Root electrotropism in Arabidopsis does not depend on auxin distribution but requires cytokinin biosynthesis.

Efficient foraging by plant roots relies on the ability to sense multiple physical and chemical cues in soil and to reorient growth accordingly (tropism). Root tropisms range from sensing gravity (gravitropism), light (phototropism), water (hydrotropism), touch (thigmotropism), and more. Electrotropism, also known as galvanotropism, is the phenomenon of aligning growth with external electric fields and currents. Although root electrotropism has been observed in a few species since the end of the 19th century, its molecular and physical mechanisms remain elusive, limiting its comparison with the more well-defined sensing pathways in plants. Here, we provide a quantitative and molecular characterization of root electrotropism in the model system Arabidopsis (Arabidopsis thaliana), showing that it does not depend on an asymmetric distribution of the plant hormone auxin, but instead requires the biosynthesis of a second hormone, cytokinin. We also show that the dose-response kinetics of the early steps of root electrotropism follows a power law analogous to the one observed in some physiological reactions in animals. Future studies involving more extensive molecular and quantitative characterization of root electrotropism would represent a step toward a better understanding of signal integration in plants and would also serve as an independent outgroup for comparative analysis of electroreception in animals and fungi.

Chemotropic Assay for Testing Fungal Response to Strigolactones and Strigolactone-Like Compounds.

Current knowledge on the mechanism of strigolactones (SLs) as signaling molecules during specific interactions in the rhizosphere is mainly related to the control of germination of parasitic weed seeds and hyphal branching of arbuscular mycorrhizal fungi. Thus, the role of plant secreted SLs in regulating the growth and development of root-colonizing fungi still remains controversial. Fusarium oxysporum can sense and respond to extracellular signals through oriented germ tube emergence and redirectioning of hyphal growth toward gradients of nutrients, sex pheromones, or plant root exudates. However, chemoattractant activity of SLs against microorganisms living in the soil has not been tested so far. Here we propose a quantitative chemotropic assay to understand if and how soil fungi could sense gradients of SLs and SLs-like sources. In the example case of F. oxysporum, hyphae of fungal representative mutants preferentially grow toward the synthetic SL analog GR24; and this chemotropic response requires conserved elements of the fungal invasive growth mitogen-activated protein kinase (MAPK) cascade.

Enhancement of tumor tropism of mPEGylated nanoparticles by anti-mPEG bispecific antibody for ovarian cancer therapy.

Ovarian cancer is highly metastatic, with a high frequency of relapse, and is the most fatal gynecologic malignancy in women worldwide. It is important to elevate the drug susceptibility and cytotoxicity of ovarian cancer cells, thereby eliminating resident cancer cells for more effective therapeutic efficacy. Here, we developed a bispecific antibody (BsAb; mPEG × HER2) that can easily provide HER2+ tumor tropism to mPEGylated liposomal doxorubicin (PLD) and further increase the drug accumulation in cancer cells via receptor-mediated endocytosis, and improve the cytotoxicity and therapeutic efficacy of HER2+ ovarian tumors. The mPEG × HER2 can simultaneously bind to mPEG molecules on the surface of PLD and HER2 antigen on the surface of ovarian cancer cells. Simply mixing the mPEG × HER2 with PLD was able to confer HER2 specificity of PLD to HER2+ ovarian cancer cells and efficiently trigger endocytosis and enhance cytotoxicity by 5.4-fold as compared to non-targeted PLD. mPEG × HER2-modified PLD was able to significantly increase the targeting and accumulation of HER2+ ovarian tumor by 220% as compared with non-targeted PLD. It could also significantly improve the anti-tumor activity of PLD (P < 0.05) with minimal obvious toxicity in a tumor-bearing mouse model. We believe that the mPEG × HER2 can significantly improve the therapeutic efficacy, potentially reduce the relapse freqency and thereby achieve good prognosis in ovarian cancer patients.

Investigation on the function tropism of Tiaoqin and Kuqin (different specification of Scutellaria baicalensis) by comparing their curative effect on different febrile disease model.

