An in vitro system for the study of the cell-mediated immune response to Jensen Sarcoma (JS) is described. The tumor grew unrestricted and lead to the demise of 80% of successfully challenged Sprague-Dawley rats (persistors) while 20% of challenged rats (regressors) destroyed the tumor by an unknown mechanism(s). Lymphocytes from both persistors and regressors were shown to be cytotoxic for tumor cells in vitro. Pretreatment of tumor target cells with \"immune\" serum from persistors or regressors had no effect on the in vitro cytotoxicity of lymphocytes from tumor-challenged rats. Pretreatment of lymphocytes with irmnune serum, however, was shown to reduce the in vitro cytotoxicity of \"immune\" lymphocytes although the effect was variable and did not correlate well with the in vivo tumor status. Lymphocyte stimulation with Phytohemmag-glutinin (PHA, a T cell mitogen) was decreased in persister rats; while Poke Weed mitogen (PWM; a B cell mitogen) stimulation was increased in persister rats. Treatment of \"immune\" lymphocytes with a) supernatants from tumor cell cultures, b) irradiated tumor cells or c) sonicated tumor cells did not result in increased DNA. synthesis. The advantages of the Jensen sarcoma system as a model to study the mechanisms of cell-mediated immunity are discussed.
","abstract_html":"<p>An in vitro system for the study of the cell-mediated immune response to Jensen Sarcoma (JS) is described. The tumor grew unrestricted and lead to the demise of 80% of successfully challenged Sprague-Dawley rats (persistors) while 20% of challenged rats (regressors) destroyed the tumor by an unknown mechanism(s). Lymphocytes from both persistors and regressors were shown to be cytotoxic for tumor cells in vitro. Pretreatment of tumor target cells with "immune" serum from persistors or regressors had no effect on the in vitro cytotoxicity of lymphocytes from tumor-challenged rats. Pretreatment of lymphocytes with irmnune serum, however, was shown to reduce the in vitro cytotoxicity of "immune" lymphocytes although the effect was variable and did not correlate well with the in vivo tumor status. Lymphocyte stimulation with Phytohemmag-glutinin (PHA, a T cell mitogen) was decreased in persister rats; while Poke Weed mitogen (PWM; a B cell mitogen) stimulation was increased in persister rats. Treatment of "immune" lymphocytes with a) supernatants from tumor cell cultures, b) irradiated tumor cells or c) sonicated tumor cells did not result in increased DNA. synthesis. The advantages of the Jensen sarcoma system as a model to study the mechanisms of cell-mediated immunity are discussed.</p>","abstract_has_math":false,"creators":["Masek, Theodore D."],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Thesis","degree_discipline":"Microbiology","degree_department":null,"school":null,"contributors":["Benjamin H. S. Lau","Robert L. Nutter","E. Clifford Herrmann"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1976,"date_issued":"1976-09-01T07:00:00Z","date_published":"1976-09-01T07:00:00Z","updated_at":"2026-07-24T02:53:08Z","subjects":["Microbiology","Cytotoxicity, Immunologic, Sarcoma, Experimental"],"languages":["English"],"rights":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsrepository.llu.edu/etd/715","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Benjamin H. S. Lau","Robert L. Nutter","E. Clifford Herrmann"]},{"key":"dc:creator","label":"Author","values":["Masek, Theodore D."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Microbiology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Microbiology","Cytotoxicity, Immunologic, Sarcoma, Experimental"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]},{"key":"dc:rights","label":"Dc Rights","values":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarsrepository.llu.edu/etd/715"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["An in vitro system for the study of the cell-mediated immune response to Jensen Sarcoma (JS) is described. The tumor grew unrestricted and lead to the demise of 80% of successfully challenged Sprague-Dawley rats (persistors) while 20% of challenged rats (regressors) destroyed the tumor by an unknown mechanism(s). Lymphocytes from both persistors and regressors were shown to be cytotoxic for tumor cells in vitro. Pretreatment of tumor target cells with \"immune\" serum from persistors or regressors had no effect on the in vitro cytotoxicity of lymphocytes from tumor-challenged rats. Pretreatment of lymphocytes with irmnune serum, however, was shown to reduce the in vitro cytotoxicity of \"immune\" lymphocytes although the effect was variable and did not correlate well with the in vivo tumor status. Lymphocyte stimulation with Phytohemmag-glutinin (PHA, a T cell mitogen) was decreased in persister rats; while Poke Weed mitogen (PWM; a B cell mitogen) stimulation was increased in persister rats. Treatment of \"immune\" lymphocytes with a) supernatants from tumor cell cultures, b) irradiated tumor cells or c) sonicated tumor cells did not result in increased DNA. synthesis. The advantages of the Jensen sarcoma system as a model to study the mechanisms of cell-mediated immunity are discussed.
"]},{"key":"dc:title","label":"Title","values":["Cell-Mediated Cytotoxicity of Jensen Tumor in Sprague-Dawley Rats"]}]}],"canonical_facts":{"dc:contributor":["Benjamin H. S. Lau","Robert L. Nutter","E. Clifford Herrmann"],"dc:creator":["Masek, Theodore D."],"dc:description.abstract":["An in vitro system for the study of the cell-mediated immune response to Jensen Sarcoma (JS) is described. The tumor grew unrestricted and lead to the demise of 80% of successfully challenged Sprague-Dawley rats (persistors) while 20% of challenged rats (regressors) destroyed the tumor by an unknown mechanism(s). Lymphocytes from both persistors and regressors were shown to be cytotoxic for tumor cells in vitro. Pretreatment of tumor target cells with \"immune\" serum from persistors or regressors had no effect on the in vitro cytotoxicity of lymphocytes from tumor-challenged rats. Pretreatment of lymphocytes with irmnune serum, however, was shown to reduce the in vitro cytotoxicity of \"immune\" lymphocytes although the effect was variable and did not correlate well with the in vivo tumor status. Lymphocyte stimulation with Phytohemmag-glutinin (PHA, a T cell mitogen) was decreased in persister rats; while Poke Weed mitogen (PWM; a B cell mitogen) stimulation was increased in persister rats. Treatment of \"immune\" lymphocytes with a) supernatants from tumor cell cultures, b) irradiated tumor cells or c) sonicated tumor cells did not result in increased DNA. synthesis. The advantages of the Jensen sarcoma system as a model to study the mechanisms of cell-mediated immunity are discussed.
"],"dc:identifier":["https://scholarsrepository.llu.edu/etd/715"],"dc:language":["English"],"dc:rights":["This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights."],"dc:subject":["Microbiology","Cytotoxicity, Immunologic, Sarcoma, Experimental"],"dc:title":["Cell-Mediated Cytotoxicity of Jensen Tumor in Sprague-Dawley Rats"],"thesis:degree_discipline":["Microbiology"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T02:53:08Z"}