Related Experiment Videos
Cytocidal activity and proliferative ability of macrophages infiltrating the EMT6 tumor
Abstract:
The EMT6 mouse tumor was selected for use in the study of cytocidal activity and proliferative ability of infiltrating macrophages because of its high plating efficiency when explanted to culture. The plating efficiency for cells directly plated in culture from the tumor was 28 +/- 9.3%, irrespective of the size of the tumor. Of the adherent cells derived from the tumor, the fraction that was macrophages increased from 27% at 7 days to 47% at 28 days after initial injection. Time-lapse cinemicrography was used to directly observe adherent cells derived from the tumor, and macrophages were found to be cytocidal. When grown in the presence of L-cell conditioned medium no macrophage colonies were found when cultures were established from untreated mice even though most tumor cell colonies contained macrophages. When mice were first treated with 0.8 mg BCNU prior to establishment of the cultures, in order to reduce the frequency of colony-forming tumor cells, approximately half the colonies found contained only macrophages. These results show that macrophages in this tumor are cytocidal and capable of proliferation.
Insights
Macrophages infiltrating the EMT6 mouse tumor exhibit significant cytocidal activity and proliferative capacity. These findings highlight the potential of tumor-infiltrating macrophages in cancer research.
Area of Science:
- Immunology
- Cancer Biology
- Cell Biology
Background:
- The EMT6 mouse tumor model is utilized for studying immune cell functions.
- Macrophages are key immune cells involved in tumor microenvironments.
Purpose of the Study:
- To investigate the cytocidal activity and proliferative ability of macrophages infiltrating the EMT6 mouse tumor.
- To characterize the role of tumor-infiltrating macrophages in a murine cancer model.
Main Methods:
- Explants of EMT6 mouse tumors were cultured to assess cell plating efficiency.
- Time-lapse cinemicrography was employed to directly observe adherent tumor-derived cells.
- Mice were treated with BCNU to modulate tumor cell frequency before culture.
Main Results:
- EMT6 tumors demonstrated high plating efficiency (28 +/- 9.3%) for explanted cells.
- The proportion of macrophages among adherent tumor-derived cells increased from 27% at 7 days to 47% at 28 days post-injection.
- Direct observation confirmed macrophages possess cytocidal properties.
- In cultures from BCNU-treated mice, approximately 50% of colonies consisted solely of macrophages, indicating their proliferative capacity.
Conclusions:
- Macrophages within the EMT6 tumor are demonstrably cytocidal and capable of proliferation.
- These findings underscore the functional significance of tumor-infiltrating macrophages in this model.