Latency reversal plus natural killer cells diminish HIV reservoir in vivo

HIV is difficult to eradicate due to the persistence of a long-lived reservoir of latently infected cells. Previous studies have shown that natural killer cells are important to inhibiting HIV infection, but it is unclear whether the administration of natural killer cells can reduce rebound viremia when anti-retroviral therapy is discontinued. Here we show the administration of allogeneic human peripheral blood natural killer cells delays viral rebound following interruption of anti-retroviral therapy in humanized mice infected with HIV-1. Utilizing genetically barcoded virus technology, we show these natural killer cells efficiently reduced viral clones rebounding from latency. Moreover, a kick and kill strategy comprised of the protein kinase C modulator and latency reversing agent SUW133 and allogeneic human peripheral blood natural killer cells during anti-retroviral therapy eliminated the viral reservoir in a subset of mice. Therefore, combinations utilizing latency reversal agents with targeted cellular killing agents may be an effective approach to eradicating the viral reservoir.

COVID-19 AND THE HUMAN EYE – CONJUNCTIVITIS A LONE COVID-19 FINDING - A case-control study

Background: The worldwide sudden appearance and drastic increase in the number of infected cases with the severe acute respiratory syndrome-Coronavirus 2 (SARS-CoV-2) determined the World Health Organization to declare it as a pandemic situation. The ‘Corona Virus Disease 2019’ (COVID-19) has varied clinical manifestations, from asymptomatic to severe cases, and conjunctivitis, seems not only to be one of them, but sometimes found to be lone initial symptom present. Aim and method: The aim was to identify the prevalence of conjunctivitis as the first symptom in COVID-19 patients, in a primary healthcare unit. A retrospective study was conducted analyzing the presenting complains/symptoms and results of COVID-19 confirmatory tests. Results: Out of the 672 cases that were sent for RT-PCR testing only 121 (18%) were found to be positive. Among this 2.67% of patients who had both conjunctivitis and COVID-19, 77.77% of patients had unilateral eye affected while 22.22% had bilateral conjunctivitis of varying degrees. 15 patients diagnosed to have both acute conjunctivitis and COVID-19, presented other symptoms associated with COVID-19 infection. While 3 patients had only acute conjunctivitis during their entire course of COVID-19. Conclusions: Conjunctivitis is a symptom of COVID-19 and maybe the first sign of the infection, until the onset of the classical manifestations, the patient serves to be a viral reservoir. The physicians should not miss unilateral conjunctivitis, as it can be the only presenting complain of the COVID-19 disease at the initial phase, which might worsen if underwent undetected and can aid in the spread of the contagion.

New Approaches to Dendritic Cell-Based Therapeutic Vaccines Against HIV-1 Infection

Due to the success of combined antiretroviral therapy (cART) in recent years, the pathological outcome of Human Immunodeficiency Virus type 1 (HIV-1) infection has improved substantially, achieving undetectable viral loads in most cases. Nevertheless, the presence of a viral reservoir formed by latently infected cells results in patients having to maintain treatment for life. In the absence of effective eradication strategies against HIV-1, research efforts are focused on obtaining a cure. One of these approaches is the creation of therapeutic vaccines. In this sense, the most promising one up to now is based on the establishing of the immunological synapse between dendritic cells (DCs) and T lymphocytes (TL). DCs are one of the first cells of the immune system to encounter HIV-1 by acting as antigen presenting cells, bringing about the interaction between innate and adaptive immune responses mediated by TL. Furthermore, TL are the end effector, and their response capacity is essential in the adaptive elimination of cells infected by pathogens. In this review, we summarize the knowledge of the interaction between DCs with TL, as well as the characterization of the specific T-cell response against HIV-1 infection. The use of nanotechnology in the design and improvement of vaccines based on DCs has been researched and presented here with a special emphasis.

Extracellular Vesicles as a New Promising Therapy in HIV Infection

Combination antiretroviral therapy (cART) effectively blocks HIV replication but cannot completely eliminate HIV from the body mainly due to establishment of a viral reservoir. To date, clinical strategies designed to replace cART for life and alternatively to eliminate the HIV reservoir have failed. The reduced expression of viral antigens in the latently infected cells is one of the main reasons behind the failure of the strategies to purge the HIV reservoir. This situation has forced the scientific community to search alternative therapeutic strategies to control HIV infection. In this regard, recent findings have pointed out extracellular vesicles as therapeutic agents with enormous potential to control HIV infection. This review focuses on their role as pro-viral and anti-viral factors, as well as their potential therapeutic applications.

