Work

Influence of Mouse Model Strains on Toxoplasmosis Disease Progression, Behavioral Changes and Microglial Response in the Dentate Gyrus of Albino Swiss and Balb/c.

Year: 2023

Type: article

Abstract: Introduction: The host immune system plays an essential role in confining Toxoplasma gondii infection, and the innate immune system is the first defense line.Objectives: To investigate microglia response, disease progressions and behavioral changes, induced by T. gondii type I (RH) strain, in two mouse models (BALB/c vs. Albino Swiss).Methods: We used T. gondii ophthalmic infection model in BALB/ c (Bc), instilling the same number of parasites (2x10 5 ) per animal in albino Swiss mice (SM) and compared the results.Control mice received an equal volume of saline (5μL in each eye).All mice were subjected to an open field (OF) and to an olfactory discrimination test (OT) for 5 min before, and 22 days after instillation.The Ethics Committee for the use of animals in research of Instituto Evandro Chagas (Protocol N o .01/2021)approved all experimental procedures.Results: Disease progression in the SM strain was much faster than in Bc.SM shortly after behavioral tests at 22 dpi had to be euthanized whereas Bc completely recovered from acute phase.All SM showed sickness behavioral at 22 dpi, including ruffled fur, hunched posture, and less exploratory activity.Two-way ANOVA demonstrated the influence of the experimental conditions on the way the two mouse models explored OF and OT compartments.The SM infected group showed a significant decrease in the time spent in the compartment with feline feces, while Bc infected mice increased time spent in this compartment.Microglia total number was greater in the molecular layer of dentate gyrus in SM (infected: 7.975 ± 376.1 vs. control 4.267.2± 98.9, p<0.001), than in Bc (infected: 5.739 ± 0.20 vs. control: 4.349 ± 0.58, p<0.05).Conclusion: Differential disease progression and the ways mouse strains explored environment and assessed risk, and contrasting microgliosis confirmed the lineage influences on the immune response to the toxoplasmosis.

Source: IBRO Neuroscience Reports

DOI: 10.1016/j.ibneur.2023.08.1134