Publications by authors named "P Ahlquist"

178 Publications

Safety and efficacy of faecal microbiota transplantation for active peripheral psoriatic arthritis: an exploratory randomised placebo-controlled trial.

Ann Rheum Dis 2021 Apr 29. Epub 2021 Apr 29.

Rheumatology Research Unit, Department of Rheumatology, Odense University Hospital, Odense, Denmark

Objectives: Although causality remains to be established, targeting dysbiosis of the intestinal microbiota by faecal microbiota transplantation (FMT) has been proposed as a novel treatment for inflammatory diseases. In this exploratory, proof-of-concept study, we evaluated the safety and efficacy of FMT in psoriatic arthritis (PsA).

Methods: In this double-blind, parallel-group, placebo-controlled, superiority trial, we randomly allocated (1:1) adults with active peripheral PsA (≥3 swollen joints) despite ongoing treatment with methotrexate to one gastroscopic-guided FMT or sham transplantation into the duodenum. Safety was monitored throughout the trial. The primary efficacy endpoint was the proportion of participants experiencing treatment failure (ie, needing treatment intensification) through 26 weeks. Key secondary endpoints were change in Health Assessment Questionnaire Disability Index (HAQ-DI) and American College of Rheumatology (ACR20) response at week 26.

Results: Of 97 screened, 31 (32%) underwent randomisation (15 allocated to FMT) and 30 (97%) completed the 26-week clinical evaluation. No serious adverse events were observed. Treatment failure occurred more frequently in the FMT group than in the sham group (9 (60%) vs 3 (19%); risk ratio, 3.20; 95% CI 1.06 to 9.62; p=0.018). Improvement in HAQ-DI differed between groups (0.07 vs 0.30) by 0.23 points (95% CI 0.02 to 0.44; p=0.031) in favour of sham. There was no difference in the proportion of ACR20 responders between groups (7 of 15 (47%) vs 8 of 16 (50%)).

Conclusions: In this first preliminary, interventional randomised controlled trial of FMT in immune-mediated arthritis, we did not observe any serious adverse events. Overall, FMT appeared to be inferior to sham in treating active peripheral PsA.

Trial Registration Number: NCT03058900.
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http://dx.doi.org/10.1136/annrheumdis-2020-219511DOI Listing
April 2021

ZBTB2 represses HIV-1 transcription and is regulated by HIV-1 Vpr and cellular DNA damage responses.

PLoS Pathog 2021 Feb 26;17(2):e1009364. Epub 2021 Feb 26.

Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, Wisconsin, United States of America.

Previously, we reported that cellular transcription factor ZASC1 facilitates DNA-dependent/RNA-independent recruitment of HIV-1 TAT and the cellular elongation factor P-TEFb to the HIV-1 promoter and is a critical factor in regulating HIV-1 transcriptional elongation (PLoS Path e1003712). Here we report that cellular transcription factor ZBTB2 is a novel repressor of HIV-1 gene expression. ZBTB2 strongly co-immunoprecipitated with ZASC1 and was dramatically relocalized by ZASC1 from the cytoplasm to the nucleus. Mutations abolishing ZASC1/ZBTB2 interaction prevented ZBTB2 nuclear relocalization. We show that ZBTB2-induced repression depends on interaction of cellular histone deacetylases (HDACs) with the ZBTB2 POZ domain. Further, ZASC1 interaction specifically recruited ZBTB2 to the HIV-1 promoter, resulting in histone deacetylation and transcription repression. Depleting ZBTB2 by siRNA knockdown or CRISPR/CAS9 knockout in T cell lines enhanced transcription from HIV-1 vectors lacking Vpr, but not from these vectors expressing Vpr. Since HIV-1 Vpr activates the viral LTR by inducing the ATR kinase/DNA damage response pathway, we investigated ZBTB2 response to Vpr and DNA damaging agents. Expressing Vpr or stimulating the ATR pathway with DNA damaging agents impaired ZASC1's ability to localize ZBTB2 to the nucleus. Moreover, the effects of DNA damaging agents and Vpr on ZBTB2 localization could be blocked by ATR kinase inhibitors. Critically, Vpr and DNA damaging agents decreased ZBTB2 binding to the HIV-1 promoter and increased promoter histone acetylation. Thus, ZBTB2 is recruited to the HIV-1 promoter by ZASC1 and represses transcription, but ATR pathway activation leads to ZBTB2 removal from the promoter, cytoplasmic sequestration and activation of viral transcription. Together, our data show that ZASC1/ZBTB2 integrate the functions of TAT and Vpr to maximize HIV-1 gene expression.
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http://dx.doi.org/10.1371/journal.ppat.1009364DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7946322PMC
February 2021

