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Small molecule lactoferrin with an inflammatory effect but no apparent antibacterial activity in mastitic mammary
Ken-ichi Komine1, Yumiko Komine, Toshinobu Kuroishi
1T-Cell Research Institute, In Kyouitsu Seiyaku Corp, Tokyo, Japan.
Abstract:
We have identified various lactoferrin (Lf) molecules in mastitic mammary gland secretions (MGSs), and these Lf molecules were examined for their physiological function in MG. These Lf molecules were isolated by Con A affinity chromatography, and then analyzed by various electrophoresis methods and N-terminal amino acid sequencing. The low Con A affinity Lf was found to have low molecular peptides as compared with the 86 kDa of the high Con A affinity Lf, which is usually detected in healthy MGSs. The N-terminal amino acid sequence of each of the small molecular Lfs were confirmed as fragments of 86 kDa Lf. This low Con A affinity Lf stimulated spleen adherent cells to produce more O(2)(-) than 86 kDa Lf. Furthermore, the low Con A affinity Lf showed low antibacterial activity against E. coli and S. aureus, and had decreased iron-binding capacity in comparison with 86 kDa Lf. Moreover, the 86 kDa Lf could stimulate bovine T cells or macrophages to produce IFN-gamma, IL-4, IL-6, and IL-1alpha. However low Con A affinity Lf induced the production of TNFalpha, but not physiological T cell or macrophage cytokines. It was also found that when the healthy MGs of dry cows were injected with the low Con A affinity Lf, there was an increase in polymorphonuclear cells together with TNFalpha, MCP-1, and IL-8 production. These results suggested that low Con A affinity Lf in mastitic MGSs differed from 86 kDa Lf in physiological characteristics, and, that it induced an inflammatory reaction in MGs.
Insights
Mastitic mammary gland secretions contain low Con A affinity lactoferrin (Lf) fragments. These fragments differ from healthy Lf, showing reduced antibacterial activity and inducing inflammatory responses in mammary glands.
Area of Science:
- Biochemistry
- Immunology
- Veterinary Science
Background:
- Lactoferrin (Lf) is a key protein in mammary gland secretions (MGSs).
- Mastitis, an inflammation of the mammary gland, alters MGS composition.
- Understanding functional differences in Lf during mastitis is crucial for disease management.
Purpose of the Study:
- To isolate and characterize lactoferrin (Lf) variants in mastitic mammary gland secretions (MGSs).
- To investigate the physiological functions of these mastitis-associated Lf molecules.
- To compare the properties of mastitic Lf with Lf found in healthy mammary glands.
Main Methods:
- Isolation of Lf molecules using Con A affinity chromatography.
- Analysis via electrophoresis and N-terminal amino acid sequencing.
- Assessment of immune cell stimulation, antibacterial activity, and iron-binding capacity.
Main Results:
- Mastitic MGSs contain low Con A affinity Lf, consisting of smaller peptide fragments of the 86 kDa Lf found in healthy MGSs.
- Low Con A affinity Lf exhibited decreased antibacterial activity and iron-binding capacity compared to 86 kDa Lf.
- Low Con A affinity Lf stimulated spleen cells to produce more O(2)(-) and induced TNFalpha production in mammary glands, unlike the physiological cytokines induced by 86 kDa Lf.
Conclusions:
- Mastitic Lf molecules possess distinct physiological characteristics compared to Lf from healthy mammary glands.
- Low Con A affinity Lf isolated from mastitic secretions can induce inflammatory reactions within the mammary gland.
- These findings highlight the altered role of Lf during bovine mastitis.
