Soluble TL and H-2 antigens prepared from a TL positive leukaemia of a TL negative mouse strain.

TL (thymus-leukaemia) antigens are specified by the TLa locus, which is closely linked to H-2, the locus responsible for the major transplantation antigens of the mouse. Unlike other non-H-2 antigens tested for, TL antigens did not separate from H-2 antigens through a series of purification steps. On DEAE ion exchange chromatography, however, certain H-2 antigens tested for were separated from one another, and TL antigens occupied a different position between them. Thus the properties of TL antigens that appear by gene activation consequent upon leukaemogenesis in TL negative mice are not distinguishable from the properties of TL antigens occurring as a normal feature of TL positive mice.