Immunologic Control of Tumors by In Vivo Fc γ Receptor-Targeted Antigen Loading in Conjunction with Double-Stranded RNA-Mediated Immune Modulation This information is current as of October 2, 2021. Adrian Bot, Dan Smith, Bill Phillips, Simona Bot, Constantin Bona and Habib Zaghouani J Immunol 2006; 176:1363-1374; ; doi: 10.4049/jimmunol.176.3.1363 http://www.jimmunol.org/content/176/3/1363 Downloaded from References This article cites 44 articles, 18 of which you can access for free at: http://www.jimmunol.org/content/176/3/1363.full#ref-list-1 http://www.jimmunol.org/ Why The JI? Submit online. • Rapid Reviews! 30 days* from submission to initial decision • No Triage! Every submission reviewed by practicing scientists • Fast Publication! 4 weeks from acceptance to publication by guest on October 2, 2021 *average Subscription Information about subscribing to The Journal of Immunology is online at: http://jimmunol.org/subscription Permissions Submit copyright permission requests at: http://www.aai.org/About/Publications/JI/copyright.html Email Alerts Receive free email-alerts when new articles cite this article. Sign up at: http://jimmunol.org/alerts The Journal of Immunology is published twice each month by The American Association of Immunologists, Inc., 1451 Rockville Pike, Suite 650, Rockville, MD 20852 Copyright © 2006 by The American Association of Immunologists All rights reserved. Print ISSN: 0022-1767 Online ISSN: 1550-6606. The Journal of Immunology Immunologic Control of Tumors by In Vivo Fc␥ Receptor-Targeted Antigen Loading in Conjunction with Double-Stranded RNA-Mediated Immune Modulation Adrian Bot,1* Dan Smith,*† Bill Phillips,*† Simona Bot,* Constantin Bona,‡ and Habib Zaghouani§ Despite the expression of non-self or neo-epitopes, many tumors such as lymphoid malignancies or cancers induced by oncogenic viruses are able to gradually overcome the immune defense mechanisms and spread. Using a preclinical model of hematological malignancy, we show that Ig-associated idiotypic determinants are recognized by the immune system in a fashion that results in immune deviation, allowing tumor progression and establishment of metastases. Using gene-targeted mice, we show that anti- ؉ ؉ idiotypic MHC class I-restricted immunity is promoted by ITAM motif (ITAM )Fc␥R, but kept in check by ITIM motif (ITIM ) Downloaded from Fc␥RIIB-mediated mechanisms. In addition to interfering with the functionality of ITIM؉ Fc␥R, effective anti-idiotypic and antitumoral immunity can be achieved by Fc␥R-targeted delivery of epitope in conjunction with administration of stimulatory motifs such as dsRNA, correcting the ineffective response to idiotypic epitopes. The immune process initiated by Fc␥R-mediated targeting of epitope together with dsRNA, resulted in control of tumor growth, establishment of immune memory and protection ,against tumors bearing antigenic variants. In summary, targeted delivery of MHC class I-restricted epitopes via ITAM؉ Fc␥R in conjunction with use of TLR-binding immune stimulatory motifs such as dsRNA, overcomes suboptimal responses to idiotypic http://www.jimmunol.org/ determinants and may constitute a novel approach for the treatment of a broad range of malignancies. Finally, the results shed light on the mechanisms regulating the idiotypic network and managing the diversity associated with immune receptors. The Journal of Immunology, 2006, 176: 1363–1374. large variety of cancers acquire mechanisms to circum- Previous reports show that malignancies caused by oncoviruses vent or avoid the immune effectors potentially capable are associated with continuous expression of non-self TAA (10– A of removing malignant cells, ranging from immune ig- 12), ruling out Ag loss as universal mechanism of immune escape. norance to deviation or active interference with immunity (1–3). Furthermore, despite the quasi-intact T cell repertoire, previous 2 by guest on October 2, 2021 Although many tumor-associated Ags (TAA) are of self-nature studies have suggested that in the case of TAA that are of non-self and thus relatively poor immunogens, a significant category of origin, a specific T cell response is present but inadequate, for cancers comprises tumor cells that, at various stages, express non- example dominated by T2 cells (13, 14), and unable to clear tu- (or neo-) self epitopes of viral origin (oncoviruses, EBV, human moral cells. Thus, immune deviation rather than Ag-loss or toler- papillomavirus, human T cell leukemia virus type-1), idiotypic ance, may be a causative factor for the lack of control of tumors markers (B or T cell lymphomas, myeloma, and certain leukemias) expressing non-self or Ags. or cryptic epitopes (products of alternate mRNA splicing). Most A particular