Cancer Immunology, Immunotherapy

, Volume 60, Issue 12, pp 1789–1800

Ab-IL2 fusion proteins mediate NK cell immune synapse formation by polarizing CD25 to the target cell-effector cell interface

  • Jennifer A. A. Gubbels
  • Brian Gadbaw
  • Ilia N. Buhtoiarov
  • Sachi Horibata
  • Arvinder K. Kapur
  • Dhara Patel
  • Jacquelyn A. Hank
  • Stephen D. Gillies
  • Paul M. Sondel
  • Manish S. Patankar
  • Joseph Connor
Original article

DOI: 10.1007/s00262-011-1072-9

Cite this article as:
Gubbels, J.A.A., Gadbaw, B., Buhtoiarov, I.N. et al. Cancer Immunol Immunother (2011) 60: 1789. doi:10.1007/s00262-011-1072-9

Abstract

The huKS-IL2 immunocytokine (IC) consists of IL2 fused to a mAb against EpCAM, while the hu14.18-IL2 IC recognizes the GD2 disialoganglioside. They are under evaluation for treatment of EpCAM+ (ovarian) and GD2+ (neuroblastoma and melanoma) malignancies because of their proven ability to enhance tumor cell killing by antibody-dependent cell-mediated cytotoxicity (ADCC) and by antitumor cytotoxic T cells. Here, we demonstrate that huKS-IL2 and hu14.18-IL2 bind to tumor cells via their antibody components and increase adhesion and activating immune synapse (AIS) formation with NK cells by engaging the immune cells’ IL-2 receptors (IL2R). The NK leukemia cell line, NKL (which expresses high affinity IL2Rs), shows fivefold increase in binding to tumor targets when treated with IC compared to matching controls. This increase in binding is effectively inhibited by blocking antibodies against CD25, the α-chain of the IL2R. NK cells isolated from the peritoneal environment of ovarian cancer patients, known to be impaired in mediating ADCC, bind to huKS-IL2 via CD25. The increased binding between tumor and effector cells via ICs is due to the formation of AIS that are characterized by the simultaneous polarization of LFA-1, CD2 and F-actin at the cellular interface. AIS formation of peritoneal NK and NKL cells is inhibited by anti-CD25 blocking antibody and is 50–200% higher with IC versus the parent antibody. These findings demonstrate that the IL-2 component of the IC allows IL2Rs to function not only as receptors for this cytokine but also as facilitators of peritoneal NK cell binding to IC-coated tumor cells.

Keywords

ImmunocytokinesNatural killerCancerImmunotherapyImmune synapse

Supplementary material

262_2011_1072_MOESM1_ESM.ppt (302 kb)
Supplemental File 1. This figure shows the schematic relationships of GD2 distribution on M21 tumor cells, IL2R on NKL cells and the localization of FITC-conjugated hu14.18-IL2 to these M21 and NKL cells, when cultured alone, or when synapses are formed via the IC, based on the actual photomicrographs shown in Figs. 6 and 7 (PPT 301 kb)

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Jennifer A. A. Gubbels
    • 1
    • 5
  • Brian Gadbaw
    • 2
  • Ilia N. Buhtoiarov
    • 3
  • Sachi Horibata
    • 1
  • Arvinder K. Kapur
    • 1
  • Dhara Patel
    • 1
  • Jacquelyn A. Hank
    • 3
  • Stephen D. Gillies
    • 4
  • Paul M. Sondel
    • 2
    • 3
    • 6
  • Manish S. Patankar
    • 1
    • 7
  • Joseph Connor
    • 1
    • 8
  1. 1.Department of Obstetrics and GynecologyUniversity of Wisconsin-MadisonMadisonUSA
  2. 2.Department of PediatricsUniversity of Wisconsin-MadisonMadisonUSA
  3. 3.Department of Human OncologyUniversity of Wisconsin-MadisonMadisonUSA
  4. 4.Provenance Biopharmaceuticals Corp.WalthamUSA
  5. 5.Department of BiologyAugustana CollegeSioux FallsUSA
  6. 6.4159 Wisconsin Institutes for Medical ResearchMadisonUSA
  7. 7.H4/657 CSCMadisonUSA
  8. 8.Clinical Science Center-H4/650MadisonUSA