Bovine enteric coronavirus structure as studied by a freeze-drying technique.

A strain of bovine coronavirus (F15) was studied by electron microscopy using a freeze-drying technique. Purified coronavirus preparations show three different categories of image: (i) 'blackberry-like' virions, (ii) virions with a smooth depression at their surface, and (iii) apparently broken particles showing very clearly the areas of spike insertion in the virus membrane. Virus projections resemble 'mushrooms' with the 'stalk' inserted at the virus membrane.

[Isolation of cell hybrids secreting specific antibodies against bovine enteric coronavirus (author's transl)].

Twelve hybrid cell lines secreting monoclonal immunoglobulins (IgG) specific of bovine enteric Coronavirus (BEC strain G110) have been obtained following fusion of non secreting variant of the myeloma P3X63Ag8, SP2O, which splenic lymphocytes of Mice immunized against this virus. Antibodies thus obtained have been studied by indirect immunofluorescence and seroneutralization with cells infected by two french strains G110 and F15 and an american strain of Coronavirus: NCDCV. Immunochemical studies have confirmed this specificity.

[A cell line particularly susceptible to bovine enteric Coronavirus replication: HRT 18 cells].

Bovine enteric Corona virus (BEC) multiplies spontaneously with very high efficiency in HRT 18 cells; this line established from human rectum adenocarcinoma presents some properties of the differentiated brush border cell of the intestinal villi. Titers obtained are very high (5 x 10(7) TCID 50/ml virus strain F15). The virus produced had the characteristic of BEC: shape, spikes, density 1.