Methylation patterns of the T cell receptor beta-chain gene in T cells, large granular lymphocytes, B cells, and monocytes.
We evaluated the methylation state of the T cell receptor beta-chain gene (T beta) DNA of T cells, large granular lymphocytes (LGL), B cells, and monocytes to determine whether methylation can be correlated with the reported transcriptional activity of this gene and whether this methylation pattern can be used as a marker for different leukocyte populations. By using the restriction enzyme isoschizomers, MspI and HpaII, we found that T beta of T cells was highly unmethylated, the gene in B cells and monocytes is highly methylated, and the methylation state of T beta of LGL is intermediate between that of T cells and B cells or monocytes. These results indicate that the methylation pattern of T beta can be a marker for T cells and LGL. The difference in methylation pattern of T beta between LGL and T cells indicated that most LGL were different from T cell populations. The methylation pattern of T beta in LGL DNA was also heterogeneous, in contrast to that of other leukocytes, suggesting that human peripheral blood LGL include several cell subsets. Only T cells, which synthesize full length 1.3-kb transcripts of T beta, have almost completely unmethylated CCGG sequences, indicating a good correlation between the reported level of 1.3-kb mRNA transcription from T beta and hypomethylation of this gene.
Sakamoto
S
S
Division of Cancer Treatment, National Cancer Institute, Frederick, MD 21701.
Ortaldo
J R
JR
Young
H A
HA
D001402:B-Lymphocytes / Q000378:metabolism; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis; D004262:DNA Restriction Enzymes; D005786:Gene Expression Regulation; D006801:Humans; D007694:Killer Cells, Natural / Q000145:classification / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008745:Methylation; D009000:Monocytes / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000235:genetics* / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism; D014158:Transcription, Genetic
D011948:Receptors, Antigen, T-Cell; D004247:DNA; D004262:DNA Restriction Enzymes