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Perinatal deletion of B cells expressing surface Ig molecules that lack V(D)J-encoded determinants in the bursa of Fabricius is not due to intrafollicular competition.
- Source :
-
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2000 May 15; Vol. 164 (10), pp. 5041-8. - Publication Year :
- 2000
-
Abstract
- During embryonic development, the avian bursa of Fabricius selects B cell precursors that have undergone productive V(D)J recombination for expansion in oligoclonal follicles. During this expansion, Ig diversity is generated by gene conversion. We have used retroviral gene transfer in vivo to introduce surface Ig molecules that lack V(D)J-encoded determinants into B cell precursors. This truncated mu heavy chain supports both B cell expansion within embryo bursal lymphoid follicles and gene conversion. We show that individual follicles can be colonized exclusively by cells expressing the truncated mu chain and lacking endogenous surface IgM, ruling out a requirement for V(D)J-encoded determinants in the establishment of bursal lymphoid follicles. In striking contrast to their normal development in the embryo, bursal cells expressing the truncated mu-chain exhibit reduced rates of cell division and increased levels of apoptosis after hatching. The level of apoptosis in individual follicles reflects the proportion of cells within the follicle that express the truncated mu-chain. In particular, high levels of apoptosis are associated with follicles containing exclusively cells expressing the truncated micro receptor. Thus, apoptotic elimination of such cells is not due to competition within the follicle by cells expressing endogenous surface IgM receptors. This provides the first direct demonstration that the regulation of B cell development in the avian bursa after hatching differs fundamentally from that seen in the embryo. The requirement for intact IgM expression when the bursa is exposed to exogenous Ag implicates a role for Ag in avian B cell development after hatching.
- Subjects :
- Animals
Animals, Newborn genetics
Avian Leukosis Virus genetics
Avian Leukosis Virus immunology
B-Lymphocyte Subsets metabolism
Bursa of Fabricius metabolism
Cell Differentiation genetics
Cell Differentiation immunology
Chickens
DNA Fragmentation genetics
DNA Fragmentation immunology
Epitopes, B-Lymphocyte genetics
Extracellular Space genetics
Extracellular Space immunology
Immunoglobulin Fab Fragments genetics
Immunoglobulin Fab Fragments metabolism
Immunoglobulin M genetics
Immunoglobulin M metabolism
Immunoglobulin Variable Region genetics
Immunoglobulin mu-Chains biosynthesis
Immunoglobulin mu-Chains genetics
Lymphocyte Count
Receptors, Antigen, B-Cell genetics
Stem Cells cytology
Stem Cells immunology
Stem Cells metabolism
Animals, Newborn immunology
B-Lymphocyte Subsets immunology
Bursa of Fabricius cytology
Bursa of Fabricius immunology
Clonal Deletion genetics
Epitopes, B-Lymphocyte biosynthesis
Immunoglobulin Variable Region biosynthesis
Receptors, Antigen, B-Cell biosynthesis
Subjects
Details
- Language :
- English
- ISSN :
- 0022-1767
- Volume :
- 164
- Issue :
- 10
- Database :
- MEDLINE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Publication Type :
- Academic Journal
- Accession number :
- 10799859
- Full Text :
- https://doi.org/10.4049/jimmunol.164.10.5041