Neutrophil function assay

In vitro or ex vivo macrophage/neutrophil functional assays including ADCC, phagocytosis, oxidative burst, and chemotaxis. 

During the safety evaluation of therapeutics, toxicities that are specific to innate immunity may be observed and there are specific assays available to determine which aspect of innate immunity is affected. These assays include NK cell, macrophage and neutrophil function assays, and the assessment of soluble mediators in serum. A selection of these assays will be described in this section. 

Recent technological developments for the assay of neutrophil functions have enabled many properties of these cells to be measured in unfractionated blood. Several important features have been observed ... 

In order to understand potential immunotoxicity observed during the safety evaluation of therapeutics, assays are available to assess whether specific components of innate immunity are affected. These assays include functional assays for the cell types involved in this phase of the immune response (NK cells, macrophages, and neutrophils) and measurement of complement proteins. The majority of these assays may be incorporated into toxicity studies thereby allowing for simultaneous measurement of specific immunotoxicologi-cal end points within the same study as toxicological end points. 

Interleukin-2 Human recombinant lL-2 aldesleukin, proleukin des-alanyl-1, serine-125 human lL-2) differs from native lL-2 in that it is not glycosylated, has no amino terminal Ala, and has an Ser substituted for the Cys at amino acid 125. The potency of the preparation is represented in International Units in a lymphocyte proliferation assay such that 1.1 mg of recombinant lL-2 protein equals 18 million International Units. Aldesleukin has the following in vitro biologic activities of native lL-2 enhancement of lymphocyte proliferation and growth of lL-2-dependent cell lines enhancement of lymphocyte-mediated cytotoxicity and killer cell activity and induction of interferon-7 activity. In vivo administration of aldesleukin in animals produces multiple immunologic effects in a dose-dependent manner. Cellular immunity is profoundly activated with lymphocytosis, eosinophilia, thrombocytopenia, and release of multiple cytokines e.g., TNF-a, lL-1, interferon-7). Aldesleukin is indicated for the treatment of adults with metastatic renal cell carcinoma and melanoma. Administration of aldesleukin has been associated with serious cardiovascular toxicity resulting from capillary leak syndrome, which involves loss of vascular tone and leak of plasma proteins and fluid into the extravascular space. Hypotension, reduced organ perfusion, and death may occur. An increased risk of disseminated infection due to impaired neutrophil function also has been associated with aldesleukin treatment. 

The most relevant bioassays measure specific activities on immune function, either as effector or regulatory, for example, assay of cytokine IL-12 by the augmentation of the cytolytic function of natural killer cells (B9), IL-10 by the inhibition of the production of TNF-o from stimulated monocytes (B13), and IL-8 and eotaxin by the chemotaxis of neutrophils and eosinophils, respectively (C2). 

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