The chicken B-cell receptor complex and its role in avian B-cell development.
The bursa of Fabricius is critical to normal B-lymphocyte development in birds. During embryonic life, B-cell precursors migrate to the bursal rudiment and those which have undergone productive V(D)J recombination colonize lymphoid follicles and undergo immunoglobulin V gene diversification by gene conversion. The chicken surface IgM complex appears structurally and functionally equivalent to its mammalian counterpart, with homologs to CD79a and CD79b. Expression of a truncated Igmu chain is sufficient to drive the early stages of B-cell development in the embryo bursa. Bursal cells expressing the truncated mu receptor complex proliferate in bursal follicles, and those which contain V gene rearrangements undergo V gene diversification by gene conversion. The bursa is a gut-associated organ and antigen is focused to bursal lymphoid follicles after hatch. While expression of the truncated mu chain is sufficient to support B-cell development in the embryo, B cells expressing this receptor are rapidly eliminated after hatch. We suggest the possibility that B-cell development in the bursa after hatch is driven by encounter with antigen leading to redistribution of B cells within the lymphoid follicle, B-cell proliferation and V gene repertoire development by gene conversion.
Sayegh
C E
CE
Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada.
Demaries
S L
SL
Pike
K A
KA
Friedman
J E
JE
Ratcliffe
M J
MJ
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D000916:Antibody Diversity; D015703:Antigens, CD / Q000737:chemistry; D001354:Avian Leukosis Virus / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology*; D002060:Bursa of Fabricius / Q000276:immunology*; D051925:CD79 Antigens; D019070:Cell Lineage; D002642:Chick Embryo; D005785:Gene Conversion; D015322:Gene Rearrangement, B-Lymphocyte; D005803:Genes, Immunoglobulin; D005822:Genetic Vectors; D007075:Immunoglobulin M / Q000737:chemistry / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D011947:Receptors, Antigen, B-Cell / Q000737:chemistry / Q000276:immunology*; D016415:Sequence Alignment
D015703:Antigens, CD; D051925:CD79 Antigens; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region; D046911:Macromolecular Substances; D011947:Receptors, Antigen, B-Cell