Related Experiment Video
Updated: Mar 8, 2026
08:46
A Neonatal Imaging Model of Gram-Negative Bacterial Sepsis
Published on: August 12, 2020
7.0K
Rapid CD8+ Function Is Critical for Protection of Neonatal Mice from an Extracellular Bacterial Enteropathogen
David T Siefker1, Becky Adkins2
1Department of Pediatrics, Le Bonheur Children's Medical Center , Memphis, TN , USA.
Frontiers in Pediatrics
|January 26, 2017
Summary
Neonatal mice resist oral Yersinia enterocolitica infection due to CD8+ T cells in the mesenteric lymph nodes. These cells are crucial for early protection against bacterial dissemination and sepsis.
Area of Science:
- Immunology
- Microbiology
- Neonatal Research
Background:
- Neonates exhibit high susceptibility to bacterial infections.
- Neonatal mice show unexpected resistance to oral Yersinia enterocolitica infection.
- Previous studies identified innate phagocytes, CD4+ T cells, and B cells in this resistance.
Purpose of the Study:
- To investigate the role of CD8+ T cells in neonatal protection against Yersinia enterocolitica.
- To determine the timing and mechanism of CD8+ T cell involvement.
- To assess the necessity of CD8+ T cells for immunological memory.
Main Methods:
- Oral infection of wild-type (wt) and beta-2-microglobulin-deficient (B2m-/-) neonatal mice with Yersinia enterocolitica.
- Analysis of CD8+ T cell populations, proportion, and IFNγ production in mesenteric lymph nodes (MLN) at 48 hours post-infection.
- Assessment of bacterial dissemination to spleen and liver in B2m-/- versus wt neonates.
- Evaluation of protection against secondary infection in the absence of CD8+ T cells.
Main Results:
- Neonatal CD8+ T cells in MLN are rapidly mobilized, increasing in proportion, number, and IFNγ production within 48 hours of Y. enterocolitica infection.
- B2m-/- neonates, lacking functional CD8+ T cells, are significantly more susceptible to primary infection.
- Absence of CD8+ T cells leads to rapid dissemination of Y. enterocolitica to peripheral tissues (spleen, liver), resulting in sepsis and mortality.
- CD8+ T cells are dispensable for generating immunological memory against secondary Y. enterocolitica infection.
Conclusions:
- CD8+ T cells in the neonatal MLN play a critical role in early protection against oral Yersinia enterocolitica infection.
- These CD8+ T cells appear to function during the innate phase of the immune response, preventing bacterial dissemination and sepsis.
- CD8+ T cell-mediated protection is essential for primary infection but not for establishing long-term immunological memory.
