Acute infection with Toxoplasma gondii oocysts preferentially activates non-neuronal cells expressing serotonin in the jejunum of rats

• Published in: Life sciences (1973) 2021-10, Vol.283, p.119872-119872, Article 119872
• Main Authors: Pastre, Maria José, Gois, Marcelo Biondaro, Casagrande, Lucas, Pereira-Severi, Letícia Sarturi, de Lima, Lainy Leiny, Trevizan, Aline Rosa, Miqueloto, Carlos Alberto, Garcia, João Luís, Costa, Silvia Lima, Nogueira-Melo, Gessilda de Alcântara, Sant'Ana, Débora de Mello Gonçales
• Format: Article
• Language: English
• Subjects: Enteric nervous system; Enterochromaffin cells; Epithelium; Extracellular matrix; Ganglia; Gastrointestinal system; Gastrointestinal tract; Immune response; Immune system; Infections; Intestine; Jejunum; Laminin; Large intestine; Mast cells; Morphology; Oocysts; Oral infection; Parasites; Permeability; Protozoa; Serotonin; Structure-function relationships; Toxoplasma gondii; Toxoplasmosis; Transposition
• ISSN: 0024-3205; 1879-0631
• DOI: 10.1016/j.lfs.2021.119872

The interaction of Toxoplasma gondii with the gastrointestinal tract of its host is highly regulated. Once ingested, the parasite crosses the epithelium without altering the permeability of the intestinal barrier. Nevertheless, many studies report alterations ranging from structural to functional damage in cells and tissues that make up the wall of the small and large intestine. Although the immune response to the parasite has been extensively studied, the role of serotonin (5-HT) in toxoplasmosis is poorly understood. Here we investigate the distribution of cells expressing 5-HT and its effects on cells and tissues of the jejunal wall of rats after 2, 3, or 7 days of T. gondii infection. Our results show that transposition of the jejunal epithelium by T. gondii leads to ruptures in the basement membrane and activation of the immune system, as confirmed by the decrease in laminin immunostaining and the increase in the number of mast cells, respectively. We showed an increase in the number of enterochromaffin cells and mast cells expressing 5-HT in the jejunal wall. We also observed that the percentage of serotonergic mast cells increased in the total population. Thus, we can suggest that oral infection by T. gondii oocysts preferentially activates non-neuronal cells expressing 5-HT. Together, these results may explain both the changes in the extracellular matrix and the morphology of the enteric ganglia. [Display omitted]