A comparison of elasticities of viral levels to specific immune response mechanisms in human immunodeficiency virus infection

Table 1 Parameter values

Parameter	Description	Value	Source
β ₁	Virus infectivity	0.000024 m l⁻¹d⁻¹	[13]
β ₂	Cell-associated	100−1000×	[14, 15, 17]
	Virus infectivity	0.000012 m l⁻¹d⁻¹
h ₁	Neutralizing efficiency	0.001 m l⁻¹d⁻¹	Est.
h ₂	CTLs killing efficiency	0.01 m l⁻¹d⁻¹	Est.
h	Cytokine killing efficiency	0.0011 m l⁻¹d⁻¹	Est.
μ _T	Death rate of CD4 ⁺ T cells	0.02 d⁻¹	[18]
ω	Saturation constant	0.01 m l⁻¹	Est.
S _T	Source term for CD 4⁺ T cells	10 cells d⁻¹	Est.
μ _C	CTL death rate	0.5 d⁻¹	Est.
$μ_{T^{*}}$	Infected cell death rate	0.5 to 1 d⁻¹	[18]
μ _B	B cell death rate	0.5 d⁻¹	Est.
θ ₁	Transition probability	1/3	[19]
θ ₂	Transition Probability	0.06315	Computed
θ ₃	Transition Probability	0.43685	Computed
ϕ	Viral production/cycle/provirus	1000	Est.
ψ	Probability of proliferation of CTLs	0.01	Est.
χ	Probability of proliferation of B cells	0.01	Est.
a ₁	Saturating constant	0.002 m l⁻¹	Est.
a ₂	Saturating constant	0.002 m l⁻¹	Est.

Parameters values that were not obtained from literature were chosen to be in the ranges 0 to 1. Est. means parameters were estimated/derived to simulate acceptable HIV dynamics. The infectivity of the cell associated virus is 10² to 10³ times greater than the infectivity of free virus stocks [14], so we multiplied the infectivity of the free virus by values in the ranges 10² to 10³ to get the infectivity of the cell associated virus.

ISSN: 1756-0500