. 2013 Dec 6;192(1):234–244. doi: 10.4049/jimmunol.1301302

Table II. LLO inhibition by neutrophil GP involves a heat-labile metalloproteinase activity.

	Erythrocyte Lysis ± SEM (%)
	—^a	PI^EDTAa	PI^a	EDTA^a	—^b	α₂-m^b	PI^EDTAb	PI^b
LLO	96.9 ± 1.2	100 ± 0.0	96.5 ± 1.7	100 ± 0.0	90.6 ± 2.3	98.3 ± 0.4^*	99.0 ± 0.7	97.6 ± 1.2
LLO + GP	22.5 ± 3.8^**	81.5 ± 7.3	10.1 ± 2.7^**	93.2 ± 2.8	1.9 ± 1.6^**	89.3 ± 2.9	69.8 ± 6.7^*	7.0 ± 4.0^**
LLO + HI-GP	97.4 ± 0.4	ND	ND	ND	ND	ND	ND	ND
LLO C484A	99.7 ± 0.2	ND	ND	ND	ND	ND	ND	ND
LLO C484A + GP	34.9 ± 10.2^**	94.6 ± 3.1	ND	ND	ND	ND	ND	ND
—	5.7 ± 1.8^**	ND	ND	ND	1.6 ± 1.6^**	ND	ND	ND

Results are the mean percent hemolysis at 30 min ± SEM of at least three independent experiments performed in duplicate. 100% lysis was determined by incubating erythrocytes with 0.05% Triton X-100.

^{^a}

Erythrocytes were incubated with LLO or LLO C484A, 6% GP (v/v), PI mixture that contains EDTA (PI^EDTA) or not (PI), or EDTA.

^{^b}

GP (6%, v/v) was incubated with α₂-macroglobulin (α₂-m) or PI mixture (PI^EDTA or PI) for 5 min at 37°C, then erythrocytes and LLO were added for further incubation at 37°C.

*p < 0.05, **p < 0.01 (comparison between LLO alone and the indicated treatments)

HI-GP, Heat-inactivated GP.