Haut PDF Molecular and functional studies of human immunodeficiency virus type 1 accessory protein

Molecular and functional studies of human immunodeficiency virus type 1 accessory protein

Molecular and functional studies of human immunodeficiency virus type 1 accessory protein

Role ofthe matrix protein in the virion association of the human immunodeficiency virus type 1 envelope glycoprotein. T cdl dynamics in HIV-1 infection.[r]

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Analysis of the human immunodeficiency virus type 1 M group Vpu domains involved in antagonizing tetherin

Analysis of the human immunodeficiency virus type 1 M group Vpu domains involved in antagonizing tetherin

MRC Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, Cruciform Building, 90 Gower Street, London WC1E 6BT, UK Zoonosis of chimpanzee simian immunodeficiency virus cpz to humans has given rise to both pandemic (M) and non-pandemic (O, N and P) groups of human immunodeficiency virus type-1 (HIV). These lentiviruses encode accessory proteins, including Vpu, which has been shown to reduce CD4 levels on the cell surface, as well as increase virion release from the cell by antagonizing tetherin (CD317, BST2). Here, we confirm that O group Vpus (Ca9 and BCF06) are unable to counteract tetherin or downregulate the protein from the cell surface, although they are still able to reduce cell-surface CD4 levels. We hypothesize that this inability to antagonize tetherin may have contributed to O group viruses failing to achieve pandemic levels of human-to- human transmission. Characterization of chimeric O/M group Vpus and Vpu mutants demonstrate that the Vpu–tetherin interaction is complex, involving several domains. We identify specific residues within the transmembrane proximal region that, along with the transmembrane domain, are crucial for tetherin counteraction and enhanced virion release. We have also shown that the critical domains are responsible for the localization of M group Vpu to the trans-Golgi network, where it relocalizes tetherin to counteract its function. This work sheds light on the acquisition of anti-tetherin activity and the molecular details of pandemic HIV infection in humans.
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Synergistic activation of human immunodeficiency virus type 1 promoter activity by NF-kappa B and inhibitors of deacetylases: Potential perspectives for the development of therapeutic strategies

Synergistic activation of human immunodeficiency virus type 1 promoter activity by NF-kappa B and inhibitors of deacetylases: Potential perspectives for the development of therapeutic strategies

Mechanistically, we showed here by gel retardation assays that TSA (or NaBut) prolonged TNF-induced NF-␬B DNA- binding activity, whereas TSA (or NaBut) alone caused no induction of NF-␬B. These in vitro binding studies coincided with a sustained nuclear p65 presence as revealed by immuno- blotting and confocal immunofluorescence microscopy. Impor- tantly, Western blot analysis also revealed a marked delay in the cytoplasmic reappearance of the inhibitory protein I␬B␣ after TNF-TSA versus TNF treatment. This delay correlated temporally with the sustained binding activity and presence of NF-␬B in the nucleus and was not due to a defect in the I␬B␣ mRNA production. These data therefore provide a molecular mechanism involving I␬B␣ for the functional synergism we observed between TNF and inhibitors of deacetylases. I␬B␣ plays a pivotal role in the NF-␬B signaling pathway. Indeed, the primary level of regulation of NF-␬B activity is through its retention in the cytoplasm through interactions with I␬B␣. Moreover, the resynthesis of de novo I␬B␣ participates in a negative feedback system ensuring a transient NF-␬B tran- scriptional response (reviewed in reference 28). We are cur- rently further investigating the role of TSA in the delayed cytoplasmic reappearance of I␬B␣ reported here. To this end, we are testing whether some proteins involved in the NF-␬B/ I␬B signaling have their expression and/or action modulated by TSA.
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Activation of the human immunodeficiency virus long terminal repeat by varicella-zoster virus IE4 protein requires nuclear factor-kB and involves both the amino-terminal and the carboxyl-terminal cysteine-rich region

