title: Immune properties of recombinant vaccinia virus encoding CD154 (CD40L) are determined by expression of virally encoded CD40L and the presence of CD40L protein in viral particles.
abstract: Expression of costimulatory molecules by recombinant poxviruses is a promising strategy for enhancing therapeutic vaccines. CD40-CD40L interactions are critical for conditioning dendritic cells (DC) and priming T- and B-cell immunity. We constructed a vaccinia virus expressing murine CD40L (rV-CD40L) and studied its immunomodulatory properties in vitro. Direct DC infection with control vaccinia or psoralen/UV-inactivated rV-CD40L stimulated high levels of interleukin 12 (IL-12) release. However, replication-competent rV-CD40L did not stimulate IL-12 under similar conditions. We observed a high level of CD40L protein on purified viral particles and demonstrated that induction of IL-12 by nonreplicating rV-CD40L was blocked by anti-CD40 antibodies suggesting that functional CD40L on viral particles contributed to alterations in IL-12 synthesis. Since cross-presentation of tumor-associated antigens by DC is augmented by viral infection of tumor cells, we infected MC38 murine colon carcinoma cells with rV-CD40L. Infected cells stimulated IL-12 secretion by DC and proliferation of B cells and DX5(+) (NK/NKT) cells through direct CD40-CD40L interaction. A subpopulation of NKT cells expressing CD40 (NK1.1(+), CD3(lo)) appeared to be a major effector population responding to MC38/rV-CD40L. These results highlight the complex immune regulatory effects of rV-CD40L defined by the cumulative effects of CD40L expression, presence of CD40L protein in viral particles, and the replication potential of the virus.
authors.affiliation: Department of Surgery and Pathology, Columbia University, New York, New York, USA.
authors.forename: Michal
authors.initials: M
authors.lastname: Bereta
authors.forename: Joanna
authors.initials: J
authors.lastname: Bereta
authors.forename: Jonas
authors.initials: J
authors.lastname: Park
authors.forename: Freddy
authors.initials: F
authors.lastname: Medina
authors.forename: Heesun
authors.initials: H
authors.lastname: Kwak
authors.forename: Howard L
authors.initials: HL
authors.lastname: Kaufman
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D023201:CD40 Ligand / Q000276:immunology / Q000378:metabolism*; D049109:Cell Proliferation; D003713:Dendritic Cells / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D015967:Gene Expression Regulation, Viral; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000276:immunology; D007111:Immunity, Cellular / Q000276:immunology*; D018664:Interleukin-12 / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D014407:Tumor Cells, Cultured; D014614:Vaccines, Synthetic / Q000276:immunology; D014616:Vaccinia virus / Q000276:immunology*
chemical_list: D000906:Antibodies; D014614:Vaccines, Synthetic; D023201:CD40 Ligand; D018664:Interleukin-12