Design aspects of a case-control clinical investigation of the effect of HIV on oral and gastrointestinal soluble innate factors and microbes

Review on the Alteration of Gut Microbiota: The Role of HIV Infection and Old Age

Human immunodeficiency virus (HIV) infection results in gut microbiota alteration and this is associated with immune activation and chronic inflammation. The gastrointestinal tract is a primary site of viral replication and thus HIV-induced loss of T-helper (Th) cells in the gut causes impairments in intestinal barriers, resulting in disruptions in intestinal immunity and precipitating into gut dysbiosis. Here, we show that late HIV diagnosis can negatively affect the immunological, virological, and clinical prognosis of the patients with its higher implication at an older age. Further, the review indicates that antiretroviral therapy affects the gut microbiota. We discussed the use of probiotics and prebiotics that have been indicated to play a promising role in reversing gut microbiota alteration in HIV patients. Though there are several studies reported with regard to such alterations in gut microbiota regarding HIV infection, there is a need to provide comprehensive updates. It is, therefore, the objective of this review to present most recently available evidence on the alteration of gut microbiota among HIV patients.

Innate immunity in HIV-1 infection: epithelial and non-specific host factors of mucosal immunity- a workshop report

The interplay between HIV-1 and epithelial cells represents a critical aspect in mucosal HIV-1 transmission. Epithelial cells lining the oral cavity cover subepithelial tissues, which contain virus-susceptible host cells including CD4(+) T lymphocytes, monocytes/macrophages, and dendritic cells. Oral epithelia are among the sites of first exposure to both cell-free and cell-associated virus HIV-1 through breast-feeding and oral-genital contact. However, oral mucosa is considered to be naturally resistant to HIV-1 transmission. Oral epithelial cells have been shown to play a crucial role in innate host defense. Nevertheless, it is not clear to what degree these local innate immune factors contribute to HIV-1 resistance of the oral mucosa. This review paper addressed the following issues that were discussed at the 7th World Workshop on Oral Health and Disease in AIDS held in Hyderabad, India, during November 6-9, 2014: (i) What is the fate of HIV-1 after interactions with oral epithelial cells?; (ii) What are the keratinocyte and other anti-HIV effector oral factors, and how do they contribute to mucosal protection?; (iii) How can HIV-1 interactions with oral epithelium affect activation and populations of local immune cells?; (iv) How can HIV-1 interactions alter functions of oral epithelial cells?

The gut and oral microbiome in HIV disease: a workshop report

Recent years have seen a massive expansion in our understanding of how we interact with our microbial colonists. The development of new, rapid sequencing techniques such as pyrosequencing and other next-generation sequencing systems have enabled us to begin to characterise the constituents of our diverse microbial communities, revealing the astonishing genetic richness that is our microbiome. Despite this, our ignorance of how these communities change over the course of an HIV infection is profound. Whilst some steps have been made to characterise the HIV microbiome at selected sites, these reports are still limited and much remains to be done. It has become apparent, however, that host-microbiota interactions are perturbed during HIV infections, with microbial translocation of potential pathogens linked to a variety of different HIV complications, including more rapid progression of disease. The use of probiotics and prebiotics has been investigated as treatments to alleviate symptoms for a variety of conditions, and is now being proposed for the treatment of symptoms associated with HIV. However, this is a new area of investigations and many questions remain unanswered. What we know about both of these topics is a drop in the ocean compared with what we need to know. In this article, we report on a workshop where these two major under-investigated research areas were presented, and future directions explored and discussed.

Modulation of the orodigestive tract microbiome in HIV-infected patients

More than 37 million people are living with human immunodeficiency virus 1 (HIV), and more people than ever received lifesaving antiretroviral therapy worldwide. HIV-1 infection disrupts the intestinal immune system, leading to microbial translocation and systemic immune activation. We investigated the impact of HIV-1 infection on the GI microbiome and its association with host immune activation. The data indicated that the microbiome was different in HIV-positive and HIV-negative individuals. The initial sequence analysis of saliva indicated that there were major differences in the phyla of Bacteroidetes, Firmicutes, Proteobacteria, and TM7. Phylum Tenericutes was only seen in HIV-positive saliva. At the family level, we identified differences in Streptococcacea, Prevotellaceae, Porphyromonadaceae, and Neisseriaceae, whereas data from various sites in GI tract indicated that Prevotella melaninigencia, Fusobacterium necrophorum, Burkholderia, Bradyrhizobium, Ralstonia, and Eubacterium biforme were predominant but differentially present at various sites. Furthermore, there was a decrease in seven proteins associated with the alternative complement pathway and an increase in 6 proteins associated with the lectin and classical complement pathways. The correlation with a shift in complement pathways suggests that compromised immunity could be responsible for the observed dysbiosis in the GI microbiome.

