Replication of HIV-1 deleted Nef mutants in chronically immune activated human T cells

Infectious diseases among Ethiopian immigrants in Israel: a descriptive literature review

The mass immigration of Ethiopian Jews to Israel began in the 1980s. For most of these immigrants this was a time of sharp transition from a village life with very basic living conditions, in most cases without a regular supply of water, electricity, or healthcare services, to a modern Western urban society. The aim of this review was to search the medical literature on the characteristics of infectious diseases that are typical in Ethiopian immigrants (EI), using relevant keywords. There has been success in coping with diseases among EI, that are rare although recognized in Israel, in terms of screening and early identification. TB was common in Ethiopia over all the years of immigration to Israel. In contrast, HIV appeared in EI from 1999 when they had long stayovers in transition camps in Gondar and Addis Ababa where there was a high risk of infection with sexually transmitted diseases. There were often delays in diagnosing 'exotic' diseases that are endemic in Africa, but not well known in Israel, such as Onchocerciasis, Schistosomiasis, Strongyloidiasis, and Bartonella endocarditis, which cause severe morbidity and mortality among EI. We describe the effect on general morbidity in Israel, and how the healthcare services coped with these diseases, including obstacles, and failures and successes. In light of the ongoing immigration of African refugees to the United States and Europe, the Israeli experience can be of value to healthcare policy makers in developing strategies for the effective management by medical staff treating these immigrants.

Genital schistosomiasis and its unacknowledged role on HIV transmission in the STD intervention studies

Treatment of sexually transmitted infections (STIs) has been hypothesised to decrease HIV transmission. Although observational studies show an association between STIs and HIV, only one prospective randomised controlled trial (RCT) has confirmed this. Female genital schistosomiasis can cause genital lesions, accompanied by bloody discharge, ulcers or malodorous discharge. Genital schistosomiasis is common, starts before puberty and symptoms can be mistaken for STIs. Three observational studies have found an association between schistosomiasis and HIV. Genital lesions that develop in childhood are chronic. This paper sought to explore the possible effects of schistosomiasis on the RCTs of STI treatment for HIV prevention.

In the study sites, schistosomiasis was a likely cause of genital lesions. The studies recruited women that may have had genital schistosomal lesions established in childhood. Schistosomiasis endemic areas with different prevalence levels may have influenced HIV incidence in intervention and control sites differently, and some control group interventions may have influenced the impact of schistosomiasis on the study results. Schistosomiasis is a neglected cause of genital tract disease. It may have been an independent cause of HIV incidence in the RCTs of STI treatment for HIV prevention and may have obscured the findings of these trials.

Interactions between Nef and AIP1 proliferate multivesicular bodies and facilitate egress of HIV-1

Background

Nef is an accessory protein of primate lentiviruses, HIV-1, HIV-2 and SIV. Besides removing CD4 and MHC class I from the surface and activating cellular signaling cascades, Nef also binds GagPol during late stages of the viral replicative cycle. In this report, we investigated further the ability of Nef to facilitate the replication of HIV-1.

Results

To this end, first the release of new viral particles was much lower in the absence of Nef in a T cell line. Since the same results were obtained in the absence of the viral envelope using pseudo-typed viruses, this phenomenon was independent of CD4 and enhanced infectivity. Next, we found that Nef not only possesses a consensus motif for but also binds AIP1 in vitro and in vivo. AIP1 is the critical intermediate in the formation of multivesicular bodies (MVBs), which play an important role in the budding and release of viruses from infected cells. Indeed, Nef proliferated MVBs in cells, but only when its AIP1-binding site was intact. Finally, these functions of Nef were reproduced in primary macrophages, where the wild type but not mutant Nef proteins led to increased release of new viral particles from infected cells.

Conclusion

We conclude that by binding GagPol and AIP1, Nef not only proliferates MVBs but also contributes to the egress of viral particles from infected cells.

Long-term productive human immunodeficiency virus infection of CD1a-sorted myeloid dendritic cells

Myeloid, CD1a-sorted dendritic cells (MDC) productively replicated human immunodeficiency virus strains encoding envelope genes of either primary X4R5 or R5 strains for up to 45 days. Cell-free supernatant collected from long-term infected MDC, which had been exposed to an X4R5 virus 45 days earlier, was still infectious when placed over activated T cells. These data imply that DC can act as a persistent reservoir of infectious virus.