title: Active antimetastatic immunotherapy in Lewis lung carcinoma with self EGFR extracellular domain protein in VSSP adjuvant.
abstract: The epidermal growth factor receptor (EGFR) plays a central role in regulating neoplastic processes. The EGFR overexpression in many human epithelial tumors has been correlated with disease progression and bad prognosis. Passive EGFR-directed immunotherapy, but not active specific approaches, has already been introduced in medical oncology practice. Then we wonder if mice immunization with the extracellular domain of murine EGFR (mEGFR-ECD) in adjuvants can circumvent tolerance to self EGFR, by inducing an immune response with consequent antitumor effect. The present study demonstrated that despite mEGFR expression in thymus, strong DTH response was induced by inoculation of mice with the mEGFR-ECD. This self-immunization, using both CFA and very small sized proteoliposomes from Neisseria meningitidis (VSSP), promoted highly specific IgG titers, predominantly IgG2a and IgG2b. Sera from mice immunized with mEGFR-ECD/VSSP not only recognized EGFR+ tumor cell lines by FACS, but also inhibited their in vitro growth, even in the absence of complement. Noteworthy, vaccination of mice with mEGFR-ECD/VSSP stimulated a potent antimetastatic effect in the EGFR+ Lewis lung carcinoma model, while reproduction-associated side effects were absent. Curiously, mice immunized with the human EGFR-ECD (Her1-ECD) in VSSP though induced highly specific IgG antibodies with strong in vitro cytotoxic effect over EGFR+ human cell lines, showed low cross-reactivity with the mEGFR-ECD. These results further encouraged the development of the Her1-ECD/VSSP vaccine project for patients with EGFR+ tumors.
authors.affiliation: Vaccine Department, Center of Molecular Immunology, Havana, Cuba. belinda@cim.sld.cu
authors.forename: Belinda Sánchez
authors.initials: BS
authors.lastname: Ramírez
authors.forename: Eduardo Suárez
authors.initials: ES
authors.lastname: Pestana
authors.forename: Greta Garrido
authors.initials: GG
authors.lastname: Hidalgo
authors.forename: Tays Hernández
authors.initials: TH
authors.lastname: García
authors.forename: Rolando Pérez
authors.initials: RP
authors.lastname: Rodríguez
authors.forename: Axel
authors.initials: A
authors.lastname: Ullrich
authors.forename: Luis Enrique
authors.initials: LE
authors.lastname: Férnandez
mesh_terms: D000276:Adjuvants, Immunologic / Q000627:therapeutic use*; D000818:Animals; D002460:Cell Line; D066246:ErbB Receptors / Q000235:genetics / Q000276:immunology*; D005822:Genetic Vectors; D006801:Humans; D007167:Immunotherapy; D008175:Lung Neoplasms / Q000276:immunology* / Q000517:prevention & control; D051379:Mice; D009362:Neoplasm Metastasis / Q000517:prevention & control*; D011993:Recombinant Fusion Proteins / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: D000276:Adjuvants, Immunologic; D011993:Recombinant Fusion Proteins; D066246:ErbB Receptors