Enhancing the immune effect of oHSV-1 therapy through TLR3 signaling in uveal melanoma

PURPOSE

Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults, with patients having a low overall survival rate. Oncolytic viruses (OVs) have been shown effective as monotherapy or combined with immunotherapy in the treatment of UM. Oncolytic herpes simplex type I virus (oHSV-1) was found to alter gene expression and immune function in UMs. We investigated whether a combination treatment would be more effective in treating UM and reactive immune cells.

METHODS

RNA sequencing analysis were used to identify the effect of oHSV-1 infection in UM cells and protein changes were validated by western blot. Cell viability assays were performed through UM cell lines (MUM2B, 92.1, and MP41) and retinal pigment epithelial cell line (ARPE-19) to identify the efficacy and safety of the combination treatment. Western blot, qRT-PCR, cell viability assay and immunocytochemistry were performed to discover the reactivation of immune cells (U937 and HMC3).

RESULTS

Through RNA sequencing analysis and in vitro molecular biology assays, this study tested the ability of oHSV-1 combined with the TLR3 agonist poly(I:C) to re-activate the TLR3 meditated NF-ƙB signaling pathway and further increase the anti-tumor activity of UM cells and macrophages, including the stimulation of macrophage polarization and proliferation.

CONCLUSIONS

These findings indicate that the treatment of UM with a combination of oHSV-1 and poly(I:C) generates immune responses and enhances anti-tumoral activity, suggesting the need for further investigations and clinical trials of this combination.

Immunotherapeutic role of cabazitaxel treatment in the activation of TLR3 signalling in metastatic castration-resistant prostate cancer in vitro

BACKGROUND

The activation of toll like receptors (TLR) potentially affect the inflammatory tumor microenvironment and thus is associated with tumor growth or inhibition. Cabazitaxel (CAB) has been effectively used for the treatment of metastatic castration-resistant prostate cancer (mCRPC). However, the immune regulatory role of CAB in the tumor microenvironment is not clear. In this context, we for the first time assessed the immunotherapeutic role of CAB in the TLR3 signalling following activation of Poly I:C in mCRPC cells.

METHODS AND RESULTS

The cytotoxic and apoptotic effects of CAB with the induction of Poly I:C were determined by WST-1, Annexin V, acridine orange, RT-PCR analysis, ELISA assay and immunofluorescence staining in DU-145 mCRPC and HUVEC control cells. Our findings showed that CAB treatment with Poly I:C significantly suppressed the proliferation of DU-145 cells through the induction of apoptosis and caspase activation. Additionally, higher concentration of CAB mediated the activation of TLR3 via increased cytoplasmic and nuclear expression of TLR3, TICAM-1 and IRF-3 in mCRPC cells.

CONCLUSIONS

Co-treatment of CAB and Poly I:C was more effective in mCRPC cells with less toxicity in control cells. However, further investigations are required to elucidate the molecular mechanisms of TLRs signalling upon CAB treatment at the molecular level to further validate the immunotherapeutic efficacy of CAB in mCRPC.

Multiphasic disseminated encephalomyelitis associated with herpes virus infection in a patient with TLR3 deficiency

We report a case of a 14-year-old girl that presented headache, amaurosis, drowsiness, fever, vomiting and diffuse reduction of muscle strength. She had been diagnosed with ADEM one year before and had a previous diagnosis of Toll-Like 3 receptor deficiency. Cerebrospinal fluid analysis revealed pleocytosis (28/mm³, 12/mm³ red blood cells, 70% lymphocytes cells, 2% monocytes cells, 28% neutrophils), normal total protein (38 pg/mL) and normal glucose level (53/mm³). Studies for CSF oligoclonal bands and serum anti-MOG were negative but polymerase chain reaction (PCR) testing was positive for herpes virus 1. In the first ADEM episode, PCR for herpes virus was also positive. Magnetic resonance imaging (MRI) of the brain revealed disseminated hyperintense lesions on T2-weighted and FLAIR images in the white matter of frontal, parietal and temporal lobes, corresponding to extensive asymmetric areas of demyelination that produced mass effect and gadolinium enhancement. Electroencephalography demonstrated irregular diffuse and generalized slow-wave activity with predominance in frontal region. The diagnosis of multiphasic disseminated encephalomyelitis (MDEM) triggered by herpes simplex virus was made. Herpes virus is a neurotropic virus that can cause a wide variety of neurological infection-triggered autoimmune disorders and that is particularly damaging to the central nervous system in situations of impaired immune system. TLR3 is expressed in astrocytes and dendritic cells of the central nervous system and is essential for natural immunity to herpes simplex. TLR3-deficient patients have already been described with herpes simplex encephalitis. TLR3 deficiency may predispose and explain autoimmune and demyelinating manifestations induced by herpes virus. The association of multiphasic disseminated encephalomyelitis triggered by herpes virus in a patient with TLR3 deficiency has not been previously reported in the literature.

A proteomic analysis of serum-derived exosomes in rheumatoid arthritis

Background

To understand the roles of serum exosomes in rheumatoid arthritis (RA), we comprehensively investigated the protein profiles of serum exosomes in patients with RA.

Methods

Exosomes were isolated from serum samples obtained from 33 patients (12 with active RA [aRA], 11 with inactive RA [iRA], 10 with osteoarthritis [OA]) and 10 healthy donors (HLs). Proteins extracted from the exosomes were separated by two-dimensional differential gel electrophoresis (2D-DIGE) and identified by mass spectrometry.

