Oligoclonal TCRBV gene usage in B-cell chronic lymphocytic leukemia: major perturbations are preferentially seen within the CD4 T-cell subset.
TCRBV (T-cell receptor B variable) gene usage and CDR3 size distribution were analyzed using reverse transcription polymerase chain reaction (RT-PCR) to assess the T-cell repertoire of 10 patients with B-cell chronic lymphocytic leukemia (B-CLL) and in nine age-matched healthy control donors. When the usage of each TCRBV gene within the CD8(+) T cells of the patients was compared with that of the controls, no statistically significant difference was noted except for BV 6S1-3. In contrast, within the CD4(+) T cells of the CLL patients, a statistically significant overexpression for four BV families (2, 3, 5S1, 6S1-3) was seen while an underrepresentation was noted for five BV families (10, 11, 15, 16, 19). Based on the criterion that a value of any BV higher than the mean + 3 standard deviation (SD) of healthy controls indicated an overexpression, individual patients were shown to overexpress several TCRBV genes compared with the controls. Analyses of the CDR3 length polymorphism showed a significantly higher degree of restriction within CD4(+) and CD8(+) T cells of the patients, as compared with the corresponding control T-cell population. There was a significant difference in the CDR3 size distribution pattern with a more polymorphic CDR3 length pattern in the age-matched controls as compared with CLL patients, suggesting different mechanisms driving the T cells towards a clonal/oligoclonal TCRBV usage in patients and controls, respectively. The results show major perturbations of T cells in CLL patients, more frequently seen in the CD4(+) T-cell subset, indicating that nonmalignant CD4(+) T cells may be involved in the pathogenesis of CLL, but also CD8(+) T cells.
Immune and Gene Therapy Lab, CCK, Karolinska Hospital, Stockholm, Sweden.
M R
MR
Rezvany
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M
Jeddi-Tehrani
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Osterborg
E
E
Kimby
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H
Wigzell
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H
Mellstedt
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000276:immunology; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*
D007135:Immunoglobulin Variable Region; D016693:Receptors, Antigen, T-Cell, alpha-beta