T cell receptor alpha-chain defines the antigen specificity of antigen-specific suppressor factor but does not impart genetic restriction.
Previous studies utilizing NP (4-hydroxy, 3-nitrophenyl acetyl hapten)-specific, T suppressor hybridomas have indicated that expression of TCR-alpha, but not TCR-beta, mRNA is required for expression of Ag-specific suppressor factor bioactivity. Suppressor-effector factor has been shown to be Ag specific and I-J restricted. Although the expression of TCR-alpha mRNA was necessary for suppressor activity, the role of TCR-alpha, as it pertained to the functional properties of T cell suppressor factor (TsF), was not established. To determine which properties of TsF could be accounted for by TCR-alpha expression, TCR-alpha cDNA, derived from NP-specific, suppressor T cell (Ts) hybridomas, was transfected into recipient Ts hybridomas of a second Ag specificity. The resulting heterologous transfectants displayed NP-specific, genetically restricted TsF activity. The Ag specificity corresponded to that of the TCR-alpha donor; however, the genetic restriction was influenced by the recipient cell, implying that TCR-alpha did not control genetic restriction of the TsF. Examination of TCR-beta expression in one of the MHC-restricted transfectants indicated that the genetic restriction of TsF could not be accounted for by TCR-beta gene products. The data support the conclusion that TCR-alpha expression is not only obligate for TsF bioactivity, but that the Ag specificity of the TCR-alpha dictates the Ag specificity of the resulting suppressor factor.
O'Hara
R M
RM
Genetics Institute, Cambridge, MA 02140.
Byrne
M C
MC
Kuchroo
V K
VK
Nagelin
A
A
Whitters
M J
MJ
Jayaraman
S
S
Henderson
S L
SL
Dorf
M E
ME
Collins
M
M
D000818:Animals; D000941:Antigens / Q000276:immunology*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D006241:Haptens / Q000276:immunology; D006462:Hemolytic Plaque Technique; D006825:Hybridomas / Q000276:immunology; D006968:Hypersensitivity, Delayed; D051379:Mice; D008969:Molecular Sequence Data; D009596:Nitrophenols / Q000276:immunology; D010648:Phenylacetates; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000378:metabolism*; D013491:Suppressor Factors, Immunologic / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D014162:Transfection
D000941:Antigens; D017931:DNA Primers; D006241:Haptens; D009596:Nitrophenols; D010648:Phenylacetates; D016693:Receptors, Antigen, T-Cell, alpha-beta; D013491:Suppressor Factors, Immunologic; C026242:4-hydroxy-5-nitrophenyl acetic acid