Previous research has suggested that human herpesvirus-6 (HHV-6) may integrate into host cell chromosomes and be vertically transmitted in the germ line, but the evidence-primarily fluorescence in situ hybridization (FISH)-is indirect. We sought, first, to definitively test these two hypotheses. Peripheral blood mononuclear cells (PBMCs) were isolated from families in which several members, including at least one parent and child, had unusually high copy numbers of HHV-6 DNA per milliliter of blood. FISH confirmed that HHV-6 DNA colocalized with telomeric regions of one allele on chromosomes 17p13.3, 18q23, and 22q13.3, and that the integration site was identical among members of the same family. Integration of the HHV-6 genome into TTAGGG telomere repeats was confirmed by additional methods and sequencing of the integration site. Partial sequencing of the viral genome identified the same integrated HHV-6A strain within members of families, confirming vertical transmission of the viral genome. We next asked whether HHV-6A infection of naïve cell lines could lead to integration. Following infection of naïve Jjhan and HEK-293 cell lines by HHV-6, the virus integrated into telomeres. Reactivation of integrated HHV-6A virus from individuals' PBMCs as well as cell lines was successfully accomplished by compounds known to induce latent herpesvirus replication. Finally, no circular episomal forms were detected even by PCR. Taken together, the data suggest that HHV-6 is unique among human herpesviruses: it specifically and efficiently integrates into telomeres of chromosomes during latency rather than forming episomes, and the integrated viral genome is capable of producing virions.

Benzodiazepines (BZs) act on gamma-aminobutyric acid type A (GABAA) receptors such as alpha1beta2gamma2 through key residues within the N-terminal region of alpha subunits, to render their sedative and anxiolytic actions. However, the molecular mechanisms underlying the BZs' other clinical actions are not known. Here we show that, with low concentrations of GABA, diazepam produces a biphasic potentiation for the alpha1beta2gamma2-receptor channel, with distinct components in the nanomolar and micromolar concentration ranges. Mutations at equivalent residues within the second transmembrane domains (TM2) of alpha, beta and gamma subunits, proven important for the action of other anesthetics, abolish the micromolar, but not the nanomolar component. Converse mutation of the corresponding TM2 residue and a TM3 residue within rho1 subunits confers diazepam sensitivity on homo-oligomeric rho1-receptor channels that are otherwise insensitive to BZs. Thus, specific and distinct residues contribute to a previously unresolved component (micromolar) of diazepam action, indicating that diazepam can modulate the GABAA-receptor channel through two separable mechanisms.

Objective. To compare the efficacy of combination therapy with methotrexate (MTX) and hydroxychloroquine (HCQ), MTX and sulfasalazine (SSZ), and MTX, HCQ, and SSZ in patients with rheumatoid arthritis (RA).Methods. RA patients (n ‫؍‬ 171) who had not previously been treated with combinations of the study medications were randomized to receive 1 of the 3 treatment combinations in this 2-year, double-blind, placebo-controlled protocol. HCQ was given at a dosage of 200 mg twice a day. The dosage of MTX was accelerated from 7.5 mg/week to 17.5 mg/week in all patients who were not in remission. Similarly, the dosage of SSZ was escalated from 500 mg twice a day to 1 gm twice a day in patients who were not in remission. The primary end point of the study was the percentage of patients who had a 20% response to therapy according to the American College of Rheumatology (ACR) criteria at 2 years.Results. Intent-to-treat analysis revealed that patients receiving the triple combination responded best, with 78% achieving an ACR 20% response at 2 years, compared with 60% of those treated with MTX and HCQ (P ‫؍‬ 0.05) and 49% of those treated with MTX and SSZ (P ‫؍‬ 0.002). Similar trends were seen for the ACR 50% response, with 55%, 40%, and 29% of patients in the 3 treatment groups, respectively, achieving these results at 2 years (P ‫؍‬ 0.005 for the triple combination group versus the MTX and SSZ group). All combination treatments were well-tolerated. Fourteen patients (evenly distributed among the 3 groups) withdrew from the protocol because of symptoms that were potentially related to the study medication.Conclusion. The triple combination of MTX, SSZ, and HCQ is well-tolerated, and its efficacy is superior to that of the double combination of MTX and SSZ and is marginally superior to that of the double combination of MTX and HCQ.

Mitochondrial dysfunction and subsequent oxidative stress has been reported for a variety of cell types in inflammatory diseases. Given the abundance of mitochondria at the peripheral terminals of sensory nerves and the sensitivity of transient receptor potential (TRP) ankyrin 1 (A1) and TRP vanilloid 1 (V1) to reactive oxygen species (ROS) and their downstream products of lipid peroxidation, we investigated the effect of nerve terminal mitochondrial dysfunction on airway sensory nerve excitability. Here we show that mitochondrial dysfunction evoked by acute treatment with antimycin A (mitochondrial complex III Q i site inhibitor) preferentially activated TRPA1-expressing "nociceptor-like" mouse bronchopulmonary C-fibers. Action potential discharge was reduced by the TRPA1 antagonist HC-030031. Inhibition of TRPV1 further reduced C-fiber activation. In mouse dissociated vagal neurons, antimycin A induced Ca 21 influx that was significantly reduced by pharmacological inhibition or genetic knockout of either TRPA1 or TRPV1. Inhibition of both TRPA1 and TRPV1 was required to abolish antimycin A-induced Ca 21 influx in vagal neurons. Using an HEK293 cell expression system, antimycin A induced concentration-dependent activation of both hTRPA1 and hTRPV1 but failed to activate nontransfected cells. Myxothiazol (complex III Q o site inhibitor) inhibited antimycin A-induced TRPA1 activation, as did the reducing agent dithiothreitol. Scavenging of both superoxide and hydrogen peroxide inhibited TRPA1 activation following mitochondrial modulation. In conclusion, we present evidence that acute mitochondrial dysfunction activates airway sensory nerves preferentially via TRPA1 through the actions of mitochondrially-derived ROS. This represents a novel mechanism by which inflammation may be transduced into nociceptive electrical signaling.