ETHNOPHARMACOLOGICAL RELEVANCE: Scutellaria baicalensis (S. baicalensis) is the root of S. baicalensis Georgi. In traditional Chinese medicine it is divided into Tiaoqin (TQ, 1-3 years old) and Kuqin (KQ, more than 3 years old). However, the differences in TQ and KQ efficacy and their exact mechanisms are still unclear. AIM OF THE STUDY: This study aimed to clarify the difference in the efficacy of TQ and KQ in relation to different fever types (damp heat and hyperpyrexia) by using rat models, as well as to determine the primary molecular mechanism. MATERIALS AND METHODS: This study compared the compositional content of TQ and KQ by UPLC-MS/MS. Then, rat models of hyperpyrexia (HP, LPS) and damp heat (DH, high-fat and high-sugar diet feeding + fumigation in artificial climate chamber + E. coli injection) were established and their clinical symptoms, blood biochemistry, histopathological sections, cell cytokines and protein expression were compared following treatment with TQ or KQ. Finally, the mechanisms underpinning the differences observed for TQ and KQ were determined by measuring the components of these treatments in different target organs. RESULTS: This study identified 31 compounds in the water extracts of both TQ and KQ, which differed significantly in their relative content. TQ and KQ showed different functional tropism in HP and DH model rats. Baicalin, wogonoside, oroxin A, baicalein, wogonin and oroxylin A appeared to be the basic functional components responsible for the functional tropism hypothesis, while the remaining compounds appeared to be the efficacy-oriented components. In addition, the difference in pharmacodynamics between TQ and KQ may be related to their absorption in vivo, which was consistent with the hypothesis of functional tropism proposed in this work. CONCLUSION: In this study we adopted TQ and KQ-different specifications of Scutellaria baicalensis with similar chemical components-as a case study to systematically reveal the functional tropism of Chinese herbal medicine (CHM). The results showed that TQ and KQ contain the basic functional components to enable the basic function of 'clearing heat', while the variation in compositional content may result in their different therapeutic effects. A greater understanding and utilisation of the functional tropism of CHM would enormously improve the accuracy and scientific basis for the application of CHM medication, as well as in promoting the multi-function mechanism of CHM and guiding new drug development of CHM.

A Novel Tissue-Based Liver-Kidney-on-a-Chip Can Mimic Liver Tropism of Extracellular Vesicles Derived from Breast Cancer Cells.

Extracellular vesicles (EVs) from cancer cells remodel distant organs to promote metastasis in vivo. A biomimetic microsystem may compensate costly and time-consuming animal models to accelerate the study of EV organotropism. A tissue-based liver-kidney-on-a-chip is developed with precision-cut tissue slices (PTSs) cultured to represent individual organs. The organotropism of breast cancer EVs is modeled using the biomimetic microsystem. A traditional animal model of EV organotropism is used to investigate the physiological similarity of the microfluidic model to animal models. It is demonstrated that breast cancer EVs show strong liver tropism rather than kidney tropism on both the microfluidic and animal models. It is found that the metastatic inhibitor AMD3100 inhibits liver tropism effectively in both the microfluidic and animal models. Overall, the tropism of EVs to different organs is reconstituted on the microfluidic model. The liver-kidney-on-a-chip may expand the capabilities of traditional cell culture models and provide a faster alternative to animal models for EV studies.

Organotropism and biomarker response in oyster Crassostrea gigas exposed to platinum in seawater.

