Depletion of CD206+ Tumour Macrophages via a Peptide Targeted Star-Shaped Polyglutamate Inhibits Tumourigenesis and Metastatic Dissemination in Mouse Breast Cancer Models

Although many studies have explored the depletion of tumour-associated macrophages (TAMs) as a therapeutic strategy for solid tumours, currently available compounds suffer from poor efficacy and dose-limiting side effects. Here, we developed a novel TAM-depleting agent ("OximUNO") that specifically targets CD206+ TAMs and demonstrated efficacy in triple negative breast cancer (TNBC) mouse models. OximUNO comprises a star-shaped polyglutamate (St-PGA) decorated with the CD206-targeting peptide mUNO that carries the chemotherapeutic drug doxorubicin (DOX). In TNBC models, a fluorescently-labelled mUNO-decorated St-PGA homed to CD206+ TAMs within primary lesions and metastases. OximUNO exhibited no acute liver or kidney toxicity in vivo. Treatment with OximUNO reduced the progression of primary tumour lesions and pulmonary metastases, significantly diminished the number of CD206+ TAMs and increased the CD8/FOXP3 expression ratio (demonstrating immunostimulation). Our findings suggest the potential benefit of OximUNO as a TAM-depleting agent for TNBC treatment. Importantly, our studies also represent the first report of a peptide-targeted St-PGA as a targeted therapeutic nanoconjugate.

Depletion of CD206+ Tumour Macrophages via a Peptide-Targeted Star-Shaped Polyglutamate Inhibits Tumourigenesis and Metastatic Dissemination in Mouse Breast Cancer Models

Although many studies have explored the depletion of tumour-associated macrophages (TAMs) as a therapeutic strategy for solid tumours, currently available compounds suffer from poor efficacy and dose-limiting side effects. Here, we developed a novel TAM-depleting agent ("OximUNO") that specifically targets CD206+ TAMs and demonstrated efficacy in triple negative breast cancer (TNBC) mouse models. OximUNO comprises a star-shaped polyglutamate (St-PGA) decorated with the CD206-targeting peptide mUNO that carries the chemotherapeutic drug doxorubicin (DOX). In TNBC models, a fluorescently-labelled mUNO-decorated St-PGA homed to CD206+ TAMs within primary lesions and metastases. OximUNO exhibited no acute liver or kidney toxicity in vivo. Treatment with OximUNO reduced the progression of primary tumour lesions and pulmonary metastases, significantly diminished the number of CD206+ TAMs and increased the CD8/FOXP3 expression ratio (demonstrating immunostimulation). Our findings suggest the potential benefit of OximUNO as a TAM-depleting agent for TNBC treatment. Importantly, our studies also represent the first report of a peptide-targeted St-PGA as a targeted therapeutic nanoconjugate.

Combination Biomarker of Immune Checkpoints Predict Prognosis of Urothelial Carcinoma

In contrast to Western counties, the incidence of urothelial carcinoma (UC) remains mar-edly elevated in Taiwan. Regulatory T cells (Tregs) play a crucial role in limiting immune responses within the tumor microenvironment. To elucidate the relationship between immune checkpoints in the tumor immune microenvironment and UC progression, we utilize the Gene Expression Omnibus (GEO) to analyze a microarray obtained from 308 patients with UC. We observed that the expression level of CD276 or TIM-3 was positively correlated with late-stage UC and poor prognosis. Patients with simultaneously high CD276 and TIM-3 expression in tumors have significantly reduced both univariate and multivariate survival, indicating that mRNA levels of these immune checkpoints could be independent prognostic biomarkers for UC overall survival and recurrence. Our cohort study showed rare CD8+ cytotoxic T-cells and Tregs infiltration during early-stage UC-known as cold tumors. Approximately 30% of late-stage tumors exhibited highly infiltrated cytotoxic T cells with high PD-1 and FOXP3 expression, which implied that cytotoxic T cells were inhibited in the advanced UC microenvironment. Collectively, our findings provide a better prognosis prediction by combined immune checkpoint biomarkers and a basis for early-stage UC standard treatment to convert cold tumors into hot tumors, followed by immune checkpoint therapy.

