in serum was thermolabile and had a MW of .apprx. 38,000. Injection of apparently caused the production or release of an endogenous mediator capable of stimulating monocytosis.