For each mouse we established five sets of splenocyte cultures. One of these was left unstimulated, to provide ''constitutive'' measurements and three others were respectively stimulated with agonists for toll-like receptor (TLR) 2, TLR4 and TLR9, which are receptors involved in the innate recognition of, and the triggering of immune responses against, invading microorganisms [20] . Cells and supernatants harvested from these cultures at 24 h were used to measure mRNA and protein expression of the proinflammatory cytokine tumour necrosis factor alpha (TNF-a) [18, 21] , mRNA expression of TLR2, TLR4 and TLR9, and mRNA expression of TGF-b1 and IL-10, which are antiinflammatory cytokines involved in the regulation of immune responses [22, 23, 24] . In the unstimulated cultures alone we measured mRNA expression of FoxP3, a transcription factor associated with the anti-inflammatory regulatory T-helper cell (T reg ) subset [25, 26] . TNF-a protein expression was also measured in 96 h supernatants from a further set of cultures stimulated with Heligmosomoides bakeri somatic antigen (HbAg).