Chronic Mycobacterium avium infection differentially affects the cytokine expression profile of three mouse strains, but has no effect on behavior

• Published in: Scientific reports Vol. 13; no. 1; p. 6199
• Main Authors: Roque, Susana, de Sá-Calçada, Daniela, Cerqueira-Rodrigues, Bruno, Monteiro, Susana, Guerreiro, Susana G., Palha, Joana A., Correia-Neves, Margarida
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17-04-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/250/254; 631/378/371; Animals; Cell growth; Cell proliferation; Central nervous system; Chronic infection; Corticosterone; Cytokines; Cytokines - metabolism; Female; Hippocampal plasticity; Hippocampus; Homeostasis; Humanities and Social Sciences; Immune system; Immunology; Infections; Inflammation; Medicin och hälsovetenskap; Mental disorders; Mice; Mice, Inbred C57BL; Mood; multidisciplinary; Mycobacterium avium; Mycobacterium avium - metabolism; Mycobacterium avium-intracellulare Infection; Nervous system; Neural plasticity; Persistent Infection; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-33121-2

One of the most remarkable findings in the immunology and neuroscience fields was the discovery of the bidirectional interaction between the immune and the central nervous systems. This interplay is tightly regulated to maintain homeostasis in physiological conditions. Disruption in this interplay has been suggested to be associated with several neuropsychiatric disorders. Most studies addressing the impact of an immune system disruption on behavioral alterations focus on acute pro-inflammatory responses. However, chronic infections are highly prevalent and associated with an altered cytokine
milieu
that persists over time. Studies addressing the potential effect of mycobacterial infections on mood behavior originated discordant results and this relationship needs to be further addressed. To increase our understanding on the effect of chronic infections on the central nervous system, we evaluated the role of
Mycobacterium avium
infection. A model of peripheral chronic infection with
M. avium
in female from three mouse strains (Balb/c, C57BL/6, and CD-1) was used. The effect of the infection was evaluated in the cytokine expression profile (spleen and hippocampus), hippocampal cell proliferation, neuronal plasticity, serum corticosterone production and mood behavior. The results show that
M. avium
peripheral chronic infection induces alterations not just in the peripheral immune system but also in the central nervous system, namely in the hippocampus. Interestingly, the cytokine expression profile alterations vary between mouse strains, and are not accompanied by hippocampal cell proliferation or neuronal plasticity changes. Accordingly, no differences were observed in locomotor, anxious and depressive-like behaviors, in any of the mouse strains used. We conclude that the
M. avium 2447
infection-induced alterations in the cytokine expression profile, both in the periphery and the hippocampus, are insufficient to alter hippocampal plasticity and behavior.