Application of IgG-Derived Natural Treg Epitopes (IgG Tregitopes) to Antigen-Specific Tolerance Induction in a Murine Model of Type 1 Diabetes

Table 1

GAD65 sequences and HLA binding IC₅₀. Sequences for GAD65 epitopes were predicted using EpiMatrix (for high cluster score and if possible for high predicted HLA DR4 binding affinity) and synthesized for testing in HLA binding assays. The calculated IC₅₀ values (μM) for four HLA alleles are provided. “NB” indicates the peptide was a non-binder. The peptides were predicted and confirmed to be promiscuous binders (see Figure 2).

Peptide Name	Sequence	EpiMatrix Cluster Score	DRB1*0101 IC50	DRB1*0401 IC50	DRB1*0701 IC50	DRB1*1501 IC50	Published?
GAD65_086–103	DVNYAFLHATDLLPACDG	12.19	<5	7.5	<5	NB	Y (NOT DR4)
GAD65_175–190	HPRYFNQLSTGLDMVG	9.98	10.7	>50	13.9	NB	N
GAD65_203–226	NMFTYEIAPVFVLLEYVTLKKMRE	14.70	—	<25	—	—	Y (NOT DR4)
GAD65_243–267	GAISNMYAMMIARFKMFPEVKEKGM	15.87	<5	NB	8.7	<5	Y (NOT DR4)
GAD65_264–287	EKGMAALPRLIAFTSEHSHFSLKK	13.77	—	<25	—	—	Y
GAD65_338–352	TTVYGAFDPLLAVAD	9.69	4.1	NB	NB	31.3	Y (NOT DR4)
GAD65_354–372	CKKYKIWMHVDAAWGGGLL	14.48	NB	6.4	<5	>50	Y
GAD65_369–392	GGLLMSRKHKWKLSGVERANSVTW	17.60	16.3	<5	<5	NB	Y
GAD65_405–424	SALLVREEGLMQNCNQMHAS	4.45	NB	>50	NB	NB	Y (NOT DR4)
GAD65_450–470	VDVFKLWLMWRAKGTTGFEAH	33.90	25.4	NB	10.2	11.4	N
GAD65_480–496	YLYNIIKNREGYEMVFD	5.90	<5	5.7	NB	<5	Y
GAD65_504–518	VCFWYIPPSLRTLED	7.58	95.8	NB	25.2	10.3	Y
GAD65_511–525	PSLRTLEDNEERMSR	−0.89	NB	NB	NB	NB	Y
GAD65_550–570	LGDKVNFFRMVISNPAATHQD	22.32	—	<25	—	—	Y