Table 1

Prion titers in spleens of LTβR-Ig–treated and control mice.

Mouse line Treatment Beginning of treatment*Weeks after inoculation Indicator mice succumbing to scrapie (unrelated causes) Days to terminal diseaseTiter
Prnp0/0 1 0/4 >150 <1.5
Prnp0/0 1 0/1 (3) >150 ND
C57BL/6 1 4/4 82, 91, 91, 113 3
C57BL/6 12/2 (2) 116, 128 1–1.5
C57BL/6 LTβR-Ig −11 0/4 >150 <1.5
C57BL/6 LTβR-Ig −11 1/4 101, >150; >150, >150 <1.5
C57BL/6LTβR-Ig −1 1 0/4 >150<1.5
Prnp0/0 3 0/4 >150 <1.5
Prnp0/0 3 0/4 >150 <1.5
C57BL/6 huIgG +1 3 0/4 >150 <1.5
C57BL/6 huIgG +1 3 3/4 80, 91, 128, >1501.5–2.5
C57BL/6 LTβR-Ig −1 3 0/4 >150<1.5
C57BL/6 LTβR-Ig −1 3 0/4 >150<1.5
C57BL/6LTβR-Ig −1 3 0/4 >150<1.5
C57BL/6 LTβR-Ig +1 3 3/4 87, 91, 136, >150 1.5–2
C57BL/6 LTβR-Ig +1 3 4/480, 82, 84, 84 4
C57BL/6 LTβR-Ig +1 3 1/4108, >150, >150, >150 <1.5
Prnp0/0 8 0/4 >150 <1.5
Prnp0/0 8 0/4 >150 <1.5
C57BL/6 huIgG +18 4/4 64, 68, 70, 70 5.5
C57BL/6 huIgG +18 3/3 (1) 74, 80, 77 4.5
C57BL/6 LTβR-Ig−1 8 0/4 >150 <1.5
C57BL/6 LTβR-Ig−1 8 0/4>150 <1.5
C57BL/6 LTβR-Ig−1 8 0/4 >150 <1.5
C57BL/6 LTβR-Ig+1 8 4/4 108, 110, 113, 144 1
C57BL/6LTβR-Ig +1 8 2/2 (2) 128, 144 1.5
C57BL/6LTβR-Ig +1 8 1/2 (2) 104, >150 ND
  • * Week relative to inoculation.

  • Spleen homogenates (10% in 0.32 M sucrose) were prepared from infected animals as described (45). Thirty microliters of heat- and sarcosyl-treated 1% homogenate (diluted 1:10 in PBS and 5% bovine serum albumin) were administered intracerebrally to groups of four tga20 mice (36) for each sample. Wherever all indicator animals of a group contracted scrapie, titers (log ID50 units/ml 10% homogenate) were calculated by the incubation time method (35) using the relation y= 11.45 − 0.088x, where y is the ID50 and x is the incubation time (in days) to terminal disease. When one or more animals survived >150 days, the titer was assumed to be close to the end point; titers are approximate. ND, not determined.