Platinum (Pt) is a technology critical element (TCE) for which biogeochemical cycles are still poorly understood. This lack of knowledge includes Pt effects on marine organisms, which proved to be able to bioconcentrate this trace element. Oysters Crassostrea gigas were exposed to stable Pt isotope spiked daily in seawater for 35 days. Seawater was renewed daily and spiked (with Pt(IV)) to three nominal Pt concentrations (50, 100, and 10,000 ng L-1) for two replicate series. Organotropism study revealed that gills, and to a lesser extent mantle, are the key organs regarding Pt accumulation, although a time- and concentration-dependent linear increase in Pt levels occurred in all the organs investigated (i.e., digestive gland, gonads, gills, mantle, and muscle). In oysters exposed to Pt concentrations of 10,000 ng L-1, significant biomarker impairments occurred, especially at cellular levels. They reflect altered lipofuscin and neutral lipid contents, as well as intralysosomal metal accumulation. These observations were attributed to activation of excretion/detoxification mechanisms, including Pt elimination through feces and clearly support the importance of the digestive gland in the response to direct Pt exposure. Despite relatively constant condition index, the integrative biological response (IBR) index suggests a generally decreasing health status of oysters.

Molecularly Engineered Macrophage-Derived Exosomes with Inflammation Tropism and Intrinsic Heme Biosynthesis for Atherosclerosis Treatment.

Atherosclerosis (AS) is a major contributor to cardiovascular diseases worldwide, and alleviating inflammation is a promising strategy for AS treatment. Here, we report molecularly engineered M2 macrophage-derived exosomes (M2 Exo) with inflammation-tropism and anti-inflammatory capabilities for AS imaging and therapy. M2 Exo are derived from M2 macrophages and further electroporated with FDA-approved hexyl 5-aminolevulinate hydrochloride (HAL). After systematic administration, the engineered M2 Exo exhibit excellent inflammation-tropism and anti-inflammation effects via the surface-bonded chemokine receptors and the anti-inflammatory cytokines released from the anti-inflammatory M2 macrophages. Moreover, the encapsulated HAL can undergo intrinsic biosynthesis and metabolism of heme to generate anti-inflammatory carbon monoxide and bilirubin, which further enhance the anti-inflammation effects and finally alleviate AS. Meanwhile, the intermediate protoporphyrin IX (PpIX) of the heme biosynthesis pathway permits the fluorescence imaging and tracking of AS.

Cancer cell-type tropism is one of crucial determinants for the efficient systemic delivery of cancer cell-derived exosomes to tumor tissues.

Exosomes are gaining increasing attention as drug delivery vehicles due to their low toxicity and ability to functionally transfer biological cargos between cells. However, the therapeutic applicability of exosomes is partially hampered by a lack of cell-type specificity. In this study, therefore, we investigated the impact of cell-type tropism on the in vivo systemic delivery of exosomes to tumor tissues. Exosomes derived from murine colorectal cancer cells (C26) (C26-Exos) and murine melanoma cells (B16BL6) (B16BL6-Exos) were collected. In vitro cellular uptake of either autologous (C26) or allogeneic (B16BL6) exosomes by C26 tumor cells was determined. In vivo tumor accumulation of each type of exosomes in mice bearing C26 tumors was monitored with an in vivo imaging system (IVIS). In in vitro studies, autologous C26-Exos were more efficiently taken up by C26 cancer cells, compared to allogeneic B16BL6-Exos. For in vivo studies, exosomes were modified with surface polyethylene glycol (PEG) to improve their circulation lifetimes. Although both types of PEGylated exosomes accumulated in C26-tumor tissue, autologous exosomes were preferentially accumulated within C26-tumor tissue compared to allogeneic exosomes. The increased tumor accumulation of autologous PEGylated exosomes was accompanied by the preferential uptake of exosomes by not only C26-tumor cells but also tumor-associated immune cells. This study implies that cancer cell-type tropism is an important factor in the achievement of tumor cell targeting with cancer cell-derived exosomes.

Does facet tropism negatively affect the response to transforaminal epidural steroid injections? A prospective clinical study.

