Evolutionary aspects of immunoglobulin heavy chain variable region (VH) gene subgroups.

Abstract

We isolated and determined the sequences oftwo human germ-line heavy chain variable region (VH) genes and compared them with mouse VH genes. The The variable region of the immunoglobulin heavy chain is encoded in the germ line in three separate DNA segments: VH, DH, andJH (1-3). Three ofthe framework regions (FRs) and two of the complementarity-determining regions (CDRs) are included in the coding region of the VH segment whereas recombination between variable (V), diversity (D), and joining (J) segments is necessary to form the expressed VH gene. It is likely that there are several hundred VH gene segments organized in tandem with spacers of 8-15 kilobases (4-6). The multitude of V region amino acid sequences has been subdivided into subgroups that show a higher extent of homology and linkage between some amino acids along the chain (7-9). However, comparison of the amino acid sequences of mouse and human VH does not always allow the affiliation of V regions from the different species to homologous subgroups (10); the DNA sequences of the VH genes may provide a better tool for comparison of homologous subgroups in various species. Hybridization with VH DNA probes showed a correlation between the extent of cross-hybridization and VH gene subgroups (11). It VH families (11) and comparison of VH genes from different species will increase our understanding of the structural features that characterize a subgroup in coding and noncoding regions. We isolated human germ-line VH genes by cross-hybridization with mouse VHII genes (6). The DNA sequence shows that the human genes are homologous to human VHI (subgroup I), as defined by Kabat et al. (14) and we will refer to the human genes analyzed here as human VHII genes. The homology between mouse and human VHII genes is preserved in the size [84 base pairs (bp)] and also in the sequence ofthe intron present at codon 4. Another VH gene subgroup (VHIII) contains a longer intron (102 bp) in both mouse and human (11). The homology in both intron and framework codons between mouse and human genes of the same subgroup is greater than between VH genes ofdifferent subgroups in the same species. The sequence also suggests that DNA repeats at the 5' and 3' regions flanking the VH gene can form a large stem-and-loop structure that may facilitate saltatory replication (15

Anti-hypervariable region antibody induced by a defined peptide: an approach for studying the structural correlates of idiotypes.

“…However, it has been proposed that structures similar or identical to the diversity (D) and joining (J) gene segments of the heavy chain might contribute in some way to the formation of the T-cell receptor (41). The third hypervariable region of human heavy chains covers all of the presumed D segment and the most diversified portion of the J heavy chain segment (42)(43)(44)(45)(46). Therefore, predefined antibodies induced by peptides corresponding to the third hypervariable region may enable us to determine the possible existence of D-J like structures on T cells.…”

A fetally expressed immunoglobulin VH1 gene belongs to a complex set of alleles.

“…PCR primers were TTC TTG GTG GCA GCA GCC ACA GG (5' primer) and AG GAT GTG GTT TCT CAC ACT GTG (3' primer), corresponding to the hv1263 sequence (33) immediately 5' of the leader intron and 3' of the VH coding region, respectively. PCR product (1)(2)(3)(4) ,gl; in some cases, first separated in an agarose gel, extracted, and ethanol precipitated) was blunt-end ligated into the HincIl or SmaI site of Ml 3mp19 (Pharmacia LKB Biotechnology Inc., Uppsala, Sweden), transformed into DH5aF' competent cells, and plated in YT agarose with JM101 lawn cells, isopropyl-f3-D-thiogalactopyranoside, and 5-bromo-4-chloro-3-indoyl-j3-D-galactoside according to standard methods. Nitrocellulose filter lifts of the primary plates were screened by hybridization with appropriate sense and antisense oligonucleotide probes (Table I) to identify clones with inserts in each orientation.…”

Restricted diversity of the variable region nucleotide sequences of the heavy and light chains of a human rheumatoid factor

“…The deduced amino acid sequence of YES8c V, is shown in Figure 5 , and is compared with other Wa-positive and G6-positive RF V, regions (BOR, KAS, WOL, and SIE), 1 vH1 complementary DNA (cDNA) (51pl) derived from fetal liver (24), 3 vH1 rearranged genes (NEI, AND, and 783c), and 4 human V,1 germline genes (25)(26)(27)(28). The YES8c V, region was extensively homologous with a fetal liver cDNA, 51~1, and was also closely related to 3 rearranged V, 1 genes (NEJ, AND, and 783c), differing by 8-9 amino acid residues (91-92% homology) ( Figure 5).…”