| Description |
Chemotactic activity and activation of macarophages by immunostimulating species of propionibacteria were investigated. Although previous publications have indicated that the immunostimulating species of Propionibacterium, P. acnes, P. avidum, and P. granulosum have a direct chemotactic effect on macrophages, an extensive examination of whole cells and supernatant medium from a culture of P. avidum 4982 failed to confirm this observation. It is suspected that the reports describing this effect may have been in error. Peritoneal macrophages, from mice injected 3 to 5 days previously was a killed suspension of P. acnes, were able to lyse tumor cells, exhibited increased spreading, contained increased numbers of granules and vacuoles, and had an increase level of acid phospatase activity. In contrast, macrophages from mice injected with a control organism, P. jensenii, did not posses the same ability to lyse tumor cells and had a lesser degree of morphological change, but did have an increased level of acid phosphatase actiavity. Neither type of macrophage had an increase in protein content. These results confirm previous reports on in vitro lysis of tumor cells by macarophages activated with P. acnes and show that morphological changes, but not acid phosphatase activity nor protein content, are correlated with activation. Studies also showed that activation could be achieved with a broad rage of different amounts of material, down to µg, suggesting that the mechanism of action of this organism is some type of trigger action. The macrophage-activating factor is a heat stable molecule which seems to resist extraction and thus appears to be firmly attached to the cell. It is not yet possible to determine the location of the factor on the bacterial cell; isolated cell walls or cytoplasmic fractions did not have activity. It appears that the integrity of the cell must be preserved for the organism to be active. A review of the literature shows that there has been confusion concerning the nature of the active component(s) of this organism. The us of macrophage activation as a measure of activity allows the results to be related to previous work and is therefore a means of resolving the confusion which has existed. |
