Morphological analysis of mouse hepatitis virus A59-induced pathology with regard to viral receptor expression

• Godfraind, C. ^[1] ; Coutelier, J. P. ^[2]
  1. [1] Laboratory of Pathology, St-Luc Hospital
  2. [2] Unit of Experimental Medicine, International Institute for Cellular and Molecular Pathology, Catholic University of Louvain, Louvain, Bruxelles, Belgium
• Localización: Histology and histopathology: cellular and molecular biology, ISSN-e 1699-5848, ISSN 0213-3911, Vol. 13, Nº. 1, 1998, págs. 181-199
• Idioma: inglés
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• Resumen

  • Mo use hepatitis virus, stra in A59 (MHVA59), is a coronav irus that triggers in susceptible mice a wide va riety of pathologies, including hepatitis, thymus in vo luti o n, B lymph ocy te po lyc lona l ac ti va tio n a nd , after intra-cerebral inocul ation, transient demye lination.

    One recepto r that med iates entry of the virus into ta rget ce lls has bee n ide nti fied: it is a g lycopro te in of the ca rc inoembryo nic a ntige n fa mil y, ca ll ed Bgpl a . Th e ava il abi lit y of a ntibo di es recogni z ing th is mo lecul e permits the analysis of its ce llular expression and of the re lationship between receptor expression and pathology induced by the virus. Bgpl a is fo und on epitheli al and e ndo th e li a l ce lls as we ll as o n B lymph ocy tes a nd macrophages. In the live r, Bgpl a expression correlates we ll with infect ion of hepatocytes and endothelia l cells, leading to the deve lopment of hepatitis. However, other ce lls ex pressing this molecul e, such as centra l nervous system endo the lia l cells, are not in fec ted by the virus.

    T his o bserva ti o n may exp la in how th e bl ood-b ra in barri er prevents d issemi natio n of MHV-AS9 from the general circu lation into the brain. Thymi c atrophy results fro m a pop tosis of imm a tur e do ubl e-positi ve T lymphocy tes w hi c h mi g ht be ca use d in d irectl y by in fec tion of a small propo rtio n of thymus epitheli al ce lls that express Bgp I a ra ther than by in fec tio n of T cells th at do no t express th e rece ptor. Fin all y, po lyc lo na l ac ti va ti o n of B lym phocy tes, lead in g to in c rease d secre tio n of anti bodies of the IgG2a isotype, involves a cascade of events, including cy tokine secre tion, that may result from the interaction of MHV-A59 with B cells and macrophages that express Bgpl a. Therefore, aft er v iral in fec ti o n , ce llul a r exp ressio n of Bg p la may have d iffe re nt res ults: ce ll lysis; a lt e ra ti o n of ce llul a r functions th at may lead to indirect dea th of other ce ll ty pes, or resistance to in fec tion