IL-12 enhances the natural killer cell cytokine response to Ab-coated tumor cells.

Department of Molecular Virology, Immunology, and Medical Genetics, The Arthur G. James Comprehensive Cancer Center, The Ohio State University College of Medicine, Columbus, Ohio 43210, USA.
Journal of Clinical Investigation (Impact Factor: 12.81). 11/2002; 110(7):983-92. DOI: 10.1172/JCI15950
Source: PubMed

ABSTRACT The anti-tumor activity of recombinant mAb's directed against tumor cell growth receptors has generally been considered to result from direct antiproliferative effects, the induction of apoptosis, or possibly Ab-dependent cellular cytotoxicity mediated against tumor targets. However, it remains unclear to what degree these mechanisms actually aid in the clearance of Ab-coated tumor cells in vivo. We show here that NK cells secrete a distinct profile of potent immunostimulatory cytokines in response to dual stimulation with Ab-coated tumor cells and IL-12. This response could not be duplicated by costimulation with other ILs and was significantly enhanced in the presence of monocytes. Cytokine production was dependent upon synergistic signals mediated by the activating receptor for the Fc portion of IgG (FcgammaRIII) and the IL-12 receptor expressed on NK cells. Coadministration of Ab-coated tumor cells and IL-12 to BALB/c mice resulted in enhanced circulating levels of NK cell-derived cytokines with the capacity to augment anti-tumor immunity. These findings suggest that, in addition to mediating cellular cytotoxicity and apoptosis, the anti-tumor activity of mAb's might also result from activation of a potent cytokine secretion program within immune effectors capable of recognizing mAb-coated targets.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The antitumor effects of therapeutic mAbs may depend on immune effector cells that express FcRs for IgG. IL-12 is a cytokine that stimulates IFN-γ production from NK cells and T cells. We hypothesized that coadministration of IL-12 with a murine anti-HER2/neu mAb (4D5) would enhance the FcR-dependent immune mechanisms that contribute to its antitumor activity. Thrice-weekly therapy with IL-12 (1 μg) and 4D5 (1 mg/kg) significantly suppressed the growth of a murine colon adenocarcinoma that was engineered to express human HER2 (CT-26(HER2/neu)) in BALB/c mice compared with the result of therapy with IL-12, 4D5, or PBS alone. Combination therapy was associated with increased circulating levels of IFN-γ, monokine induced by IFN-γ, and RANTES. Experiments with IFN-γ-deficient mice demonstrated that this cytokine was necessary for the observed antitumor effects of therapy with IL-12 plus 4D5. Immune cell depletion experiments showed that NK cells (but not CD4(+) or CD8(+) T cells) mediated the antitumor effects of this treatment combination. Therapy of HER2/neu-positive tumors with trastuzumab plus IL-12 induced tumor necrosis but did not affect tumor proliferation, apoptosis, vascularity, or lymphocyte infiltration. In vitro experiments with CT-26(HER2/neu) tumor cells revealed that IFN-γ induced an intracellular signal but did not inhibit cellular proliferation or induce apoptosis. Taken together, these data suggest that tumor regression in response to trastuzumab plus IL-12 is mediated through NK cell IFN-γ production and provide a rationale for the coadministration of NK cell-activating cytokines with therapeutic mAbs.
    The Journal of Immunology 02/2011; 186(6):3401-9. · 5.52 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Several studies suggest that the progression of malignant tumors as well as the response to chemotherapy and targeted therapy is critically dependent on the immunological parameters that are derived from the host immune system as well as a modulation of the immune system by therapeutic antibodies. It has been shown for many tumor types that the presence of a lymphocytic infiltrate in different types of cancers is a positive factor for clinical outcome and that the response to neoadjuvant chemotherapy is increased in a tumor with a prominent pretherapeutic infiltrate. Furthermore, new targeted