OBJECTIVE: To examine the impact of the presence of facet tropism on the results of transforaminal epidural steroid injection for unilateral radicular pain induced by lumbar disc herniation. MATERIALS AND METHODS: We included 112 patients diagnosed with unilateral, single-level lumbar disc herniation-induced radicular pain. Injection was planned at relevant levels. The patients were assessed using the Numerical Rating Scale, the Modified Oswestry Disability Index, and the Beck Depression Inventory before the injection and at hour 1, week 3, and month 3 after the injection. Presence of facet tropism was assessed by measuring the facet angles in the L3-4, L4-5, and L5-S1 segments of lumbar MRI T2 sequence axial section. RESULTS: A significant decrease in the Numerical Rating Scale and an increase in the Modified Oswestry Disability Index scores were detected at all follow-ups in groups comprising 39 patients with and 61 without facet tropism (p < 0.05). On comparison, improvement in clinical parameters at week 3 and month 3 in the group without facet tropism was greater (p < 0.05). As treatment success is considered to be a ≥ 50% reduction in the Numerical Rating Scale scores, 55.2% of the patients attained treatment success at month 3. Further, although the treatment success rate in the group with facet tropism was 34.2%, it was 69% in that without facet tropism (p < 0.05). CONCLUSION: Facet tropism correlates with less success of transforaminal epidural steroid injection; therefore, facet tropism may be a worthwhile measurement in a discussion with patients of the benefits of the procedure.

Annurca Apple Nutraceutical Formulation Enhances Keratin Expression in a Human Model of Skin and Promotes Hair Growth and Tropism in a Randomized Clinical Trial.

Several pharmaceutical products have been formulated over the past decades for the treatment of male and female alopecia, and pattern baldness, but relatively few metadata on their efficacy have been published. For these reasons, the pharmaceutical and medical attention has recently focused on the discovery of new and safer remedies. Particularly, great interest has been attracted by oligomeric procyanidin bioactivity, able to promote hair epithelial cell growth as well as to induce the anagen phase. Specifically, the procyanidin B2, a dimeric derivative extracted from apples, has demonstrated to be one of the most effective and safest natural compounds in promoting hair growth, both in vitro and in humans by topical applications. By evaluating the polyphenolic content of different apple varieties, we have recently found in the apple fruits of cv Annurca (AFA), native to Southern Italy, one of the highest contents of oligomeric procyanidins, and, specifically, of procyanidin B2. Thus, in the present work we explored the in vitro bioactivity of AFA polyphenolic extract as a nutraceutical formulation, named AppleMets (AMS), highlighting its effects on the cellular keratin expression in a human experimental model of adult skin. Successively, testing the effects of AMS on hair growth and tropism in healthy subjects, we observed significant results in terms of increased hair growth, density, and keratin content, already after 2 months. This study proves for the first time the impact of apple procyanidin B2 on keratin biosynthesis in vitro, and highlights its effect as a nutraceutical on human hair growth and tropism.

Reactive Oxygen Species Tune Root Tropic Responses.

The default growth pattern of primary roots of land plants is directed by gravity. However, roots possess the ability to sense and respond directionally to other chemical and physical stimuli, separately and in combination. Therefore, these root tropic responses must be antagonistic to gravitropism. The role of reactive oxygen species (ROS) in gravitropism of maize and Arabidopsis (Arabidopsis thaliana) roots has been previously described. However, which cellular signals underlie the integration of the different environmental stimuli, which lead to an appropriate root tropic response, is currently unknown. In gravity-responding roots, we observed, by applying the ROS-sensitive fluorescent dye dihydrorhodamine-123 and confocal microscopy, a transient asymmetric ROS distribution, higher at the concave side of the root. The asymmetry, detected at the distal elongation zone, was built in the first 2 h of the gravitropic response and dissipated after another 2 h. In contrast, hydrotropically responding roots show no transient asymmetric distribution of ROS Decreasing ROS levels by applying the antioxidant ascorbate, or the ROS-generation inhibitor diphenylene iodonium attenuated gravitropism while enhancing hydrotropism. Arabidopsis mutants deficient in Ascorbate Peroxidase 1 showed attenuated hydrotropic root bending. Mutants of the root-expressed NADPH oxidase RBOH C, but not rbohD, showed enhanced hydrotropism and less ROS in their roots apices (tested in tissue extracts with Amplex Red). Finally, hydrostimulation prior to gravistimulation attenuated the gravistimulated asymmetric ROS and auxin signals that are required for gravity-directed curvature. We suggest that ROS, presumably H2O2, function in tuning root tropic responses by promoting gravitropism and negatively regulating hydrotropism.

