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Published on: November 21, 2011
Superoxide production by phagocytes in myeloid Graffi tumor-bearing hamsters
P A Dimitrova1, R A Toshkova, E H Ivanova
1Institute of Microbiology, Bulgarian Academy of Sciences, Sofia.
Abstract:
A progressive suppression of the phagocytic ability of peritoneal macrophages and polymorphonuclears (PMNs) in hamsters with transplanted myeloid tumors was previously established. The i.p. application of Cu/Zn SOD, isolated from the fungal strain Humicola lutea (HLSOD) (2 injections before and 5 injections after tumor transplantation) induced the mean survival time of the animals as well as a temporally stimulating action on the macrophage and PMNs phagocyting indices. In the present work, the superoxide production of peritoneal macrophages and PMNs during 30 days of tumor progression was followed. Effects of the application of HLSOD in an optimal protective dose on the superoxide production in peritoneal macrophages and blood PMNs were examined. The spontaneous and phorbol-myristate acetate (PMA)-inducible O2- production in both types of phagocytes was 4-5-fold increased in tumor-bearing hamsters (TBH), as compared to the controls, at day 14 after tumor transplantation (the day of tumor appearance in transplanted animals). Furthermore, O2- production was also similar to the control values for the following days of observation. HLSOD treatment of TBH induced a normalization of superoxide production in macrophages and PMNs. Therefore, the established decrease of superoxide anions in phagocyting cells of TBH indicates possible effects of HLSOD on the host antioxidant defense.
Insights
Fungal superoxide dismutase (SOD) treatment normalized phagocyte function in tumor-bearing hamsters. This suggests HLSOD may enhance the host
Area of Science:
- Biochemistry
- Immunology
- Mycology
Background:
- Phagocytic activity of macrophages and polymorphonuclears (PMNs) is suppressed in hamsters with myeloid tumors.
- Cu/Zn SOD from Humicola lutea (HLSOD) previously improved survival and phagocytic indices in tumor-bearing hamsters.
Purpose of the Study:
- To investigate the effect of HLSOD on superoxide production in peritoneal macrophages and blood PMNs during tumor progression.
- To determine if HLSOD normalizes phagocyte superoxide production in tumor-bearing hamsters.
Main Methods:
- Measuring spontaneous and PMA-inducible superoxide (O2-) production in peritoneal macrophages and blood PMNs.
- Administering HLSOD to tumor-bearing hamsters at an optimal protective dose.
- Comparing superoxide production in tumor-bearing hamsters with and without HLSOD treatment to control hamsters.
Main Results:
- Superoxide production in phagocytes of tumor-bearing hamsters was significantly increased at day 14 post-transplantation compared to controls.
- HLSOD treatment normalized superoxide production in both macrophages and PMNs of tumor-bearing hamsters.
- The study observed a decrease in superoxide anions in phagocytic cells of tumor-bearing hamsters, suggesting HLSOD's impact on host antioxidant defense.
Conclusions:
- HLSOD treatment normalizes aberrant superoxide production in phagocytes of tumor-bearing hamsters.
- The findings indicate HLSOD may play a role in bolstering the host's antioxidant defense mechanisms against tumor progression.
- Further research into HLSOD's effects on host antioxidant defense is warranted.
