Insights into the mechanisms of thymus involution and regeneration by modeling the glucocorticoid-induced perturbation of thymocyte populations dynamics.
T-cells develop in the thymus and based on CD4 and CD8 expressions there are four main thymocyte populations in a normal mouse thymus. Currently, there are several mathematical models that describe the dynamics of thymocyte populations in a normal thymus, but only a few of them model the transient perturbation of their homeostasis. Our aim is to model the perturbation in the dynamics of each thymocyte population which is induced by the administration of a glucocorticoid, i.e. dexamethasone. The proposed approach relies on extending a four compartment thymus model based on differential equations by adding perturbation terms either globally (at the level of each equation) or locally (at the level of proliferation, death, and transfer rates). By fitting the perturbed model with experimental data on mice thymi collected before and after the administration of dexamethasone, it was possible to estimate the relevant parameters using a population-based stochastic search method. The fitted model is further used to conduct a quantitative analysis on the differentiated impact of dexamethasone on each T-cell population and on proliferation, death, and transfer processes. The obtained quantitative information on the perturbation could be used to explore and modify the flow of thymocytes between thymus compartments in order to elucidate the mechanisms of thymus involution and its subsequent regeneration. Since glucocorticoids are raised in many pathological situations, such a model could be useful in evaluating the impact of diseases on thymocyte dynamics in the thymus.
Faculty of Mathematics and Computer Science, West University of Timisoara, 4 Vasile Parvan Blvd., Timisoara, Romania.
Radu Dumitru
RD
Moleriu
Faculty of Mathematics and Computer Science, West University of Timisoara, 4 Vasile Parvan Blvd., Timisoara, Romania.
Daniela
D
Zaharie
Faculty of Mathematics and Computer Science, West University of Timisoara, 4 Vasile Parvan Blvd., Timisoara, Romania; Department of Functional Sciences, Victor Babes University of Medicine and Pharmacy, 2 Eftimie Murgu Sq. Timisoara, Romania.
Lavinia Cristina
LC
Moatar-Moleriu
County Clinical Emergency Hospital Timisoara, Regional Centre for Immunology and Transplant, 10 Iosif Bulbuca Blvd. Timisoara, Romania.
Alexandra Teodora
AT
Gruia
Department of Functional Sciences, Victor Babes University of Medicine and Pharmacy, 2 Eftimie Murgu Sq. Timisoara, Romania.
Ani Aurora
AA
Mic
Department of Functional Sciences, Victor Babes University of Medicine and Pharmacy, 2 Eftimie Murgu Sq. Timisoara, Romania. Electronic address: mafelix@umft.ro.
Felix Aurel
FA
Mic
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003907:Dexamethasone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005938:Glucocorticoids / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D051379:Mice; D008815:Mice, Inbred Strains; D008954:Models, Biological; D009929:Organ Size / Q000187:drug effects; D012038:Regeneration / Q000187:drug effects*; D060168:Thymocytes / Q000187:drug effects*; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology* / Q000502:physiology
D005938:Glucocorticoids; D003907:Dexamethasone
Modeling; Perturbation; Proliferation; Simulation; Thymocyte death