Protein Interaction Mapping Identifies RBBP6 as a Negative Regulator of Ebola Virus Replication

Ebola virus (EBOV) infection often results in fatal illness in humans, yet little is known about how EBOV usurps host pathways during infection. To address this, we used affinity tag-purification mass spectrometry (AP-MS) to generate an EBOV-host protein-protein interaction (PPI) map. We uncovered 194 high-confidence EBOV-human PPIs, including one between the viral transcription regulator VP30 and the host ubiquitin ligase RBBP6. Domain mapping identified a 23 amino acid region within RBBP6 that binds to VP30. A crystal structure of the VP30-RBBP6 peptide complex revealed that RBBP6 mimics the viral nucleoprotein (NP) binding to the same interface of VP30. Knockdown of endogenous RBBP6 stimulated viral transcription and increased EBOV replication, whereas overexpression of either RBBP6 or the peptide strongly inhibited both. These results demonstrate the therapeutic potential of biologics that target this interface and identify additional PPIs that may be leveraged for novel therapeutic strategies.

Systematic review and meta-analysis of psychological interventions in people with diabetes and elevated diabetes-distress

AIMS

The clinical relevance of diabetes-distress is increasingly recognized, but little is known about the efficacy of interventions specifically targeted to treat elevated diabetes-distress. Therefore, this systematic review sought to determine the efficacy of psychological interventions aimed at treating elevated diabetes-distress in people with Type 1 or Type 2 diabetes.

METHODS

We systematically searched literature from five databases. Randomized controlled trials (RCTs) with an English abstract, describing the results of a psychological intervention in adults with diabetes were included. Articles were eligible for inclusion if the primary outcome was diabetes-distress measured by the Problem Areas in Diabetes Scale (PAID-5/PAID-20) or the Diabetes Distress Scale (DDS-17). Only mean group diabetes-distress values above cut-off at baseline or the results of a subgroup above cut-off (PAID-5 ≥ 8, PAID-20 ≥ 40 or DDS-17 ≥ 3) were included.

RESULTS

The search yielded 8907 articles. After removing 2800 duplicates, 6107 articles remained. Titles and abstracts were screened, leaving 394 potential articles of interest, nine of which were RCTs. In a random-effects meta-analysis, the pooled effect size for diabetes-distress was 0.48 (Cohen's d), Z = 3.91, P < 0.0001. Statistical heterogeneity was I² = 46.67% (confidence intervals 45.06% to 48.28%). Diabetes-tailored psychological interventions reduced HbA1c (Cohen's d = 0.57), whereas mindfulness-based interventions did not (Cohen's d = 0.11).

CONCLUSIONS

This systematic review shows that specifically diabetes-tailored psychological interventions are effective in reducing elevated diabetes-distress and HbA1c . More rigorous studies are warranted to establish the full potential of these interventions. PROSPERO database registration ID: CRD42017075290.

Depletion of gamma/delta T cells does not prevent or ameliorate, but rather aggravates, rat adjuvant arthritis

OBJECTIVE

To investigate the role of gamma/delta T cells in Mycobacterium tuberculosis-induced rat adjuvant arthritis.

METHODS

Rats with adjuvant arthritis were injected with anti-T cell receptor gamma/delta (anti-TCRgamma/delta) monoclonal antibody V65 according to a preventive protocol, a pre-arthritis peak protocol, and a late therapeutic protocol. Arthritis severity and joint destruction were monitored, and depletion of target cells was analyzed by flow cytometry.

RESULTS

Although all protocols led to successful depletion of TCRgamma/delta(bright) cells in peripheral blood and lymph nodes, none of the regimens influenced clinical parameters of adjuvant arthritis. If rats were treated before the clinical peak of adjuvant arthritis, however, joint destruction was significantly more severe than in vehicle-treated rats.

CONCLUSION

Rat adjuvant arthritis is not promoted or perpetuated by gamma/delta T cells. Aggravation of joint destruction with pre-arthritis peak anti-gamma/delta treatment suggests a stage-dependent protective role of gamma/delta T cells in adjuvant arthritis.

Treatment of rat arthritides with clodronate-containing liposomes

Large multilamellar liposomes containing dichloro-methylene-bisphosphonate (clodronate; Clo), a bisphosphonate that becomes toxic when intracellularly concentrated, were used to therapeutically target macrophages (M phi) in rats with established adjuvant arthritis (AA; i.v. on days 10,11,12) or antigen-induced arthritis (AIA; i.v. or i.a. on 3 h, days 1,2). In established AA, i.v. injection of Clo-liposomes led to significant, long-lasting amelioration of clinical parameters, and to reduced destruction of the ankle joint even several weeks after termination of treatment. In the acute phase of established AIA, intravenous treatment induced transient clinical amelioration, but did not counteract joint destruction. I.a. treatment in AIA was ineffective. Systemic treatment with anti-M phi principles induces amelioration of both AA and AIA; the improvement appears more profound in AA, i.e., the model with a more systemic character. Preliminary data indicate that depletion of M phi occurs in the liver rather than in spleen, draining lymph nodes or synovial membrane. In addition, local treatment with the same principle is ineffective in AIA. Therefore, systemic elimination of M phi in different sites may be crucial for effective therapy of arthritis with anti-M phi agents.