E Pillemer

Isolation of molecules recognized by monoclonal antibodies and antisera: the solid phase immunoisolation technique

A simple technique for the isolation of antigens recognized by antisera and monoclonal antibodies has been developed. This method, the solid-phase immunoisolation technique, employs the protein-binding properties of polyvinylchloride microtiter plates. Antibodies are adsorbed to the plates either directly or via an anti-immunoglobulin reagent. Antigen is then placed in the wells, and allowed to adsorb to the antibody. The well is washed, and the antigen is then eluted with a denaturing electrophoresis sample buffer for one- or two-dimensional analysis. The solid-phase immunoisolation technique has been used to isolate a variety of cell membrane antigens with high signals and low backgrounds. The ease of the procedure and the high signal-to-noise ratio make this method preferable to the use of a staphylococcal adsorbent for many applications.

The Role of MuLV Receptors on T-Lymphoma Cells in Lymphoma Cell Proliferation

The induction of thymic lymphocytic neoplasms in mice by murine leukemia viruses (MuLV) involves a complex series of interactions between endogenous retroviral gene sequences and target cells in the thymus (Kaplan, 1967). This virus-cell interaction is characterized by an exquisite target cell specificity for transformation, as compared to infection. Thus, some highly purified retroviruses (e.g., Moloney) can be obtained which can infect both mouse fibroblasts and thymic (or T) cells, but which are capable of transforming only a limited subset of thymocytes (N. Rosenberg, personal communication; Buchhagen et al., 1976). Since isolates from leukemic cells infect fibroblasts without transformation, and isolates from fibroblasts can both infect and transform some T lymphocytes, it is apparent that some very special relationship must exist between the transforming virus and its target cell (reviewed by Weissman and Baird, 1977).

Receptor mediated murine leukemogenesis: monoclonal antibody induced lymphoma cell growth arrest.

We have proposed a receptor-mediated leukemogenesis hypothesis wherein T lymphomas would be clones of T cells bearing mitogen-linked surface receptors specific for the envelope determinants of the inducing MuLV (Weissman and Baird 1977: McGrath and Weissman 1978, 1979). We have tested a wide range of murine thymic lymphomas induced by thymotropic retroviruses and have shown that these cells indeed bear surface receptors highly specific for the retrovirus envelope glycoproteins produced by these cells (McGrath et al. 1978a,b). Even closely related recombinant retroviruses bound less well than the autologous retroviruses (McGrath et al. 1978b, McGrath and Weissman 1979). That these retroviruses and their interactions with T lymphoma cell receptors might be involved in the pathogenesis of murine leukemia was suggested by two kinds of experiments: First, only the leukemogenic viral isolates bound specifically to lymphoma cell receptors, while nonleukemogenic but closely related viral preparations bound less well or not at all (McGrath et al. 1978b, McGrath and Weissman 1979). Second, if one examined the distribution of receptor bearing cells in the thymus of a preleukemic AKR mouse, only T cells bearing cell surface receptors recognizing the inducing MuLV were capable of adoptive transfer of the leukemic state, whereas morphologically similar cells within the same thymus were not capable of leukemic proliferation in syngeneic hosts (McGrath and Weissman 1978, 1979).