Activation of the human immunodeficiency virus long terminal repeat by varicella-zoster virus IE4 protein requires nuclear factor-kB and involves both the amino-terminal and the carboxyl-terminal cysteine-rich region

Because viruses are intracellular parasites, they appropriate the cellular machinery for their own benefit. NF- κ B belongs to the host transcription factors used by a number of viruses to induce their own expression or that of specific host genes (19). Inducible human immunodeficiency virus type 1 (HIV-1) gene expression is generally mediated by the binding of NF- κ B to the enhancer κ B-binding sites in the long terminal repeat (22, 26, 27). Molecular interactions among herpesviruses and HIV-1 have been frequently investigated, as the most common opportunistic viral infections in individuals with AIDS are caused by herpesviruses (28–30). Herpesviruses could act as co-factors in enhancing HIV-1 replication. Direct effects of herpesvirus proteins on HIV-1 LTR activity have been detected in the case of HSV-1 (31–33), cytomegalovirus (CMV) (34, 35), and Epstein-Barr virus (EBV) (36). Some of these effects could be associated with NF- κ B induction (27, 33, 36–38), although some controversy exists as to the identity of the responsible proteins in HSV-1 (32, 37, 39, 40) and CMV (34, 35,41). Such discrepancies might possibly be attributed to the different cell lines used in the various studies (31, 34, 35). The mechanisms of NF- κ B induction by the latent membrane protein (LMP1) of EBV, for example, are post-translational and involve I κ B- α degradation (38). Little is known about the mechanism of LTR induction by VZV, but it was shown that VZV infection of HeLa cells could stimulate HIV-1 LTR activity (42). It has also been demonstrated that a DNA fragment carrying ORFs 61, 62, and 63 could transactivate the HIV-1 LTR in transient transfection (32). We and others have shown that IE4 could also stimulate the LTR in CAT assays (12, 13, 43). This
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Contribution of the C-terminal tri-lysine regions of human immunodeficiency virus type 1 integrase for efficient reverse transcription and viral DNA nuclear import

Contribution of the C-terminal tri-lysine regions of human immunodeficiency virus type 1 integrase for efficient reverse transcription and viral DNA nuclear import

import still remain to be determined. Previous report has suggested an atypical bipartite NLS ( 186 KRK and 211 KELQKQITK) by showing that IN mutants K186Q and Q214/216L in these regions lost the protein nuclear local- ization and their inability to bind to karyopherin α in vitro [3]. However, in attempt to analyze the effect of these mutants during HIV-1 replication, other studies did not reveal the importance of these IN mutants (K186Q and Q214/216L) for viral nuclear import; rather they appear to be required for reverse transcription, integration or undefined post-nuclear entry steps [16,18,23]. Also, another IN amino acid sequence IIGQVRDQAEHLK (aa161–173), was initially identified as an atypical NLS, which is required for viral DNA nuclear import [19]. How- ever, reassessments of this putative NLS function failed to confirm this conclusion [24,25]. Some reports have also acknowledged that IN localization could result from pas- sive diffusion of the protein and its DNA binding property [26,27], but DNA binding alone does not fully explain a rapid, ATP- and temperature-dependent nuclear import of IN [20]. It has recently been reported that the nuclear translocation of HIV-1 IN can be attributed to its interac- tion with a cellular component, human lens epithelium- derived growth factor/transcription coactivator p75 (LEDGF/p75) and LEDGF/p75 was also shown to be a component of HIV PIC [28,29]. However, whether this IN/LEDGF/p75 interaction plays an important role for HIV-1 nuclear import still remains to be elucidated, since HIV-1 infection and replication in LEDGF/p75-deficient cells was equivalent to that in control cells, regardless whether cells were dividing or growth arrested [29]. Thus, even though extensive studies have been dedicated in this specific research field, the contribution of HIV-1 IN to viral PIC nuclear import remains to be defined.
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Human immunodeficiency virus type 1 Tat protein induces an intracellular calcium increase in human monocytes that requires DHP receptors: involvement in TNF-alpha production

