Mouse hepatitis virus and its pathogenic action

Abstract

PLATE XCIV) IN 1951 Gledhill and Andrewes described a flterable agent which produced fatal hepatitis in mice. It was believed to have originated in P strain mice*, since it produced hepatitis in VSBS(VS) strain mice t when suspensions of viscera of P mice were passed blindly several times in VS mice. Later, Gledhill et al. (1952) showed that this agent consisted of two flbrable components ; a relatively labile one which was identified as Eperythrozoiin coccoides (Schilling, 1928, quoted by McCluskie andNiven, 1934) and a stable one which is now termed mouse hepatitis virus (MHV). It was shown that E . coccoides was carried by the P mice but not by VS mice and it was possible to separate E . coccoides from MHV by passage in VS mice with liver-spleen suspensions diluted to MHV was separated from contamination with E. coccoides by treating mice infected with the dual agent (MHV and E. coccoides mixture) with terramycin (oxytetracycline), to which E . coccoides is susceptible, or by filtration. It wm thus possible to maintain pure lines of both agents. The absence of E. coccoides in passes of MHV was confirmed by examination of blood 61ms and the absence of MHV in E. coccoides passages by histological studies. I n order to explain the original isolation it was considered probable that VS mice carry MHV which was liberated by passage in them of E. coccoides derived from P mice (Gledhill et al.). I n this paper the disease which MHV causes in normal and in E . codes-treated mice and the properties of the virus are discussed. M E T a O D SThe general methods conform to those already dmribed (Gledhill and Andrewes ; Gledhill et d.), except that undiluted liver-spleen suspensions are now atated to be 10-I dilutions. Batches of about 500 ml. of MHV were prepared by making 10 per cent. liver-spleen suspensions from VS mice infected with MHV 5-7 days previously. These suspensions were lightly centrifuged and aliquota were stored a t -7OoC. All references to E. wccoides-infected mice mean that they have been inoculated 2 or 3 days previously with a liver-spleen suspension containing E. wccoides in a dilution of 10-8.

The Appearance of a Hepatotrophic Virus in Mice Thymectomized at Birth

“…Although in weanlings not infected with E. coccoides small liver lesions were seen only irregularly, in all instances typical lesions were found on histological examination. In tissues from thymectomized wasting mice which showed liver lesions Dr. Niven stated that the histological appearances were compatible with the presence of a mouse hepatitis virus, probably MHV-1, as described by Gledhill, Dick, and Niven (10). It should be noted in this context that we have not detected E. coccoides in blood smears taken from thymectomized wasting C3H/Bi, C57BL, hybrid C57BL X C3H/Bi, or TO mice.…”

Viral Hepatitis in Encephalomyocarditis Virus-Infected Mice

“…In viral hepatitis in mice, necrosis of parenchymal cells has not been ob served histologically until 48-72 h after viral inoculation [21,25,35]. The studies reported here with the aid of the electron microscope have shown early changes that occur within 24 h following EMC virus inoculation.…”

The Propagation and Preservation of Eperythrozoon coccoides

“…E. coccoides was present in 10-6 dilutions of the yolk sac from two of the lqter passages. Gledhill, Dick & Andrewes (1952) and Gledhill, Dick & Niven, 1955), using a similar diluent, found that E. coccoides could be passaged in dilutions of a suspension of mouse liver and spleen. The successful cultivation of Eperythrozom coccoides in embryonated eggs suggests that these are at present the most suitable media for the cultivation of other species of Eperythrozoon and perhaps of Haemobartonella.…”