Expressed antibody repertoires in human cord blood cells: 454 sequencing and IMGT/HighV-QUEST analysis of germline gene usage, junctional diversity, and somatic mutations |
| |
Authors: | Ponraj Prabakaran Weizao Chen Maria G Singarayan Claudia C Stewart Emily Streaker Yang Feng Dimiter S Dimitrov |
| |
Institution: | (1) Protein Interactions Group, Center for Cancer Research Nanobiology Program, National Cancer Institute (NCI)-Frederick, National Institutes of Health (NIH), Bldg 469, Rm 150B, Frederick, MD 21702, USA;(2) Basic Research Program, Science Applications International Corporation-Frederick, Inc., NCI-Frederick, Frederick, MD 21702, USA;(3) The Laboratory of Molecular Technology, Science Applications International Corporation-Frederick, Inc., NCI-Frederick, Frederick, MD 21702, USA;(4) 1901 Harpers Court, Frederick, MD 21702, USA; |
| |
Abstract: | Human cord blood cell-derived IgM antibodies are important for the neonate immune responses and construction of germline-based
immunoglobulin libraries. Several previous studies of a relatively small number of sequences found that they exhibit restrictions
in the usage of germline genes and in the diversity of the variable heavy chain complementarity determining region 3 compared
to adults. To further characterize such restrictions on a larger scale and to compare the early B-cell diversity to adult
IgM repertoires, we performed 454 sequencing and IMGT/HighV-QUEST analysis of cord blood IG libraries from two babies and
determined germline gene usage, V-D-J rearrangement, VHCDR3 diversity, and somatic mutations to characterize human neonate
repertoire. Most of the germline subgroups were identified with frequencies comparable to those present in the adult IgM repertoire
except for the IGHV1-2 gene that was preferentially expressed in the cord blood cells. The gene usage diversity contributed
to 1,430 unique IGH V-D-J rearrangement patterns while the exonuclease trimming and N region addition at the V-D-J junctions
along with gene diversity created a wide range of VHCDR3 with different lengths and sequence variability. We observed a lower
degree of somatic mutations in the CDR and framework regions of antibodies from cord blood cells compared to adults. These
results provide insights into the characteristics of human cord blood antibody repertoires, which have gene usage diversity
and VHCDR3 lengths similar to that of the adult IgM repertoire but differ significantly in some of the gene usages, V-D-J
rearrangements, junctional diversity, and somatic mutations. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|