Long-term effects of intermittent IL-2 in HIV infection: extended follow-up of the INSIGHT STALWART Study

Heavily treatment-experienced persons living with HIV currently in care in Italy: characteristics, risk factors, and therapeutic options-the ICONA Foundation cohort study

OBJECTIVES

Heavily treatment-experienced (HTE) people living with HIV (PLWH) pose unique challenges due to limited antiretroviral treatment (ART) options. Our study aimed to investigate the prevalence and features of HTE individuals followed up in the Italian Cohort Naïve Antiretrovirals (ICONA) cohort as of December 31, 2021.

METHODS

HTE were defined based on meeting specific conditions concerning their current ART and their ART history up to December 31, 2021. Descriptive statistics were performed by HTE status. Regression analyses explored factors associated with becoming HTE based on pre-ART patients' characteristics. Cluster dendrogram analysis provided insights into subgroups with inadequate responses based on clusters of differentiation (CD4) counts and viral load (VL) trajectories.

RESULTS

Among the 8758 PLWH actively followed in our cohort, 163 individuals (1.9%), mainly female, younger, Italian, and infected through heterosexual contact, met the HTE criteria. A lower CD4 count at ART initiation (odds ratio [OR] 1.60 per 100 cells/mmc lower CD4, 95% confidence interval [CI] 1.06-2.41, P = 0.03) and hepatitis C virus antibody positivity (OR 1.90, 95% CI 1.16-3.11, P = 0.01) were associated with higher HTE risk. Thirty PLWH exhibited ongoing immune-virological failure (18% of the HTE subgroup and 0.003% of the total population). Thirty PLWH exhibited ongoing immune-virological failure (i.e., with a current CD4 count <200 cells/mmc or VL>200 copies/mL). A cluster analysis identified 13 (43%) with a current CD4 count <200 cells/mmc. Also, notably, 19/30 (63%) had major acquired resistance-associated mutations to at least one antiretroviral drug class.

CONCLUSIONS

HTE is rare in our cohort and tends to co-exist with major resistance mutations. A focused investigation into treatment history and immuno-virological response is warranted, particularly given the availability of new antiretroviral drugs.

Immunomodulatory Therapy of Visceral Leishmaniasis in Human Immunodeficiency Virus-Coinfected Patients

Patients with visceral leishmaniasis (VL)–human immunodeficiency virus (HIV) coinfection experience increased drug toxicity and treatment failure rates compared to VL patients, with more frequent VL relapse and death. In the era of VL elimination strategies, HIV coinfection is progressively becoming a key challenge, because HIV-coinfected patients respond poorly to conventional VL treatment and play an important role in parasite transmission. With limited chemotherapeutic options and a paucity of novel anti-parasitic drugs, new interventions that target host immunity may offer an effective alternative. In this review, we first summarize current views on how VL immunopathology is significantly affected by HIV coinfection. We then review current clinical and promising preclinical immunomodulatory interventions in the field of VL and discuss how these may operate in the context of a concurrent HIV infection. Caveats are formulated as these interventions may unpredictably impact the delicate balance between boosting of beneficial VL-specific responses and deleterious immune activation/hyperinflammation, activation of latent provirus or increased HIV-susceptibility of target cells. Evidence is lacking to prioritize a target molecule and a more detailed account of the immunological status induced by the coinfection as well as surrogate markers of cure and protection are still required. We do, however, argue that virologically suppressed VL patients with a recovered immune system, in whom effective antiretroviral therapy alone is not able to restore protective immunity, can be considered a relevant target group for an immunomodulatory intervention. Finally, we provide perspectives on the translation of novel theories on synergistic immune cell cross-talk into an effective treatment strategy for VL–HIV-coinfected patients.

Increasing procaspase 8 expression using repurposed drugs to induce HIV infected cell death in ex vivo patient cells

HIV persists because a reservoir of latently infected CD4 T cells do not express viral proteins and are indistinguishable from uninfected cells. One approach to HIV cure suggests that reactivating HIV will activate cytotoxic pathways; yet when tested in vivo, reactivating cells do not die sufficiently to reduce cell-associated HIV DNA levels. We recently showed that following reactivation from latency, HIV infected cells generate the HIV specific cytotoxic protein Casp8p41 which is produced by HIV protease cleaving procaspase 8. However, cell death is prevented, possibly due to low procaspase 8 expression. Here, we tested whether increasing procaspase 8 levels in CD4 T cells will produce more Casp8p41 following HIV reactivation, causing more reactivated cells to die. Screening 1277 FDA approved drugs identified 168 that increased procaspase 8 expression by at least 1.7-fold. Of these 30 were tested for anti-HIV effects in an acute HIV_IIIb infection model, and 9 drugs at physiologic relevant levels significantly reduced cell-associated HIV DNA. Primary CD4 T cells from ART suppressed HIV patients were treated with one of these 9 drugs and reactivated with αCD3/αCD28. Four drugs significantly increased Casp8p41 levels following HIV reactivation, and decreased total cell associated HIV DNA levels (flurbiprofen: p = 0.014; doxycycline: p = 0.044; indomethacin: p = 0.025; bezafibrate: P = 0.018) without effecting the viability of uninfected cells. Thus procaspase 8 levels can be increased pharmacologically and, in the context of HIV reactivation, increase Casp8p41 causing death of reactivating cells and decreased HIV DNA levels. Future studies will be required to define the clinical utility of this or similar approaches.

