Selective expression of V delta 6 genes by B2A2- CD4- CD8- T cell receptor gamma/delta thymocytes.
Most CD4-CD8- adult murine thymocytes characterized by absence of the B2A2 (J11d) antigen express T cell receptors (TcR) alpha/beta and utilize preferentially V beta 8.2 segments. To a much lesser extent, B2A2-CD4-CD8- thymocytes also express TcR gamma/delta, as evidenced by biochemical and Northern blot analysis. We have now been able to exclude the possibility that these cells might co-express both types of TcR: V beta 8+ B2A2- CD4-CD8- thymocytes expressed no TcR delta mRNA whereas the corresponding V beta 8- subset transcribed full-length TcR gamma as well as delta mRNA. Furthermore, the TcR gamma/delta expressing B2A2- thymocytes were found to use preferentially V delta 6 genes. Conversely, they did not express V delta 5 genes which are most frequently used by other TcR gamma/delta-bearing populations such as B2A2+ CD4-CD8- thymocytes or CD4-CD8- peripheral lymph node cells. RNase protection experiments showed that two particular V delta 6 transcripts predominate in these gamma/delta populations, the most prominent V delta 6 sequence being highly homologous if not identical to V alpha 7.1. Our observations extend previous information on overlapping V alpha and V delta gene repertoires, particularly in the cross-hybridizing V alpha 7/V delta 6 gene family. Moreover, our data suggest that B2A2-CD4-CD8- thymocytes represent a developmentally unique subset in which both V delta and V beta segments are nonrandomly expressed.
Miescher
G C
GC
Ludwig Institute for Cancer Research, Lausanne Branch, Epalinges, Switzerland.
Liao
N S
NS
Lees
R K
RK
MacDonald
H R
HR
Raulet
D H
DH
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D015152:Blotting, Northern; D005260:Female; D015870:Gene Expression; D008198:Lymph Nodes / Q000502:physiology; D051379:Mice; D008815:Mice, Inbred Strains; D012333:RNA, Messenger / Q000235:genetics; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D012260:Ribonucleases / Q000494:pharmacology; D013601:T-Lymphocytes / Q000502:physiology*; D013950:Thymus Gland / Q000502:physiology
D000945:Antigens, Differentiation, T-Lymphocyte; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D012260:Ribonucleases