Tumor necrosis factor-alpha (TNF-α) is a cytokine produced primarily by macrophages during acute inflammation. In this study we examined the differential effect of retinoic acid (RA) and phorbol 12-myristate 13-acetate (PMA) on the induction of TNF-α secretion from U937 monocytic cell populations by using the reverse hemolytic plaque assay (RHPA). The RHPA will allow us to investigate both changes in TNF-α secreting populations as well as monitor the relative amount of TNF-α released from individual cells. Our results indicate that treatment of U937 cells with RA (10-6M) moderately increases the secreting cell populations, and dramatically enhances the amount of TNF-α secreted from cells already committed to secretion. In contrast, treatment with PMA (250ng/ml) drastically increased the secreting population, but only slightly increasing the amount of TNF-α released. These results suggest that induction of TNF-α secretion from U937 cells occurs by different pathways.
","abstract_html":"<p>Tumor necrosis factor-alpha (TNF-α) is a cytokine produced primarily by macrophages during acute inflammation. In this study we examined the differential effect of retinoic acid (RA) and phorbol 12-myristate 13-acetate (PMA) on the induction of TNF-α secretion from U937 monocytic cell populations by using the reverse hemolytic plaque assay (RHPA). The RHPA will allow us to investigate both changes in TNF-α secreting populations as well as monitor the relative amount of TNF-α released from individual cells. Our results indicate that treatment of U937 cells with RA (10<sup>-6</sup>M) moderately increases the secreting cell populations, and dramatically enhances the amount of TNF-α secreted from cells already committed to secretion. In contrast, treatment with PMA (250ng/ml) drastically increased the secreting population, but only slightly increasing the amount of TNF-α released. These results suggest that induction of TNF-α secretion from U937 cells occurs by different pathways.</p>","abstract_has_math":false,"creators":["Tran, An Xuong"],"institution":null,"degree_name":"MS (Master of Science)","degree_level":"Thesis - restricted","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002-08-16T07:00:00Z","date_published":"2002-08-16T07:00:00Z","updated_at":"2026-07-24T02:19:21Z","subjects":["TNF-alpha","U937","Reverse hemolytic plaque assay","Cytokine","Biology","Life Sciences"],"languages":[],"rights":["Copyright by the authors."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://dc.etsu.edu/etd/685","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Tran, An Xuong"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2002-08-16T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis - restricted"]},{"key":"thesis:degree_name","label":"Degree Name","values":["MS (Master of Science)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["TNF-alpha","U937","Reverse hemolytic plaque assay","Cytokine","Biology","Life Sciences"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["Copyright by the authors."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://dc.etsu.edu/context/etd/article/1842/viewcontent/TranA062402.pdf","https://dc.etsu.edu/etd/685"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Tumor necrosis factor-alpha (TNF-α) is a cytokine produced primarily by macrophages during acute inflammation. In this study we examined the differential effect of retinoic acid (RA) and phorbol 12-myristate 13-acetate (PMA) on the induction of TNF-α secretion from U937 monocytic cell populations by using the reverse hemolytic plaque assay (RHPA). The RHPA will allow us to investigate both changes in TNF-α secreting populations as well as monitor the relative amount of TNF-α released from individual cells. Our results indicate that treatment of U937 cells with RA (10-6M) moderately increases the secreting cell populations, and dramatically enhances the amount of TNF-α secreted from cells already committed to secretion. In contrast, treatment with PMA (250ng/ml) drastically increased the secreting population, but only slightly increasing the amount of TNF-α released. These results suggest that induction of TNF-α secretion from U937 cells occurs by different pathways.
"]},{"key":"dc:title","label":"Title","values":["Measuring the Changes in Tumor Necrosis Factor-Alpha (TNF-α) from Secretory Populations of U937 Monocytic Cells during Differentiation."]}]}],"canonical_facts":{"dc:creator":["Tran, An Xuong"],"dc:date.issued":["2002-08-16T07:00:00Z"],"dc:description.abstract":["Tumor necrosis factor-alpha (TNF-α) is a cytokine produced primarily by macrophages during acute inflammation. In this study we examined the differential effect of retinoic acid (RA) and phorbol 12-myristate 13-acetate (PMA) on the induction of TNF-α secretion from U937 monocytic cell populations by using the reverse hemolytic plaque assay (RHPA). The RHPA will allow us to investigate both changes in TNF-α secreting populations as well as monitor the relative amount of TNF-α released from individual cells. Our results indicate that treatment of U937 cells with RA (10-6M) moderately increases the secreting cell populations, and dramatically enhances the amount of TNF-α secreted from cells already committed to secretion. In contrast, treatment with PMA (250ng/ml) drastically increased the secreting population, but only slightly increasing the amount of TNF-α released. These results suggest that induction of TNF-α secretion from U937 cells occurs by different pathways.
"],"dc:identifier":["https://dc.etsu.edu/context/etd/article/1842/viewcontent/TranA062402.pdf","https://dc.etsu.edu/etd/685"],"dc:rights":["Copyright by the authors."],"dc:subject":["TNF-alpha","U937","Reverse hemolytic plaque assay","Cytokine","Biology","Life Sciences"],"dc:title":["Measuring the Changes in Tumor Necrosis Factor-Alpha (TNF-α) from Secretory Populations of U937 Monocytic Cells during Differentiation."],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Thesis - restricted"],"thesis:degree_name":["MS (Master of Science)"]},"updated_at":"2026-07-24T02:19:21Z"}