Spleen cells from random-bred chickens bearing Rous sarcomas were commonly more reactive against the neoplastic target cells'in autochthonous than in allogeneic interactions in vitro. This difference was observed both in cytotoxic assays (hCr release from labeled target cells) and in an immunoadherence test measuring attachment of $"Cr-labeled splenocytes to Rous sarcoma cells. Specific splenocyte reactivity was not observed with normal embryonic chicken fibroblasts, 3T3 cells, or embryonic mouse C3H fibro'blasts. The immunoadherence technique required only 2 hr to perform, and revealed a more consistent superiority of autochthonous recognition of Rous sarcoma cells than the cytotoxicity assay. Experiments in which both procedures were used simultaneously with identical cell populations yielded similar resiilts, indicating that splenocyte adherence may be a precursor of and/or concomitant to target cell damage and that individual-specific tumor antigencity may play a part in cellular immunity against Rouis sarcomas.The host-tumor relationship of chickens bearing Rous sarcomas has a number of advantages as a model pertinent to neoplasia in man. The tumor host is an outbred, nonlaboratory adapted animal, and the virus that induces the neoplastic transformation is one of a family of agents whose members are oncogenic in nature as well as in the laboratory, and active in a broad range of species in addition to the chicken (1). Cellular and humoral immunity in this system is well established both in vito and in vitro (2,3), and the chicken lends itself uniquely to the separation of lymphoid cell populations of diverse origin, and thereby to a differential definition of immunological capacity (4).The purpose of the present investigation was to compare splenocyte-target cell interaction in both autochthonous and allogeneic confrontations between Rous sarcoma cells and effector cells, by use of splenocytes sensitized during the course of the host's experience with a primary, actively growing tumor-a situation reflecting the only type of interaction that can be studied in man.This interaction was evaluated by a newly developed quantitative immunoadherence test, and by the cytotoxicity assay based on the liberation of labeled chromium from target cells.The [Medium 199 (Grand Island Biological Co., Grand Island, N.Y.) supplemented, with 5-10% inactivated calf serum (In Vitro, Jerusalem), 10% tryptose phosphate broth (Difco Laboratories), 200 units/ml of penicillin, 200 jg/ml of streptomycin, and 15-25 ml/liter of 5% NaHCOs]. The cells were washed by centrifugation, pooled, counted, and seeded.Other Cell Types. Normal chicken embryo cells (CEC) were secondary cultures (2-to 3-days-old) derived from 9-to 11-
Complement-medicated cytotoxicity and indirect immunofluorescence assays showed that sera from random-bred chickens bearing Rous sarcoma (RS) tumors are usually more reactive in vitro against RS cells of autochthonous than of allogeneic origin. Absorption of such sera with autochthonous, but not with allogeneic, RS cells abrogated the fluorescence staining capacity. Sera from tumor-bearing birds did not stain normal chicken embryo cells (CEC), but reacted with a higher proportion of CEC transformed by the RS virus than with cultured PS tumor cells. Tumor cells incubated at 37 degrees C with autochthonous serum and fluorescent horse anti-chicken immunoglobulin conjugate displayed cell surface fluorescence patching.
The mixed haemadsorption (MHA) method was employed for detection of several normal antigenic components on the surface of human colon carcinoma cells (HT-29). The antigens were expressed by cells in monolayer cultures and in suspensions prepared by monolayer trypsinization, and by cells of tumours growing progressively in athymic mice. The plasma of such animals bearing medium sized and large, non-necrotic tumours contained all the antigens, as determined by the radial diffusion immune haemolysis method (RDIH); the plasma of animals with small or large heavily necrotic tumours did not contain detectable amounts of any of the determinants. The half-life of the determinants in the circulation as extracellular entities was ca. 20 h. The same antigens, and fibronectin, were found to be ubiquitously represented in normal human plasma. It is proposed that the presence of membrane antigens in plasma is the result of physiological shedding of cell surface constituents by living cells.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.