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Published on: September 7, 2022
Changes in Tonsil B Cell Phenotypes and EBV Receptor Expression in Children Under 5-Years-Old
Eric M Wohlford1, Paul C Baresel1, Joel R Wilmore1
1Department of Microbiology and Immunology, State University of New York, Upstate Medical University, Syracuse, New York.
Insights
Young children have more naive B cells in their palatine tonsils, which express higher levels of the Epstein-Barr virus (EBV) receptor. This suggests a greater susceptibility to EBV infection in early childhood.
Area of Science:
- Immunology
- Pediatric Research
- Virology
Background:
- Palatine tonsils are crucial B cell organs for oral defense and pathogen infection.
- Tonsil cellular changes in early childhood (first five years) are understudied despite significant size variations.
- Epstein-Barr virus (EBV) infects tonsillar B cells, with naive B cells being the suspected primary target.
Purpose of the Study:
- To characterize B cell subpopulation dynamics in human palatine tonsils during the first five years of life.
- To establish reference ranges for tonsil B cell subpopulations in healthy young children.
- To investigate changes in naive B cell surface markers, including the EBV receptor (CD21), in early childhood.
Main Methods:
- Utilized an 11-color flow cytometry panel.
- Analyzed tonsil samples from 33 healthy US children aged 0-5 years.
- Quantified and compared B cell subpopulations and their surface marker expression.
Main Results:
- Established reference ranges for tonsil B cell subpopulations in the first five years of life.
- Observed a decrease in the frequency of naive B cells as children age.
- Found that naive B cells in young children express higher surface levels of CD21 compared to other tonsil B cell populations.
Conclusions:
- Young children possess a higher frequency of naive tonsil B cells.
- These naive B cells exhibit increased surface expression of the EBV receptor (CD21).
- This suggests a larger pool of susceptible cells for EBV infection in infants and young children.
Background:
Palatine tonsils are principally B cell organs that are the initial line of defense against many oral pathogens, as well as the site of infection for others. While the size of palatine tonsils changes greatly in the first five years of life, the cellular changes during this period are not well studied. Epstein Barr virus (EBV) is a common orally transmitted virus that infects tonsillar B cells. Naïve B cells are thought to be the target of primary infection with EBV in vivo, suggesting that they are targeted by the virus. EBV enters B cells through CD21, but studies of older children and adults have not shown differences in surface CD21 between naïve B cells and other tonsil B cell populations.
Methods:
In this study, we used an 11-color flow cytometry panel to detail the changes in B cell subpopulations in human tonsils over the first five years of life from 33 healthy US children.
Results:
We provide reference ranges for tonsil B cell subpopulations over this age range. We show that the frequency of naïve tonsil B cells decreases over the early years of life, and that naïve B cells expressed higher surface levels of CD21 relative to other tonsil B cell populations.
Conclusions:
We show that young children have a higher frequency of naïve tonsil B cells, and importantly that these cells express increased surface EBV receptor, suggesting that young children have a larger pool of cells that can be infected by the virus. © 2017 International Clinical Cytometry Society.
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