Monoclonal antibodies specific for a murine cytotoxic T-lymphocyte clone.

Abstract

Two antibody-secreting murine hybridomas, F1G3.1 and F2A11.5, have been established from B1O.D2 mice immunized with cells from the murine cytotoxic T-lymphocyte clone G4. The two clones used, G4 and B10, were derived from BALB.B (H-2b) mice and the target antigen specificity of both maps to the Dd region of the murine H-2 complex. However, B10 has a lower affinity for the target cells, as shown by its lower specific killing of blasts and its higher susceptibility to blocking by anti-Lyt-2 monoclonal antibody 53-6.75. The monoclonal antibodies, FlG3.1 and F2A11.5, react only with cells from clone G4. Similarly, they block only the specific cytolysis mediated by G4; no effect on cytotoxicity mediated by B10 or by heterogeneous populations of cytotoxic T lymphocytes was found. FlG3.1, especially, is very active in stimulating G4 to secrete immune interferon; B10 in contrast did not show any induction on treatment with these monoclonal antibodies. The structure of the surface antigen on G4 cells recognized by these monoclonal antibodies was revealed by immunoprecipitation studies of radioiodinated cell surface proteins. A protein dimer could be identified with an apparent molecular size of 80,000 daltons consisting of monomers migrating as 42,000-dalton proteins on reduction. So far, electrophoresis in the presence of NaDodSO4 does not indicate any heterogeneity in the size of the monomers. This molecule can be distinguished from the Lyt-2 complex.Recent reports from a number of laboratories indicate a consensus of opinion on a candidate for the T-cell antigen receptor. These reports describe similar approaches using monoclonal antibodies generated against cloned T-cell lines. The derived antibodies react only with the T cells used as immunogen. Allison et al.(1) reported a monoclonal antibody specific for a murine radiation-induced T-cell lymphoma of unknown antigen specificity and function. Meuer et al. (2) immunized mice with a human cytotoxic T-lymphocyte (CTL) clone and generated monoclonal antibodies that inhibit the specific lytic activity of the CTLs. Haskins et al. (3) described a monoclonal antibody specific for an Ia (class II)-restricted antigen-specific murine T-cell hybridoma, probably belonging to the helper T-cell lineage. In this case, the monoclonal antibody inhibited the antigen-induced secretion of interleukin 2 (IL-2). In all reports cited, the clone-specific monoclonal antibodies precipitate a surface protein of -80,000 daltons that separates into two chains of -40,000 daltons on reduction.In addition to the apparent clone-specific nature of the determinants and the ability of the antibodies to block antigenspecific function, there are other reasons to consider that the determinants recognized are idiotypes on the T-cell antigen receptor. For example, there are some comparative data suggesting microheterogeneity among the 40,000-dalton protein chains derived from different T-cell clones (4). Furthermore, it has been shown that the putative idiotypic determinant is intimately associated ...

Rearrangement and transcription of a T-cell receptor beta-chain gene in different T-cell subsets.

“…Since the above results indicate that CTL clones transcribe at least one of the C region genes into appropriate-sized mRNA, we conclude that class II MHC-restricted Th and class I MHC-restricted CTL may use at least the C region of the ,3 chain in common. This is consistent with previously published protein data comparing the receptors from class I-and class II-restricted T-cell clones (49)(50)(51)(52)(53)(54)(55).…”

Antigen-receptor interaction requirement for conjugate formation and lethal-hit triggering by cytotoxic T lymphocytes can be bypassed by protein kinase C activators and Ca2+ ionophores.

“…1), which implies involvement of the Ag-recognizing T-cell receptor in the triggering mechanism of the CTL. This assumption is supported by experiments with a monoclonal antibody against the CTL Ag receptor (2)(3)(4)(5)(6)(7)(8) and by studies of Agnonspecific cytotoxicity (9)(10)(11). Results (12) are also consistent with the view that the T-cell receptor is involved in the triggering of CTL.…”

Expression of T-cell receptor alpha-chain genes in transgenic mice.

“…The question of whether 2B4 alpha-chain expression suppresses endogenous alpha-chain rearrangement and expression was addressed first by costaining of peripheral lymph node cells with the A2B4-2 monoclonal antibody versus anti-CD3. As a control, lymph node cells from both a 2B4a and a 2B4aEH transgenic mouse were stained with the anti-VP8 monoclonal antibody, F23.1 (53), and an anti-CD3 monoclonal antibody (1) and analyzed by FACS. In both cases, the cells staining positively with both antibodies lay along a diagonal; individual cells which stained more brightly with anti-T cell receptor antibody also stained more brightly with CD3.…”