Human immunodeficiency virus type 1 Tat protein induces an intracellular calcium increase in human monocytes that requires DHP receptors: involvement in TNF-alpha production

In addition to their presence in primary human mono- cytes, several lines of evidence support that these channels are also functional. Firstly, the stimulation of human monocytes by BayK8644-, a DHP receptor agonist, induced an intracytoplasmic increase of calcium level similar to that obtained with Tat. Secondly, preincubation of monocytes with nimodipine or calcicludine, two antagonists of DHP receptors, completely blocked the ability of Tat to stimulate calcium entry into cells. It is interesting to note that these channels seem to be voltage independent since no calcium increase was induced following stimulation of monocytes with 50 mM KCl (data not shown). This statement is in agreement with previous results showing that L-type calcium channels (DHP receptors) in immune cells, includ- ing dendritic and NK cells, are also independent of voltage ( Poggi et al., 1998; Zocchi et al., 1998 ). More recently, it was shown that DHP receptors can be selectively expressed on Th2 but not Th1 T lymphocytes ( Savignac et al., 2001 ), thus suggesting that DHP receptors are directly implicated in the production of IL-4 cytokine and in the modulation of Th2 effector function. Interestingly, the same group using the Norway rat model described a direct relationship between DHP-sensitive calcium channels and the auto- immune disease induced by chronic injection of gold salts. Indeed, treatment of rats with calcium channel blockers appeared to prevent development of the disease ( Fournie et al., 2002 ).
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Requirements for the selective degradation of CD4 receptor molecules by the human immunodeficiency virus type 1 Vpu protein in the endoplasmic reticulum

Requirements for the selective degradation of CD4 receptor molecules by the human immunodeficiency virus type 1 Vpu protein in the endoplasmic reticulum

Results: Here, we provide direct evidence indicating that Vpu promotes trans-ubiquitination of CD4 through recruitment of SCF β−TrCP in human cells. To examine whether Ub conjugation occurs on the cytosolic tail of CD4, we substituted all four Ub acceptor lysine residues for arginines. Replacement of cytosolic lysine residues reduced but did not prevent Vpu-mediated CD4 degradation and ubiquitination, suggesting that Vpu-mediated CD4 degradation is not entirely dependent on the ubiquitination of cytosolic lysines and as such might also involve ubiquitination of other sites. Cell fractionation studies revealed that Vpu enhanced the levels of ubiquitinated forms of CD4 detected in association with not only the ER membrane but also the cytosol. Interestingly, significant amounts of membrane-associated ubiquitinated CD4 appeared to be fully dislocated since they could be recovered following sodium carbonate salt treatment. Finally, expression of a transdominant negative mutant of the AAA ATPase Cdc48/p97 involved in the extraction of ERAD substrates from the ER membrane inhibited Vpu-mediated CD4 degradation.
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Human Immunodeficiency Virus Type 1 Vif causes dysfunction of Cdk1 and CyclinB1: implications for cell cycle arrest.

Human Immunodeficiency Virus Type 1 Vif causes dysfunction of Cdk1 and CyclinB1: implications for cell cycle arrest.

The HIV-1 accessory proteins Vif and Vpr block cells at the G2 phase of the cell cycle [3]. We now provide some molecular insights on how Vif induces cell cycle Figure 3 Vif-induced abnormalities in CyclinB1 and PLK1. Jurkat cells were synchronized and infected as in Figure 1 with the GFP-expressing viruses. These data are representative of three experiments with infection efficiencies ranging from 85-95% based on GFP expression. (A) CyclinB1 localizes to the nucleus in Vif-expressing cells, but is not degraded normally. Subcellular localization of CyclinB1 and Vif was determined by immunofluorescent confocal microscopy as in Figure 2 panel A using a mouse anti-Vif antibody (ARRRP) [54-56] and a rabbit anti-CyclinB1 antibody (Santa Cruz Biotechnology). (B) At least 350 cells were counted from representative fields, and the percentage of cells showing either a degraded, nuclear, or cytoplasmic phenotype for CyclinB1 were plotted at each time point. (C) CyclinB1 degradation is not observed in infected cells, and PLK1 expression is elevated in infected cells. A duplicate blot from Figure 2 panel C was probed with a mouse anti-CyclinB1 antibody (Cell Signaling Technology). PLK1 expression was examined using a mouse anti-PLK1 antibody (Upstate/Millipore). The expression of b-actin using a mouse-anti b-actin antibody (anti-b-actin, Sigma-Aldrich) is provided as a loading control.
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Manipulation of the ubiquitin-proteasome system by HIV-1 : role of the accessory protein Vpr

