Attenuation of pathogenic immune responses during infection with human and simian immunodeficiency virus (HIV/SIV) by the tetracycline derivative minocycline

SN38-loaded nanomedicine mediates chemo-radiotherapy against CD44-expressing cancer growth

Background

Chemo-radiotherapy is the combined chemotherapy and radiotherapy on tumor treatment to obtain the local radiosensitization and local cytotoxicity of the tumor and to control the microscopic metastatic disease.

Methods

In this study, 7-ethyl-10-hydroxycamptothecin (SN38) molecules could be successfully loaded into human serum albumin (HSA)–hyaluronic acid (HA) nanoparticles (SH/HA NPs) by the hydrophobic side groups of amino acid in HSA.

Results

HSA could be used to increase the biocompatibility and residence time of the nanoparticles in the blood, whereas HA could improve the benefits and overall treatment effect on CD44-expressing colorectal cancer (CRC), and reduce drug side effects. In addition to its role as a chemotherapeutic agent, SN38 could be used as a radiosensitizer, able to arrest the cell cycle, and allowing cells to stay in the G2/M stage, to improve the sensitivity of tumor cells to radiation. In vivo results demonstrated that SH/HA NPs could accumulate in the tumor and produce significant tumor suppression, with no adverse effects observed when combined with γ-ray irradiation. This SH/HA NPs-medicated chemo-radiotherapy could induce an anti-tumor immune response to inhibit the growth of distal tumors, and produce an abscopal effect.

Conclusions

Therefore, this SN38-loaded and HA-incorporated nanoparticle combined with radiotherapy may be a promising therapeutic artifice for CRC in the future.

Cisplatin-loaded gold nanoshells mediate chemo-photothermal therapy against primary and distal lung cancers growth

Lung cancer is the most common cause of cancer mortality worldwide. The advances in surgery, radiotherapy, chemotherapeutic and immunotherapeutic drugs have progressed in the past decades, but the prognosis of lung cancer is still poor. In this study, we developed cisplatin (CDDP)-loaded human serum albumin (HSA)-based gold nanoshells (HCP@GNSs) for synergistic chemo-photothermal therapy (chemo-PTT). The HCP@GNSs not only acted as drug nanocarriers for chemotherapy but also serve as a superior mediator for PTT, which could exhibit a temperature increase upon a near infrared (NIR) laser exposure that was sufficient for photothermal ablation. HCP@GNSs were highly biocompatible and hemocompatible nanocarriers, while the synergistic chemo-PTT resulting from HCP@GNSs plus NIR exposure displayed stronger cytotoxicity effect than HCP@GNSs or PTT alone, especially at a low CDDP concentration. In vivo analysis demonstrated that HCP@GNSs-mediated chemo-PTT increased necrosis in tumors to achieve a high tumor clearance rate with no adverse side effects. Moreover, HCP@GNSs-medicated chemo-PTT induced the recruitment of dendritic cells, B-cells, and natural killer T-cells in distal tumors to inhibit the growth of the tumors. Therefore, the CDDP-loaded HCP@GNSs may be a potential nanomedicine candidate for curative lung cancer treatment in the future.

Tumor necroptosis is correlated with a favorable immune cell signature and programmed death-ligand 1 expression in cholangiocarcinoma

Necroptosis, a regulated form of necrosis, has emerged as a novel therapeutic strategy that could enhance cancer immunotherapy. However, its role in tumorigenesis is still debated because recent studies have reported both anti- and pro-tumoral effects. Here, we aimed to systematically evaluate the associations between tumor necroptosis (mixed lineage kinase domain-like protein, MLKL; phosphorylated MLKL, pMLKL; and receptor-interacting protein kinase 1-receptor-interacting protein kinase 3, RIPK1-RIPK3 interaction) and tumor-infiltrating immune cells (CD8+ and FOXp3+ T cells and CD163+ M2 macrophages) and tumor PD-L1 by immunohistochemistry in 88 cholangiocarcinoma (CCA) patients who had undergone surgical resection. Their associations with clinicopathological characteristics, survival data, and prognosis were evaluated. MLKL was found to be an unfavorable prognostic factor (p-value = 0.023, HR = 2.070) and was inversely correlated with a clinically favorable immune cell signature (high CD8+/high FOXp3+/low CD163+). Both pMLKL and RIPK1-RIPK3 interaction were detected in CCA primary tissues. In contrast to MLKL, pMLKL status was significantly positively correlated with a favorable immune signature (high CD8+/high FOXp3+/low CD163+) and PD-L1 expression. Patients with high pMLKL-positive staining were significantly associated with an increased abundance of CD8+ T cell intratumoral infiltration (p-value = 0.006). Patients with high pMLKL and PD-L1 expressions had a longer overall survival (OS). The results from in vitro experiments showed that necroptosis activation in an RMCCA-1 human CCA cell line selectively promoted proinflammatory cytokine and chemokine expression. Jurkat T cells stimulated with necroptotic RMCCA-1-derived conditioned medium promoted PD-L1 expression in RMCCA-1. Our findings demonstrated the differential associations of necroptosis activation (pMLKL) and MLKL with a clinically favorable immune signature and survival rates and highlighted a novel therapeutic possibility for combining a necroptosis-based therapeutic approach with immune checkpoint inhibitors for more efficient treatment of CCA patients.

