title: Discordant neural tissue xenografts survive longer in immunoglobulin deficient mice.
abstract: BACKGROUND
  The immune response against discordant xenografts in the brain is incompletely understood and remains a major obstacle for future clinical applications of xenogeneic neural tissue transplants in neurodegenerative disorders. To determine the role of antibodies in the rejection process, we compared graft survival and immune reactions between immunoglobulin deficient (IgKO) and normal mice.
  
  
  METHODS
  A cell suspension of embryonic porcine ventral mesencephalon was injected into the striatum of adult normal and IgKO mice. Graft sizes and number of infiltrating CD4- and CD8-positive lymphocytes were determined by stereological methods at 4 days and 2, 4, and 6 weeks after the transplants. Microglial accumulation was determined using the optical densitometrical method. Intraparenchymal deposition of IgG was investigated at 4 days and 2 weeks.
  
  
  RESULTS
  The majority of IgKO mice had surviving grafts for up to 4 weeks, whereas survival was minimal in control mice beyond 4 days. Graft sizes differed significantly between IgKO and control mice at 2 weeks (P<0.01, Kruskal Wallis ANOVA, followed by Mann Whitney test). The majority of infiltrating lymphocytes were CD4-positive in control mice but CD8-positive in IgKO mice. Microglial accumulation was strong around surviving grafts in IgKO mice at 4 weeks. Prominent staining of IgG, diffuse in the transplanted hemisphere and specific on grafted neurons, was found in control mice.
  
  
  CONCLUSIONS
  Our results suggest that immunoglobulins play an initiating role in rejection of discordant neural xenografts. After a prolonged graft survival of approximately 4 weeks, a cellular response with a large proportion CD8-positive cells leads to rejection in IgKO mice.
authors.affiliation: Section for Neuronal Survival, Wallenberg Neuroscience Center, Lund University, Sweden. lena.larsson@mphy.lu.SE
authors.forename: L C
authors.initials: LC
authors.lastname: Larsson
authors.forename: K A
authors.initials: KA
authors.lastname: Czech
authors.forename: H
authors.initials: H
authors.lastname: Widner
authors.forename: O
authors.initials: O
authors.lastname: Korsgren
mesh_terms: D000818:Animals; D017252:CD3 Complex / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000473:pathology / Q000502:physiology; D018414:CD8-Positive T-Lymphocytes / Q000473:pathology / Q000502:physiology; D002465:Cell Movement; D003342:Corpus Striatum / Q000473:pathology / Q000601:surgery; D016332:Fetal Tissue Transplantation / Q000276:immunology; D006085:Graft Survival; D007136:Immunoglobulins / Q000172:deficiency*; D007150:Immunohistochemistry; D008636:Mesencephalon / Q000196:embryology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D017628:Microglia / Q000473:pathology; D013552:Swine; D014183:Transplantation, Heterologous
chemical_list: D017252:CD3 Complex; D007136:Immunoglobulins