Analysis of a clonal lineage of HIV-1 envelope V2/V3 conformational epitope-specific broadly neutralizing antibodies and their inferred unmutated common ancestors

V2/V3 conformational epitope antibodies that broadly neutralize HIV-1 (PG9 and PG16) have been recently described. Since an elicitation of previously known broadly neutralizing antibodies has proven elusive, the induction of antibodies with such specificity is an important goal for HIV-1 vaccine development. A critical question is which immunogens and vaccine formulations might be used to trigger and drive the development of memory B cell precursors with V2/V3 conformational epitope specificity. In this paper we identified a clonal lineage of four V2/V3 conformational epitope broadly neutralizing antibodies (CH01 to CH04) from an African HIV-1-infected broad neutralizer and inferred their common reverted unmutated ancestor (RUA) antibodies. While conformational epitope antibodies rarely bind recombinant Env monomers, a screen of 32 recombinant envelopes for binding to the CH01 to CH04 antibodies showed monoclonal antibody (MAb) binding to the E.A244 gp120 Env and to chronic Env AE.CM243; MAbs CH01 and CH02 also bound to transmitted/founder Env B.9021. CH01 to CH04 neutralized 38% to 49% of a panel of 91 HIV-1 tier 2 pseudoviruses, while the RUAs neutralized only 16% of HIV-1 isolates. Although the reverted unmutated ancestors showed restricted neutralizing activity, they retained the ability to bind to the E.A244 gp120 HIV-1 envelope with an affinity predicted to trigger B cell development. Thus, E.A244, B.9021, and AE.CM243 Envs are three potential immunogen candidates for studies aimed at defining strategies to induce V2/V3 conformational epitope-specific antibodies.     

Radix/Rhizoma Notoginseng extract (Sanchitongtshu) for ischemic stroke: A randomized controlled study

Agents of sanchi have been widely used as a complementary medicine for stroke in China. Sanchitongshu is a new Chinese patent medicine extracted from sanchi which has stronger anti-platelet activity than other agents of sanchi. Our aim was to investigate the synergistic action of low dose of aspirin combined with sanchitongshu capsule in the treatment of patients with light and moderate ischemic stroke in acute and subacute stages.This was a multi-center, double-blinded, randomized controlled clinical trial conducted in four hospitals in China from July 2004 to 2006. 140 patients of ischemic stroke in anterior cerebral circulation within 30 days of onset were enrolled. Participants were assigned either to receive aspirin (50 mg per day) and sanchitongshu capsule (200 mg three times a day) or aspirin (50 mg per day) and placebo capsule.Low dose of aspirin combined with sanchitongshu capsule significantly ameliorated neurological deficit (increased score of ESS: t = −5.02, p < 0.0001) and activities of daily living (increased score of BI: t = −2.4, p = 0.0178) after treatment compared with aspirin alone. Adverse reaction which occurred equally in both arms, was light to moderate and disappeared without special treatment.Sanchitongshu capsule, as a complementary medicine to aspirin, was effective in improving outcomes after ischemic stroke. It was a safe drug in our trial.     

ATR autophosphorylation as a molecular switch for checkpoint activation

The ataxia telangiectasia-mutated and Rad3-related (ATR) kinase is a master checkpoint regulator safeguarding the genome. Upon DNA damage, the ATR-ATRIP complex is recruited to sites of DNA damage by RPA-coated single-stranded DNA and activated by an elusive process. Here, we show that ATR is transformed into a hyperphosphorylated state after DNA damage, and that a single autophosphorylation event at Thr 1989 is crucial for ATR activation. Phosphorylation of Thr 1989 relies on RPA, ATRIP, and ATR kinase activity, but unexpectedly not on the ATR stimulator TopBP1. Recruitment of ATR-ATRIP to RPA-ssDNA leads to congregation of ATR-ATRIP complexes and promotes Thr 1989 phosphorylation in trans. Phosphorylated Thr 1989 is directly recognized by TopBP1 via the BRCT domains 7 and 8, enabling TopBP1 to engage ATR-ATRIP, to stimulate the ATR kinase, and to facilitate ATR substrate recognition. Thus, ATR autophosphorylation on RPA-ssDNA is a molecular switch to launch robust checkpoint response.     

Development of a multiplex amplification refractory mutation system for simultaneous authentication of Korean ginseng cultivars "Gumpoong" and "Chungsun"

BACKGROUND AND AIMS. Molecular authentication of Korean ginseng cultivars was investigated using the mitochondrial nicotinamide adenine dinucleotide (NADH) dehydrogenase subunit 7 (nad7) intron 3 region. MATERIALS AND METHODS. A mutation site specific to Panax ginseng "Gumpoong" and "Chungsun" cultivars was detected within the sequence data. Based on this mutation site and the "Gumpoong"-specific single nucleotide polymorphism site reported in 26S rDNA, two modified allele-specific primer pairs were designed and a multiplex amplification refractory mutation system (MARMS) was applied to identify "Gumpoong" and "Chungsun." RESULTS. The results showed that "Gumpoong" and "Chungsun" can be clearly discriminated from the other Korean ginseng cultivars by simultaneously identifying the haplotype of "Gumpoong" and the specific allele of "Chungsun" by applying the MARMS. CONCLUSION. This study, therefore, provides a simple and reliable method for simultaneous authentication of "Gumpoong" and "Chungsun" cultivars.     

