Detection of functional V(H)81X heavy chains in adult mice with an assessment of complementarity-determining region 3 diversity and capacity to form pre-B cell receptor.
Recent reports have indicated that up to 50% of all H chain proteins formed cannot associate with the surrogate L chain complex and therefore fail to form a pre-B cell receptor (pBCR), which is required for allelic exclusion and, in most cases, verifies that the H chain can assemble with the L chain to form an Ab molecule. Certain V(H) genes, such as V(H)81X, appear to be particularly prone to encoding for nonpairing (dysfunctional) H chains. It has been suggested that sequence variability at complementarity-determining region 3, especially when increased by the enzyme TdT, often precludes the ability of V(H)81X-using H chains to form pBCR. To determine whether a motif exists that accounts for the ability of H chains to pair with surrogate L chain complex/L chain, we have bred a mouse line in which H chain recombination can only occur on one allele, allowing us to compile a pool of H chains capable of forming Ab molecules in the absence of dysfunctional H chains. Somewhat unexpectedly, we have found V(H)81X H chains capable of Ab formation and cell surface expression in the presence of TdT. Scrutiny of these H chains has revealed that, although highly prone to encode for dysfunctional H chains, sequence variability is not severely limited among functional V(H)81X H chains. We also demonstrate that surface Ig expression is highly indicative of the capacity of a H chain to form pBCR.
Hayden
Tracy A
TA
Basel Institute for Immunology, Basel, Switzerland.
Riegert
Patricia
P
Kline
Gregory H
GH
D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D000916:Antibody Diversity / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology; D001483:Base Sequence; D022801:Complementarity Determining Regions / Q000235:genetics*; D004247:DNA / Q000235:genetics; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D005803:Genes, Immunoglobulin; D006412:Hematopoietic Stem Cells / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D054420:Pre-B Cell Receptors; D011947:Receptors, Antigen, B-Cell
D022801:Complementarity Determining Regions; D007143:Immunoglobulin Heavy Chains; D008562:Membrane Glycoproteins; D054420:Pre-B Cell Receptors; D011947:Receptors, Antigen, B-Cell; D004247:DNA