CD8+ T-cell-mediated cross-clade protection in the genital tract following intranasal immunization with inactivated human immunodeficiency virus antigen plus CpG oligodeoxynucleotides

Human immunodeficiency virus (HIV) is a mucosally transmitted infection that rapidly targets and depletes CD4+ T cells in mucosal tissues and establishes a major reservoir for viral persistence in gut-associated lymphoid tissues. Therefore, vaccines designed to prevent HIV infections must induce potent and durable mucosal immune responses, especially in the genital tract. Here we investigated whether intranasal (i.n.) immunization with inactivated gp120-depleted HIV-1 antigen (Ag) plus CpG oligodeoxynucleotide (ODN) as an adjuvant induced local immune responses in the genital tract and cross-clade protection against intravaginal (IVAG) challenge. Lymphocytes isolated from the iliac lymph nodes (ILNs) and genital tracts of female mice i.n. immunized with HIV-1 Ag plus CpG showed significant HIV-specific proliferation and produced significantly higher levels of gamma interferon (IFN-gamma) and beta-chemokines than mice immunized with HIV-1 Ag alone or mixed with non-CpG ODN. CD8+ lymphocytes were dramatically increased in the genital tracts of mice immunized with HIV-1 Ag plus CpG, and protection following IVAG challenge with recombinant vaccinia viruses (rVVs) expressing HIV-1 gag was shown to be CD8 dependent. Finally, cross-clade protection was observed between clades A, C, and G but not B following IVAG challenge with rVVs expressing HIV-1 gag from different clades. These studies provide evidence that mucosal (i.n.) immunization induced strong local T-cell-mediated immune responses in the genital tract and cross-clade protection against IVAG challenge.     

Selective effects of isomeric cis and trans fatty acids on fatty acyl delta 9 and delta 6 desaturation by human skin fibroblasts

Human skin fibroblasts incorporate and actively desaturate long-chain fatty acids. Growth of these cells in lipid-free medium can be used to enhance delta 9 and delta 6 desaturation of [14C]stearate and [14C]linoleate, respectively. Medium supplementation with cis fatty acids inhibits delta 9 desaturation; effectiveness as inhibitors is linoleate (9c,12c-18:2) greater than oleate (9c-18:1) greater than vaccenate (11c-18:1). Linoelaidate (9t,12t-18:2), trans-vaccenate (11t-18:1) and saturated fatty acids are without effect; elaidate (9t-18:1) appears stimulatory. By contrast, the trans fatty acids elaidate and linoelaidate are potent inhibitors of delta 6 desaturation; inhibition by trans-vaccenate is 50% of that of elaidate. Desaturation of [14C]linoleate is only slightly inhibited by oleate, cis-vaccenate, or (6c,9c,12c)-linolenate. The relative effectiveness of isomeric cis- and trans-octadecenoic acids as inhibitors of delta 9 and delta 6 desaturation in intact human cells is different from that found in microsomal studies. The cell culture system can thus be important in evaluating physiological effects of isomeric fatty acids on cellular metabolic processes.     

Muscle-specific expression of insulin-like growth factor I counters muscle decline in mdx mice

The Rho GTPase and Fyn tyrosine kinase have been implicated previously in positive control of keratinocyte cell-cell adhesion. Here, we show that Rho and Fyn operate along the same signaling pathway. Endogenous Rho activity increases in differentiating keratinocytes and is required for both Fyn kinase activation and increased tyrosine phosphorylation of beta- and gamma-catenin, which is associated with the establishment of keratinocyte cell-cell adhesion. Conversely, expression of constitutive active Rho is sufficient to promote cell-cell adhesion through a tyrosine kinase- and Fyn-dependent mechanism, trigger Fyn kinase activation, and induce tyrosine phosphorylation of beta- and gamma-catenin and p120ctn. The positive effects of activated Rho on cell-cell adhesion are not induced by an activated Rho mutant with defective binding to the serine/threonine PRK2/PKN kinases. Endogenous PRK2 kinase activity increases with keratinocyte differentiation, and, like activated Rho, increased PRK2 activity promotes keratinocyte cell-cell adhesion and induces tyrosine phosphorylation of beta- and gamma-catenin and Fyn kinase activation. Thus, these findings reveal a novel role of Fyn as a downstream mediator of Rho in control of keratinocyte cell-cell adhesion and implicate the PRK2 kinase, a direct Rho effector, as a link between Rho and Fyn activation.     

