REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Goat Anti-Rabbit IgG, polyclonal antibody, Horseradish Peroxidase conjugated (1:10000; WB)	abcam	Abcam Cat# ab6721, RRID: AB_955447
DYKDDDDK Tag (D6W5B) Rabbit, monoclonal antibody, unconjugated (1/1,000 WB and ChIP)	Cell Signaling Technology	Cell Signaling Technology Cat# 14793, RRID: AB_2572291
Rabbit Anti-Actin, polyclonal antibody, unconjugated (1/1,000 WB)	Sigma-Aldrich	Sigma-Aldrich Cat# A2066, RRID: AB_476693
Rabbit Recombinant Anti-ICOS Ligand/ICOSL, monoclonal antibody, unconjugated (1/1,000 WB)	abcam	ab209262 RRID not found
Mouse Anti-Human CD3, monoclonal antibody, APC-H7 conjugated (flow cytometry)	BD	BD Biosciences Cat# 560176, RRID: AB_1645475
Mouse Anti-Human CD4, monoclonal antibody, PE-Cy7 conjugated (flow cytometry)	BD	BD Biosciences Cat# 557852, RRID: AB_396897
Mouse Anti-Human CD8, monoclonal antibody, BV510 conjugated (flow cytometry)	BD	BD Biosciences Cat# 563919, RRID: AB_2722546
Mouse Anti-Human CD25 (IL-2 Receptor α), monoclonal antibody, BV421 conjugated (flow cytometry)	BD	BD Biosciences Cat# 564033, RRID: AB_2738555
Mouse Anti-Human FoxP3, monoclonal antibody, AF647 conjugated (flow cytometry)	BD	BD Biosciences Cat# 561184, RRID: AB_10584328
Mouse Anti-Human CD278 (ICOS), monoclonal antibody, BB515 conjugated (flow cytometry)	BD	BD Biosciences Cat# 564549, RRID: AB_2738840
Mouse Anti-Human B7-h2, monoclonal antibody, neutralizing, unconjugated (neutralization assays)	RnD Systems	R and D Systems Cat# MAB165, RRID: AB_2122734
Mouse IgG1 kappa isotype control, functional grade (neutralization assays)	Thermo Fisher	Thermo Fisher Scientific Cat# 16-4714-85, RRID: AB_470162
Bacterial and virus strains
NEB® 5-alpha competent E. coli; DH5α™ derivative	NEB	NEB Cat# C2987
Biological samples
see Tables
Chemicals, peptides, and recombinant proteins
Q5® High-Fidelity DNA Polymerase	NEB	NEB Cat# M0491L
SuperScript™ II Reverse Transcriptase	Invitrogen	Invitrogen 18064071
Annexin V Pacific Blue	Invitrogen	Invitrogen A35122
SfiI restriction enzyme	NEB	NEB Cat# R0123L
T4 DNA ligase	NEB	NEB Cat# M0202S
Clarity Max Western ECL Substrate	Bio-Rad	Bio-Rad Cat# 1705062
Protease inhibitory cocktail tablets	Roche	Roche 4693116001
Critical commercial assays
AmaxaTM Cell Line NucleofectorTM Kit R	Lonza	VCA-1001
PierceTM BCA Protein Assay Kit (23225, thermo scientific)	Thermo Scientific	Thermo Scientific 23225
IL-10 (human) ELISA Kit	Enzo	Enzo ADI-900-036
IL-2 ELISA Kit (human)	Aviva	Aviva OKBB00179
Accel-NGS® 2S plus DNA library kit	Swift Biosciences	Swift Biosciences 21024
Swift Unique Dual Indexing Primer Kit	Swift Biosciences	Swift Biosciences X9096