The Significance of Interferon-γ in HIV-1 Pathogenesis, Therapy, and Prophylaxis

Interferon-γ (IFNγ) plays various roles in the pathogenesis of HIV/AIDS. In an HIV-1 infected individual, the production of IFNγ is detected as early as the acute phase and continually detected throughout the course of infection. Initially produced to clear the primary infection, IFNγ together with other inflammatory cytokines are involved in establishing a chronic immune activation that exacerbates clinical diseases associated with AIDS. Unlike Type 1 IFNs, IFNγ has no direct antiviral activity against HIV-1 in primary cultures, as supported by the in vivo findings of IFNγ therapy in infected subjects. Results from both in vitro and ex vivo studies show that IFNγ can instead enhance HIV-1 replication and its associated diseases, and therapies aimed at decreasing its production are under consideration. On the other hand, IFNγ has been shown to enhance cytotoxic T lymphocytes and NK cell activities against HIV-1 infected cells. These activities are important in controlling HIV-1 replication in an individual and will most likely play a role in the prophylaxis of an effective vaccine against HIV-1. Additionally, IFNγ has been used in combination with HIV-1 vaccine to augment antiviral immunity. Technological advancements have focused on using IFNγ as a biological marker to analyze the type(s) of immunity generated by candidate HIV vaccines and the levels of immunity restored by anti-retroviral drug therapies or novel immunotherapies. Hence, in addition to its valuable ancillary role as a biological marker for the development of effective HIV-1 prophylactic and therapeutic strategies, IFNγ has a vital role in promoting the pathogenesis of HIV.

Novel approaches and challenges to treatment of central nervous system viral infections

Existing and emerging viral central nervous system (CNS) infections are major sources of human morbidity and mortality. Treatments of proven efficacy are currently limited predominantly to herpesviruses and human immunodeficiency virus (HIV). Development of new therapies has been hampered by the lack of appropriate animal model systems for some important viruses and by the difficulty in conducting human clinical trials for diseases that may be rare, or in the case of arboviral infections, often have variable seasonal and geographic incidence. Nonetheless, many novel approaches to antiviral therapy are available, including candidate thiazolide and pyrazinecarboxamide derivatives with potential broad‐spectrum antiviral efficacy. New herpesvirus drugs include viral helicase‐primase and terminase inhibitors. The use of antisense oligonucleotides and other strategies to interfere with viral RNA translation has shown efficacy in experimental models of CNS viral disease. Identifying specific molecular targets within viral replication cycles has led to many existing antiviral agents and will undoubtedly continue to be the basis of future drug design. A promising new area of research involves therapies based on enhanced understanding of host antiviral immune responses. Toll‐like receptor agonists and drugs that inhibit specific cytokines as well as interferon preparations have all shown potential therapeutic efficacy. Passive transfer of virus‐specific cytotoxic T lymphocytes has been used in humans and may provide an effective therapy for some herpesvirus infections and potentially for progressive multifocal leukoencephalopathy. Humanized monoclonal antibodies directed against specific viral proteins have been developed and in several cases evaluated in humans in settings including West Nile virus and HIV infection and in pre‐exposure prophylaxis for rabies. Ann Neurol 2013;74:412–422

Polyactin A increases CD4+ T-cell counts in HIV-infected individuals with insufficient immunologic response to highly active antiretroviral therapy

We conducted a study to determine whether an immunomodulator, polyactin A, is able to enhance the immunologic response in patients with insufficient immunologic response to highly active antiretroviral therapy. From 783 patients, 48 were eligible and were randomly assigned to an experimental group receiving polyactin A for 3 months or a control group. CD4+ T-cell counts in the experimental group increased from 201 ± 31 to 228 ± 38 cells/µl after treatment ( p < 0.001). CD4+ T-cell counts in the control group and CD8+ T-cell counts and CD4+/CD8+ ratios in both groups did not differ significantly between baseline and month 3. The experimental group had a higher CD4+ T-cell count than the control group at month 3 (228 ± 38 versus 205 ± 35, p < 0.05). Our work demonstrated that polyactin A can increase CD4+ T-cell counts in patients with insufficient immunologic response to highly active antiretroviral therapy, but further studies are required to determine its clinical benefits.