Table 3.

Combination therapy using the UCLA1 aptamer, T20, and b12 against subtype C Env pseudotype viruses

Virus	CIa	Concn of UCLA1	Concn of UCLA1 + T20 or b12	Dose reduction indexc	Concn of T20 or b12	Concn of T20 or b12 + UCLA1	Dose reduction indexc
		UCLA1 (nM)b	UCLA1 + T20 (μM)		T20 (μg/ml)d	T20 + UCLA1 (μM)
Du156.12	0.37	1.20	0.31	3.9	2.87	0.31	9.3
Du172.17	0.43	1.83	0.34	5.4	1.39	0.34	4.1
Du422.1	0.13	3.69	0.33	11.2	8.90	0.33	27.0
SW7.14	0.43	0.74	0.27	2.7	3.98	0.27	14.7
ZM53 M.PB12	0.46	6.22	1.73	3.6	9.72	1.73	5.6
ZM249 M.PL1	0.84	2.80	1.60	1.8	5.85	1.60	3.7
		UCLA1 (nM)b	UCLA1 + b12 (μM)		b12 (μg/ml)d	b12 + UCLA1 (μM)
Du156.12	0.93	1.20	0.30	4.0	0.44	0.30	1.5
Du172.17	0.56	1.83	0.22	8.3	0.50	0.22	2.3
Du422.1	0.65	3.69	0.53	7.0	1.04	0.53	2.0
SW7.14	1.62	0.74	1.19	0.6	50.00	1.19	42.0
ZM53 M.PB12	0.5	6.22	2.82	2.2	46.14	2.82	16.4
ZM249 M.PL1	0.7	2.80	0.87	3.2	2.26	0.87	2.6

^aThe combination index (CI) was calculated using the Chou and Talalay equation (7). CI values of 0.3 to 0.7, 0.7 to 0.85, 0.85 to 0.9, 0.9 to 1.1, and >1.1 represent synergism, moderate synergism, slight synergism, additive effect, and antagonism, respectively. CI values representing synergism are in bold.

^bThe UCLA1 aptamer was used at an initial concentration of 50 nM alone and in combination with T20 or b12.

^cDose reduction index is calculated as the ratio of drug concentration required for inhibition when the drug is used alone or in combination.

^dT20 and b12 were used at an initial concentration of 50 μg/ml (equivalent to 312 μM and 11,131 μM, respectively) alone or in combination with UCLA1.