PCR strategies to type the rearrangement status of human IgH and TCRβ loci.

The human IgH locus harbors about 90 to 123 V_H gene segments (depending on haplotype), 27 D_H genes, and 6 J_H genes. The human TCRβ locus is composed of 65 V_β gene segments and 2 tandemly arranged D-J-C clusters: the first with 1 D_β, 6 J_β, and 1 C_β genes, the second with 1 D_β, 7 J_β, and 1 C_β genes. (A) IgH germline configuration is detected with a primer upstream of the most 3′ D_H element (D_H7-27) and the nested J_H1 primers. Because D_H7-27 is located only 80 base pairs upstream of the J_H1 gene segment, the D_H7-27–J_H primer combination not only detects D_H7-27–J_H rearrangements but also the germline configuration of the IgH locus. (B) D_HJ_H joints are amplified with a collection of 7 D_H-family–specific primers and the nested J_H primer mixes. (C) V_HD_HJ_H rearrangements are amplified with 6 V_H-family–specific primers binding to the framework region 1 of human V_H genes and the nested J_Hprimer mixes. (D) Germline configuration of the TCRβ locus is detected with primers binding intronic sequences 5′ and 3′ of the D_β1 and D_β2 genes. (E) D_βJ_β joints are amplified with the 5′ D_β primers and nested J_β primer mixes. (F) TCRβ VDJ rearrangements are amplified with a collection of 24 V_β-family–specific primers and the 2 J_βprimer mixes. Arrows indicate location of primers.