title: Leukocyte-hepatocyte interaction in calicivirus infection: differences between rabbits that are resistant or susceptible to rabbit haemorrhagic disease (RHD).
abstract: Calicivirus infection is lethal for adult rabbits, whereas young rabbits (less than 8-weeks-old) are resistant to the same infectious agent. The virus replicates in the liver and causes a fulminant hepatitis in adult rabbits leading to rabbit haemorrhagic disease (RHD); this is in contrast with the mild and transient hepatitis observed in infected young rabbits. We have used electron microscopy to compare liver leukocyte infiltrates between young (resistant) and adult (susceptible) rabbits, 36-48 h after inoculation of the animals with caliciviruses. In adult rabbits, liver infiltrates were made up mostly of heterophils, and they were located near hepatocytes showing severe cellular damage. In contrast, liver leukocyte infiltrates of RHD-resistant young rabbits were dominated by lymphocytes that depicted membrane contacts with the cell surface of undamaged hepatocytes. We conclude that: (i) the cellular inflammatory response of the liver to calicivirus infection is different in rabbits that are susceptible (adult) or resistant (young) to RHD; (ii) leukocyte infiltration of the adult liver by heterophils is probably directed at the removal of dead hepatocytes, whereas the liver lymphocytic infiltration of young rabbits suggests the expression of viral antigens on the surface of liver cells of the RHD-resistant animals.
authors.affiliation: Department of Anatomy, Abel Salazar Institute for Biomedical Science (ICBAS), Unit for Multidisciplinary for Biomedical Research (UMIB), Largo Prof. Abel Salazar, 2, 4099-003 Porto, Portugal. pferreir@icbas.up.pt
authors.forename: P G
authors.initials: PG
authors.lastname: Ferreira
authors.forename: A
authors.initials: A
authors.lastname: Costa-E-Silva
authors.forename: M J R
authors.initials: MJ
authors.lastname: Oliveira
authors.forename: E
authors.initials: E
authors.lastname: Monteiro
authors.forename: A P
authors.initials: AP
authors.lastname: Aguas
mesh_terms: D000367:Age Factors; D000818:Animals; D002139:Caliciviridae / Q000276:immunology*; D017250:Caliciviridae Infections / Q000276:immunology / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D002450:Cell Communication / Q000276:immunology*; D022781:Hepatocytes / Q000166:cytology* / Q000276:immunology / Q000821:virology; D007962:Leukocytes / Q000166:cytology* / Q000276:immunology / Q000821:virology; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D011817:Rabbits / Q000276:immunology / Q000821:virology*