Advances in biomarker detection: Alternative approaches for blood-based biomarker detection

In the clinical setting, a blood sample is typically the starting point for biomarker search and discovery. Mass spectrometry (MS) is a highly sensitive and informative method for characterizing a very wide range of metabolites and proteins and is therefore a potentially powerful tool for biomarker discovery. However, the physicochemical characteristics of blood coupled with very large ranges of protein and metabolite concentrations present a significant technical obstacle for resolving and quantifying putative biomarkers by MS. Blood fractionation procedures are being developed to reduce the proteome/metabolome complexity and concentration ranges, allowing a greater diversity of analytes, including those at very low concentrations, to be quantified. In this chapter, several strategies for enriching and/or isolating specific blood components are summarized, including methods for the analysis of low and high molecular weight compounds, usually neglected in this type of assays, extracellular vesicles, and peripheral blood mononuclear cells (PBMCs). For each method, relevant practical information is presented for effective implementation.

Early type I Interferon response induces upregulation of human β-defensin 1 during acute HIV-1 infection

HIV-1 is able to evade innate antiviral responses during acute infection to establish a chronic systemic infection which, in the absence of antiretroviral therapy (ART), typically progresses to severe immunodeficiency. Understanding these early innate immune responses against HIV-1 and their mechanisms of failure is relevant to the development of interventions to better prevent HIV-1 transmission. Human beta defensins (HBDs) are antibacterial peptides but have recently also been associated with control of viral replication. HBD1 and 2 are expressed in PBMCs as well as intestinal tissue, but their expression in vivo during HIV-1 infection has not been characterized. We demonstrate that during acute HIV-1 infection, HBD1 but not HBD2 is highly upregulated in circulating monocytes but returns to baseline levels during chronic infection. HBD1 expression in monocytes can be induced by HIV-1 in vitro, although direct infection may not entirely account for the increase in HBD1 during acute infection. We provide evidence that HIV-1 triggers antiviral IFN-α responses, which act as a potent inducer of HBD1. Our results show the first characterization of induction of an HBD during acute and chronic viral infection in humans. HBD1 has been reported to have low activity against HIV-1 compared to other defensins, suggesting that in vivo induced defensins may not significantly contribute to the robust early antiviral response against HIV-1. These data provide important insight into the in vivo kinetics of HBD expression, the mechanism of HBD1 induction by HIV-1, and the role of HBDs in the early innate response to HIV-1 during acute infection.

Distinct Patterns of Tryptophan Maintenance in Tissues during Kynurenine Pathway Activation in Simian Immunodeficiency Virus-Infected Macaques

Induction of the kynurenine pathway (KP) of tryptophan (TRP) catabolism has been proposed to contribute to T cell dysfunction during human/simian immunodeficiency virus (SIV) infection via depletion of local TRP levels and production of immunomodulatory KP metabolites. However, while changes in TRP and KP metabolites have been observed in plasma, their levels in lymphoid tissues and levels of enzymes downstream of indoleamine 2,3-dioxygenase (IDO1) have been relatively unexplored. We used our SIV-infected pigtailed macaque model to analyze longitudinal changes in KP metabolites and enzymes by gas chromatography/mass spectrometry and NanoString nCounter gene expression analysis, respectively, in spleen and blood compared to changes previously established in brain and CSF. We found that TRP levels were remarkably stable in tissue sites despite robust depletion in the circulating plasma and CSF. We also demonstrated that intracellular TRP reserves were maintained in cultured cells even in the presence of depleted extracellular TRP levels. Kynurenine (KYN), 3-hydroxykynurenine, quinolinic acid, and the KP enzymes all displayed highly divergent patterns in the sites examined, though IDO1 expression always correlated with local KYN/TRP ratios. Finally, we demonstrated by fluorescence-activated cell sorting that myeloid dendritic cells and cells of monocytic lineage were the highest producers of IDO1 in chronically infected spleens. Overall, our study reveals insights into the tissue-specific regulation of KP enzymes and metabolites and, in particular, highlights the multiple mechanisms by which cells and tissues seek to prevent TRP starvation during inflammation.

Is Minocycline an Antiviral Agent? A Review of Current Literature

Minocycline is a second-generation semi-synthetic derivative of tetracycline and has well-known anti-bacterial effects. The drug possesses anti-inflammatory, anti-oxidant, anti-apoptotic and immunomodulatory effects. The drug is widely used in bacterial infections and non-infectious conditions such as acne, dermatitis, periodontitis and neurodegenerative conditions. Minocycline was shown to have antiviral activity in vitro and also against different viruses in some animal models. Some studies have been done on human patients infected with Human Immunodeficiency Virus. We have review the available data regarding minocycline activity as an antiviral agent.

Altered antigen-presenting cells during HIV-1 infection

PURPOSE OF REVIEW

The purpose of this study is to describe the alterations that HIV-1 induces in antigen-presenting cells (APCs), in vitro, ex vivo and in vivo.

RECENT FINDINGS

HIV-1 disarms several arms of the immune system including APCs. We summarize here recent findings on the impact of the virus on APC.

SUMMARY

HIV-1 can invade APC and overall reduce their capacity to present antigens effectively, mostly by reducing their numbers and inducing permanent hyperactivation. This occurs via a combination of alterations; however, the host can counteract, at least in part, some of these defects via restriction factors, autophagy, the production of type I interferon, antiviral cytokines, among others. However, these specific mechanisms of viral evasion from APCs' control lead to a chronic hyperactivation of the immune system implicated in AIDS-related and non-AIDS related pathogenesis. Unfortunately, the current regimens of antiretroviral therapy are unable to dampen sufficiently APC-driven viral-induced immune hyperactivation. Understanding how HIV alters APC will help to tune appropriately both intrinsic immunity and innate immunity, as well as achieve efficient antigen presentation to the adaptive immune system, without inducing a detrimental pervasive hyperactivation of the immune system.