Table 3 Definition, baseline values and units for the epithelial barrier and immune response model parameters given in36.

From: Modelling the influence of vitamin D and probiotics on inflammation and the intestinal microbiota in older adults

Parameter

Description

Value & Units

\(\epsilon _{1}\)

Proliferation rate of intestinal epithelial cells

\(\mathrm {4.9\times 10}^{-13}\) (ng day)−1

\(\epsilon _{2}\)

Rate of repair of damaged epithelial cells by VDR

\(\mathrm {2\times 10}^{9}\) ml/(ng day)

\(\epsilon _{3}\)

Removal rate of damaged epithelial cells by macrophages

\(\mathrm {3.17\times 10}^{-6}\) ml/day

\(\epsilon _{4}\)

Damage to epithelial cells by pro-inflammatory mediators

\(\mathrm {2.7\times 10}^{3}\) ml/(ng day)

\(\epsilon _{5}\)

Damage to epithelial cells by pathogenic bacteria

\(\mathrm {1\times 10}^{-12}\) (CFU day)−1

\(\iota _{1}\)

Rate of activation of macrophages by pro-inflammatory cytokines

\(\mathrm {1.35\times 10}^{9}\) (ng day)−1

\(\iota _{2}\)

Rate of inhibition of macrophages by anti-inflammatory cytokines

\(\mathrm {1.13\times 10}^{2}\) ml/(ng day)

\(\iota _{3}\)

Natural death rate of macrophages

1 day−1

\(\iota _{4}\)

Rate that T/B cells are differentiated into T/B regulatory cells in presence of VDR

\(\mathrm {2.38\times 10}^{11}\) (ng day)−1

\(\iota _{5}\)

Rate that T/B cells are differentiated into T/B regulatory cells in presence of commensal bacteria

\(\mathrm {8.5\times 10}^{-11}\) (CFU ml day)−1

\(\iota _{6}\)

Rate at which differentiation into regulatory cells is inhibited by pathogenic bacteria

\(\mathrm {1\times 10}^{-14}\) CFU−1

\(\iota _{7}\)

Combined natural death rate of T/B regulatory cells

1 day−1

\(\iota _{8}\)

Rate of utilisation of metabolites for T-helper cell proliferation

\(\mathrm {2.57\times 10}^{-8}\) (ng ml day)−1

\(\iota _{9}\)

Rate of T-helper cell proliferation in response to pro-inflammatory cytokines

\(\mathrm {1.12\times 10}^{9}\) (ng day)−1

\(\iota _{10}\)

Rate of T-helper cell proliferation in response to pathogenic bacteria

\(\mathrm {1.05\times 10}^{-7}\) (CFU ml day)−1

\(\iota _{11}\)

Rate of inhibition to T helper cell proliferation by VDR

\(\mathrm {4\times 10}^{6}\) ml/ng

\(\iota _{12}\)

Rate of inhibition to T helper cell proliferation by commensals

\(\mathrm {1\times 10}^{-15}\) CFU−1

\(\iota _{13}\)

Natural rate of T-helper cell death

10 day−1

\(\iota _{14}\)

Rate of activation of plasma B cells by bacterial products

\(\mathrm {1.28\times 10}^{-8}\) (ng ml day)−1

\(\iota _{15}\)

Rate of maturation of plasma B cells in presence of pro-inflammatory cytokines

\(\mathrm {5\times 10}^{8}\) (ng day)−1

\(\iota _{16}\)

Rate of inhibition of plasma B cells by VDR

\(\mathrm {4\times 10}^{8}\) ml/ng

\(\iota _{17}\)

Natural death rate of plasma B cells

0.81 day−1

\(\alpha _{1}\)

Production rate of anti-inflammatory cytokines by epithelial cells upregulated by VDR

\(\mathrm {7.08\times 10}^{5}\) day−1

\(\alpha _{2}\)

Production rate of anti-inflammatory cytokines by T and B regulatory cells stimulated by commensal bacteria

\(\mathrm {2.07\times 10}^{-21}\) ng/(CFU day)

\(\alpha _{3}\)

Production rate of anti-inflammatory cytokines by macrophages after consuming damaged epithelial cells

\(\mathrm {1.13\times 10}^{-7}\) ng/day

\(\alpha _{4}\)

Production rate of anti-inflammatory cytokines by macrophages after consuming pathogenic bacteria

\(\mathrm {1.69\times 10}^{-20}\) ng/(CFU day)

\(\alpha _{5}\)

Natural degradation rate of anti-inflammatory cytokines

\(\mathrm {7.5\times 10}^{2}\) day−1

\(\alpha _{6}\)

Production rate of pro-inflammatory cytokines in response to damaged epithelial cells

\(\mathrm {9.3\times 10}^{-18}\) ng/(CFU ml day)

\(\alpha _{7}\)

Production rate of pro-inflammatory cytokines by activated innate immune cells

\(\mathrm {5.94\times 10}^{-11}\) ng/day

\(\alpha _{8}\)

Inhibition of pro-inflammatory cytokines by VDR

\(\mathrm {4\times 10}^{7}\) ml/ng

\(\alpha _{9}\)

Inhibition of pro-inflammatory cytokines by commensals

\(\mathrm {5\times 10}^{-15}\) CFU−1

\(\alpha _{10}\)

Production rate of pro-inflammatory cytokines by T helper cells

\(\mathrm {8.78\times 10}^{-24}\) ng/(CFU day)

\(\alpha _{11}\)

Natural degradation rate of pro-inflammatory cytokines

1.2 day−1

\(\alpha _{c}\)

Rate of pro-inflammatory cytokine release by damaged epithelial cells

\(\mathrm {2.3\times 10}^{-3}\) ng/(ml day)

\(\alpha _{g}\)

Rate of anti-inflammatory cytokine release by healthy epithelial cells

\(\mathrm {1.77\times 10}^{-3}\) ng/(ml day)

\(\gamma _{c}\)

Background production rate of pro-inflammatory cytokines

\(\mathrm {3\times 10}^{-4}\) ng/(ml day)

\(\gamma _{g}\)

Background production rate of anti-inflammatory cytokines

0.35 ng/(ml day)