Chloroquine could be used for the treatment of filoviral infections and other viral infections that emerge or emerged from viruses requiring an acidic pH for infectivity.

Viruses from the Filoviridae family, as many other virus families, require an acidic pH for successful infection and are therefore susceptible to the actions of 4-aminoquinolines, such as chloroquine. Although the mechanisms of action of chloroquine clearly indicate that it might inhibit filoviral infections, several clinical trials that attempted to use chloroquine in the treatment of other acute viral infections - including dengue and influenza A and B - caused by low pH-dependent viruses, have reported that chloroquine had no clinical efficacy, and these results demoted chloroquine from the potential treatments for other virus families requiring low pH for infectivity. The present review is aimed at investigating whether chloroquine could combat the present Ebola virus epidemic, and also at exploring the main reasons for the reported lack of efficacy. Literature was sourced from PubMed, Scopus, Google Scholar, reference list of articles and textbooks - Fields Virology (Volumes 1and 2), the cytokine handbook, Pharmacology in Medicine: Principles and Practice, and hydroxychloroquine and chloroquine retinopathy. The present analysis concludes that (1) chloroquine might find a place in the treatment of Ebola, either as a monotherapy or in combination therapies; (2) the ineffectiveness of chloroquine, or its analogue, hydroxychloroquine, at treating infections from low pH-dependent viruses is a result of the failure to attain and sustain a steady state concentration sufficient to increase and keep the pH of the acidic organelles to approximately neutral levels; (3) to successfully treat filoviral infections - or other viral infections that emerge or emerged from low pH-dependent viruses - a steady state chloroquine plasma concentration of at least 1 µg/mL(~3.125 µM/L) or a whole blood concentration of 16 µM/L must be achieved and be sustained until the patients' viraemia becomes undetectable. These concentrations, however, do not rule out the efficacy of other, higher, steady state concentrations - although such concentrations might be accompanied by severe adverse effects or toxicities. The feasibility of the conclusion in the preceding texts has recently been supported by a subsequent study that shows that amodiaquine, a derivative of CQ, is able to protect humans infected with Ebola from death.

Intestinal microbiota sustains inflammation and autoimmunity induced by hypomorphic RAG defects.

Omenn syndrome (OS) is caused by hypomorphic Rag mutations and characterized by a profound immunodeficiency associated with autoimmune-like manifestations. Both in humans and mice, OS is mediated by oligoclonal activated T and B cells. The role of microbial signals in disease pathogenesis is debated. Here, we show that Rag2(R229Q) knock-in mice developed an inflammatory bowel disease affecting both the small bowel and colon. Lymphocytes were sufficient for disease induction, as intestinal CD4 T cells with a Th1/Th17 phenotype reproduced the pathological picture when transplanted into immunocompromised hosts. Moreover, oral tolerance was impaired in Rag2(R229Q) mice, and transfer of wild-type (WT) regulatory T cells ameliorated bowel inflammation. Mucosal immunoglobulin A (IgA) deficiency in the gut resulted in enhanced absorption of microbial products and altered composition of commensal communities. The Rag2(R229Q) microbiota further contributed to the immunopathology because its transplant into WT recipients promoted Th1/Th17 immune response. Consistently, long-term dosing of broad-spectrum antibiotics (ABXs) in Rag2(R229Q) mice ameliorated intestinal and systemic autoimmunity by diminishing the frequency of mucosal and circulating gut-tropic CCR9(+) Th1 and Th17 T cells. Remarkably, serum hyper-IgE, a hallmark of the disease, was also normalized by ABX treatment. These results indicate that intestinal microbes may play a critical role in the distinctive immune dysregulation of OS.

Evolution of HIV-1 tropism at quasispecies level after 5 years of combination antiretroviral therapy in patients always suppressed or experiencing episodes of virological failure.

