TABLE 1.

Key Resources Table. Table showing details of reagents used in the Experimental Procedures

Reagent	Source	Species	Identifier	Clone
Antibodies—anti‐human	Invitrogen	Anti‐human	45–0037–42	OKT3
CD3‐PerCPCy5.5	eBioscience	Anti‐human	56–0048–82	OKT4
CD4‐AF700	eBioscience	Anti‐human	56–0049–41	RPA‐T4
CD45RA‐FITC	BioLegend	Anti‐human	304106	HI100
CD27‐PECy7	BioLegend	Anti‐human/mouse	123216	LG.3A10
CXCR5‐PE	BioLegend	Anti‐human	356904	D252D4
ICOS‐APC	eBioscience	Anti‐human	17–9948–42	ISA−3
PD−1‐AF647	BioLegend	Anti‐human	329910	EH12.2H7
IRF4‐PE	BioLegend	Anti‐human, mouse, rat	646404	IRF4.3F4
BCL6	BD	Anti‐human, mouse, rat	561522	KI 12–91
CD3	BD Bioscience	Anti‐human	300402	UCHT1
CD28	Invitrogen	Anti‐human	16–0289–85	CD28.1
pCD247	Invitrogen	Anti‐human, mouse, rat	12–28–41	32BR45
pErk‐PE	BD Bioscience	Anti‐human	612566	20A
pS6‐AF647	Cell Signalling	Anti‐human	48s1 s	D57.2.2E
CD25‐APC	eBioscience	Anti‐human	17–0259–41	BC96
CD28	eBioscience	Anti‐human	302912	CD28.2
CD28	BD Pharmingen	Anti‐human	555726	CD28.2
CD3	BioLegend	Anti‐human	300401	UCHT1
IFNg	eBioscience	Anti‐human	25–7319–41	45.B3
IL−21	eBioscience	Anti‐human	12–7219–42	eBIO3A3‐N2
Notch1‐PE	BD	Anti‐mouse	552768	mN1A
Actin	Sigma	Anti‐human, mouse, rat	A5441	AC−15
Notch1	BD Pharmingen	Anti‐human	563421	MH1 N1‐519
Notch2	BioLegend	Anti‐human	34803	MHN2‐25
Activin A	RnD Systems	Anti‐human, mouse, rat	MAB3381	69403
IL−12 p70	RnD Systems	Anti‐human	MAB219	24916
IL−12p35	Invitrogen	Anti‐human	14–7128–82	BT21
TGFB	RnD Systems	Anti‐human	MAB1835	1D11
pStat5‐PE	eBioscience	Anti‐human/mouse	12–9010–42	SRBCZX
pStat3‐AF647	BD Pharmingen	Anti‐human	557815	pY705
Fc block	eBioscience	Anti‐human	14–9161–73	N/A
Antibodies ‐ anti‐mouse
CD3‐PerCPCy5.5	Invitrogen	Anti‐mouse	45–0031–82	145‐2C11
CD4‐APC	Invitrogen	Anti‐mouse	17–0041–83	GK1.5
CD44‐AF700	BioLegend	Anti‐mouse	103026	Im7
CD62L‐PECy7	eBioscience	Anti‐mouse	25–0621–82	Mel14
IRF4	BioLegend	Anti‐human, mouse, rat	646404	IRF4.3F4
BCL6‐PE	BD	Anti‐human, mouse, rat	561522	KI 12–91
BCL6‐PECy7	BD	Anti‐human, mouse, rat	583582	KI 12–91
CXCR5‐APC	BioLegend	Anti‐mouse	145506	L138D7
FoxP3‐APC	Invitrogen	Anti‐mouse	17–5773–82	FKJ−16S
PD−1‐PECy7	BioLegend	Anti‐mouse	109110	RMP1‐30
Va2	Invitrogen	Anti‐mouse	17–5812–82	20.1
CD45.1‐PECy7	eBioscience	Anti‐mouse	25–0453–82	A20
CD45.2‐PerCPCy5.5	eBioscience	Anti‐mouse	45–0454–82	104
CD4‐BV605	BioLegend	Anti‐mouse	100547	RM4‐5
PD−1‐e780	eBioscience	Anti‐mouse	47–9985–82	J43
CXCR5‐BV421	BioLegend	Anti‐mouse	145512	38D7
B220‐BV785	BioLegend	Anti‐mouse	103246	RA3‐6B2
CD19‐PerCPCy5.5	BioLegend	Anti‐mouse	115533	6D5
B220‐BV510	BioLegend	Anti‐mouse	103247	38D7
CD44‐PerCPCy5.5	BioLegend	Anti‐mouse	103032	IM7
Ki67‐AF700	Invitrogen	Anti‐mouse/human	56–5698–82	SolA15
Ki67‐FITC	Invitrogen	Anti‐mouse/human	11–5698–82	SolA15
CD4‐PerCPCy5.5	Invitrogen	Anti‐mouse	45–0042–82	RM4‐5
CD4‐APC	Invitrogen	Anti‐mouse	17–0041–83	GK1.5
Fc block	Invitrogen	Anti‐mouse	14–0161–82	91
live/dead‐e780	Invitrogen	N/A	65–0865–14	N/A
Enrichment kits
Magnisort Human Naïve CD4+ Cell Enrichment Kit	Invitrogen	Human	N/A	8804–6814–74
Magnisort Murine Naïve CD4+ Cell Enrichment Kit	Invitrogen	Murine	N/A	8804–6824–74
Real‐time PCR primers
Taqman probes
FOXP3	Invitrogen	Human	Hs01085334
RBPJ	Invitrogen	Human	Hs00794653
BCL6	Invitrogen	Human	Hs00153368
TBX21	Invitrogen	Human	Hs00894392
PRDM1	Invitrogen	Human	Hs00153357
18S	Invitrogen	Human	Hs03003631
B2 M	Invitrogen	Human	Hs99999907
SYBR green‐based primers
CMAF	Bio‐Rad	Human	10025636	qHsaCDD0047317
			Forward primer	Reverse primer
GAPDH	Sigma	Human	ACAGTTGCCATGTAGACC	TTTTTGGTTGAGCACAGG
VCP	Sigma	Human	TAGAGGAATCCTGCTTTAG	CCATTGATCAAGAAGAAGAAGG
CXCL13	Sigma	Human	GAGGCAGATGGAACTTGAGC	CTGGGGATCTTCGAATGCTA
IL21	Sigma	Human	GAATGCGTCCTTATAGA	GTCTCTACATCTTCTGGA