Manipulation of the ubiquitin-proteasome system by HIV-1 : role of the accessory protein Vpr

polyprotein via a ribosomal frameshift. Proteolytic processing of Gag-pol yields the viral enzymatic proteins protease (Pr), reverse transcriptase (RT), and integrase (IN). The env gene encodes the two envelope subunits, gp120 and gp41, which are first expressed as a single precursor protein (gp160) and later cleaved by a cellular furin-like protease. The HIV-1 genome also contains six additional genes that encode the two regulatory proteins Tat (transcriptional transactivator) and Rev (regulator of virion gene expression) and the four accessory proteins: Nef (negative factor), Vif (viral infectivity factor), Vpr (viral protein R), and Vpu (viral protein U). HIV-2 (human immunodeficiency virus type 2) and some simian immunodeficiency virus (SIV) isolates of the HIV-2/SIV sm (sooty mangabey) lineage possess a fifth accessory gene called Vpx (viral protein X), but do not encode for a Vpu protein. Tat and Rev are involved in HIV gene expression and proper splicing and export of the different mRNA species whereas the accessory proteins modulate host immune responses and facilitate viral replication in specific cell types. Except for Vpu and Env, which are expressed from the same mRNA, and Pol, which is expressed following a ribosomal frameshift, all the other HIV proteins are expressed from their own unique singly or multiply spliced mRNA. HIV genes are enclosed between two identical copies of the long terminal repeat (LTR). The LTR is subdivided in three regions: U3 (unique to 3’end), R (repeated sequence), and U5 (unique to 5’end). The transcription start site is located at the junction of U3 and R whereas the poly(A) signal is at the boundary of R and U5. Finally, the U3 region contains most of the transcriptional regulatory elements [13].
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Association between disruption of CD4 receptor dimerization and increased human immunodeficiency virus type 1 entry

Association between disruption of CD4 receptor dimerization and increased human immunodeficiency virus type 1 entry

The extracellular portion of CD4 is composed of four immunoglobulin (Ig)-like domains, designated D1 to D4; D4 being the membrane proximal domain. Crystallo- graphic studies have provided structural evidence indicat- ing that D4 is involved in dimerization of the receptor. More precisely, residues in the CC' loop and the CDR3- like region of the D4 domain were shown to be part of a putative dimer interface, with residues Q344 and Q344' having the potential to be linked by a hydrogen-bond [11]. In fact, it was shown that mutation of this highly conserved glutamine residue by a glutamic acid (Q344E) impaired the dimerization of the receptor [4]. In addition to the D4 region, two other domains have been proposed to contribute to CD4 dimerization. First, structural and functional evidence suggest that the D1 domain is impli- cated in the formation of CD4 dimers. The negatively charged CDR3-like region and the positively charged CC' loop of D1 are involved in electrostatic interactions between two CD4 molecules [12]. Moreover, Briant et al. have found that the E91K, E92K mutations in D1 reduce the capacity of the receptor to induce NF-κB nuclear trans- location following HIV-1 binding, thus suggesting that these mutations could reduce CD4 dimerization levels [13]. Finally, disulfide bonds in D2 also appear to play an important role in the formation of CD4 dimers since treatment with reducing agents was shown to strongly attenuate receptor dimerization [6].
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Production and characterization of virus-like particles of grapevine fanleaf virus presenting L2 epitope of human papillomavirus minor capsid protein.

