Related Experiment Videos
Relationship between expression of IgA by Peyer's patch cells and functional IgA memory cells.
D A Lebman1, P M Griffin, J J Cebra
1Department of Biology, University of Pennsylvania, Philadelphia 19104.
The Journal of Experimental Medicine
|November 1, 1987
Summary
IgA memory B cells are identified by their exclusive secretion of IgA antibodies. A specific subset of these B cells in Peyer
Area of Science:
- Immunology
- Cell Biology
- B cell differentiation
Background:
- Immunoglobulin A (IgA) plays a crucial role in mucosal immunity.
- Identifying and characterizing IgA-producing B cells is essential for understanding immune responses.
- Previous definitions of IgA memory B cells relied on functional assays in specific culture systems.
Purpose of the Study:
- To operationally define and characterize IgA memory B cells.
- To distinguish between different subsets of IgA-positive (sIgA+) B cells in Peyer's patches.
- To identify the precursors responsible for IgA-specific antibody secretion.
Main Methods:
- Analysis of Peyer's patch lymphocytes.
- Cell cycle analysis (S, G2, M, G0, G1 phases).
- Assessment of surface IgA (sIgA) expression.
- Measurement of mRNA alpha levels (cytoplasmic dot blotting).
- Characterization using S kappa and peanut agglutinin (PNA) staining.
- Functional assessment in T-cell dependent splenic fragment culture.
Main Results:
- sIgA+ B cells in Peyer's patches comprise two subsets.
- The majority of sIgA+ B cells are germinal center B cells (S kappa low, PNAhigh), in active cell cycle, and contain high mRNA alpha, but are not immediately responsive to antigen.
- A distinct subset of sIgA+ B cells (S kappa high, PNAlow), in G0/G1 phase with low mRNA alpha, contains the majority of IgA-committed clonal precursors (functional IgA memory cells).
- A population of B cells lacking detectable sIgA and mRNA alpha also contains functional IgA memory cells.
Conclusions:
- Functional IgA memory B cells are primarily identified within a specific subset of sIgA+ B cells characterized by low mRNA alpha and specific cell cycle status.
- Germinal center sIgA+ B cells, despite high numbers, do not appear to be the primary source of immediate IgA antibody secretion upon stimulation.
- The study refines the definition and identification of IgA memory B cells, highlighting distinct subsets with different functional potentials.