Accumulation of Treg cells is detrimental in late-onset (aged) mouse model of multiple sclerosis

Although typically associated with onset in young adults, multiple sclerosis (MS) also attacks aged people, which is termed late-onset MS. The disease can be recapitulated and studied in the aged mouse model of experimental autoimmune encephalomyelitis (EAE). The onset of induced EAE is delayed in aged mice, but the disease severity is increased relative to standard EAE in young mice. Given that CD4+FoxP3+ regulatory T (Treg) cells play an ameliorative role in MS/EAE severity and the aged immune system accumulates Treg cells, failure of these cells to prevent or ameliorate EAE disease is enigmatic. When analyzing the distribution of Treg cells in EAE mice, the aged mice exhibited a higher proportion of polyclonal(pan) Treg cells and a lower proportion of antigen-specific-Treg cells in their periphery, but lower proportions of pan- and antigen-specific-Treg cells in the central nervous system (CNS). Furthermore, in the aged CNS, Treg cells exhibited a higher plasticity and T effector (Teff) cells exhibited a greater clonal expansion, which disrupted the Treg/Teff balance. Transiently inhibiting FoxP3 expression in peripheral Treg cells partially ameliorated the disease and corrected Treg distribution in the aged mice. These results provide evidence that accumulated aged Treg cells play a detrimental role in neuronal inflammation of aged MS.

Decrease in Regulatory T-cells and Increase in T Helper 17 Cells in Women With Recurrent Spontaneous Abortion

BackgroundAppearance of improper immune responses against the fetus and/or inadequate immunoregulatory mechanisms during pregnancy may lead to recurrent spontaneous abortion (RSA). TH17 cells play a significant role in inducing inflammation, autoimmune disease, and acute transplant rejection, while regulatory T (Treg) cells moderate the function of immune system in order to retain homeostasis.MethodsThis case-control study was designed to evaluate TH17 as well as Treg cells in 25 women with RSA and 25 age-matched healthy non-pregnant women. Flow cytometric assay was performed using monoclonal antibodies to detect CD4+CD25+ Treg cells (CD25dim and CD25bright). FoxP3 and RORγt expressions were compared using real-time PCR, and pro-inflammatory and anti-inflammatory cytokines were measured by ELISA kits. Independent-samples T test was employed for statistical analysis. ResultsThe ratio of CD4+CD25bright T cells was remarkably lower in women with RSA (P<0.05), and CD4+CD25dim T cells did not show any significant difference among the groups (P>0.05). RORγt was up-regulated, and FoxP3 was down-regulated significantly in case group (P<0.05). The significant increase of IL-6 and IL-17 as well as the decrease of TGF-β was indicated in RSA group (P<0.05). Also, IL-10 did not vary among the groups (P>0.05). ConclusionThese remarks prove that the decrease in regulatory factors such as CD4+CD25bright T-cells, TGF-β and FoxP3 expression may disrupt immune tolerance and homeostasis during pregnancy. Also, the environment rich in RORγt, IL-6, and IL-17 suggests the detrimental role of TH17 cells, which may lead to fetal rejection.

Oxidative Stress Promotes Instability of Regulatory T Cells in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

