. 2014 Feb;88(4):2056–2070. doi: 10.1128/JVI.03051-13

TABLE 3.

Attenuation of virus spread in the CNS

Virus^a	Time (days p.i.)	Mouse	No. of infected cells (mean)/brain section^b
Virus^a	Time (days p.i.)	Mouse	Section area 1	Section area 2	Section area 3	Mean
MVEV.wt	1	B1-1	35	183	13	77
		B2-1	28	171	12	68
	2	B1-2	106	120	14	80
		B2-2	126	342	375	278
	4	B1-4	>1,000^c,d	>1,000^c,d	>1,000^c,d	>1,000^c,d
		B2-4	>1,000^c,d	>1,000^c,d	>1,000^c,d	>1,000^c,d
		B3-4	>1,000^c,d	>1,000^c,d	>1,000^c,d	>1,000^c,d
	7	B1-7	Died^d
		B2-7	Died^d
		B3-7	Died^d
MVEV.C-IRES	1	C1-1	0	0	0	0
		C2-1	0	0	0	0
	2	C1-2	2	0	0	1
		C2-2	0	0	0	0
	4	C1-4	37	118	22	59
		C2-4	1	0	1	1
	7	C1-7	2	2	5	3
		C2-7	9	3	4	5
	16	C1-16	0	0	1	0
		C2-16	0	0	0	0
MVEV.IFN-β	1	D1-1	1	0	0	0
		D2-1	0	0	0	0
		D3-1	2	0	0	1
	2	D1-2	0	1	0	0
		D2-2	1	0	0	0
		D3-2	0	0	0	0
	4	D1-4	2	1	1	1
		D2-4	1	0	2	1
		D3-4	1	0	0	0
	7	D1-7	0	0	0	0
		D2-7	0	0	0	0
		D3-7	1	0	0	0
	16	D1-16	0	2	0	1
		D2-16	0	0	0	0
		D3-16	0	0	0	0

Groups of 3-week-old BALB.A2G-Mx1 mice were i.c. inoculated with 10⁴ PFU of MVEV.wt, MVEV.C-IRES, or MVEV.IFN-β, and groups of 2 or 3 mice were euthanized at the indicated time points for tissue collection.

Sagittal brain sections (excluding cerebellum) were prepared and immune stained for the viral NS1 protein. For each section area (i.e., 1, 2, and 3), the number of cells with detectable antigen levels was determined by evaluating 2 neighboring sections of 4-μm nominal thickness. Section areas are separated by at least 250 μm. Sections from mock-treated control animals (inoculated with virus diluent only) were also examined, but as expected, no virus-infected cells could be identified (data not included).

There were too many infected cells to count.

All animals infected with MVEV.wt showed signs of disease at day 4 p.i. and either were killed or died the following night.