Initiation of abnormal tau phosphorylation requires the initiation of early and/or late protein synthesis.

<p>Vero cells were infected for 16 hours with HSV1 strain 17 or with HSV1 recombinants, each at an MOI of 5, and tested for abnormal tau phosphorylation (pS214) by immunocytochemistry. Infection with <i>in</i>1374 did not lead to abnormal tau phosphorylation (A) whereas infection with <i>in</i>1863 did show phosphorylation (B). Infection with recombinant <i>ts</i>K/<i>lacZ</i> showed no abnormal tau phosphorylation at the restrictive temperature (C). Infection with recombinant <i>in</i>1404 did show staining (D). Mock-infected cells at 37°C (E) or at 38.5°C (F) showed no staining. Scale bar: 50 µm.</p

Acyclovir inhibits HSV1-induced β-amyloid accumulation.

<p>Vero cells were infected with HSV1 SC16 at an MOI of 1 for 16 hours. Cells were treated with 0 µM, 50 µM, 100 µM or 200 µM acyclovir (ACV), which was present throughout infection. After fixation the slides were tested for β-amyloid (Aβ) accumulation using immunocytochemistry. These results clearly show that ACV reduces Aβ significantly. Scale bar: 50 µm.</p

Details of primary antibodies used for immunocytochemistry in this study.

<p>For the nicastrin and BACE1 antibodies the blocking buffer used was TBS containing 10% goat serum and 1% bovine serum albumin. For the other antibodies 10% milk was used.</p

Acyclovir inhibits HSV1 replication.

<p>Vero cells were infected with HSV1 SC16 at an MOI of 1 for 16 hours. Cells were treated with 0 µM, 50 µM, 100 µM or 200 µM acyclovir (ACV), which was present throughout infection. After fixation the slides were tested for HSV1 proteins using immunocytochemistry. Reactivity with HSV1 proteins was significantly reduced in the presence of ACV. Scale bar: 50 µm.</p

Antiviral agents reduce the HSV1-induced increases in β-amyloid-related enzymes.

<p>Vero cells were infected with HSV1 SC16 at an MOI of 1 for 16 hours. Cells were treated with 0 µM, 50 µM, 100 µM or 200 µM acyclovir (ACV), penciclovir (PCV) or foscarnet (FOS) which was present throughout infection. After fixation the slides were tested for (A) β-site amyloid precursor protein cleaving enzyme 1 (BACE1) and (B) nicastrin. Images for no antiviral, 50 µM ACV, 50 µM PCV and 200 µM FOS are shown. Scale bar: 50 µm.</p

Antiviral agents reduce the HSV1-induced increases in tau-related enzymes.

<p>Vero cells were infected with HSV1 SC16 at an MOI of 1 for 16 hours. Cells were treated with 0 µM, 50 µM, 100 µM or 200 µM acyclovir (ACV), penciclovir (PCV) or foscarnet (FOS) which was present throughout infection. After fixation the slides were tested for (A) protein kinase A (PKA) and (B) glycogen synthase kinase 3β (GSK3β). Images for no antiviral, 50 µM ACV, 50 µM PCV and 100 µM FOS are shown. Scale bar: 50 µm.</p

Acyclovir inhibits HSV1-induced abnormal tau phosphorylation.

<p>Vero cells were infected with HSV1 SC16 at an MOI of 1 for 16 hours. Cells were treated with 0 µM, 50 µM, 100 µM or 200 µM acyclovir (ACV), which was present throughout infection. After fixation the slides were tested for abnormal tau phosphorylation (AT100) using immunocytochemistry. ACV significantly reduces AT100 staining. Scale bar: 50 µm.</p

Properties of HSV1 strain 17-derived viruses.

<p>Properties of HSV1 strain 17-derived viruses.</p

Quantification of the effect of antiviral agents on the HSV1-induced increases in amyloid- and tau-related enzymes.

<p>The immunocytochemistry results in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025152#pone-0025152-g008" target="_blank">Figures 8</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0025152#pone-0025152-g009" target="_blank">9</a> were quantified using Image J. (A) β-site amyloid precursor protein cleaving enzyme 1, (B) nicastrin, (C) protein kinase A and (D) glycogen synthase kinase 3β.</p

Comparison of different antiviral agents on proteins accumulating during HSV1 infection.

<p>Vero cells were infected with HSV1 SC16 at an MOI of 1 for 16 hours. Cells were treated with 0 µM, 50 µM, 100 µM or 200 µM penciclovir (PCV) or foscarnet (FOS) which was present throughout infection. After fixation the slides were tested for (A) β-amyloid (Aβ) accumulation, (B) abnormal tau phosphorylation (AT100), and (C) HSV1 proteins using immunocytochemistry and the amount of staining was quantified using Image J. Values are expressed as a percentage of staining produced when no antiviral is used. These values were used to determine the antiviral concentration required to reduce staining to 50%. The results are a combination of two independent experiments. Values for mock-infected cells were between 0 and 8% (data not shown).</p