V-region directed selection in differentiating B lymphocytes.

Abstract

We here analyse the repertoire of VH7183 rearrangements isolated from different stages of B cell differentiation in adult mice. The nucleotide sequence analyses of VH7183‐D‐JH rearrangements derived from large pre‐B cells (B220+, mu‐), small pre‐B cells (B220+, mu‐) and mature B cells (B220+, mu+) isolated from adult bone marrow revealed a sequential accumulation, among functional rearrangements, of D segments of the FL16 family and a depletion of D segments using the second and the third reading frame (RF). One member (VH7183.1) of the VH7183 gene family was utilized in 60–80% of the rearrangements of all populations analysed. In neonates the majority of the rearrangements utilizing this gene was found to be functional. In contrast, > 96% of the VH7183 rearrangements isolated from adult spleen were non‐functional. These data provide evidence for cellular selection of VH regions acting at different points of the B cell differentiation pathway and at the transition of B cells from the bone marrow to the periphery.

Development of the Expressed Ig CDR-H3 Repertoire Is Marked by Focusing of Constraints in Length, Amino Acid Use, and Charge That Are First Established in Early B Cell Progenitors

“…Our work confirms and extends a previous observation regarding the enhanced use of D H reading frame 2 at the earliest stages of B cell development (25). The primary mechanism postulated to limit use of reading frame 2 in the expressed repertoire is of the ability of D protein to create a pre-BCR complex (37,38), which can then activate the allelic exclusion signal transduction pathway to prevent further V3 DJ rearrangement.…”

“…The relative prevalence of the various D H families in fraction B remained relatively unchanged from fraction B through fraction F. The rank order of J H prevalence that was first established in fraction C was maintained through fraction F. Consistent with previous reports that focused on rearrangement preference (23,25,26,29), we found a high frequency of transcripts using the V H 81X (V H 7183.1) gene segment in fraction B. The prevalence of V H 81X then steadily diminished in the progression from fraction C to fraction F. A preference for V H 7183.10 was established in fraction C, and its prevalence remained remarkably stable from fraction C to fraction F. Thus, the dominant pattern of V H , D H , and J H use remained essentially unchanged from fraction C to F.…”

“…In accordance with previous studies by other investigators (23,25,26,29), the prevalence of V H 7183.1 (V H 81X) declined with development (B3 F; p Ͻ 0.001). V H 81X represented 38% of the FIGURE 1.…”

“…We chose to look at RNA message, as this is most representative of the expressed, and thus functional, Ig repertoire. We focused on the V H 7183 family because its germline complement in IgH a alleles has been well defined (23); it represents a manageable 10% of the active repertoire (24); patterns of V H 7183 use during ontogeny and development have been well established (23,25,26); and it contributes to both self and nonself reactivities (reviewed in Ref. 27).…”

Annexin V Binds to Positively Selected B Cells

“…First, DNA sequence analyses have demonstrated that the Ig repertoires of pre-B, immature B, and mature peripheral B cells in normal mice are distinct. While the use of a broad array of V H genes characterizes B cells at early stages of development, mature splenic B cells are more restricted in their V H gene usage, suggesting that the expansion of Ig-expressing B cells is ligand dependent (35)(36)(37). Second, only a small proportion (10 -20%) of newly formed B cells populate the peripheral lymphoid organs, indirectly suggesting that only actively selected cells migrate from the bone marrow or that only a subset of B cells receive signals enabling their survival in the periphery (38 -40).…”