Transmembrane redox regulation of genome replication functions in positive-strand RNA viruses.

Curr Opin Virol 2021 Apr 28;47:25-31. Epub 2020 Dec 28.

John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, WI 53715, United States; Institute for Molecular Virology, University of Wisconsin-Madison, Madison, WI 53706, United States; McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, WI 53706, United States; Howard Hughes Medical Institute, United States. Electronic address:

Positive-strand RNA virus genome replication takes place on intracellular membranes that separate the reduced cytosol from the oxidized extracellular/luminal milieu. Ongoing studies of these membrane-bounded genome replication complexes have revealed underlying common principles in their structure, assembly and functionalization, including transmembrane features and redox dependencies. Among these, members of the alphavirus, flavivirus, and picornavirus supergroups all encode membrane-permeabilizing viroporins required for efficient RNA replication. For flaviviruses and particularly alphavirus supergroup members, these viroporins are linked to activating viral RNA capping and potentially other later-stage RNA replication functions, and to local transmembrane release of oxidizing potential to trigger these changes in cytoplasmic RNA replication complexes. Further exploration of these emerging shared principles could spur development of broad-spectrum antivirals.
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http://dx.doi.org/10.1016/j.coviro.2020.12.003DOI Listing
April 2021

Coronavirus dons a new crown.

Science 2020 09;369(6509):1306-1307

John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, WI, USA.

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http://dx.doi.org/10.1126/science.abe0322DOI Listing
September 2020

Subdomain cryo-EM structure of nodaviral replication protein A crown complex provides mechanistic insights into RNA genome replication.

Proc Natl Acad Sci U S A 2020 08 20;117(31):18680-18691. Epub 2020 Jul 20.

John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, WI 53715;

For positive-strand RNA [(+)RNA] viruses, the major target for antiviral therapies is genomic RNA replication, which occurs at poorly understood membrane-bound viral RNA replication complexes. Recent cryoelectron microscopy (cryo-EM) of nodavirus RNA replication complexes revealed that the viral double-stranded RNA replication template is coiled inside a 30- to 90-nm invagination of the outer mitochondrial membrane, whose necked aperture to the cytoplasm is gated by a 12-fold symmetric, 35-nm diameter "crown" complex that contains multifunctional viral RNA replication protein A. Here we report optimizing cryo-EM tomography and image processing to improve crown resolution from 33 to 8.5 Å. This resolves the crown into 12 distinct vertical segments, each with 3 major subdomains: A membrane-connected basal lobe and an apical lobe that together comprise the ∼19-nm-diameter central turret, and a leg emerging from the basal lobe that connects to the membrane at ∼35-nm diameter. Despite widely varying replication vesicle diameters, the resulting two rings of membrane interaction sites constrain the vesicle neck to a highly uniform shape. Labeling protein A with a His-tag that binds 5-nm Ni-nanogold allowed cryo-EM tomography mapping of the C terminus of protein A to the apical lobe, which correlates well with the predicted structure of the C-proximal polymerase domain of protein A. These and other results indicate that the crown contains 12 copies of protein A arranged basally to apically in an N-to-C orientation. Moreover, the apical polymerase localization has significant mechanistic implications for template RNA recruitment and (-) and (+)RNA synthesis.
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http://dx.doi.org/10.1073/pnas.2006165117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7414174PMC
August 2020