Production and characterization of virus-like particles of grapevine fanleaf virus presenting L2 epitope of human papillomavirus minor capsid protein.

VLPs based on several plant viruses were tested, in- cluding cowpea mosaic virus (CPMV), alfalfa mosaic virus, tobacco mosaic virus, potato virus C, tomato bushy stunt virus, zucchini yellow mosaic virus, plum pox virus, papaya mosaic virus, cucumber mosaic virus and cowpea chlorotic mottle virus (CCMV) [ 22 – 27 ]. In some cases, VLP assembly takes place under certain con- ditions such as pH, ionic strength and presence of the viral genomic RNA. Morever, the potential insertion sites within the VLPs are usually limited based on the protein structure [ 28 ]. Therefore, there is a need for searching novel and versatile VLP systems. To this end, grapevine fanleaf virus (GFLV) has not been extensively studied as VLP-based platform for foreign epitope pres- entation. GFLV is a bipartite, linear, single stranded positive sense RNA genome virus which belongs to the genus Nepovirus. Considering the structural features of the GFLV capsid, it is composed of 60 copies of a single coat protein (504 amino acids, 56 kDa) without any en- velope. The ternary structure of the CP subunit is de- fined by three jelly-roll domains named C, B and A from the N- to C- termini, respectively. The viral structure has been elucidated at 2.7 Å resolution [ 29 ].
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Virus infections in pathogenesis of type 1 diabetes

Virus infections in pathogenesis of type 1 diabetes

Diabetogenic mechanisms of CVB infection Much research effort is currently focused on defining the cellular and molecular mechanisms behind the epidemiological relationship between CVB4 infection and the incidence of type 1 dia- betes. The hypothesis of a diabetogenic autoim- mune response driven by molecular mimicry between viral antigen(s) and type 1 diabetes- related autoantigens was favoured for a long time when a significant homology was discov- ered between a sequence of the P2C non-struc- tural protein of CVB4 and the glutamic acid decarboxylase 65 sequence 247–279 [8]. This hypothesis was, however, contradicted when it was found that mice with susceptible major his- tocompatibility complex alleles did not display acceleration of diabetes after CVB4 infection [9]. However, CVB4 inoculation in genetically modified mice with a T cell receptor transgene specific for an islet autoantigen led to the rapid development of diabetes [9]. This study strong- ly suggests that an autoimmune diabetogenic process follows CVB4 infection of the pancreas with local inflammation, release of islet
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Le role des virus dans la pathogenie du diabete de type 1

Le role des virus dans la pathogenie du diabete de type 1

Virus R OLE OF VIRAL INFECTIONS IN THE PATHOGENESIS OF TYPE 1 DIABETES SUMMARY : The precise role of viral infections in the patho- genesis of type 1 diabetes is still the subject of an important dis- cussion. Coxsackievirus B4 (CVB4) is the virus the most implicated by a series of epidemiological studies. Pathogenic mechanisms underlying such a relationship implicate a mole- cular mimicry between CVB4 sequences and ß-cell autoanti- gens, but mainly a persistent CVB4 infection of pancreatic ß cells followed by a release of sequestered ß antigens and a «bys- tander» activation of autoreactive T cells. The demonstration of intrathymic expression of antigens specific of peripheral tissues has opened a novel research perspective. We have shown that CVB4 is able to infect in a persistent and producive manner human thymic epithelial cell cultures and human fetal thymic lobes in organotypic cultures. This infection induces an impor- tant thymic dysfunction characterized by a severe depletion of thymocytes (thymic T cells) and an up-regulated expression by thymic epithelial and T cells of class I proteins encoded by the major histocompatibility complex (MHC-I). Such thymic dys- function might be responsible for a decrease of ß-cell central self-tolerance and anti-CVB4 cytotoxic CD8 T-cell activity. CVB4-induced thymic dysfunction would contribute in close association with the peripheral «bystander» effect to the des- truction of insulin-secreting islet ß cells and to the development of type 1 diabetes.
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Human T-cell leukemia virus type 1 (HTLV-1) Tax oncoprotein induces DNA damages through Activation-Induced cytidine Deaminase (AID)

