Table 1.
Study design.
Fig 1.
Kaplan-Meier curves of cynomogus macaques (n = 30) infected with MARV-Musoke and then treated once daily for 14 d with bolus IV infection of 15 mg/kg AVI-7288 at 1 (n = 6), 24 (n = 6), 48 (n = 6), or 96 h (n = 6) after virus challenge. Saline-treated animals were used as controls (n = 6). Statistically significant differences (*p<0.0001) between survival curves (Mantel-Cox Log-rank test) of AVI-7288 treatments are indicated.
Fig 2.
Viral titers and genome equivalents in serum.
Mean serum (A) infectious virus and (B) viral RNA concentration in each treatment group. Infectious virus was determined by plaque assay with a lower limit of quantitation of 1,000 PFU/mL, and viral RNA was determined by quantitative RT-PCR with a lower limit of quantitation of 1.33 x 105 genome equivalents/mL. Serum viral RNA on day 8 with the peak serum infectious virus for each animal and the mean and standard deviation indicated by horizontal line and error bar. ANOVA P < 0.01 and Tukey’s multiple comparisons significant differences are indicated by (**) for P = 0.001. (C) Area under the serum viremia versus time curve on the ordinate versus time to treatment initiation on the abscissa. The blue open circles represent viral RNA/mL and the filled green circles represent PFU. The slope of the genome equivalents/mL is 0.0154 ± 0.00104 and r2 of 0.991, P = 0.045. The slope of the PFU/mL is 0.0172 ± 0.006, r2 of 0.782, P = 0.116. Values <LLOQ were converted to LLOQ for display and analysis.
Fig 3.
Analysis of the (A) aspartate aminotransferase (AST) and (B) blood urea nitrogen (BUN) for animals on day 10 post challenge. Treatment with AVI-7288 prevented elevation of BUN (P < 0.0001), but treatment did not significantly prevent elevation in ALT (P ≤ 0.206). Open symbols represent animals that succumbed and closed symbols are for survivors. Means are indicated as a horizontal line. Statistically significant differences (*P < 0.05; **P < 0.01; ***P < 0.005) between means of AVI-7288 treatments and control group are indicated.
Fig 4.
Neutrophil and coagulation results.
Analysis of (A) neutrophils on day 8 PI, (B) thrombin time, and (C) prothrombin time. Open symbols represent animals that succumbed and closed symbols are for survivors. Statistically significant differences (*P < 0.05) between means of AVI-7288 treatment groups and saline control group are indicated. Means are indicated as a horizontal line.
Fig 5.
MARV-specific anti-GP (A) IgM and (B) IgG antibody titers for each animal at day 10 and day 14 post challenge.
Fig 6.
(A) Eotaxin concentrations on day 8 post infection for each animal. ANOVA indicates significant differences, P = 0.012 and Dunnett’s multiple comparisons test indicates individual treatment groups are each significantly different from saline controls, P < 0.05 indicated with single asterisk. (B) MIP-1β on day 8 post-infection for each animal. ANOVA indicates individual treatment groups are significantly different from saline controls, P = 0.0057 and Dunnett’s multiple comparisons test indicates individual treatment groups are each significantly different from saline controls, P < 0.01 indicated with an asterisk.
Fig 7.
Photomicrographs of liver from two macaques that were challenged with MARV.
(A) Liver from a control animal that died on day 11 PI has an area of hepatocellular degeneration and necrosis (upper right corner). (B) IHC of a replicate section of area shown in A demonstrating abundant brown-staining MARV antigen in the lesion. (C) Normal liver from an animal that was treated with AVI-7288 beginning 96 h PI and which survived the viral challenge. (D) IHC of a replicate section of area shown in C demonstrating that no MARV antigen is present. 40X objective magnification for all photos. Hematoxylin & eosin stain for A and C. Immunoperoxidase with hematoxylin counter-stain for B and D.
Fig 8.
Photomicrographs of spleen from two macaques that were challenged with MARV.
(A) Spleen from a control animal that died on day 9 PI has an oval lymphoid nodule (center of photo) with markedly reduced numbers of lymphocytes (i.e. lymphoid depletion); there are pale pink deposits of fibrin in the surrounding red pulp. (B) IHC of a replicate section of area shown in A demonstrating brown-staining MARV antigen in the lymphoid nodule and especially in the red pulp. (C) Lymphocyte proliferation (i.e. lymphoid hyperplasia) is present in a splenic lymphoid nodule from an animal that was treated with AVI-7288 beginning 48 h PI and which survived the viral challenge. (D) IHC of a replicate section of area shown in C demonstrating that no MARV antigen is present. 10X objective magnification for all photos. Hematoxylin & eosin stain for A and C. Immunoperoxidase with hematoxylin counter-stain for B and D.