OBJECTIVES: Tropism evolution of HIV-1 quasispecies was analysed by ultra-deep pyrosequencing (UDPS) in patients on first-line combination antiretroviral therapy (cART) always suppressed or experiencing virological failure episodes. METHODS: Among ICONA patients, two groups of 20 patients on cART for ≥5 years, matched for baseline viraemia and therapy duration, were analysed [Group I, patients always suppressed; and Group II, patients experiencing episode(s) of virological failure]. Viral tropism was assessed by V3 UDPS on plasma RNA before therapy (T0) and on peripheral blood mononuclear cell proviral DNA before-after therapy (T0-T1), using geno2pheno false positive rate (FPR) (threshold for X4: 5.75). For each sample, quasispecies tropism was assigned according to X4 variant frequency: R5, <0.3% X4; minority X4, 0.3%-19.9% X4; and X4, ≥20% X4. An R5-X4 switch was defined as a change from R5/minority X4 in plasma/proviral genomes at T0 to X4 in provirus at T1. RESULTS: At baseline, mean FPR and %X4 of viral RNA were positively correlated with those of proviral DNA. After therapy, proviral DNA load significantly decreased in Group I; mean FPR of proviral quasispecies significantly decreased and %X4 increased in Group II. An R5-X4 switch was observed in five patients (two in Group I and three in Group II), all harbouring minority X4 variants at T0. CONCLUSIONS: UDPS analysis reveals that the tropism switch is not an 'on-off' phenomenon, but may result from a profound re-shaping of viral quasispecies, even under suppressive cART. However, episodes of virological failure seem to prevent reduction of proviral DNA and to accelerate viral evolution, as suggested by decreased FPR and increased %X4 at T1 in Group II patients.

[Studies on the lymphatic tropism and lymph cells apoptosis of cisplatin-nano carbon suspension in the rats].

OBJECTIVE: To research the lymphatic tropism and lymph cell apoptosis of cisplatin-nano carbon suspension in rats with the aim of proposing a new way for chemotherapy. METHODS: A total of 72 Wistar rats were randomly divided into two groups. For the experimental group, cisplatin-nano carbon suspension 0.3 ml (4 mg/ml) was injected subcutaneously into Wistar rats' plantar. For the control group, cisplatin 0.3 ml (4 mg/ml) was injected intravenously. Cisplatin concentration in the inguinal lymphatic tissue and plasma was determined by high performance liquid chromatography (HPLC) at 1, 2, 3, 4, 5 and 6 hours after drug administration. The apoptosis of lymph cell was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay (TUNEL). Targeting ability were evaluated and compared by targeting index (TI), selecting index (SI) and relative extraction efficiency (RE). SPSS 17.0 statistical software was used to analyze the differentiation of the cisplatin concentration and apoptosis index (AI) among various groups. DAS software was used to evaluate the lymphatic tropism. RESULTS: The cisplatin concentration of lymphatic tissue in experimental group were respectively (1.03± 0.32), (3.00±0.91), (2.20±0.73), (1.56±0.38), (1.30±0.74) and (0.78±0.34)µg/g after administration 1, 2, 3, 4, 5 and 6 hours, while in control group were (0.49±0.21), (1.02±0.70), (0.59±0.50), (0.56±0.21), (0.47±0.18) and (0.36±0.13)µg/g, in which there were significant difference at every times (all P < 0.05)except at 1 hour(P = 0.173). The cisplatin concentration in plasma were significant higher in the experimental group than those in the control group at various times(all P < 0.05), the former were respectively (0.57±0.28), (1.22 ± 0.45), (0.61 ± 0.18), (0.51 ± 0.13), (0.45 ± 0.13) and (0.40 ± 0.07) µg/ml, while the latter were respectively (3.12±0.33), (4.09±0.48), (2.56±0.38), (2.05±0.13), (1.81±0.28) and (1.44±0.40) µg/ml. Values of TI were respectively 2.12, 2.93, 3.73, 2.78, 2.76 and 2.19 and SI were 1.80, 2.45, 3.63, 3.07, 2.86 and 1.93. Value of RE was 2.86. The AI in experimental group were respectively (16.5±5.2)%, (30.2±2.8)%, (51.7 ± 4.3)%, (69.8 ± 3.2)%, (80.1 ± 4.3)% and (89.7 ± 8.5)% , while in control group were respectively(1.3±0.8)%, (2.4±1.7)%, (3.2±1.1)%, (3.9±2.6)%, (5.1±2.1)% and (6.3±2.3)%, in which there were significant difference at every points(all P < 0.05). CONCLUSIONS: The nano carbon has the character of lymphatic tropism, and could send cisplatin to lymphatic tissue to achieve a higher concentration. The trait may break a new way for chemotherapy targeting lymph metastasis.

