Comparative evaluation of multiple lymphoid and recombinant human interleukin-2 preparations

Gary B. Thurman, Annette E. Maluish, Jeffrey L. Rossio, Eric Schlick, Kikuo Onozaki, James E. Talmadge, Antonio D.G. Procopio, John R. Ortaldo, Francis W. Ruscetti, Henry C. Stevenson, Grace B. Cannon, Shankar Iyar, Ronald B. Herberman

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24 Scopus citations


Six lymphoid human interleukin-2s (nIL-2s) [four from peripheral blood mononuclear cells (PBMC) and two from JURKAT cells] and six recom-binant IL-2s (rIL-2s) were obtained for comparative evaluation. The main issues addressed were possible differences among the preparations in potency in T cell growth assays and other functional assays, and the possible presence of other cytokine activities or contaminants. Each preparation was assigned a standardized IL-2 activity in reference units (RU) by comparing its T cell growth promoting activity against the Biological Response Modifiers Program IL-2 (JURKAT) reference reagent. Relative to the IL-2 unitage indicated by the suppliers, the RU varied from 110-fold less to 8.5-fold more for the various preparations. Two nIL-2s and two rIL-2s contained significant levels of endotoxin. One nIL-2 contained low levels of both alpha and gamma interferon (IFN), and one nIL-2 had a high level of gamma IFN. All other IL-2s were negative for IFN activity. All IL-2 preparations significantly augmented human natural killer (NK) activity, although the amount of RU required varied from 0.1 to 50 RU. Four nIL-2s and three rIL-2s induced human PBMC to produce gamma IFN, whereas two nIL-2s and one rIL2 did not. All nIL-2s had substantial amounts of B cell growth factor activity, whereas none of the rIL-2s consistently displayed this activity. All IL-2s stimulated the tritiated thymidine [3H]TdR incorporation of human PBMC in the absence of other stimuli, in addition to augmenting the response to mitogen or alloantigens. Some nILs and IL-2s had effects on human monocytes such as inhibiting migration, inducing cytotoxic or growth inhibitory activity against tumor cells, and causing changes in cell surface markers. The IL-2s were also tested for activity in vitro and in vivo in mice. Although there was a 12-fold variation in activity among the preparations, all but one of the IL-2s showed augmentation of the mixed lymphocyte reaction activity and all IL-2s tested stimulated macrophage cytotoxicity in vitro. All IL-2s tested enhanced the mixed lymphocyte-allogeneic tumor cell reaction resulting in greater production of cytotoxic T cells. However, significant quantitative differences in potency were evident among the various IL-2 preparations, especially the nIL-2s. Only very high doses of IL-2 (intraperitoneal injection of 100,000 RU/animal) induced in vivo augmentation of splenic or peritoneal NK cells, although all IL-2s tested increased NK activity against tumor target cells in vitro with substantially lower doses (10-100 RU/ml). This comparative study of nlL-2 and rIL-2 preparations demonstrates mat different preparations of partially purified and purified nIL-2s and purified rlL-2s from different sources can vary substantially in their activity in various biological assays. In addition, the rIL-2s and nIL-2s had effects on the function of cell types other than T cells or NK cells, indicating that the role of IL-2 in the immune response may be broader than is generally appreciated.

Original languageEnglish (US)
Pages (from-to)85
Number of pages1
JournalJournal of Biological Response Modifiers
Issue number1
StatePublished - Feb 1986
Externally publishedYes


  • B-cell growth factor
  • Cell surface markers
  • InterIcukin-2
  • Interferons
  • Monocyte function
  • Natural killer cells
  • Tumor cell cytotoxicity

ASJC Scopus subject areas

  • Immunology
  • Pharmacology
  • Cancer Research


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