Pulmonary Immune Dysregulation and Viral Persistence During HIV Infection

Despite the success of antiretroviral therapy (ART), people living with HIV continue to suffer from high burdens of respiratory infections, lung cancers and chronic lung disease at a higher rate than the general population. The lung mucosa, a previously neglected HIV reservoir site, is of particular importance in this phenomenon. Because ART does not eliminate the virus, residual levels of HIV that remain in deep tissues lead to chronic immune activation and pulmonary inflammatory pathologies. In turn, continuous pulmonary and systemic inflammation cause immune cell exhaustion and pulmonary immune dysregulation, creating a pro-inflammatory environment ideal for HIV reservoir persistence. Moreover, smoking, gut and lung dysbiosis and co-infections further fuel the vicious cycle of residual viral replication which, in turn, contributes to inflammation and immune cell proliferation, further maintaining the HIV reservoir. Herein, we discuss the recent evidence supporting the notion that the lungs serve as an HIV viral reservoir. We will explore how smoking, changes in the microbiome, and common co-infections seen in PLWH contribute to HIV persistence, pulmonary immune dysregulation, and high rates of infectious and non-infectious lung disease among these individuals.

Fine-tuning Mast Cells is Essential for the Maintenance and Regulation of the Systemic and Immune Homeostasis

During the past decades, populous expansion in mast cell scientific literature came forth with more, than forty-four thousand PubMed publications available to date. Such surge is due to the appreciation of the momentous role of mast cells in the evolution of species, in the development and maintenance of vital physiological functions, such as reproduction, homeostasis, and fluids, diverse immunological roles, and the potential of far-reaching effects despite minute numbers. While the emerging knowledge of the importance of mast cells in equilibrium comes of age when looking at the matter from an evolutionary perspective, the recognition of mast cells beyond detrimental performance in allergies and asthma, during protection against parasites, falters. Beyond well known classical functions, mast cells can process and present antigens,can serve as a viral reservoir, can respond to hormones and xenobiotics,initiate antiviral and antibacterial responses, phagocytosis, apoptosis, and participate in important developmental cornerstones. During evolution,upon the development of a sophisticated niche of innate and adaptive cell populations, certain mast cell functions became partially transmutable,yet the potency of mast cells remained considerable. Reviewing mast cells enables us to reflect on the certitude, that our sophisticated, complex physiology is rooted deeply in evolution, which we carry ancient remnants of, ones that may have decisive roles in our functioning. This communication sets out the goal of characterizing mast cells, particularly the aspects less in limelight yet of immense significance, without the aspiration exhaust it all.

Quantification of Total HIV DNA as a Marker to Measure Viral Reservoir: Methods and Potential Implications for Clinical Practice

The focus of this review is to examine the importance of quantifying total HIV DNA to target the HIV reservoir and the clinical implications and challenges involved in its future application in clinical practice. Despite intrinsic limitations, the quantification of total HIV DNA is currently the most widely used marker for exploring the HIV reservoir. As it allows estimating all forms of HIV DNA in the infected cells, total HIV DNA load is the biomarker of the HIV reservoir that provides most of the insights into HIV pathogenesis. The clinical role of total HIV-DNA in both untreated and treated patients is extensively supported by important lines of evidence. Thus, predictive models that include total HIV DNA load together with other variables could constitute a prognostic tool for use in clinical practice. To date, however, this marker has been primarily used in experimental evaluations. The main challenge is technical. Although the implementation of droplet digital PCR could improve analytical performance over real-time PCR, the lack of standardization has made cross-comparisons of the data difficult. An effort by investigators to compare protocols is needed. Furthermore, the main effort now should be to involve the biomedical industry in the development of certified assays for in vitro diagnostics use.

