Cytotoxic T cells: Lyt phenotype and blocking of killing activity by Lyt antisera

Abstract

We reexamined two questions concerning Lyt antigens of cytotoxic T cells of the mouse: is Lyt-1 antigen expressed on cytotoxic effector cells and can cytotoxicity be blocked by antibody to Lyt antigens in the absence of added complement? A 3-hrblCr-release assay with splenic effector cells and leukemia or myeloma target cells was used to measure cell-mediated cytotoxicity. The cytotoxic activity of effector cells against allogeneic targets was abolished by exposure to Lyt-1, Lyt-2, or Lyt-3 antiserum and complement. Specificity was established by tests with C57BL/6 Lyt congenic mice and absorption studies with thymocytes. Similarly, the cytotoxicity of effector cells directed against semisyngeneic myeloma targets was reduced by Lyt-1, -2, or -3 antiserum and complement. Effector cell cytotoxicity against another semisyngeneic target was only marginally affected by Lyt-1 antiserum and complement, but was abolished by Lyt-2 or -3 antiserum and complement. It appears likely that cytotoxic T cells are a heterogeneous population with regard to Lyt-1 expression and that past studies indicating an apparent absence of Lyt-l on cytotoxic T cells revealed a quantitative, not qualitative, feature of these cells. With regard to the activity of Lyt antisera in the absence of added complement, selective blocking of effector cell cytotoxicity for allogeneic and semisyngeneic targets was found with Lyt-2 and Lyt-3 antisera but not with Lyt-1 antiserum. The specificity of blocking was established by tests with Lyt congenic mice and absorption studies with thymocytes. With the exception of blocking by antisera to the H-2 haplotype expressed by the target cell, no effector cell blocking was observed with alloantisera or heteroantisera to a range ofother cell surface molecules present on mouse lymphoid cells. One possibility to account for the selective blocking by Lyt-2 and Lyt-3 antisera is that Lyt-2,3 determinants on the surface of cytotoxic T cells have a close spatial relation to the T cell receptor.

Does OKT3 monoclonal antibody react with an antigen-recognition structure on human T cells?

“…Little is known of the functional roles of cell surface antigens. Antisera against murine Lyt 2 and 3 antigens, which are present on the cytotoxic/suppressor T-cell subset (17) were found to inhibit T-cell mediated lysis, suggesting that the Lyt 2 or 3 antigens may be associated with the cytolytic apparatus (22,23).…”

Interaction of 2C T Cells with a Hybrid Ld Molecule Bearing an α3 Domain Derived from the Class Ib Molecule, Qa‐2

“…First, studies with transgenic (TG) mice established that TCR specificity to Class I (Cl I) or Cl II MHC antigens determines the CD4/CD8 phenotype of developing T cells [2][3][4][5][6]. Second, injection of anti-CD4 or anti-CD8 antibodies (Abs) into mice blocks development of CD4 þ and CD8 þ cells, respectively [7][8][9][10][11][12][13]. Finally, studies in mice lacking expression of CD4 or CD8 confirm that these molecules play an important role during T cell development, since there is a marked impairment in the development of Cl IIand Cl I-restricted T cells in these mice, respectively [14,15].…”

Study on cellular events in postthymectomy autoimmune oophoritis in mice. I. Requirement of Lyt-1 effector cells for oocytes damage after adoptive transfer.

“…Bulk treatment of spleen cells with antisera and nontoxic rabbit C was carried out according to the methods of Nakayama et al (16). Briefly, 1.0-1.5 × 10 v spleen cells were suspended in 0.2 ml of medium 199 (Gibco Laboratories, Grand Island Biological Co., Grand Island, NY) with 2% fetal calf serum (Gibco Laboratories) containing the appropriate antiserum at a final dilution of 1:7 in the case of anti-Thy-1, anti-Lyt, and anti-Qa-1 treatment or at 1:10 for anti-Ia k treatment.…”