Expression of CD27 and CD23 on peripheral blood B lymphocytes in humans of different ages
Dino Veneri1, Riccardo Ortolani, Massimo Franchini
1Dipartimento di Medicina Clinica e Sperimentale, Sezione di Ematologia, Università di Verona, Italia. dino.veneri@univr.it
Insights
Peripheral blood B cell populations change with age, with naive cells decreasing and memory cells increasing. These age-related shifts in B cell markers suggest functional adaptations following antigen exposure.
Area of Science:
- Immunology
- Hematology
- Cell Biology
Background:
- Coexpression of CD23 and CD27 is observed in B lymphocytic leukaemic clones.
- There is ongoing debate regarding CD23 expression on memory B cells.
- B cells are classified into naive (CD23-/CD27-) and memory (CD27+) subsets, and further into B2 (CD5-) and B1-a (CD5+) types.
Purpose of the Study:
- To evaluate the behavior of naive and memory B cells in peripheral blood across all human age groups.
- To investigate the expression patterns of CD23 and CD27 on different B cell subsets.
- To analyze age-associated changes in B cell populations and their surface markers.
Main Methods:
- Immunophenotyping of peripheral blood lymphocytes.
- Assessment of cell surface expression of CD19, CD5, CD23, and CD27.
- Analysis of data from 1,427 subjects of diverse ages.
Main Results:
- Absolute B lymphocyte counts and the percentage of naive cells (CD23-/CD27-) decline with age.
- The proportion of memory cells (CD27+) increases with age.
- A minor subset of B cells coexpressing CD23 and CD27 exists across all ages; however, most CD27+ cells are CD23-.
Conclusions:
- Age-associated changes in B cell surface markers are finely balanced and likely linked to functional alterations post-antigen encounter.
- The peripheral blood B cell compartment undergoes a quantitative regression with increasing age.
- B1-a cells (CD5+) show slightly higher percentages and rates of increase with age compared to B2 counterparts, particularly in the CD23+/CD27+ subset.
Background:
Due to the fact that the coexpression of CD23 and CD27 has been reported to occur in B lymphocytic leukaemic clones and that there is debate about CD23 expression on memory B cells, we evaluated the behaviour of naive B cells (CD23-/CD27-) and memory B cells (CD27+) in the peripheral blood of a large number of humans of all ages. B cells were also distinguished into B2 (CD5-) and B1-a cells (CD5+).
Methods:
The cell surface expression of CD19, CD5, CD23 and CD27 was assessed on peripheral blood lymphocytes from 1,427 subjects of all ages undergoing peripheral blood immunophenotyping for a variety of reasons.
Results:
The absolute number of B lymphocytes and the percentage of naive cells (CD23-/CD27-) decreased with age whereas there was an increase in memory cells (CD27+). A small subset of B cells co-expressing CD23 and CD27 was present in humans of all ages, although the majority of CD27+ cells were CD23-. The percentages and rate of increase with age of B1-a CD23+/CD27+ were slightly higher than those of B2 cell counterparts.
Conclusions:
On the basis of our data, age-associated changes in surface markers of B cells seem to be finely balanced and probably related to functional changes after antigen encounters, while the whole peripheral blood B-cell compartment undergoes a quantitative regression.