Results

In total, 204 protein spots were detected by 2D-DIGE. In the aRA, iRA, and OA groups, 24, 5, and 7 spots showed approximately ≥ ±1.3-fold intensity differences compared with the HL group, respectively. We were able to identify proteins in six protein spots. Among them, the protein spot identified as Toll-like receptor 3 (TLR3) showed approximately 6-fold higher intensity in the aRA group than in the other groups.

Conclusions

Patients with active RA possessed considerably different protein profiles of serum exosomes from patients with iRA, patients with OA, and healthy donors. The unique protein profile of serum exosomes, such as the possession of abundant TLR3 fragments, may reflect the pathophysiology of active RA.

Electronic supplementary material

The online version of this article (10.1186/s41927-018-0041-8) contains supplementary material, which is available to authorized users.

The role of toll-like receptor 3 in chronic contact hypersensitivity induced by repeated elicitation

BACKGROUND

Accumulating evidence suggests that Toll-like receptor (TLR)-3 signaling is involved in non-infectious immune and inflammatory reactions as well as in viral infections. The skin of patients with atopic dermatitis (AD) is often infected with virus and bacteria, leading to the aggravation of atopic symptoms. These findings suggest TLR3 signaling may be involved in the pathogenesis of AD, but the exact role of TLR3 in AD remains to be defined.

OBJECTIVE

The purpose of this study was to investigate the role of TLR3 in chronic contact hypersensitivity reactions induced by repeated elicitation, resembling the features of AD.

METHODS

Wild-type (WT) and Toll-like receptor 3 knockout (Tlr3 KO) mice were sensitized, and chronic contact hypersensitivity reactions were elicited in their ear skin via repeated application of a hapten, 2,4,6-trinitro-1-chlorobenzene (TNCB) or oxazolone.

RESULTS

The Tlr3 KO mice exhibited less ear swelling, less leukocyte infiltration into the skin, and lower serum total IgE levels than WT mice after hapten challenge. The Tlr3 KO mice also displayed lower expression levels of inflammatory cytokines (interleukin (IL)-33, IL-4, IL-10, and interferon-ɤ in their TNCB-treated ear skin than WT mice.

CONCLUSION

These results showed that TLR3 deficiency suppressed the development of chronic contact hypersensitivity reactions, suggesting that TLR3 signaling may participate in the pathogenesis of AD.

Activation of toll like receptor-3 induces corneal epithelial barrier dysfunction

The epithelial barrier is critical in the maintenance of the homeostasis of the cornea. A number of eye disorders are associated with the corneal epithelial barrier dysfunction. Viral infection is one common eye disease type. This study aims to elucidate the mechanism by which the activation of toll like receptor 3 (TLR3) in the disruption of the corneal epithelial barrier. In this study, HCE cells (a human corneal epithelial cell line) were cultured into epithelial layers using as an in vitro model of the corneal epithelial barrier. PolyI:C was used as a ligand of TLR3. The transepithelial electric resistance (TER) and permeability of the HCE epithelial layer were assessed using as the parameters to evaluate the corneal epithelial barrier integrity. The results showed that exposure to PolyI:C markedly decreased the TER and increased the permeability of the HCE epithelial layers; the levels of cell junction protein, E-cadherin, were repressed by PolyI:C via increasing histone deacetylase-1 (HDAC1), the latter binding to the promoter of E-cadherin and repressed the transcription of E-cadherin. The addition of butyrate (an inhibitor of HDAC1) to the culture blocked the corneal epithelial barrier dysfunction caused by PolyI:C. In conclusion, activation of TLR3 can disrupt the corneal epithelial barrier, which can be blocked by the inhibitor of HDAC1.

Dengue virus and antiplatelet autoantibodies synergistically induce haemorrhage through Nlrp3-inflammasome and FcγRIII

Dengue haemorrhagic fever (DHF) typically occurs during secondary infections with dengue viruses (DENVs). Although it is generally accepted that antibody-dependent enhancement is the primary reason why patients with secondary infection are at an increased risk of developing DHF, a growing body of evidence shows that other mechanisms, such as the elicitation of antiplatelet autoantibodies by DENV nonstructural protein NS1, also play crucial roles in the pathogenesis of DHF. In this study, we developed a "two-hit" model of secondary DENV infection to examine the respective roles of DENV (first hit) and antiplatelet Igs (second hit) on the induction of haemorrhage. Mice were first exposed to DENV and then exposed to antiplatelet or anti-NS1 Igs 24 hours later. The two-hit treatment induced substantial haemorrhage, coagulopathy, and cytokine surge, and additional treatment with antagonists of TNF-α, IL-1, caspase-1, and FcγRIII ameliorated such effects. In addition, knockout mice lacking the Fcγ receptor III, Toll-like receptor 3, and inflammasome components Nlrp3 and caspase-1 exhibited considerably fewer pathological alterations than did wild type controls. These findings may provide new perspectives for developing feasible approaches to treat patients with DHF.

Mannan binding lectin attenuates double-stranded RNA-mediated TLR3 activation and innate immunity

Mannan binding lectin (MBL) functions as a pattern recognition molecule (PRM) which is able to initiate complement activation. Here, we characterize a previously unrecognized attribute of MBL as a double-stranded RNA (dsRNA) binding protein capable of modifying Toll like receptor 3 (TLR3) activation. MBL interacts with poly(I:C) and suppresses poly(I:C)-induced activation of TLR3 pathways and subsequent cytokine production. In addition, MBL binds to TLR3 directly. Surprisingly, disrupting the interaction between MBL and complement receptor 1 (CR1) or restraining the traffic of MBL to phagosome reversed the MBL limited TLR3 activation. We demonstrate the importance of MBL guided ligands intracellular localization, emphasizing the significance of understanding the dynamics of TLR agonists complexed with MBL or other PRMs inside the cell in immune defense.