Natural Microbial Exposure from the Earliest Natural Time Point Enhances Immune Development by Expanding Immune Cell Progenitors and Mature Immune Cells

Autor: Sarah Burger, Terran Stenger, Mark Pierson, Adhvaith Sridhar, Matthew A. Huggins, Tamara A. Kucaba, Thomas S. Griffith, Sara E. Hamilton, Nathaniel J. Schuldt
Rok vydání: 2023
Předmět:
Zdroj: The Journal of Immunology. 210:1740-1751
ISSN: 1550-6606
0022-1767
DOI: 10.4049/jimmunol.2300061
Popis: Microbial experience fundamentally shapes immunity, particularly during the perinatal period when the immune system is underdeveloped, and novel microbial encounters are common. Most animal models are raised in specific pathogen-free (SPF) conditions with relatively uniform microbial communities. How SPF housing conditions alter early-life immune development relative to natural microbial exposure (NME) has not been thoroughly investigated. In this article, we compare immune development in SPF-raised mice with mice born from immunologically experienced mothers in microbially diverse environments. NME induced broad immune cell expansion, including naive cells, suggesting mechanisms besides activation-induced proliferation contribute to the increase in immune cell numbers. We found NME conditions also expanded immune cell progenitor cell populations in the bone marrow, suggesting microbial experience enhances immune development at the earliest stages of immune cell differentiation. Multiple immune functions characteristically impaired in infants were also enhanced by NME, including T cell memory and Th1 polarization, B cell class switching and Ab production, proinflammatory cytokine expression, and bacterial clearance after Listeria monocytogenes challenge. Collectively, our studies reveal numerous impairments in immune development in SPF conditions relative to natural immune development.
Databáze: OpenAIRE