Receptor specificity, functional characteristics, and cell-surface phenotype of a highly selected anti-I-Ab-specific, long-term T-cell line.

A highly selected alloreactive T-cell line was developed by repeated restimulation of B10.D2/n lymph-node cells with irradiated C57BL/10Sn (B10) spleen cells in long-term MLC for up to 21/2 years. Continuous growth of the line requires restimulation every 2 to 4 weeks with fresh H-2b stimulator cells. The line proliferates strongly against H-2b but not against H-2d, H-2f, H-2q, H-2r, or H-2s stimulators. Analysis of recombinant mouse strains showed that the proliferative response is directed against I-Ab, but not Kb or Db determinants. During the growth period of the line, strong cross-reactivity with H-2p (B10.P) and weak cross-reactivity with H-2k strains (e.g., CBA/J and B10.BR) was observed. A clone with exquisite specificity for I-Ab, but with no cross-reactivity with H-2p or H-2k was isolated from the line; thus clonal heterogeneity of the line still exists despite the highly selective growth conditions.--The majority of T cells from the line or clone were shown to bind I-Ab but not Kb or Db determinants either spontaneously during restimulation with fresh B10 stimulator cells or via membrane vesicles expressing I-Ab determinants. No killing activity by the line in either specific or nonspecific cytolytic T-cell assays was observed nor was the T 145 glycoprotein, characteristic of killer T cells, detected.