Induction of arthritis by high mobility group box chromosomal protein 1 is independent of tumour necrosis factor signalling

Table 1 Production of IL-6 following 24 hours and 48 hours of stimulation with different doses of purified recombinant endotoxin-free high mobility group box chromosomal protein 1 (pHMGB1) and mouse recombinant high mobility group box chromosomal protein 1 (rHMGB1)

Time	Mice	IL-6 production (pg/ml)				Lipopolysaccharide^a
		0 μg/ml HMGB1	0.05 μg/ml HMGB1	0.5 μg/ml HMGB1	5 μg/ml HMGB1
PHMGB1
24 hours	TNFα^-/-	17.0 ± 2.3	17.6 ± 2.2	17.8 ± 2.4	13.1 ± 4.6	2,460 ± 226
	TNFα^+/+	16.2 ± 1.9	15.9 ± 2.0	16.8 ± 3.2	7.3 ± 3.1	6,905 ± 1,763
48 hours	TNFα^-/-	19.1 ± 3.0	20.1 ± 2.9	17.0 ± 1.6	26.3 ± 3.8
	TNFα^+/+	19.8 ± 2.2	18.3 ± 2.2	14.2 ± 2.3	20.2 ± 3.2
RHMGB1
24 hours	TNFα^-/-	28 ± 16		304 ± 50* (314)	2,317 ± 264 (2,271)	146 ± 46* (130)
	TNFα^+/+	68 ± 11		602 ± 112 (558)	3,046 ± 757 (2,504)	344 ± 63 (359)
48 hours	TNFα^-/-	213 ± 58		468 ± 56* (500)	2,541 ± 258 (2,588)	238 ± 79 (207)
	TNFα^+/+	263 ± 33		1,133 ± 202 (1,062)	4,114 ± 941 (3,527)	438 ± 62 (408)

Data presented as the mean ± standard error of the mean of 10 mice per each group (pHMGB1), and the mean ± standard error of the mean (median) of four mice in each group (rHMGB1). HMGB1, high mobility group box chromosomal protein 1. ^apHMGB1, 5 μg/ml; rHMGB1, 10 ng/ml. *P < 0.05 TNFα^-/- mice versus control mice.