Ig VH gene expression among human follicular lymphomas

Thirty-six randomly selected cases of low grade follicular lymphoma (FL) were analyzed for Ig heavy chain variable region (VH) gene expression. Assignment to one of the six human VH gene families (VH1 to VH6) was made with a polymerase chain reaction-based technique using family-specific leader primers. The frequency of VH family use in FL was found to be similar to that reported for normal peripheral blood lymphocytes and is therefore also roughly proportional to VH family size. To evaluate expression within an individual family, all of the lymphoma VH genes from the middle size VH4 family were sequenced and compared with previously published sequences. Of these eight lymphoma VH sequences, six were most closely related to just two of the 10 known functional VH4 germline genes. Nonrandom usage by FL of the JH3, JH4, and JH5 joining segments was also observed. Nucleotide sequences were also determined for 10 randomly selected lymphoma VH genes from the large VH3 family. With one possible exception, none of these lymphoma VH sequences appear to represent any of the VH3 genes that may be preferentially used in the fetal repertoire.