Accel-NGS 2S Truncated Adapters	Swift Biosciences	Swift Biosciences 28196
Deposited data
All Chip-Seq data have been deposited in the NCBI Geobus database		GSE205652
Experimental models: Cell lines
SEM	DSMZ	ACC 546
Oligonucleotides
GAPDH_fwd_short 5′-GGTCACCAGGGCTGC-3′	this paper	N/A
GAPDH_rev_short 5′-CGTTCTCAGCCTTGA-3′	this paper	N/A
ICOSLG_fwd 5′-TGACATCGGAGAGAGAGACAAG-3′	this paper	N/A
ICOSLG_rev 5′-ACGCTTTTGAAAGGGCCTCA-3′	this paper	N/A
EGR3.SfiI_fwd 5′-GGCCTCTGAGGCCACCATGAC CGGCAAACTCGCC-3′	this paper	N/A
EGR3cFLAG.SfiI_rev 5′-GGCCTGACAGGCCTTACTTATCG TCATCGTCCTTGTAGTC-3′	this paper	N/A
EGR3.SF1_fwd 5′-GGCCTAGCAAGACACCGC-3′	this paper	N/A
HOXA9_fwd_short 5′-CCACGCTTGACACTCACACT-3′	this paper	N/A
HOXA9_rev_short 5′-AGTTGGCTGCTGGGTTATTG-3′	this paper	N/A
IRX1_fwd_short 5′-GGATCTCAGCCTCTTCTCG-3′	this paper	N/A
IRX1_rev_short 5′-GTGGAGACCTGCGTGAGG-3′	this paper	N/A
EGR3_fwd_short 5′-CAGCGACTCGGTAGTCCATT-3′	this paper	N/A
EGR3_rev_short 5′-TAGGTCACGGTCTTGTTGCC-3′	this paper	N/A
ICOSLG_fwd_short 5′-AGTCCGGAGACAGAGCTCAC-3′	this paper	N/A
ICOSLG_rev_short 5′-CAGTCTGGGAGTCCATGCTC-3′	this paper	N/A
ICOSLG_fwd_ChIP1 5′-ACCGGGACCCATGGCA-3′	this paper	N/A
ICOSLG_rev_ChIP1 5′-CTCCCTCCTTCCAGCGTTC-3′	this paper	N/A
ICOSLG_fwd_ChIP2 5′-GTGAGCCGGGGAAGGA-3′	this paper	N/A
ICOSLG_rev_ChIP2 5′-ATGGGTCCCGGTGCCA-3′	this paper	N/A
ICOSLG_fwd_ChIP3 5′-GCAGAGCCGAACTTTCCG-3′	this paper	N/A
ICOSLG_rev_ChIP3 5′-TGGAGGCAGCCGTGTC-3′	this paper	N/A
ICOSLG_fwd_ChIP4 5′-CCTCAGAGCCAGTGTTAAGC-3′	this paper	N/A
ICOSLG_rev_ChIP4 5′-CGCATGCATGAATGGAAGGA-3′	this paper	N/A
ICOSLG_fwd_ChIP5 5′-GCCCTGCCCAGCTCTT-3′	this paper	N/A
ICOSLG_rev_ChIP5 5′-CAGGCCACGCTGAGAGAC-3′	this paper	N/A
ICOSLG_fwd_ChIP6 5′-GCTCTCCAAGGCCAGCTG-3′	this paper	N/A
ICOSLG_rev_ChIP6 5′-AAGCTGTCACTCCTGGTTCA-3′	this paper	N/A
Recombinant DNA
pSBtet_Puro sleeping beauty vector backbone	Kowarz et al. (2015)	AddGene #60507
EGR3 open reading frame	this paper	HEK293T cDNA
Sleeping beauty transposase plasmid pcGLobin-SB100XCO	Moudgil et al. (2020)	AddGene #154887
Software and algorithms
GraphPad Prism 7.01	GraphPad Software Inc.	GraphPad Prism 7.01
ClustVis (Metsalu and Vilo, 2015)	open source	N/A
TrimGalore	open source	N/A
Bowtie2	open source	N/A
SAMtools	open source	N/A
MACS3	open source	N/A
R package “ChIPseeker”	open source	N/A
R package “encodeChIPqc”	open source	N/A
python tool “deepTools”	open source	N/A
Integrative Genomics Viewer (IGV)	open source	N/A
Other
Low Fluorescence PVDF Western Membrane	Abcam	Abcam Cat# ab133411
Precision Plus Protein™ All Blue Standards; marker used for Western Blots with fluorescence detection	Bio-Rad	Bio-Rad Cat# 1610373EDU
Color Protein Standard Broad Range	NEB	NEB P7719S