Understanding channel tropism in traditional Chinese medicine in the context of systems biology.

Channel tropism is investigated and developed through long-term clinical practice. In recent years, the development of channel tropism theory has attracted increasing attention. This study analyzed channel tropism theory and the problems associated with it. Results showed that this theory and systems biology have a similar holistic viewpoint. Systems biology could provide novel insights and platform in the study of channel tropism. Some problems in channel tropism theory, including pharmacology and action mechanism, were investigated.

Selective impact of HIV disease progression on the innate immune system in the human female reproductive tract.

BACKGROUND: We have previously demonstrated intrinsic anti-HIV activity in cervicovaginal lavage (CVL) from HIV-infected women with high CD4 counts and not on antiretroviral therapy. However, the impact of HIV disease progression on CVL innate immune responses has not been delineated. METHODS: CVL from 57 HIV-infected women not on antiretroviral therapy were collected by washing the cervicovaginal area with 10 ml of sterile normal saline. We characterized subject HIV disease progression by CD4 count strata: >500 cells/µl, 200-500 cells/µl, or <200 cells/µl of blood. To assess CVL anti-HIV activity, we incubated TZM-bl cells with HIV plus or minus CVL. Antimicrobials, cytokines, chemokines and anti-gp160 HIV IgG antibodies were measured by ELISA and Luminex. RESULTS: CVL exhibited broad anti-HIV activity against multiple laboratory-adapted and transmitted/founder (T/F) viruses, with anti-HIV activity ranging from 0 to 100% showing wide variation between viral strains. Although there was broad CVL inhibition of most both laboratory-adapted and T/F virus strains, there was practically no inhibition of T/F strain RHPA.c, which was isolated from a woman newly infected via heterosexual intercourse. HIV disease progression, measured by declining CD4 T cell counts, resulted in a selective reduction in intrinsic anti-HIV activity in CVL that paralleled CVL decreases in human beta-defensin 2 and increases in Elafin and secretory leukocyte protease inhibitor. HIV disease progress predicted decreased CVL anti-HIV activity against both laboratory-adapted and T/F strains of HIV. Anti-HIV activity exhibited close associations with CVL levels of fourteen cytokines and chemokines. CONCLUSIONS: Amid a multifaceted immune defense against HIV-1 and other sexually transmitted pathogens, HIV disease progression is associated with selective disturbances in both CVL anti-HIV activity and specific innate immune defenses in the human female reproductive tract (FRT). Overall, these studies indicate that innate immune protection in the FRT is compromised as women progress to AIDS.

HIV type 1 coreceptor tropism, CCR5 genotype, and integrase inhibitor resistance profiles in Vietnam: implications for the introduction of new antiretroviral regimens.