Host Restriction Factors Modulating HIV Latency and Replication in Myeloid Cells

In addition to CD4+ T lymphocytes, myeloid cells, and, particularly, differentiated macrophages, are targets of the human immunodeficiency virus type-1 (HIV-1) infection via interaction of gp120Env with CD4 and CCR5 or CXCR4. Both T cells and macrophages support virus replication although with substantial differences. In contrast to activated CD4+ T lymphocytes, HIV-1 replication in macrophages occurs in nondividing cells and it is characterized by virtual absence of cytopathicity both in vitro and in vivo. These general features should be considered in evaluating the role of cell-associated restriction factors aiming at preventing of curtailing virus replication in macrophages and T cells particularly in the context of designing strategies to tackle the viral reservoir in infected individuals receiving combination antiretroviral therapy. In this regard, we will here also discuss a model of reversible HIV-1 latency in primary human macrophages and the role of host factor determining restriction or reactivation of virus replication in myeloid cells.

Latently KSHV-Infected Cells Promote Further Establishment of Latency upon Superinfection with KSHV

Kaposi’s sarcoma-associated herpesvirus (KSHV) is a cancer-related virus which engages in two forms of infection: latent and lytic. Latent infection allows the virus to establish long-term persistent infection, whereas the lytic cycle is needed for the maintenance of the viral reservoir and for virus spread. By using recombinant KSHV viruses encoding mNeonGreen and mCherry fluorescent proteins, we show that various cell types that are latently-infected with KSHV can be superinfected, and that the new incoming viruses establish latent infection. Moreover, we show that latency establishment is enhanced in superinfected cells compared to primary infected ones. Further analysis revealed that cells that ectopically express the major latency protein of KSHV, LANA-1, prior to and during infection exhibit enhanced establishment of latency, but not cells expressing LANA-1 fragments. This observation supports the notion that the expression level of LANA-1 following infection determines the efficiency of latency establishment and avoids loss of viral genomes. These findings imply that a host can be infected with more than a single viral genome and that superinfection may support the maintenance of long-term latency.

Cohort profile: the Netherlands Cohort Study on Acute HIV infection (NOVA), a prospective cohort study of people with acute or early HIV infection who immediately initiate HIV treatment

PurposeInitiation of combination antiretroviral therapy (cART) during acute or early HIV-infection (AEHI) limits the size of the viral reservoir and preserves immune function. This renders individuals who started cART during AEHI promising participants in HIV-cure trials. Therefore, we established a multicentre prospective cohort study in the Netherlands that enrols people with AEHI. In anticipation of future cure trials, we will longitudinally investigate the properties of the viral reservoir size and HIV-specific immune responses among cohort participants.ParticipantsParticipants immediately initiate intensified cART: dolutegravir, emtricitabine/tenofovir and darunavir/ritonavir (DRV/r). After 4 weeks, once baseline resistance data are available, DRV/r is discontinued. Three study groups are assembled based on the preparedness of individuals to participate in the extensiveness of sampling. Participants accepting immediate treatment and follow-up but declining additional sampling are included in study group 1 (‘standard’) and routine diagnostic procedures are performed. Participants willing to undergo blood, leukapheresis and semen sampling are included in study group 2 (‘less invasive’). In study group 3 (‘extended’), additional tissue (gut-associated lymphoid tissue, peripheral lymph node) and cerebrospinal fluid sampling are performed.Findings to dateBetween 2015 and 2020, 140 individuals with AEHI have been enrolled at nine study sites. At enrolment, median age was 36 (IQR 28–47) years, and 134 (95.7%) participants were men. Distribution of Fiebig stages was as follows: Fiebig I, 3 (2.1%); II, 20 (14.3%); III, 7 (5.0%); IV, 49 (35.0%); V, 39 (27.9%); VI, 22 (15.7%). Median plasma HIV RNA was 5.9 (IQR 4.7–6.7) log10 copies/mL and CD4 count 510 (IQR 370–700) cells/mm3. Median time from cART initiation to viral suppression was 8.0 (IQR 4.0–16.0) weeks.Future plansThe Netherlands Cohort Study on Acute HIV infection remains open for participant enrolment and for additional sites to join the network. This cohort provides a unique nationwide platform for conducting future in-depth virological, immunological, host genetic and interventional studies investigating HIV-cure strategies.