title: Consequences of cytotoxic T lymphocyte interaction with major histocompatibility complex class I-expressing neurons in vivo.
abstract: Neurons have evolved strategies to evade immune surveillance that include an inability to synthesize the heavy chain of the class I major histocompatibility complex (MHC), proteins that are necessary for cytotoxic T lymphocyte (CTL) recognition of target cells. Multiple viruses have taken advantage of the lack of CTL-mediated recognition and killing of neurons by establishing persistent neuronal infections and thereby escaping attack by antiviral CTL. We have expressed a class I MHC molecule (Db) in neurons of transgenic mice using the neuron-specific enolase (NSE) promoter to determine the pathogenic consequences of CTL recognition of virally infected, MHC-expressing central nervous system (CNS) neurons. The NSE-Db transgene was expressed in H-2b founder mice, and transgene-derived messenger RNA was detected by reverse transcriptase-polymerase chain reaction in transgenic brains from several lines. Purified primary neurons from transgenic but not from nontransgenic mice adhered to coverslips coated with a conformation-dependent monoclonal antibody directed against the Dv molecule and presented viral peptide to CTL in an MHC-restricted manner, indicating that the Db molecule was expressed on transgenic neurons in a functional form. Transgenic mice infected with the neurotropic lymphocytic choriomeningitis virus (LCMV) and given anti-LCMV, MHC-restricted CTL displayed a high morbidity and mortality when compared with controls receiving MHC-mismatched CTL or expressing alternative transgenes. After CTL transfer, transgenic brains showed an increased number of CD8+ cells compared with nontransgenic controls as well as an increased rate of clearance of infectious virus from the CNS. Additionally, an increase in blood-brain barrier permeability was detected during viral clearance in NSE-Db transgenic mice and lasted several months after clearance of virus from neurons. In contrast, LCMV-infected, nontransgenic littermates and mice expressing other gene products from the NSE promoter showed no CNS disease, no increased intraparenchymal CTL, and no blood-brain barrier damage after the adoptive transfer of antiviral CTL. Our study indicates that viral infections and CTL-CNS interactions may induce blood-brain barrier disruptions and neurologic disease by a "hit-and-run" mechanism, triggering a cascade of pathogenic events that proceeds in the absence of continual viral stimulation.
authors.affiliation: Scripps Research Institute, Department of Neuropharmacology, La Jolla, California 92037, USA.
authors.forename: G F
authors.initials: GF
authors.lastname: Rall
authors.forename: L
authors.initials: L
authors.lastname: Mucke
authors.forename: M B
authors.initials: MB
authors.lastname: Oldstone
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001812:Blood-Brain Barrier; D003602:Cytotoxicity, Immunologic; D005786:Gene Expression Regulation; D006183:H-2 Antigens / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D064532:Histocompatibility Antigen H-2D; D016219:Immunotherapy, Adoptive; D008216:Lymphocytic Choriomeningitis / Q000276:immunology*; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009474:Neurons / Q000276:immunology*; D010751:Phosphopyruvate Hydratase / Q000235:genetics; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D019076:Transgenes
chemical_list: D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D011993:Recombinant Fusion Proteins; D010751:Phosphopyruvate Hydratase