Seasonal variation in conduction velocity of action potentials in squid giant axons

To determine whether the electrical properties of the squid giant axon are seasonally acclimated, action potentials, recorded at different temperatures, were compared between giant axons isolated from Loligo pealei caught in May, from relatively cold waters (approximately 10 degrees-12 degrees C), and in August, from relatively warm waters (approximately 20 degrees C). Parameters relating to the duration of the action potential (e.g., maximum rate of rise, maximum rate of fall, and duration at half-peak) did not change seasonally. The relationship between conduction velocity and temperature remained constant between seasons as well, in spite of the fact that May axons were significantly larger than August axons. When normalized to the fiber diameter, mean May conduction velocities were 83% of the August values at all temperatures tested, and analysis of the rise time of the action potential foot suggested that a change in the axoplasmic resistivity was responsible for this difference. Direct measurements of axoplasmic resistance further supported this hypothesis. Thus seasonal changes in the giant axon's size and resistivity are not consistent with compensatory thermal acclimation, but instead serve to maintain a constant relationship between conduction velocity and temperature.     

Meta-analysis: Four-Drug, Three-Antibiotic, Non-bismuth-Containing "Concomitant Therapy" Versus Triple Therapy for Helicobacter pylori Eradication

Background: Low success rates with triple therapy for Helicobacter pylori infections have prompted search for alternatives. In one, a proton-pump inhibitor (PPI) and amoxicillin was followed by the PPI plus clarithromycin and a nitroimidazole (sequential therapy); in another, these four drugs were given concomitantly (concomitant therapy).
Aim: To compare concomitant therapy with standard triple therapy for H. pylori infection.
Methods: By searching PubMed, EMBASE, the Cochrane Central Register of Controlled Trials and abstracts of major gastrointestinal meeting, two independent reviewers systemically identified randomized controlled trials (RCT) comparing concomitant quadruple to standard triple therapies as well as studies reporting eradication rates of concomitant quadruple therapy in treatment of H. pylori . Pooled eradication rates and odds ratios (OR) with 95% confidence intervals (CI) were calculated, and univariable metaregression analysis for all extracted variables was conducted.
Results: We identified nine studies (10 treatment arms) including five qualifying RCTs (576 subjects) comparing concomitant (293 subjects, duration 3 to 5 days) and triple therapy (283 subjects, duration 5 to 10 days) and four other studies evaluating concomitant therapy (478 subjects, duration 3 to 7 days). Pooled estimates of the five RCTs showed superiority of concomitant therapy over triple therapy; with intention-to-treat) pooled OR of 2.86 (95% CI: 1.73–4.73) and per-protocol (PP) pooled OR of 3.52 (95% CI: 1.95–6.38). Considering all 10 treatment arms, the ITT eradication rate was 89.7% (95% CI: 86.8–92.1%) and PP was 92.9% (95% CI: 90.2–94.8%).
Conclusion: Concomitant therapy appears to be an effective alternative to triple therapy and is less complex than sequential therapy.     

Daily dosing of rifapentine cures tuberculosis in three months or less in the murine model

Background

Availability of an ultra-short-course drug regimen capable of curing patients with tuberculosis in 2 to 3 mo would significantly improve global control efforts. Because immediate prospects for novel treatment-shortening drugs remain uncertain, we examined whether better use of existing drugs could shorten the duration of treatment. Rifapentine is a long-lived rifamycin derivative currently recommended only in once-weekly continuation-phase regimens. Moxifloxacin is an 8-methoxyfluoroquinolone currently used in second-line regimens.

Methods and Findings

Using a well-established mouse model with a high bacterial burden and human-equivalent drug dosing, we compared the efficacy of rifapentine- and moxifloxacin-containing regimens with that of the standard daily short-course regimen based on rifampin, isoniazid, and pyrazinamide. Bactericidal activity was assessed by lung colony-forming unit counts, and sterilizing activity was assessed by the proportion of mice with culture-positive relapse after 2, 3, 4, and 6 mo of treatment. Here, we demonstrate that replacing rifampin with rifapentine and isoniazid with moxifloxacin dramatically increased the activity of the standard daily regimen. After just 2 mo of treatment, mice receiving rifapentine- and moxifloxacin-containing regimens were found to have negative lung cultures, while those given the standard regimen still harbored 3.17 log₁₀ colony-forming units in the lungs (p < 0.01). No relapse was observed after just 3 mo of treatment with daily and thrice-weekly administered rifapentine- and moxifloxacin-containing regimens, whereas the standard daily regimen required 6 mo to prevent relapse in all mice.

Conclusions

Rifapentine should no longer be viewed solely as a rifamycin for once-weekly administration. Our results suggest that treatment regimens based on daily and thrice-weekly administration of rifapentine and moxifloxacin may permit shortening the current 6 mo duration of treatment to 3 mo or less. Such regimens warrant urgent clinical investigation.