Mouse model for sublethal Leptospira interrogans infection

Area of Science:

• Infectious Diseases
• Immunology
• Microbiology

Background:

• Leptospira infects many mammals, with hamsters showing acute disease and rats exhibiting chronic infection.
• Previous mouse studies focused on young mice, limiting understanding of infection in adult reservoir hosts.

Purpose of the Study:

• To investigate the outcome of sublethal Leptospira interrogans serovar Copenhageni infection in adult C3H/HeJ mice.
• To establish a mouse model for studying bacterial and host factors in Leptospira immune evasion.

Main Methods:

• Sublethal infection of adult C3H/HeJ mice with Leptospira interrogans serovar Copenhageni.
• Analysis of bacterial dissemination, host response (inflammation markers), and immune cell populations (flow cytometry).

Main Results:

• Infection led to bloodstream dissemination, urinary shedding, weight loss, hypothermia, and kidney colonization.
• Significant kidney inflammation, indicated by elevated inflammatory mRNA transcripts, was observed.
• Humoral response showed IgG1 production; T cell analysis revealed expansion of CD4+ and double-negative T cells with an effector phenotype.

Conclusions:

• Adult mice can develop a sublethal Leptospira infection model with distinct pathological features.
• This model provides insights into immune evasion mechanisms contributing to varied leptospirosis outcomes.
• Further research can utilize this model to explore host-pathogen interactions and develop interventions.