REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Anti SiglecF-BV421 (clone E50-2440)	BD Biosciences	Cat# 562681; RRID: AB_2722581
Anti SiglecF-PE (clone E50-2440)	BD Biosciences	Cat# 552126; RRID: AB_394341
Anti CD11b-PerCP-Cy5.5 (clone M1/70	Biolegend	Cat# 101228; RRID: AB_893232
Anti CD11c-BV510 (clone N418)	Biolegend	Cat# 117338; RRID: AB_2562016
Anti MHCII-FITC (clone M5/114.15.2)	Biolegend	Cat# 107606; RRID: AB_313321
Anti Ly6C-BV711 (clone HK1.4)	Biolegend	Cat# 128037; RRID: AB_2562630
Anti CD64-BV711 (clone X54-5/7.1)	Biolegend	Cat# 139311; RRID: AB_2563846
Anti CD64-PE (clone X54-5/7.1)	Biolegend	Cat# 139304; RRID: AB_10612740
Anti MerTK- APC (clone 2B10C42)	Biolegend	Cat# 151508; RRID: AB_2650739
Anti MerTK- FITC (clone 2B10C42)	Biolegend	Cat# 151504; RRID: AB_2617035
Anti Ki67-FITC (clone SolA15)	eBioscience	Cat# 11-5698-82; RRID: AB_11151330
Anti Ki67-APC (clone SolA15)	eBioscience	Cat# 17-5698-82; RRID: AB_2688057
Anti CD45-APC-Cy7 (clone 30-F11)	Biolegend	Cat# 103116; RRID: AB_312981
Anti CBFb (clone EPR6322)	Abcam	Cat# ab133600; RRID:
IRDye® 800CW Goat anti-Rabbit IgG Secondary Antibod	LI-COR	Cat# 926-32211
IRDye® 680RD Donkey anti-Mouse IgG Secondary Antibody	LI-COR	Cat# 926-68072
Chemicals, peptides, and recombinant proteins
Zombie NIR™ Fixable Viability Kit	Biolegend	Cat# 423106
Zombie Aqua™ Fixable Viability Kit	Biolegend	Cat# 423102
Recombinant mouse GM-CSF	Biolegend	Cat# 576308
Recombinant mouse M-CSF	Biolegend	Cat# 574804
Ro 5-3335	TargetMol	Cat# T4687
Protease Inhibitor Cocktail	Sigma	Cat# P8340-5ML
Critical commercial assays
Cellular Senescence Detection Kit - SPiDER-βGal	Donjindo	SG04-01
GenElute Mammalian Total RNAMiniprep Kit	Sigma-Aldrich	Cat# RTN350
BD PharMingen BrdU Flow Kits	BD Biosciences	Cat# 552598
eBioscience Foxp3 / TranscriptionFactor Staining Buffer Set	Thermo Fisher Scientific	Cat# 00-5523-00
Pierce BCA Protein Assay Kit	Thermo Scientific	Cat# 23225
NE-PER™ Nuclear and Cytoplasmic Extraction Reagents	Thermofisher	Cat# 78833
Revert™ 700 Total Protein Stain Kits for Western Blot Normalization	LI-COR	Cat# 926-11010
Deposited data
Raw and analyzed scRNAseq of AMs from young and aged mice	This paper	GEO: GSE205982
Microarray of AMs from young and aged mice (Figure 3J)	(Wong et al., 2017)21	GEO: GSE84901
Bulk-RNA-seq of AMs from young and aged mice (Figure 3K)	(McQuattie-Pimentel et al., 2021)22	GEO: GSE134397
sc-RNA-seq of pneumoncytes of "Healthy" individuals (Figures 5 and S5)	(Habermann et al., 2020)51	GEO: GSE135893
sc-RNA-seq of pneumoncytes of "Healthy" individuals (Figures 5 and S5)	(Reyfman et al., 2019)52	GEO: GSE122960
sc-RNA-seq of pneumoncytes of rejected organ donors (Figures 5 and S5)	(Morse et al., 2019)53	GEO: GSE128033
sc-RNA-seq of pneumoncytes of "Healthy" individuals (Figures 5 and S5)	(Adams et al., 2020)54	GEO: GSE136831
Bulk-RNA-seq of different macrophages (Figure S1C)	(Heng et al., 2008)35	ImmGen
sc-RNA-seq of pneumoncytes of young (3-month) and aged (24-month) mice (Figure S2B and S2C)	(Simon LM et al., 2019)37	GEO: GSE124872
Experimental models: organisms/strains
C57BL/6J	The Jackson Laboratory	Cat# 000664
C57BL/6N	National Institutes of Aging	N/A
Lyz2-cre	The Jackson Laboratory	Cat# 004781
Cbfbfl/fl	Laboratory of Dr. Thomas J. Braciale	(Cardani et al., 2017)
Oligonucleotides
Cdkn1a-F qPCR	GTCAGGCTGGTCTGCCTCCG	N/A
Cdkn1a-R qPCR	CGGTCCCGTGGACAGTGAGCAG	N/A
Cdkn2a-F qPCR	CCCAACGCCCCGAACT	N/A
Cdkn2a-R qPCR	GCAGAAGAGCTGCTACGTGAA	N/A
Serpine1-F qPCR	GACACCCTCAGCATGTTCATC	N/A
Serpine1-R qPCR	AGGGTTGCACTAAACATGTCAG	N/A
mHprt qPCR-F	CTCCGCCGGCTTCCTCCTCA	N/A
mHprt qPCR-R	ACCTGGTTCATCATCGCTAATC	N/A
Software and algorithms
GraphPad Prism 9	GraphPad Software	http://www.graphpad.com
FlowJo (version 10.3)	LLC	https://www.flowjo.com/
Image Studio™ Lite Quantification Software	LI-COR	N/A
Cell Ranger v2.0.0	10X Genomics
R project		https://www.r-project.org/
R studio	Posit	https://posit.co/
Seurat	Satija lab	https://satijalab.org/seurat/
Monocle3	Trapnell lab	https://cole-trapnell-lab.github.io/monocle3/
Gene Set Enrichment Anlaysis (GSEA)	UC San Diego and Broad Institute	http://www.gsea-msigdb.org/gsea/index.jsp