Parameter	Notation	Value	Reference
Equilibrium constant for pMHC-TCR complex formation	$K_{TCR•pMHC}$	$\mathrm{30,000}$	Huppa et al., 2003
Equilibrium constant for IL-2R pre-assembly	$K_{IL2R\alpha •IL2R\beta \gamma }$	$\mathrm{2,700}$	Figure S16 in Cotari et al., 2013
Efficiency of TCR inhibition on STAT5 phosphorylation	${\sigma }_{TCR\searrow IL2R}$	0.01	Adjusted to fit Figure 4A
${\text{EC}}_{50}$ of conversion of full IL-2$•$ IL-2R into pSTAT5	$K_{IL2>pSTAT5}$	${10}^4$	Adjusted to fit Figure 4A
Rate of antigen consumption	$k_{antigen}^{consumption}$	$\text{ln}\left(2\right)/3.5h^{-1}$	von Essen et al., 2004
Threshold number of pMHC–engaged TCR to start activation	${\tau }_{pMHC-TCR}^{activation}$	1	Huang et al., 2013
TCR–dependent IL2Rα expression plateau	$n_{TCR>IL2R\alpha }^{max}$	1000	Cotari et al., 2013
Rate of internalization for IL2Rα	$k_{receptor}^{degradation}$	$\text{ln}\left(2\right)/5h^{-1}$	Duprez et al., 1988
pSTAT5–dependent plateau for IL2Rα expression	$n_{pSTAT5>IL2R\alpha }^{max}$	${2.10}^6$	Figure 1D in Cotari et al., 2013
Abundance of IL–2Rβ without TCR activation	$n_{IL2R\beta }^{\left(0\right)}$	1000	Figure S8 in Cotari et al., 2013
Maximal abundance of IL2Rβ upon TCR activation	$n_{IL2R\beta }^{max}$	10,000	Figure 8—figure supplement 1C
Rate of IL-2 binding to full IL-2R	$k_{IL2•IL2R}^{association}$	$1\times {10}^{11}{h}^{-1}$	Table I in Wang and Smith, 1987
Rate of internalization of full complex (IL-2$•$ IL-2R)	$k_{IL-2•IL-2R}^{endocytosis}$	$\text{ln}\left(2\right)/0.25h^{-1}$	Duprez et al., 1988
TCR-dependent secretion rate of IL-2	$k_{TCR>IL2}^{production}$	$7.5\times 3600h^{-1}$	Figure 8—figure supplement 1B
$pSTAT5$–dependent inhibition of $IL2$ production	${\sigma }_{pSTAT5\searrow IL2}$	${3.10}^5$	Fit in this study
Total number of Boost molecules	$n_{{\mathit{Boost}}_{total}}$	${10}^5$	Fit in this study
TCR–dependent activation of IL-2 Boost	$k_{TCR>Boost}^{activation}$	${10}^{-3}$	Fit in this study
Positive feedback on the activation of Boost	$k_{Boost>Boost}^{activation}$	${3.10}^{-1}$	Fit in this study
Boost-dependent secretion rate of IL-2	$k_{Boost>IL2}^{production}$	$30\times k_{TCR>IL2}^{production}$	Figure 8—figure supplement 1B