Human T-cell leukemia virus type 1 (HTLV-1) Tax oncoprotein induces DNA damages through Activation-Induced cytidine Deaminase (AID)

How T cells are transformed by HTLV-1 is still unclear, but it is well accepted that the viral oncoprotein Tax is associated with genomic instability of infected cells. Tax has recently been shown to directly induce, in T cells, the expression of AID (Ishikawa C et al., Carcinogenesis, 2011), a cytidine deaminase whose physiologic expres- sion is usually restricted to B cells, in which it initiates class-switch recombination and somatic hypermutations to reshape the primary antibody repertoire after antigen encounter. It is also well established that AID-mediated mutations outside of immunoglobulin gene locus are involved in the oncogenic transformation of B lympho- cytes. Besides its role in B cell lymphomagenesis, AID was recently proposed to play a key role in different human cancers linked to chronic inflammation, or in cancers associated with infectious agents. We first con- firmed that both Tax+ and HTLV-1-infected T-cell lines, but not uninfected T cells expressed aid mRNA as well as AID protein. We further demonstrated that, pri- mary CD4+ T cells and MOLT-4 T-cell line transduced with lentiviral vector expressing Tax expressed high level of AID. More importantly, we also observed a high level of aid in splenic T lymphoma cells obtained from HTLV-1-infected humanized Rag2 -/- gamma c -/- mice that have developed lymphomas. We demonstrate that AID up-regulation in T cells is associated with DNA damage accumulation. Finally, inhibiting AID expression by small hairpin RNA strategy strongly decreases Tax- induced DNA damages. Altogether our data strongly
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Patient Preference and Adherence Dovepress evaluating patient preference and satisfaction for human immunodeficiency virus therapy in France

Patient Preference and Adherence Dovepress evaluating patient preference and satisfaction for human immunodeficiency virus therapy in France

Certain limitations associated with the DCE methodol- ogy should be considered. This powerful multidimensional tool is used to analyze simultaneously the influence of multiple attributes, the ORs providing information about the relative importance of each attribute. However, the performed analysis does not allow comparison of the ORs between the different attributes. It is also difficult to compare the importance of different attributes, expressed in different units. For example, the viral load is expressed as copies/mL, whereas other attributes are presented as probabilities or categorical variables. Finally, although the chosen attributes and their levels had been selected from a literature review and from discussion with clinicians and expert patients, it is possible that other characteristics of treatments influencing patient preferences were not evalu- ated. One of the main limitations of the qualitative part of the study is that the trends and themes developed are only representative of those patients in the study sample and may not be generalized to represent the views of PLWH across the whole country.
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Isolation of Nontuberculous Mycobacteria in Southeast Asian and African Human Immunodeficiency Virus-infected Children With Suspected Tuberculosis

Isolation of Nontuberculous Mycobacteria in Southeast Asian and African Human Immunodeficiency Virus-infected Children With Suspected Tuberculosis

ATS criteria for NTM diagnosis and treatment decision in adults have not been validated for children, especially HIV- infected children with severe immunodeficiency, and there is currently no internationally accepted definition for NTM respiratory disease in children [ 2 ]. In children with severe immunodeficiency, NTM isolation was more frequent, MAC being isolated in more than half of cases, and frequently con- firmed on another sample, supporting the hypothesis of NTM- related opportunistic infection in children from our study. However, unlike bacteriologically confirmed TB, which was associated with a 5-fold increase in mortality in ART-naive children in our study despite access to anti-TB treatment, NTM or MAC isolation was not associated with a higher risk of death in children with severe immunodeficiency [ 12 ]. In
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Structural and functional studies of the HIV-1 pre-integration complex

