8 research outputs found
Molecular interactions between human herpesviruses and the human immunodeficiency virus type 1
Human immunodeficiency virus type 1 (HIV-1) is the etiologic agent that causes acquired immunodeficiency syndrome (AIDS). HIV-1 infected individuals frequently are infected with other viruses, including herpesviruses. Lymphocytic cells infected with both HIV-1 and human herpesvirus 6 (HHV-6), can enhance cytopathic effects caused by viral infection. Previously, several HHV-6 genes have been identified that enhance transcription of HIV-1. Since HIV-1 is capable of trans-activating herpesviruses, a reciprocal interaction between the two viruses is possible. Interactions between HIV-1 and HHV-6 were analyzed in lymphocytes. Dually infected cells show an increased HHV-6 viral titer, an increase in HHV-6 RNA, and an increase in HHV-6 protein synthesis. Similarly, T-cells transfected with the entire HIV proviral genome, or the HIV-1 trans-activator gene, tat, displayed an increase in HHV-6 viral production. The bi-directional interactions between HHV-6 and HIV-1 may accelerate depletion of CD4\sp+ T-cells, leading to progression to AIDS. Molecular mechanisms of tat activation include transcriptional activation of several HHV-6 promoters. However, tat-containing cell extracts did not contain factors that can bind specifically to the HHV-6 promoter DNA elements. Body cavity-based lymphoma, a rare lymphocytic tumor, and Kaposi\u27s sarcoma (KS) associated with human herpesvirus type 8 (HHV-8) are manifestations seen in HIV-1 infected individuals with more frequency then uninfected individuals. Recent work indicates that HIV-tat is important in the pathogenesis of KS; thus, we wanted to analyze the effect of tat on HHV-8. We have found that HIV-1 tat can stimulate HHV-8 viral DNA load in two chronically infected cell lines as well as in monocytic cells from immunosuppressed individuals. The promoters of several HHV-8 genes were found to be activated by tat in transfection assays, suggesting a mechanism for up-regulation of HHV-8 by tat. These results indicate that HIV-1 may play a role in the development of HHV-8-associated diseases via tat-mediated activation of HHV-8
HUMAN HERPESVIRUS 8 CAN BE TRANSMITTED THROUGH BLOOD IN DRUG ADDICTS
Human Herpes virus type-8 (HHV-8) seroprevalence was studied in a population of HIV positive intravenous drug users (IVDUs) from Argentina. Analysis of this population also indirectly made it possible to study HHV-8 blood transmission, because these individuals frequently engage in needle sharing behavior and are capable of acquiring a broad array of blood borne pathogens, including Hepatitis B/C virus. The seroprevalence of HHV-8 in IVDUs was compared to a group of non-IVDUs and HIV negative individuals. Of the 223 individuals tested, 13.45% were HHV-8 positive, 16.99% in the IVDUs group, and 5.71% in the non-IVDUs. Among HIV positive IVDUs, 25/144 (17.36%) were also HHV-8 seropositive. The seropositivity rate of HHV-8 in HIV negative IVDUs was 11.1%. In contrast, HHV-8 seroprevalence in HIV negative heterosexual individuals without drug usage behavior was even lower (5.71%). The rate of HHV-8 infection in HIV positive IVDUs was three times as high compared to the non IVDU HIV negative individuals, suggesting that IVDU is a risk for HHV-8 infection. Furthermore, it was found that IVDUs showed a very high rate of Hepatitis B/C (52.77%), which also correlate with HHV-8 infection in this population (23.68%). All Hepatitis B/C positive individuals were also HIV positive. Our data confirm other studies showing that individuals who share needles are at risk for acquiring Hepatitis B/C and HIV infections. In addition, our results suggest that they are also at risk to acquiring HHV-8 infection by the same route
Herpesvirus-like DNA in AIDS Kaposi’s Sarcoma in Argentina [Letter to the Editor]
First paragraph: Recently, Chang et al., using a new molecular biology technique termed Representational Difference Analysis, found herpesvirus-like DNA (KSHV) in AIDS patients with Kaposi’s sarcoma (KS). The presence of KSHV DNA sequences suggests that a new human herpesvirus may be associated with KS. The 5′ end of the 1853-bp flanking region of KSHV (nucleotides 1 to 607) was found to have 66 and 67% homologies to the corresponding regions of the major capsid protein gene of Herpesvirus Saimiri (ORF25) and Epstein Barr virus (BcLF1), respectively, both members of the gammaherpesvirus family. This finding is an important breakthrough, because a sexually transmitted agent was suspected to cause KS. The putative virus was also detected in classical KS and in African endemic KS found in young black individuals from sub-Saharan regions. KSHV sequences have also been identified in KS tissues from Taiwanese and French patients
Effect of sequential inoculation (Torulaspora delbrueckii/Saccharomyces cerevisiae) in the first fermentation on the foam properties of sparkling wine (Cava)
