[Cloning of Ig Fab genes of patients with chronic B lymphocytic leukemia and sequences analysis of their variable regions].
OBJECTIVE
Sequences analysis of Ig variable regions from the peripheral blood mononuclear cells (PBMC) of patients with chronic B lymphocytic leukemia.


METHODS
Total RNA was isolated from PBMC of patients with chronic B lymphocytic leukemia, oligo-dT-primed cDNA was synthesized from RNA. The cDNA was amplified by Taq DNA polymerase with a set of specific 5' primers corresponding to Ig FR1 and 3' primers corresponding to CH1 (C micro /C) or CL (Ckappa/Clambda), the PCR products of variable regions of Ig heavy (IgH) and light (IgL) chains were sequenced by ABI PRISM Dye terminator cycle sequencing ready reaction kit and ABI PRISM 310 Genetic Analyzer. The gene homology of variable regions of IgH and IgL chains was compared by using DNA tools 5.1 system and "the international immunogenetics database".


RESULTS
Four light chains and 3 heavy chains were amplified from 4 and 3 patients respectively. Homology analysis of the sequences of 4 light chains and 3 heavy chains were performed by DNA tools system. The sequences of light chains are high homologous. And the sequences of heavy chains are quite different. The homologous analysis of the sequences of variable region by using "the international immunogenetics database" showed that the sequences were higher homologous to idiotype gene of some B lymphocytic leukemia. Four VL genes belong to human Ig Vkappa subgroup I, 2 of 3 VH genes belong to VH3 family and 1 belongs to VH5 family.


CONCLUSIONS
Ig genes have idiotype and same disease may have same idiotype.
Zhu
Huifen
H
Department of Immunology, Tongji Medical College, Huazhong University of Technology and Science, Wuhan 430030, China.
Wang
Feng
F
Zhang
Yue
Y
Shen
Guanxin
G
D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000235:genetics*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction
D018076:DNA, Complementary; D007140:Immunoglobulin Fab Fragments; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region