INVESTIGATION OF A FACTOR RELEASED BY NEOPLASTIC CELLS WHICH PRODUCES A CHEMOKINETIC RESPONSE IN ACTIVATED MACROPHAGES

• Main Author: Lane, Richard Durelle
• Format: Others
• Published: VCU Scholars Compass 1980
• Subjects: Anatomy
• Online Access: http://scholarscompass.vcu.edu/etd/4981; http://scholarscompass.vcu.edu/cgi/viewcontent.cgi?article=6067&context=etd

The increase in rate of random migration (chemokinesis) of C. parvum activated macrophages in media conditioned by Lewis Lung (LL) carcinoma cells was attributed to a trypsin sensitive, heat stable, high molecular weight factor released from the membrane of the tumor cells. A capillary tube assay was developed to expediently monitor the chemokinetic activity of macrophages incubated in whole and fractionated media. The capillary tube assay was found to be capable of detecting both chemokinetic and chemotactic (directional movement) factors present in the test media. Statistical analysis revealed the capillary tube assay provided reproducible data both within and between experiments. Media conditioned by 6 different syngeneic and allogeneic mouse tumor cell lines demonstrated significantly higher chemokinetic activity compared to unconditioned or normal fibroblast conditioned media. The release of the chemokinetic factor (CKF) by Lewis Lung cultures was demonstrated to be maximum during the logarithmic growth phase of these neoplastic cells. Molecular seive chromatography of the Lewis Lung conditioned media revealed the CKF to have a molecular weight of approximately 360,000 daltons. Similarly to the C. parvum activated macrophages, the pyran activated macrophages responded chemokinetically to LL conditioned media. However oyster glycogen and thioglycolate elicited macrophages demonstrated no significant chemokinetic response in the presence of the LL-CKF. The Lewis Lung chemokinetic factor demonstrated no chemotactic activity in the Boyden chamber assay. In fact, the CKF actually inhibited the response of these macrophages to a known chemotactic factor. Indirect immunofluorescent staining of the CKF indicated that it was a membrane protein shed by the LL cells and bound by activated macrophages. The possibility is discussed that CKF may be a glycocalyx protein shed by tumor cells which interferes with macrophage- neoplastic cell interactions involved in the tumoricidal activity of macrophages.