Design, synthesis and biological evaluation of novel L-lysine ureido derivatives as aminopeptidase N inhibitors

As the exopeptidase over-expressed in the cell surface of endothelial cells, aminopeptidase N (APN/CD13) is an essential target for tumor angiogenesis and metastasis. Based on the previous work of L-lysine amide derivatives in our laboratory, we designed and synthesized two series of L-lysine ureido derivatives as APN inhibitors. Within these compounds, one compound, 5d (IC?? = 4.51 μM), showed similar inhibitory effect compared with Bestatin (IC?? = 5.87 μM).     

Effect of a fermented nutraceutical on thioredoxin level and TNF-alpha signalling in cirrhotic patients

The aim of this study is to gain further insights into the possible nutraceutical effect on redox balance via thioredoxin (Trx) modulation and on the intrinsic susceptibility of monocytes to generate an inflammatory response. The study group consisted of thirty-two patients with compensated Child A-C, HCV-related cirrhosis. The patients were supplemented for 6 months with 6g/day of a certified fermented papaya preparation (FPP). Fifteen unsupplemented, age/gender-matched healthy subjects served as controls. The patients filled in a detailed diet-life style questionnaire, and blood samples were collected to test routine biochemistry, Trx, redox status (GSH, GSSG, GSH/GSSG ratio, 4-HNE and alpha-tocopherol). Moreover, isolated monocytes were tested for ex-vivo LPS-stimulated TNF-alpha production and TNF-alpha mRNA. As compared to control, patients with liver cirrhosis showed a significantly higher serum level of Trx. A significant correlation occurred with GSH/GSSG ratio in Child B and C patients. FPP supplementation brought about a significant reduction of Trx with levels comparable to the ones of healthy controls. Ten patients Child C (31.2 percent) showed borderline low levels of alpha-tocopherol while all cirrhotic patients, as a whole, showed a significantly abnormal redox balance. Supplementation with FPP did not modify alpha-tocopherol depletion but significantly improved redox balance parameters. Patients with liver cirrhosis showed a significantly upregulated TNF-alpha production in a time-dependent manner and this effect was more pronounced in more advanced stages of the disease and showed a significant correlation with alpha-tocopherol level. Supplementation with FPP significantly, although partially, downregulated TNF-alpha production from monocytes. Taken altogether, it would appear that the typical oxidative-inflammatory biochemical milieu of these patients is mirrored by a significant TNF-alpha upregulation at a monocyte level while a targeted nutraceutical might be a potentially amenable intervention to be part of validated scheduled treatments.     

Atorvastatin suppresses LPS-induced rapid upregulation of Toll-like receptor 4 and its signaling pathway in endothelial cells

In the present study, we tested our hypothesis that atorvastatin exerts its anti-inflammation effect via suppressing LPS-induced rapid upregulation of Toll-like receptor 4 (TLR4) mRNA and its downstream p38, ERK, and NF-κB signaling pathways in human umbilical-vein endothelial cells (HUVECs) and human aortic endothelial cells (HAECs). TLR4 mRNA expression and its downstream kinase activities induced by LPS alone or atorvastatin + LPS in endothelial cells were quantified using quantitative real-time PCR and enzyme-linked immunosorbent assay. Preincubation of LPS-stimulated endothelial cells with TLR4 siRNA was conducted to identify the target of the anti-inflammatory effects of atorvastatin. Atorvastatin incubation resulted in the reduction of LPS-induced TLR4 mRNA expression, ERK1/2 and P38 MAPK phosphorylation, and NF-κB binding activity. Pretreatment with MEK/ERK1/2 inhibitor PD98059 attenuated atorvastatin + LPS-induced NF-κB activity but had no effect on P38 MAPK phosphorylation. In contrast, pretreatment with P38 MAPK inhibitor SB203580 resulted in upregulation of atorvastatin + LPS-induced ERK1/2 phosphorylation but had no significant effects on NF-κB activity. On the other hand, blocking NF-κB with SN50 produced no effects on atorvastatin + LPS-induced ERK1/2 and P38 MAPK phosphorylation. Moreover, TLR4 gene silencing produced the same effects as the atorvastatin treatment. In conclusion, atorvastatin downregulated TLR4 mRNA expression by two distinct signaling pathways. First, atorvastatin stabilized Iκ-Bα, which directly inhibited NF-κB activation. Second, atorvastatin inactivated ERK phosphorylation, which indirectly inhibited NF-κB activation. Suppression of p38 MAPK by atorvastatin upregulates ERK but exerts no effect on NF-κB.