case is represented by lymphoid malignancies that malignant B and T cell myelomas and lymphomas are monoclonal express neo-self Ags in the form of Id borne by TCR or Ig recep- and thus express Id on the Ig receptors or TCRs, stochastically tors. It is not clear to what extent such determinants are recognized generated during somatic rearrangement of the V, D, and J or what the nature of immune response is during the progression of genomic segments (4), with subsequent point mutations within ϩ complementarity-determining regions (CDRs) or addition of nu- Id lymphoid malignancies. For example, despite the neo-self na- cleotides. Id may represent B epitopes, Th or Tc epitopes, or both, ture of such determinants, the immune response against Id ex- and in certain conditions, are able to induce anti-idiotypic re- pressed by malignant cells may occur (15–17) but in a suboptimal sponses (5–9). fashion, in particular in later stage disease, resulting in a failure of the endogenous defense mechanisms to control the tumoral pro- cess. In support of this possibility, clinical studies conducted over *Alliance Pharmaceuticals and †MultiCell Immunotherapeutics, San Diego, CA the last decade using Id in combination with KLH or GM-CSF, or 92121; ‡Mount Sinai School of Medicine, New York, NY 11029; and §University of infusion of Id-pulsed immature dendritic cells (DC), showed that Missouri, Columbia, MO 65212 although numerous patients mounted anti-Id immunity (i.e., Ab, Received for publication June 1, 2005. Accepted for publication November 8, 2005. Th, and/or CTL), the magnitude was generally reduced, the im- The costs of publication of this article were defrayed in part by the payment of page mune profile dominated by T2 cells and the clinical impact rela- charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. tively modest (17, 18), somewhat moderating the optimism gen- 1 Address correspondence and reprint requests to Dr. Adrian Bot at the current ad- erated by earlier data (19). In general, despite the acknowledged dress: Mannkind Corporation, 28903 North Avenue Paine, Valencia, CA 91355. capability of CTL immune responses to remove cells that express E-mail address: [email protected] new Ags and the documented circumstantial evidence on genera- 2 Abbreviations used in this paper: TAA, tumor-associated Ag; CDR, complementa- rity-determining region; DC, dendritic cell; NP, nucleoprotein; HA, hemagglutinin; tion of anti-Id cytotoxic immunity in mice (20, 21) and humans IC, immune complex. (22), it is not known whether neo-self MHC class I-restricted Id Copyright © 2006 by The American Association of Immunologists, Inc. 0022-1767/06/$02.00 1364 IMMUNOTHERAPY WITH RECOMBINANT Ig AND dsRNA generated stochastically can play a significant role in the immune- retained binding to Fc␥R, which is critical in effective targeting of APC mediated containment of malignant or nonmalignant lymphoid (23, 25). The recombinant Ig peptides were obtained by cell culture and proliferations. purified using affinity chromatography (23, 25, 28, 29). The strain of influenza virus used in this study was A/WSN/32 H1N1, From a different point of view, Igs have been used as carriers for with mouse as permissive host. The virus was grown on Madine Darby B and T cell epitopes, for the purpose of induction of prophylactic Bovine Kidney carcinoma cells and purified, and titers were measured by and therapeutic responses in preclinical models (23, 24). That conventional techniques (35). Synthetic dsRNA (pA:pU), previously char- method has been largely promoted by the fact that peptides have a acterized as a T1 adjuvant (36), was obtained from Sigma-Aldrich. SP2/0 myelomatous cells, of MHC class Iϩ of H-2d background, widely rather poor immune activity, due to their suboptimal pharmacoki- used as partners for cell fusions in generating B cell hybridomas were netic profile. The alternative, ex vivo peptide loading of APC, previously described (37). Tumorigenic cells expressing secreted or re- implies individualized therapies and thus, it is more difficult to tained Ags were obtained by transfection, selection, and subcloning of implement therapeutically on a large scale. It has been shown that SP2/0 cells with plasmids carrying H chain and L chain of IgNP, IgHA, the recombinant Ig, carrying an MHC class II-restricted epitope de- IgG2b backbone, or whole-length influenza virus NP (encompassing a nu- clear targeting motif) (38). Cells were characterized as previously de- rived from influenza virus within CDR3 of the H chain, effectively scribed and the production of Ag confirmed by standard immunochemistry targets DC via Fc␥R, resulting in enhanced presentation to Th cells techniques. The mouse breast carcinoma cell line