The Autoantigenic Proinsulin B-Chain Peptide B11-23 Synergises with the 70 kDa Heat Shock Protein DnaK in Macrophage Stimulation

Table 2

Release of IL-6, TNFα, and IL-1β from MonoMac 6 cells exposed to proinsulin-derived 13mer peptides alone or in combination with DnaK.

	IL-6 (ng/ml)	TNFα (ng/ml)	IL-1β (ng/ml)
Medium	<0.1	<0.1	<0.2
LPS	76.3 ± 9.0b	45.44 ± 8.14	12.70 ± 1.02
B11-23	<0.1	<0.1	<0.2
B11-23 + DnaK	19.0 ± 4.3	10.9 ± 1.9	5.5 ± 1.0
B18-30	<0.1	<0.1	<0.2
B18-30 + DnaK	<0.1	<0.1	<0.2
A8-20	<0.1	<0.1	<0.2
A8-20 + DnaK	5.7 ± 4.9	0.6 ± 0.9	<0.2
C8-20	<0.1	<0.1	<0.2
C8-20 + DnaK	7.7 ± 5.5	<0.1	<0.2
C19-31	<0.1	<0.1	<0.2
C19-31 + DnaK	<0.1	<0.1	<0.2

MonoMac 6 cells were incubated in the absence (medium) or in the presence of LPS (10 ng/ml) or DnaK (1 μg/ml) in the absence or presence of proinsulin peptides (10 μg/ml). Concentrations of TNFα were determined after 6 h of incubation and concentrations of IL-6 and IL-1β were determined after 24 h of incubation in the culture supernatants. Results from peptide-DnaK combinations were corrected by cytokine levels induced by stimulation with DnaK alone. Data are given as means ± SD from three experiments performed in triplicates. The multiplex system used here for cytokine measurements yielded lower results than ELISA (Figure 2), but the relative differences between LPS, peptide B11-23, and peptide B11-23 + DnaK were not affected. for the difference to medium. for the differences between peptide and peptide + DnaK. for the differences between peptide and peptide + DnaK.