Advisor(s)
Harry Schroeder
Committee Member(s)
Peter Burrows
John Kearney
Paul Geopfert
Randall Davis
Document Type
Dissertation
Date of Award
2012
Abstract
Developing B cells exhibit sequential changes in the representation of immunoglobulin (Ig) heavy (H) chain sequences with excess hydrophobic or charged amino acids in complementarity determining region 3 (CDR-H3). To begin to elucidate the mechanisms by which this process occurs, we used Bromodeoxy Uridine (BrdU) incorporation and Annexin V binding to quantify B cell turnover and cell cycle progression in developing B cell subsets in the bone marrow, spleen and peritoneal cavity of wild-type BALB/c mice. To magnify the effects of hydrophobicity and charge, we included in this analysis mice limited to the use of an IgH allele with a single DH gene segment biased in incorporation of neutral, charged, or hydrophobic amino acids; as well as mice lacking the lambda 5 component of the surrogate light chain (SLC). We found that B cells expressing Igs with hydrophobic CDR-H3s exhibited reduced turnover and inefficient cell cycle progression in the transition from the early to late pre-B cell stage, a developmental checkpoint that requires the association of the H chain with SLC to create the pre-B cell receptor. The pattern of cell loss at these stages was similar to that observed in cells lacking lambda 5, and thus constitutionally unable to generate a pre-B cell receptor. B cells with charged or hydrophobic CDR-H3s also exhibited increased loss in the transition from late pre-B to immature B; as well as in the transitions from immature B to mature B in the spleen. In the peritoneal cavity B cells with hydrophobic CDR-H3s exhibited normal turnover, whereas those with charged CDR-H3s contents exhibited increased loss. These findings provide new insight into the mechanisms that limit the production of broadly neutralizing antibodies HIV whose CDR-H3s are enriched for patches of charged or hydrophobic amino acids as well as into the mechanisms that limit the production of highly charged CDR-H3s that are commonly found in pathogenic dsDNA binding antibodies in systemic lupus erythematosus.
ProQuest Publication Number
ISBN
978-1-267-87650-8
Recommended Citation
Khass, Mohamed, "A Study Of The Genetic Mechanisms Used To Regulate The Third Complementarity Determining Region Of The Immunoglobulin H Chain" (2012). All ETDs from UAB. 2137.
https://digitalcommons.library.uab.edu/etd-collection/2137
Comments
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