Persistent But Not Replicating HIV-1 Cell-Associated DNA in Semen of Long-Term ART Experienced Men.

BACKGROUND: The semen of HIV-1 infected men represents the main vector of HIV-1 spread following sexual transmission of cell-free or cell-associated virions. OBJECTIVE: The present study aimed to assess the impact of HAART on HIV-1 RNA/DNA and on inflammatory environment in the semen of long-term HAART-experienced men. METHODS: Forty-five paired samples of semen and blood were obtained from 37 consenting men, 10 untreated and 27 under HAART. Blood and seminal HIV RNA and DNA loads were quantified by the Abbott RealTime m2000rt assay and an inhouse real-time PCR protocol, respectively. Tat/rev/nef intra-cellular mRNA was tested by qualitative PCR. Interleukin (IL)- 1ß, IL-2, IL-6, IL-7, IL-8, IL-10, GM-CSF and TNFα were quantified in 20 paired samples by Bio-plex® assay. RESULTS: No semen was found HIV RNA positive in men under HAART. Twenty-six percent of semen samples from HAART-experienced men remained positive for HIV DNA. Seminal HIV DNA was significantly associated with the duration of infection and the HIV DNA load in blood. No seminal mononuclear cells were found positive for intracellular HIV RNA in HAART experienced men. All the tested chemokines exhibited significantly higher concentration in semen than in blood in both treated and untreated men. No effect of HAART on cytokines/chimiokines loads was observed. CONCLUSION: These results demonstrate the efficacy of HAART on the reduction of seminal RNA HIV-1 loads despite the persistence of local inflammation. Moreover, in our hands the seminal cell-associated virus reservoir was not reactivated in an inflammatory environment was not productive and its reactivation seems unlikely.

Study of Coxsackie B viruses interactions with Coxsackie Adenovirus receptor and Decay-Accelerating Factor using Human CaCo-2 cell line.

BACKGROUND: Decay Accelerating Factor (DAF) and Coxsackievirus-Adenovirus Receptor (CAR) have been identified as cellular receptors for Coxsackie B viruses (CV-B). The aim of this study is to elucidate the different binding properties of CV-B serotypes and to find out if there are any amino acid changes that could be associated to the different phenotypes.Twenty clinical CV-B isolates were tested on CaCo-2 cell line using anti-DAF (BRIC216) and anti-CAR (RmcB) antibodies. CV-B3 Nancy prototype strain and a recombinant strain (Rec, CV-B3/B4) were tested in parallel. The P1 genomic region of 12 CV-B isolates from different serotypes was sequenced and the Trans-Epithelial Electrical Resistance (TEER) along with the virus growth cycle was measured. RESULTS: Infectivity assays revealed clear differences between CV-B isolates with regard to their interactions with DAF and CAR. All tested CV-B isolates showed an absolute requirement for CAR but varied in their binding to DAF. We also reported that for some isolates of CV-B, DAF attachment was not adapted. Genetic analysis of the P1 region detected multiple differences in the deduced amino acid sequences. CONCLUSION: Within a given serotype, variations exist in the capacity of virus isolates to bind to specific receptors, and variants with different additional ligands may arise during infection in humans as well as in tissue culture.

Basic rationale, current methods and future directions for molecular typing of human enterovirus.

Enterovirus is a genus of the Picornaviridae family including more than 80 serotypes belonging to four species designed Human enterovirus A to D. The antigens of the structural proteins support the subdivision of enteroviruses into multiple serotypes. Comparative phylogeny based on molecular typing methods has been of great help to classify former and new types of enterovirus, and to investigate the diversity of enteroviruses and the evolutionary mechanisms involved in their diversity. By now, molecular typing methods of enterovirus rely mainly on the sequencing of an amplicon targeting a variable part of the region coding for the capsid proteins (VP1 and, alternatively, VP2 or VP4), either from a strain recovered by cell culture or, more recently, by direct amplification of a clinical or environmental specimen. In the future, microarrays are thought to play a major role in enterovirus typing and in the analysis of the determinants of virulence that support the puzzling diversity of the pathological conditions associated with human infection by these viruses.

Natural recombination event within the capsid genomic region leading to a chimeric strain of human enterovirus B.

Recombination between two strains is a known phenomenon for enteroviruses replicating within a single cell. We describe a recombinant strain recovered from human stools, typed as coxsackievirus B4 (CV-B4) and CV-B3 after partial sequencing of the VP1 and VP2 coding regions, respectively. The strain was neutralized by a polyclonal CV-B3-specific antiserum but not by a CV-B4-specific antiserum. The nucleotide sequence analysis of the whole structural genomic region showed the occurrence of a recombination event at position 1950 within the VP3 capsid gene, in a region coding for the 2b antigenic site previously described for CV-B3. This observation evidences for the first time the occurrence of an interserotypic recombination within the VP2-VP3-VP1 capsid region between two nonpoliovirus enterovirus strains. The neutralization pattern suggests that the major antigenic site is located within the VP2 protein.

Typing of human enterovirus by partial sequencing of VP2.

The sequencing of the VP1 hypervariable region of the human enterovirus (HEV) genome has become the reference test for typing field isolates. This study describes a new strategy for typing HEV at the serotype level that uses a reverse transcription-PCR assay targeting the central part of the VP2 capsid protein. Two pairs of primers were used to amplify a fragment of 584 bp (with reference to the PV-1 sequence) or a part of it (368 bp) for typing. For a few strains not amplified by the first PCR, seminested primers enhanced the sensitivity (which was found to be approximately 10(-1) and 10(-4) 50% tissue culture infective dose per reaction tube for the first and seminested assay, respectively). The typing method was then applied to 116 clinical and environmental strains of HEV. Sixty-one typeable isolates were correctly identified at the serotype level by comparison to seroneutralization. Forty-eight of 55 "untypeable" strains (87.3%) exhibited the same serotype using VP1 and VP2 sequencing methods. For six strains (four identified as EV-71, one as E-9, and one as E-30 by the VP2 method), no amplification was obtained by the VP1 method. The last strain, typed as CV-B4 by VP1 and CV-B3 by VP2 and monovalent antiserum, could exhibit recombination within the capsid region. Although the VP2 method was tested on only 36 of the 68 HEV serotypes, it appears to be a promising strategy for typing HEV strains isolated on a routine basis. The good sensitivity of the seminested technique could avoid cell culture and allow HEV typing directly from PCR products.

Enterovirus in arteriosclerosis: a pilot study.

BACKGROUND: Various pathogens have been suspected to play a role in the initiation or amplification of the atherosclerotic lesions. Both experimental and epidemiological arguments plead for a possible role of enterovirus in this process. OBJECTIVE: To determine the prevalence of enterovirus genome in atherosclerotic plaques, in comparison with Chlamydia pneumoniae, human cytomegalovirus (hCMV) and herpes simplex virus. STUDY DESIGN: Pilot study on 18 patients who underwent artery resection. Five artery samples were tested for each patient and each pathogen by using PCR techniques whose sensitivity was evaluated for this kind of specimen. The quality of the extraction step was assessed by amplification of a fragment of the human aldolase A gene. RESULTS: The genome of at least one infectious agent was detected in artery samples from 7 of the 18 patients (38.9%). In all cases, only one of the five aliquots was found positive; a confirmation was done by sequencing the PCR product. With regards to enterovirus, four patients (22.2%) were detected positive (one of them being also positive for hCMV). CONCLUSIONS: These results suggest that small amounts of enterovirus genome are commonly found in lesions of patients with advanced arteriosclerosis. Further studies are needed to evaluate the clinical significance of this association.