Mouse Isoantigens: Separation of Soluble Tl (Thymus-Leukemia) Antigen From Soluble H-2 Histocompatibility Antigen by Column Chromatography

Abstract

Serological study of cell membrane antigens in the mouse has revealed several isoanfigenic systems demonstrable by cytotoxic isoantisera. Four of these systems of antigens are exclusively or predominantly represented on thymocytes. One of these, TL (thymus-leukemia) (1), is exclusively represented on thymocytes: two (Ly-A and Ly-B) have predominant representation on thymocytes and are present also on lymphocytes, but not on any other cell type (reference 2 and unpublished data1); another, designated 0 (3), also is predominantly represented on thymocytes and in lower concentration on lymphocytes, but is found in at least one other tissue---adult brain. The major histocompatibility isoantigen of the mouse, H-2, also is demonstrable on thymocytes by the cytotoxic test, but in contrast to the first four systems (TL, Ly-A, Ly-B, and 0), H-2 is represented poorly on thymocytes in comparison with lymphocytes and some other tissues.Of these five systems, TL has particular importance in tumor immunology because of its appearance in leukemias of strains that do not have the antigen on their normal thymocytes. In normal mice TL has the properties of an organspecific isoantigen.

Antigenic Modulation

“…3, showing that modulation of components TL.1 and TL.2 can occur despite absence of corresponding antibody from the serum used for modulation. All three TL specificities may well be on one molecule (11) in which case modulation may be envisaged as loss of this entire molecule following the attachment of antibody. On the other hand, the attachment of TL antibody to this site does not inevitably entail modulation, because anti-TL.2 does not induce modulation, in fact the attachment of anti-TL.2 hinders modulation.…”

TL and CD8αα: Enigmatic partners in mucosal immunity

“…The T3 gene product is only expressed on the surface of IEC, whereas the T18 gene is expressed in both the intestine and immature thymocytes [41–43]. Based on the expression of TL in thymocytes, mouse strains have been classified as either TL + or TL − .…”