Comorbidities associated with HIV and antiretroviral therapy (clinical sciences): a workshop report

In the era of combination antiretroviral therapy (ART), parsing out the effects of HIV vs ART on health outcomes is challenging. Nadir CD4 count, a marker of the extent of immunosuppression, has significant long-term impact on an array of disease states in HIV+ persons; however, in the dental literature, reporting of pre-ART exposure to immunosuppression has largely been ignored and this limits the validity of previous studies. In Workshop A1, we explain fully the importance of nadir CD4, pre-ART immunosuppression, and identify a need to include specific variables in future research. The questions posed herein are challenging, typically not neatly addressed by any one study and require integration of the latest evidence from the wider medical literature. We consider topics beyond the confines of the oral cavity and examine oral health in the complex context of ART era HIV immunopathophysiology. We depict how variability in geographic setting and time period (pre- and post-ART era) can impact oral conditions - influencing when HIV infection was detected (at what CD4 count), the type and timing of ART as well as social determinants such as strong stigma and limited access to care. We hope our Workshop will stir debate and energize a rigorous focus on relevant areas of future research in HIV/AIDS.

A Rapid, Self-confirming Assay for HIV: Simultaneous Detection of Anti-HIV Antibodies and Viral RNA

Objective

We developed a microfluidic system to simultaneously detect host anti-HIV antibodies and viral RNA in the same specimen in order to satisfy two important diagnostic criteria, especially within resource-limited settings. First, the system can detect acute HIV infection and allow immediate confirmation of a seropositive screening result by detection of HIV RNA. It also addresses the well-known "seroconversion window" during early HIV infection when antibodies are not yet detectable and viral loads are at their highest.

Methods

We first developed and optimized two separate manual assays for the detection of host anti-HIV antibodies and viral RNA and then converted them to the microfluidic system. We optimized a commercially available serologic assay to run within the microfluidic device while we incorporated the isothermal LAMP assay to detect the presence of viral RNA. The microfluidic device and instrumentation were developed to simultaneously perform both assays without any user intervention.

Results

The finalized system consists of a disposable injection molded and film-laminated microfluidic CARD disposable device and a portable, software controlled instrument, which together can automatically perform all steps of both assays without any user intervention after the initial loading of samples and reagents. The microfluidic CARD cartridge has multiple microchannels, valves, pumps and reservoirs, which perform the immunoassay, isolates viral RNA for detection by magnetic bead based purification, and Reverse Transcriptase loop-mediated isothermal amplification (RT-LAMP). The microfluidic system was able to detect host anti-HIV antibodies and viral RNA in either a blood or saliva sample.

Conclusion

The ability to detect antibodies and simultaneously confirm a seropositive HIV-RNA result provides healthcare workers with a complete and accurate appraisal of a patient's infection status in the earliest stages of the disease and represents an important tool for the "Test and Treat" and "Treatment as Prevention" approaches for controlling the HIV epidemic.

Rapid Point-of-Care Isothermal Amplification Assay for the Detection of Malaria without Nucleic Acid Purification

Malaria remains one of the most prevalent infectious diseases and results in significant mortality. Isothermal amplification (loop-mediated isothermal amplification) is used to detect malarial DNA at levels of ~1 parasite/µL blood in ≤30 minutes without the isolation of parasite nucleic acid from subject’s blood or saliva. The technique targets the mitochondrial cytochrome oxidase subunit 1 gene and is capable of distinguishing Plasmodium falciparum from Plasmodium vivax. Malarial diagnosis by the gold standard microscopic examination of blood smears is generally carried out only after moderate-to-severe symptoms appear. Rapid diagnostic antigen tests are available but generally require infection levels in the range of 200–2,000 parasites/µL for a positive diagnosis and cannot distinguish if the disease has been cleared due to the persistence of circulating antigen. This study describes a rapid and simple molecular assay to detect malarial genes directly from whole blood or saliva without DNA isolation.