therapies in breast cancer, such as trastuzumab, as well as in hematological malignancies, such as rituximab and alemtuzumab, have been shown to interact with immunological pathways, and this interaction is critical for response and clinical outcome. In neoplasms of lymphoid and hematopoietic tissues, targeted therapies not only reduce toxic effects on normal tissues but also lead to modulations of the immune system depending on the target molecule, its physiological function and cellular distribution. This review gives an overview on clinical data on response to classical chemotherapy as well as molecular targeted therapy and its interaction with the immune system.
    Seminars in Immunopathology 04/2011; 33(4):341-51. · 5.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Squamous cell carcinoma of the head and neck (SCCHN) is the sixth most common cancer worldwide. Greater than 90% of SCCHN of the oropharynx overexpress the epidermal growth factor receptor (EGFR or HER1). Cetuximab (Erbitux-TM) is a humanized anti-HER1 monoclonal antibody (mAb) that binds to HER1 overexpressing tumor cells. Cetuximab has a direct effect on HER1-positive cancer cells, but it also can activate immune cells that bear receptors for the Fc (constant portion) of IgG such as natural killer (NK) cells. NK cells have an activating Fc receptor for IgG (FcγRIIIa), which mediates Ab dependent cellular cytotoxicity (ADCC) and enhances production of interferon-γ (IFN-γ) in response to Ab-coated targets. Interleukin-12 (IL-12) is a cytokine produced by antigen-presenting cells that stimulates IFN-γ production from NK cells. We hypothesized that IL-12 would enhance the anti-tumor activity of cetuximab by activating the FcR effector mechanisms of NK cells. Expression of HER1 was measured on human papilloma virus (HPV)-positive (UD-SCC2, UM-SCC47) and HPV-negative (Cal27, UM-SCC74B) SCCHN cell lines by immunoblot analysis and flow cytometry. NK cells from normal donors were treated overnight with IL-2 (100 U), IL-12, IL-15, or IL-21 (all 10 ng/mL) and tested for ADCC versus cetuximab-coated cancer cells in a 4 hr (51)Cr assay. Release of cytokines by NK cells in response to cetuximab-coated cells was measured by ELISA. Phosphorylation of the ERK transcription factor in NK cells was measured by flow cytometry. The efficacy of combination therapy with cetuximab plus IL-12 was evaluated in a murine tumor model of head and neck cancer. All cell lines showed >99% expression of HER1 by flow cytometry and immunoblot analysis except UM-SCC74B (73%). Normal NK cells mediated 49.4% lysis of cetuximab-coated SCCHN cell lines as compared to 7.6% lysis of cells treated with control IgG (P = .0002). NK cell lysis of cetuximab-coated SCCHN cells was markedly enhanced by 12 hr pre-treatment of NK cells with IL-12 (71.6% lysis, P = .005 vs cetuximab alone). As a control, IL-12-activated NK cells were tested against IgG-treated cells. ADCC under these conditions was just 21.7%. Similar levels of lysis were noted for both HPV-positive and HPV-negative and cell lines. Other NK cell activating factors such as IL-2, IL-15, and IL-21 were also able to enhance NK cell ADCC. The stimulus of IL-12 and cetuximab-coated tumor cells induced the synergistic production of nanogram levels of IFN-γ (>6-fold increase over controls) (P < .001). A similar effect was seen for NK cell production of the chemokines RANTES, MIP-1α, and IL-8. Phosphorylation of ERK (which is critical for FcR-mediated ADCC and cytokine production) was enhanced in NK cells exposed to IL-12 and IgG as compared to control conditions. The combination of cetuximab plus IL-12 resulted in a reduction in tumor burden when compared to either agent alone in a murine xenograft model of SCCHN. Cytokine stimulation of NK cells in the presence of cetuximab-coated head and neck cancer cells leads to enhanced NK cell mediated ADCC and cytokine secretion independent of tumor cell HPV-status. Cytokine administration could be a useful adjuvant in the cetuximab treatment of HER1-positive head and neck cancer.
    Surgery 07/2012; 152(3):431-40. · 3.37 Impact Factor


Available from