title: 4-1BB costimulation is required for protective anti-viral immunity after peptide vaccination.
abstract: Peptide vaccination induces T cell activation and cytotoxic T cell development. In an effort to understand what factors can improve immune responses to peptide vaccination, the role of 4-1BB (CD137) costimulation was examined, since 4-1BB has been shown to promote T cell responses in other systems. 4-1BBL-deficient (-/-) and wild-type (+/+) mice were immunized with a lipidated lymphocytic choriomeningitis virus (LCMV) peptide NP396-404. Analysis of peptide-specific responses early after immunization by CTL assay, intracellular IFN-gamma staining, and IFN-gamma enzyme-linked immunospot assay (ELISPOT) indicated that CD8 T cell responses were reduced 3- to 10-fold in the absence of 4-1BB costimulation. Moreover, when agonistic anti-4-1BB Ab was given, CD8 T cell responses in 4-1BBL-/- mice were augmented to levels similar to those in 4-1BBL+/+ mice. Two months after immunization, 4-1BBL+/+ mice still had epitope-specific cells and were protected against viral challenge, demonstrating that peptide vaccination can induce long-term protection. In fact, 70% of CD8 T cells were specific for the immunizing peptide after viral challenge, demonstrating that strong, epitope-specific CD8 T cell responses are generated after peptide vaccination. In contrast, peptide-immunized 4-1BBL-/- mice had fewer epitope-specific cells and were impaired in their ability to resolve the infection. These results show that immunization with a single LCMV peptide provides long term protection against LCMV infection and point to costimulatory molecules such as 4-1BB as important components for generating protective immunity after vaccination.
authors.affiliation: The Carlos and Marguerite Mason Transplantation Biology Research Center and Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: J T
authors.initials: JT
authors.lastname: Tan
authors.forename: J K
authors.initials: JK
authors.lastname: Whitmire
authors.forename: K
authors.initials: K
authors.lastname: Murali-Krishna
authors.forename: R
authors.initials: R
authors.lastname: Ahmed
authors.forename: J D
authors.initials: JD
authors.lastname: Altman
authors.forename: R S
authors.initials: RS
authors.lastname: Mittler
authors.forename: A
authors.initials: A
authors.lastname: Sette
authors.forename: T C
authors.initials: TC
authors.lastname: Pearson
authors.forename: C P
authors.initials: CP
authors.lastname: Larsen
mesh_terms: D000818:Animals; D015703:Antigens, CD; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000821:virology; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D007279:Injections, Subcutaneous; D008216:Lymphocytic Choriomeningitis / Q000235:genetics / Q000276:immunology* / Q000517:prevention & control*; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology; D010446:Peptide Fragments / Q000008:administration & dosage / Q000276:immunology*; D017475:Receptors, Nerve Growth Factor / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D018124:Receptors, Tumor Necrosis Factor / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9; D014764:Viral Proteins / Q000008:administration & dosage / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D010446:Peptide Fragments; D017475:Receptors, Nerve Growth Factor; D018124:Receptors, Tumor Necrosis Factor; C505715:Tnfrsf9 protein, mouse; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9; D014764:Viral Proteins; D014765:Viral Vaccines; D010047:Ovalbumin