In a previous study we reported that sequential inoculation of Torulaspora delbrueckii and Saccharomyces cerevisiae during the first fermentation increased the protein concentration and improved the foaming properties of a base wine. Since effervescence and foam of sparkling wines are key quality factors, the interest of this practice for sparkling wine industry is obvious. In this paper we study whether the foaming properties of the sparkling wines produced from the base wines obtained by sequential inoculation with T. delbrueckii and S. cerevisiae remains better than those of their controls produced from base wines fermented only with S. cerevisiae. The obtained results confirmed that sequential inoculation in the production of the base wine originated sparkling wines with significantly higher maximum heights of foam than conventional inoculation, probably because autolysis of the T. delbrueckii cells in the base wine released higher amounts of proteins, especially of the low molecular weight fraction
Effect of sequential inoculation (Torulaspora delbrueckii/Saccharomyces cerevisiae) in the first fermentation on the foam properties of sparkling wine (Cava)
In a previous study we reported that sequential inoculation of Torulaspora delbrueckii and Saccharomyces cerevisiae during the first fermentation increased the protein concentration and improved the foaming properties of a base wine. Since effervescence and foam of sparkling wines are key quality factors, the interest of this practice for sparkling wine industry is obvious. In this paper we study whether the foaming properties of the sparkling wines produced from the base wines obtained by sequential inoculation with T. delbrueckii and S. cerevisiae remains better than those of their controls produced from base wines fermented only with S. cerevisiae. The obtained results confirmed that sequential inoculation in the production of the base wine originated sparkling wines with significantly higher maximum heights of foam than conventional inoculation, probably because autolysis of the T. delbrueckii cells in the base wine released higher amounts of proteins, especially of the low molecular weight fraction
Influence of supplementation with inactivated dry yeasts during the tirage of sparkling wines (Cava) on its composition, its foaming properties and its sensorial quality
Different sparkling wines were elaborated with a base wine of Macabeo from the AOC Cava using the traditional method with supplementation or not of inactivated dry yeasts of Saccharomyces cerevisiae (OptimumwhiteTM) or Torulaspora delburueckii (TD291). After 9 months, the samples were analyzed and tasted. The supplementation with both IDY (S. cerevisiae and T. delbrueckii) produced Cavas with better foaming properties than the Cava control. The tasters could significantly distinguish between the Cavas supplemented with both IDY from the Cava control. Moreover, taster clearly preferred the Cava elaborated with supplementation of IDY of T. delburueckii than the control one
Influence of supplementation with inactivated dry yeasts during the tirage of sparkling wines (Cava) on its composition, its foaming properties and its sensorial quality
Different sparkling wines were elaborated with a base wine of Macabeo from the AOC Cava using the traditional method with supplementation or not of inactivated dry yeasts of Saccharomyces cerevisiae (OptimumwhiteTM) or Torulaspora delburueckii (TD291). After 9 months, the samples were analyzed and tasted. The supplementation with both IDY (S. cerevisiae and T. delbrueckii) produced Cavas with better foaming properties than the Cava control. The tasters could significantly distinguish between the Cavas supplemented with both IDY from the Cava control. Moreover, taster clearly preferred the Cava elaborated with supplementation of IDY of T. delburueckii than the control one
Food Microbiol
Lot of articles report on the impact of polyphenols on wine lactic acid bacteria, but it is clear that the results still remain confusing, because the system is complicated both in term of chemical composition and of diversity of strains. In addition, red wines polyphenols are multiple, complex and reactive molecules. Moreover, the final composition of wine varies according to grape variety and to extraction during winemaking. Therefore it is nearly impossible to deduce their effects on bacteria from experiments in oversimplified conditions. In the present work, effect of tannins preparations, currently considered as possible technological adjuvants, was assessed on growth and malolactic fermentation for two malolactic starters. Experiments were conducted in a laboratory medium and in a white wine. Likewise, impact of total polyphenolic extracts obtained from different grape variety red wines was evaluated in the white wine as culture medium. As expected growth and activity of both strains were affected whatever the additions. Results suggest some interpretations to the observed impacts on bacterial populations. Influence of tannins should be, at least partly, due to redox potential change. Results on wine extracts show the need for investigating the bacterial metabolism of some galloylated molecules. Indeed, they should play on bacterial physiology and probably affect the sensory qualities of wines