Insight into lymphoid development by gene expression profiling of avian B cells.
The avian immune system provides an excellent model to track B-cell development from prebursal stem cells throughout B-cell differentiation and maturation. Bursal B cells are uniquely positioned at the crossroads of B-cell development, having properties of both stem cells and of mature B cells, as demonstrated by their ability to reconstruct the bursal B-cell compartment and to express and diversify the B-cell receptor at their cell surface. To understand avian B-cell development better, we determined the gene expression profile of different B-cell stages using a bursal expressed sequence tag array. The expression profile of bursal B cells reveals the presence of factors associated with B-cell signaling and defines novel B-cell-specific genes. Genes associated with proliferation, apoptosis, DNA repair and recombination are abundantly expressed. The expression profile of the DT40 cell line is most similar to bursal B cells rather than to other stages of B-cell development, confirming the suitability of DT40 for studies of B-cell physiology. Interestingly, prebursal stem cells express genes involved in B-cell receptor signaling, although they express only low levels of immunoglobulin genes. This suggests that B-cell receptor-mediated selection is present before bursal colonization. The gene expression signatures of germinal centers and cells of the Harderian gland indicate that evolutionarily conserved genetic programs regulate B-cell activation and terminal differentiation.
Koskela
Kimmo
K
Turku Graduate School of Biomedical Sciences, University of Turku, Kiinamyllynkatu 13, 20520 Turku, Finland. kimmo.koskela@utu.fi
Kohonen
Pekka
P
Nieminen
Pia
P
Buerstedde
Jean-Marie
JM
Lassila
Olli
O
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology*; D002645:Chickens; D020869:Gene Expression Profiling; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism