Case report: Mafb promoter activity may define the alveolar macrophage dichotomy
Cre-LoxP system has been widely used to induce recombination of floxed genes of interest. Currently available macrophage promoter-specific Cre recombinase mice strains have various limitations that warrants the testing of additional Cre strains. V-maf musculoaponeurotic fibrosarcoma oncogene family,...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-12-01
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| Series: | Frontiers in Immunology |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fimmu.2022.1050494/full |
| _version_ | 1811177894720831488 |
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| author | Thao Vo Yogesh Saini |
| author_facet | Thao Vo Yogesh Saini |
| author_sort | Thao Vo |
| collection | DOAJ |
| description | Cre-LoxP system has been widely used to induce recombination of floxed genes of interest. Currently available macrophage promoter-specific Cre recombinase mice strains have various limitations that warrants the testing of additional Cre strains. V-maf musculoaponeurotic fibrosarcoma oncogene family, protein b -Cre (Mafb-Cre) mice label macrophages in most organs such as spleen, small intestine, lung, bone marrow, and peritoneal cavity. However, whether Mafb-Cre recombinase targets the gene recombination in alveolar macrophage remains untested. Here, we utilized MafbCre/WTR26mTmG/WT strain that expresses mTOM protein in all the cells of mouse body except for those that express Mafb-Cre-regulated mEGFP. We performed fluorescent microscopy and flow cytometry to analyze mTOM and mEGFP expression in alveolar macrophages from MafbCre/WTR26mTmG/WT mice. Our analyses revealed that the Mafb-Cre is active in only ~40% of the alveolar macrophages in an age-independent manner. While Mafb- (mTOM+/mEGFP-) and Mafb+ (mEGFP+) alveolar macrophages exhibit comparable expression of CD11b and CD11c surface markers, the surface expression of MHCII is elevated in the Mafb+ (mEGFP+) macrophages. The bone marrow-derived macrophages from MafbCre/WTR26mTmG/WT mice are highly amenable to Cre-LoxP recombination in vitro. The bone marrow depletion and reconstitution experiment revealed that ~98% of alveolar macrophages from MafbCre/WTR26mTmG/WT → WT chimera are amenable to the Mafb-Cre-mediated recombination. Finally, the Th2 stimulation and ozone exposure to the MafbCre/WTR26mTmG/WT mice promote the Mafb-Cre-mediated recombination in alveolar macrophages. In conclusion, while the Mafb-/Mafb+ dichotomy thwarts the use of Mafb-Cre for the induction of floxed alleles in the entire alveolar macrophage population, this strain provides a unique tool to induce gene deletion in alveolar macrophages that encounter Th2 microenvironment in the lung airspaces. |
| first_indexed | 2024-04-11T06:08:59Z |
| format | Article |
| id | doaj.art-b80aae091d514e42a97149206ce78a79 |
| institution | Directory Open Access Journal |
| issn | 1664-3224 |
| language | English |
| last_indexed | 2024-04-11T06:08:59Z |
| publishDate | 2022-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Immunology |
| spelling | doaj.art-b80aae091d514e42a97149206ce78a792022-12-22T04:41:24ZengFrontiers Media S.A.Frontiers in Immunology1664-32242022-12-011310.3389/fimmu.2022.10504941050494Case report: Mafb promoter activity may define the alveolar macrophage dichotomyThao VoYogesh SainiCre-LoxP system has been widely used to induce recombination of floxed genes of interest. Currently available macrophage promoter-specific Cre recombinase mice strains have various limitations that warrants the testing of additional Cre strains. V-maf musculoaponeurotic fibrosarcoma oncogene family, protein b -Cre (Mafb-Cre) mice label macrophages in most organs such as spleen, small intestine, lung, bone marrow, and peritoneal cavity. However, whether Mafb-Cre recombinase targets the gene recombination in alveolar macrophage remains untested. Here, we utilized MafbCre/WTR26mTmG/WT strain that expresses mTOM protein in all the cells of mouse body except for those that express Mafb-Cre-regulated mEGFP. We performed fluorescent microscopy and flow cytometry to analyze mTOM and mEGFP expression in alveolar macrophages from MafbCre/WTR26mTmG/WT mice. Our analyses revealed that the Mafb-Cre is active in only ~40% of the alveolar macrophages in an age-independent manner. While Mafb- (mTOM+/mEGFP-) and Mafb+ (mEGFP+) alveolar macrophages exhibit comparable expression of CD11b and CD11c surface markers, the surface expression of MHCII is elevated in the Mafb+ (mEGFP+) macrophages. The bone marrow-derived macrophages from MafbCre/WTR26mTmG/WT mice are highly amenable to Cre-LoxP recombination in vitro. The bone marrow depletion and reconstitution experiment revealed that ~98% of alveolar macrophages from MafbCre/WTR26mTmG/WT → WT chimera are amenable to the Mafb-Cre-mediated recombination. Finally, the Th2 stimulation and ozone exposure to the MafbCre/WTR26mTmG/WT mice promote the Mafb-Cre-mediated recombination in alveolar macrophages. In conclusion, while the Mafb-/Mafb+ dichotomy thwarts the use of Mafb-Cre for the induction of floxed alleles in the entire alveolar macrophage population, this strain provides a unique tool to induce gene deletion in alveolar macrophages that encounter Th2 microenvironment in the lung airspaces.https://www.frontiersin.org/articles/10.3389/fimmu.2022.1050494/fullMAFBCre-LoxPmacrophage-specific Crealveolar macrophageslung |
| spellingShingle | Thao Vo Yogesh Saini Case report: Mafb promoter activity may define the alveolar macrophage dichotomy Frontiers in Immunology MAFB Cre-LoxP macrophage-specific Cre alveolar macrophages lung |
| title | Case report: Mafb promoter activity may define the alveolar macrophage dichotomy |
| title_full | Case report: Mafb promoter activity may define the alveolar macrophage dichotomy |
| title_fullStr | Case report: Mafb promoter activity may define the alveolar macrophage dichotomy |
| title_full_unstemmed | Case report: Mafb promoter activity may define the alveolar macrophage dichotomy |
| title_short | Case report: Mafb promoter activity may define the alveolar macrophage dichotomy |
| title_sort | case report mafb promoter activity may define the alveolar macrophage dichotomy |
| topic | MAFB Cre-LoxP macrophage-specific Cre alveolar macrophages lung |
| url | https://www.frontiersin.org/articles/10.3389/fimmu.2022.1050494/full |
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