In Vietnam, where an estimated 280,000 people will be HIV-positive by 2012, recommended antiretroviral regimens do not include more recently developed therapeutics, such as Integrase inhibitors (INI) and coreceptor antagonists. This study examined HIV-1 coreceptor tropism and INI drug resistance profiles, in parallel with CCR5 genotypes, in a cohort of 60 HIV-positive individuals from different regions of Vietnam. No evidence of INI resistance was detected. Some 40% of individuals had X4-tropic HIV-1, making them unsuitable for treatment with CCR5 antagonists. We identified a novel CCR5 variant-S272P-along with other, previously reported variants: G106R, C178R, W153C, R223Q, and S336I. Interestingly, CCR5 variants known to affect HIV-1 infectivity were observed only in individuals harboring X4-tropic virus. Together, this study presents valuable baseline information on HIV-1 INI resistance, coreceptor tropism, and CCR5 variants in HIV-positive individuals in Vietnam. This should help inform policy on the future use of novel antiretrovirals in Vietnam.

Modulation of ethylene- and heat-controlled hyponastic leaf movement in Arabidopsis thaliana by the plant defence hormones jasmonate and salicylate.

Upward leaf movement (hyponastic growth) is adopted by several plant species including Arabidopsis thaliana, as a mechanism to escape adverse growth conditions. Among the signals that trigger hyponastic growth are, the gaseous hormone ethylene, low light intensities, and supra-optimal temperatures (heat). Recent studies indicated that the defence-related phytohormones jasmonic acid (JA) and salicylic acid (SA) synthesized by the plant upon biotic infestation repress low light-induced hyponastic growth. The hyponastic growth response induced by high temperature (heat) treatment and upon application of the gaseous hormone ethylene is highly similar to the response induced by low light. To test if these environmental signals induce hyponastic growth via parallel pathways or converge downstream, we studied here the roles of Methyl-JA (MeJA) and SA on ethylene- and heat-induced hyponastic growth. For this, we used a time-lapse camera setup. Our study includes pharmacological application of MeJA and SA and biological infestation using the JA-inducing caterpillar Pieris rapae as well as mutants lacking JA or SA signalling components. The data demonstrate that MeJA is a positive, and SA, a negative regulator of ethylene-induced hyponastic growth and that both hormones repress the response to heat. Taking previous studies into account, we conclude that SA is the first among many tested components which is repressing hyponastic growth under all tested inductive environmental stimuli. However, since MeJA is a positive regulator of ethylene-induced hyponastic growth and is inhibiting low light- and heat-induced leaf movement, we conclude that defence hormones control hyponastic growth by affecting stimulus-specific signalling pathways.

Impact of the HIV-1 env genetic context outside HR1-HR2 on resistance to the fusion inhibitor enfuvirtide and viral infectivity in clinical isolates.

Resistance mutations to the HIV-1 fusion inhibitor enfuvirtide emerge mainly within the drug's target region, HR1, and compensatory mutations have been described within HR2. The surrounding envelope (env) genetic context might also contribute to resistance, although to what extent and through which determinants remains elusive. To quantify the direct role of the env context in resistance to enfuvirtide and in viral infectivity, we compared enfuvirtide susceptibility and infectivity of recombinant viral pairs harboring the HR1-HR2 region or the full Env ectodomain of longitudinal env clones from 5 heavily treated patients failing enfuvirtide therapy. Prior to enfuvirtide treatment onset, no env carried known resistance mutations and full Env viruses were on average less susceptible than HR1-HR2 recombinants. All escape clones carried at least one of G36D, V38A, N42D and/or N43D/S in HR1, and accordingly, resistance increased 11- to 2800-fold relative to baseline. Resistance of full Env recombinant viruses was similar to resistance of their HR1-HR2 counterpart, indicating that HR1 and HR2 are the main contributors to resistance. Strictly X4 viruses were more resistant than strictly R5 viruses, while dual-tropic Envs featured similar resistance levels irrespective of the coreceptor expressed by the cell line used. Full Env recombinants from all patients gained infectivity under prolonged drug pressure; for HR1-HR2 viruses, infectivity remained steady for 3/5 patients, while for 2/5 patients, gains in infectivity paralleled those of the corresponding full Env recombinants, indicating that the env genetic context accounts mainly for infectivity adjustments. Phylogenetic analyses revealed that quasispecies selection is a step-wise process where selection of enfuvirtide resistance is a dominant factor early during therapy, while increased infectivity is the prominent driver under prolonged therapy.