Table 2. Estimates of parameters governing CD4⁺ T_CM and T_EM homeostasis in adult mice.

			CD4+ TCM		CD4+ TEM
Model	Parameter	Quantity	Clean	Dirty	Clean	Dirty
Two-phase	Force of recruitment (d–1)	$\phi$	1.4 (1.2, 2.3) × 10-3	1.5 (0.77, 54) × 10-3	1.2 (0.76, 12)	1.1 (0.29, 23)
	Daily cell influx at age ${\displaystyle t^{\ast }}$ = 20 wk	$\phi S(t^{*})$	2.3 (2.0, 3.9) × 10-3	3.2 (1.7, 120) × 104	36 (22, 370) × 104	84 (21, 1700) × 104
	Net loss rate of fast subset (d–1)	${\lambda }_{\text{fast}}$	0.082 (0.063, 0.14)	0.10 (0.043, 5.2)	0.23 (0.12, 2.4)	0.39 (0.045, 9.0)
	Net loss rate of slow subset (d–1)	${\lambda }_{\text{slow}}$	5.9 (3.0, 9.4) × 10-3	4.8 (2.7, 6.9) × 10-3	2.5 (0.81, 4.6) × 10-3	4.8 (1.0, 8.8) × 10-3
	Clonal half-life of fast subset (d)	$\ln (2)/{\lambda }_{\text{fast}}$	8.4 (5.0, 11)	6.7 (0.14, 16)	3.0 (0.30, 5.8)	1.8 (0.078, 16)
	Clonal half-life of slow subset (d)	$\ln (2)/{\lambda }_{\text{slow}}$	120 (75, 230)	140 (101, 260)	270 (150, 770)	140 (75, 570)
	% of memory transitioning to slow	$100\gamma /({\lambda }_{\text{fast}}+\gamma )$	3.4 (0.46, 4.1)	5.0 (0.18, 10)	1.8 (0.21, 2.4)	9.1 (0.36, 38)
	Proportion slow at ${\displaystyle t^{\ast }}$ = 20 wk	$M_{\text{slow}}(t^{*})/M(t^{*})$	0.25 (0.12, 0.30)	0.61 (0.45, 0.75)	0.36 (0.25, 0.41)	0.72 (0.41, 0.87)
Age-dependent	Force of recruitment (d–1)	$\phi$	0.43 (0.38, 0.57) × 10-3	0.26 (0.18, 0.43) × 10-3	0.10 (0.086, 0.13)	0.062 (0.049, 0.26)
loss	Daily cell influx at age ${\displaystyle t^{\ast }}$ = 20 wk	$\phi S(t^{*})$	0.70 (0.62, 0.93) × 104	0.57 (0.39, 0.96) × 104	3.0 (2.5, 3.8) × 104	4.6 (3.7, 19) × 104
	Net loss rate of new memory (d–1)	${\lambda }_0$	2.2 (2.0, 2.7) × 10-2	1.2 (0.79, 2.0) × 10-2	1.2 (0.91, 1.5) × 10-2	1.1 (-44, 26) × 10-5
	Memory age threshold* (d)	$A$	150 (140, 200)	190 (130, 310)	150 (130, 230)	NA

95% confidence intervals are shown in parentheses. *In the age-dependent loss model, the threshold cell age $A$ defines the beginning of the more persistent phase of memory maintenance ($\lambda (a)={\lambda }_0/(1+{(a/A)}^3)$); for T_EM in dirty mice, estimates of ${\lambda }_0$ were close to zero, and $A$ was poorly constrained.