Impact of Streptococcus pneumoniae experimental infection on intestinal mucosal immunity

• Grant number: 24/18352-5
• Support Opportunities: Scholarships in Brazil - Program to Stimulate Scientific Vocations
• Start date: March 17, 2025
• End date: May 04, 2025
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Denise Morais da Fonseca
• Grantee: Letícia Ferreira Machado
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Infectious episodes can permanently compromise tissue-specific immune responses, especially in the mucosae. In the intestine and lungs, these infections have long-term consequences, altering both the function and composition of the microbiota and disrupting the homeostasis of distant systems. The Laboratory of Mucosal Immunology of the Institute of Biomedical Sciences (ICB/USP) studies the effects of acute infections on mucosal immunity, emphasizing how these infections alter immune function in the lungs and intestine over time. In addition, it is known that the intestinal microbiota plays a key role in modulating local and systemic immunity so that changes in its composition can lead to dysregulated immune responses and exacerbated production of inflammatory cytokines. This process is often associated with inflammatory bowel diseases and may increase susceptibility to respiratory infections. Although communication in the gut-lung axis is widely documented, this interaction may be bidirectional, forming the so-called "lung-gut axis".Given this scenario, lung infections, such as those caused by Streptococcus pneumoniae, may generate adverse systemic effects, affecting the gastrointestinal tract. Therefore, this work aims to explore how lung inflammation caused by S. pneumoniae affects the immune system associated with the intestinal mucosa. To this end, experimental studies will be carried out to characterize the immune responses in the gastrointestinal tract after lung infection. The cellular profile in the lung and intestinal mucosa and the integrity of the intestinal barrier will be evaluated. By studying the communication between the lung and the intestine, we hope to expand knowledge about the systemic immunological mechanisms involved in bacterial infections and contribute to developing more effective therapeutic strategies to prevent complications associated with respiratory and gastrointestinal infections. (AU)