Structural and functional studies of the HIV-1 pre-integration complex

P O S T E R P R E S E N T A T I O N Open Access Structural and functional studies of the HIV-1 pre-integration complex Nicolas Levy 1 , Sylvia Eiler 1 , Karine Pradeau-Aubreton 1 , Corinne Crucifix 1 , Aurélie Schaetzel 1 , Robert Drillien 1 , Vincent Parissi 2 , Stéphane Emiliani 3 , Yves Mely 4 , Patrick Schultz 1 , Marc Ruff 1*

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Syphilis treatment in the human immunodeficiency virus-infected patient: follow the guidelines.

Syphilis treatment in the human immunodeficiency virus-infected patient: follow the guidelines.

Corr. Author : Fre´de´ric Frippiat INSTRUCTIONS We encourage you to use Adobe’s editing tools (please see the next page for instructions). If this is not possible, please (i) reply to this message and send a list of corrections (in an email or as an attachment (either as a Word.doc or as a scan)) that lists each change in the following manner: line number, current text, change to be made, or (ii) print out the proof, mark your corrections clearly in black ink, and fax it to [144 (0) 1865 313489]. Please do not send corrections as track changed Word documents.

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Caractérisation de la migration du virus Herpès simplex de type 1 (HSV-1) par protéomique

Caractérisation de la migration du virus Herpès simplex de type 1 (HSV-1) par protéomique

DISCUSSION Efficacy of the proteomic approach. Three criteria are essential for proteomics studies, namely purity, sensitivity and accuracy. First, examination of sample purity by EM revealed a homogeneous virion preparation free of cellular debris, small contaminating vesicles and L-particles (Fig. 3). Importantly, the latter were not expected as the sample was passed over a Ficoll gradient known to effectively segregate them (92). Moreover, the purified sample was highly infectious (data not shown). Contamination by other components was also deemed non significant based on the lack of intracellular naked capsids, mitochondria, nuclei and other organelles that would result from extensive cell lysis (Fig. 3). In addition, preVP22a, VP21 or full length U L 26, all markers of immature capsids (reviewed in Baines et al (4)), were absent in our sample (Tables 1 & 2). Similarly, the absence of U L 31 and U L 34, known to solely interact with nuclear capsids, is additional evidence that cell lysis and cellular contamination were minimal. Finally, further purification of the virions by additional means did not improve sample purity, suggesting the virions were already pure (data not shown). Second, sensitivity was very high as the assay readily detected both low copy (U L 6) and low molecular weight proteins (ex: U L 11 and U S 9). Moreover, this extended to hydrophobic proteins, such as the multi-membrane spanning gM glycoprotein. Third, accuracy was very significant with an estimated 95.1% overall rate. The similar detection of the viral proteins in the two unrelated HeLa and BHK cell lines is further evidence of the accuracy of the data (Fig. 7). Finally, the results were validated by Western blotting against several individual proteins. The proteomics approach was thus an accurate and efficient mean to address HSV-1 virion composition.
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Impact of Human Immunodeficiency Virus on the Severity of Buruli Ulcer Disease: Results of a Retrospective Study in Cameroon

Impact of Human Immunodeficiency Virus on the Severity of Buruli Ulcer Disease: Results of a Retrospective Study in Cameroon

Our study has some limitations. Observational studies suffer the inherent drawback of uncontrolled bias. Bone involvement, surgical care, antimycobacterial treatment, and ART can all be confounders in the time-to-heal BU analysis. However, we were unable to include these in the analysis due to a lack of data or because they were time- and physician-dependent variables and would have required other statistical models. No conclusion can be drawn on the effect of ART on BU, including possible wors- ening of BU lesions due to its initiation (immune reconstitution in flammatory syndrome). Finally, not all BU cases could be confirmed with a second diagnostic method as recommended by WHO [ 11 ]. However, the number of misdiagnosed BU is most probably very low given the high proportion of PCR- con firmed cases and the clear clinical picture of most of our patients.
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