TABLE 1.

Ability of treated mycobacterial lysates to expand inhibitory γ₉δ₂ T cells

Treatment of MtbWL	Expansion indexa	% inhibitionb	% inhibition × EI	Sp actc
None	10.84 ± 5.740	71.39 ± 13.03	773.87	71.01
Reduction and alkylation	7.14 ± 2.56	66.63 ± 12.11	475.74	47.55
Delipidation	27.87 ± 8.30	69.04 ± 5.17	1,924.14	12.45
RNase and DNase digestion	14.27 ± 5.820	82.57 ± 2.760	1,178.27	12.58
Base hydrolysis	28.35 ± 10.58	74.5 ± 6.86	2,112.08	11.89
Acid hydrolysis	2.98 ± 1.96	−10.55 ± 0.28	−31.44	0.68
Pronase digestion	35.04 ± 11.15	64.22 ± 6.400	2,250.27	12.81
Trypsin digestion	13.16 ± 1.840	67.76 ± 10.80	891.72	5.90

^aExpansion index is calculated as the fold expansion of the absolute number of γ₉δ₂ T cells after stimulation with treated lysates compared to the absolute number of γ₉δ₂ T cells after rest in medium. Results are presented as means ± SE.

^bPercent inhibition is calculated as described in Materials and Methods. Results are presented as means ± SE.

^cSpecific activity is calculated as (percent inhibition × EI)/dry weight of the material.