TABLE 2.

Analysis of distinct epitope binding of MAbs by competition ELISA^a

MAb	Epitope group	% Inhibition of the biotin-labeled MAbb:
		M1	M2	M3	M4	M5	M6	M7	M8	M9	M10	M11	M12	M13	M14	M15	M16	M17	M18	M19	M20
M1	I	97	98	13	19	5	0	0	0	11	5	11	0	0	0	0	21	0	22	18	15
M2	I	97	97	11	0	0	0	0	0	0	0	0	0	0	0	0	0	0	6	3	0
M3	II	39	0	94	35	38	30	38	18	23	14	35	20	9	7	22	27	0	22	29	23
M4	III	31	0	10	96	94	84	67	89	94	91	84	0	0	0	0	29	2	18	26	6
M5	III	8	0	4	92	93	79	67	82	92	87	78	4	0	0	0	19	0	20	16	13
M6	III	36	0	12	93	90	90	78	86	89	81	84	13	0	0	0	0	0	0	0	0
M7	III	3	0	29	96	96	94	97	94	96	96	93	0	0	0	5	32	3	20	25	19
M8	III	17	0	13	96	95	90	74	92	96	95	90	5	5	0	0	29	3	26	30	23
M9	III	20	7	23	95	95	81	76	92	95	94	84	25	32	15	36	10	0	23	24	14
M10	III	0	1	6	95	95	82	71	92	96	95	87	21	17	12	13	20	3	22	29	13
M11	III	9	0	31	83	83	73	75	78	81	71	89	24	0	0	8	10	0	12	18	4
M12	IV	28	0	17	7	18	0	0	0	28	36	34	92	93	94	91	93	94	90	92	84
M13	IV	41	2	0	23	24	4	0	12	23	28	0	63	85	81	74	80	60	69	73	63
M14	IV	33	0	17	16	21	0	0	0	21	13	0	95	90	96	95	96	87	96	96	94
M15	IV	0	0	17	14	15	5	42	0	24	15	0	89	90	91	95	95	88	82	86	89
M16	IV	17	0	22	26	5	2	0	0	14	14	11	90	90	94	94	96	85	87	89	93
M17	IV	0	5	34	37	42	8	0	3	29	40	0	94	90	94	96	97	97	89	92	96
M18	IV	0	0	19	14	4	0	36	0	22	39	0	92	92	95	92	95	81	96	96	91
M19	IV	27	0	19	27	27	0	0	0	20	35	0	90	92	94	90	92	69	92	92	83
M20	IV	6	5	38	5	0	3	0	8	28	21	0	93	91	95	96	97	91	90	92	95

^aThe competition ELISA was performed to analyze the binding epitopes of the different MAbs. By use of the criteria described in Materials and Methods, MAbs M1 and M2 effectively competed (≥97% inhibition) with each other, which suggested that these two MAbs recognized the same epitope. Similarly, the 60 to 97% inhibition of each other's binding of MAbs M4, M5, M6, M7, M8, M9, M10, and M11 and MAbs M12, M13, M14, M15, M16, M17, M18, M19, and M20 suggested that they form two other distinct groups. MAb M3 did not interfere with heterologous MAb binding (≤39% inhibition), suggesting that this MAb may recognize a fourth discrete epitope. Therefore, these 20 MAbs recognized four distinct epitopes, and MAbs in each group reacted with the same epitope or with sterically overlapping epitopes on the DENV2 NS1 protein. The experiment was repeated with similar results.

^bCompetitive inhibition values of ≥75% are in boldface type.