title: Induction of antitumor immunity via intratumoral tetra-costimulator protein transfer.
abstract: Our group recently described a novel two-step Fc(gamma1) fusion protein transfer method, which entails the docking of Fc(gamma1) fusion proteins onto cells precoated with chemically palmitated protein A (pal-prot A). In the present study, we have adapted this protein transfer method, originally used in an ex vivo context, for in situ tumor cell engineering, and in so doing, we have evaluated its utility for the induction of antitumor immunity via combinatorial costimulator protein transfer on to tumor cell surfaces. The feasibility of "painting" cells with preformed conjugates of a murine B7-1 costimulator derivative, B7-1.Fc(gamma1), and pal-prot A in a single step was first established ex vivo. Next, B7-1.Fc(gamma1):pal-prot A transfer was accomplished in vivo by directly injecting the preformed conjugates into highly aggressive L5178Y-R lymphomas grown intradermally in syngeneic mice. The presence of cell surface-associated B7-1 epitopes on cells of the injected tumors was documented by flow cytometric analysis of cells recovered subsequently from the injected tumors. B7-1.Fc(gamma1), along with Fc(gamma1) fusion protein derivatives of three additional costimulators (Fc(gamma1).4-1BBL, CD48.Fc(gamma1), and Fc(gamma1).CD40L) geared toward a variety of immune effectors, were together preconjugated with pal-prot A and injected directly into tumor beds. Significantly, this "tetra-costimulator" combination, delivered intratumorally, induced complete tumor regression in approximately 45% of treated mice, whereas control injections of pal-prot A alone had no therapeutic effect. Furthermore, there was evidence for systemic antitumor immunity in that tumor-specific CTLs were detected in spleens recovered from cured mice, and these mice were uniformly protected against tumor rechallenge at distant tumor sites. Hence, combinatorial costimulator transfer, coupled to intratumoral delivery, may have special advantages for the induction of antitumor immunity.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.
authors.forename: G
authors.initials: G
authors.lastname: Zheng
authors.forename: A
authors.initials: A
authors.lastname: Chen
authors.forename: R E
authors.initials: RE
authors.lastname: Sterner
authors.forename: P J
authors.initials: PJ
authors.lastname: Zhang
authors.forename: T
authors.initials: T
authors.lastname: Pan
authors.forename: N
authors.initials: N
authors.lastname: Kiyatkin
authors.forename: M L
authors.initials: ML
authors.lastname: Tykocinski
mesh_terms: D053330:4-1BB Ligand; D000818:Animals; D015703:Antigens, CD / Q000008:administration & dosage / Q000276:immunology*; D018122:B7-1 Antigen / Q000008:administration & dosage / Q000276:immunology*; D023201:CD40 Ligand / Q000008:administration & dosage / Q000276:immunology*; D000071178:CD48 Antigen; D005260:Female; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000008:administration & dosage / Q000276:immunology; D007074:Immunoglobulin G / Q000008:administration & dosage / Q000276:immunology; D007167:Immunotherapy; D015552:Injections, Intralesional; D051379:Mice; D008811:Mice, Inbred DBA; D009374:Neoplasms, Experimental / Q000276:immunology* / Q000628:therapy; D010168:Palmitates / Q000008:administration & dosage / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000276:immunology*; D013205:Staphylococcal Protein A / Q000008:administration & dosage / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D053330:4-1BB Ligand; D015703:Antigens, CD; D018122:B7-1 Antigen; D000071178:CD48 Antigen; C000604065:CD48 protein, human; C000604066:Cd48 protein, mouse; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D010168:Palmitates; D011993:Recombinant Fusion Proteins; D013205:Staphylococcal Protein A; C505974:TNFSF9 protein, human; C505975:Tnfsf9 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D023201:CD40 Ligand