We investigated the characteristics of regulatory T cells (Tregs), focusing on the relationship between their stability and reactive oxygen species (ROS), in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Intracellular expressions of effector cytokines, forkhead box protein 3 (FoxP3), ROS, phosphorylated mammalian target of rapamycin (mTOR), and sirtuin 1 (SIRT1) in Tregs from peripheral blood mononuclear cells (PBMCs) of patients with AAV and healthy controls (HC) were analyzed. The alterations in and functional ability of Tregs were compared before and after resveratrol (RVL) treatment of PBMCs in patients with AAV. Significantly higher expressions of interferon (IFN)-γ, interleukin (IL)-17, IL-4, ROS, and phosphorylated mTOR (pho-mTOR) and lower expression of SIRT1 in CD4+CD25+FoxP3+ cells were found in patients with AAV than in the HC. FoxP3 expression in CD4+CD25+ cells and suppressive function of Tregs were significantly lower in patients with AAV than in the HC. Tregs after RVL treatment demonstrated significant decreases in IFN-γ, ROS, and pho-mTOR levels and increases in FoxP3, SIRT1 levels, and functional activity. Conversely, the direct activation of SIRT1 by SRT1720 resulted in decreased FoxP3 expression, with no reduction in ROS levels. The pho-mTOR levels were significantly higher in Tregs after activation by SRT1720 than in those after RVL treatment. This study suggested that imbalanced changes in Tregs could be attributed to mTOR activation, in which ROS overproduction was predominantly implicated. Therefore, ROS is a key mediator for promoting Tregs instability in AAV.

Association between Foxp3 Tumor Infiltrating Lymphocyte Expression and Response After Chemoradiation in Nasopharyngeal Carcinoma

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a carcinoma originating from the surface epithelium of the nasopharynx with the highest incidence in China and South East Asia. Currently, many researchers are developing tumor microenvironment which can be assessed by tumor-infiltrating lymphochyte, and its association with treatment response in several tumors, including NPC. Foxp3, known as a regulatory T cell (Treg) marker, plays a role in the immunoregulatory environment of tumor cells and can be used as a prognostic factor. The relationship between Foxp3 expression and treatment response is considered as one of the factors affecting the prognosis of NPC. AIM: This study aims to determine the relationship between Foxp3 expression and treatment response in NPC. MATERIALS AND METHODS: A cross-sectional study was done to analyze the association between Foxp3 and treatment response in NPC. This study included 60 samples who were diagnosed with non-keratinizing NPC at the Department of Anatomical Pathology, Faculty of Medicine Universitas Indonesia/Cipto Mangunkusumo Hospital from January 2018 until December 2020. Immunohistochemistry was done to evaluate the expression of Foxp3. Foxp3 expression was evaluated in the intratumoral and peritumoral areas. RESULTS: Among 60 patients, the number of males were more than females (66.7%, 33.3%, respectively) with a ratio of 2:1. There was statistically significant difference between intratumoral and total Foxp3 expression and treatment response (p < 0.05, p = 0.001, respectively); however, no significant differences found between peritumoral Foxp3 expression and treatment response (p = 0.114). CONCLUSION: Foxp3 expression had a statistically significant relationship with response therapy after chemoradiation.

The Extracellular Vesicles from the Commensal Staphylococcus Epidermidis ATCC12228 Strain Regulate Skin Inflammation in the Imiquimod-Induced Psoriasis Murine Model

Extracellular vesicles (EVs) are evaginations of the cytoplasmic membrane, containing nucleic acids, proteins, lipids, enzymes, and toxins. EVs participate in various bacterial physiological processes. Staphylococcus epidermidis interacts and communicates with the host skin. S. epidermidis’ EVs may have an essential role in this communication mechanism, modulating the immunological environment. This work aimed to evaluate if S. epidermidis’ EVs can modulate cytokine production by keratinocytes in vitro and in vivo using the imiquimod-induced psoriasis murine model. S. epidermidis’ EVs were obtained from a commensal strain (ATC12228EVs) and a clinical isolated strain (983EVs). EVs from both origins induced IL-6 expression in HaCaT keratinocyte cultures; nevertheless, 983EVs promoted a higher expression of the pro-inflammatory cytokines VEGF-A, LL37, IL-8, and IL-17F than ATCC12228EVs. Moreover, in vivo imiquimod-induced psoriatic skin treated with ATCC12228EVs reduced the characteristic psoriatic skin features, such as acanthosis and cellular infiltrate, as well as VEGF-A, IL-6, KC, IL-23, IL-17F, IL-36γ, and IL-36R expression in a more efficient manner than 983EVs; however, in contrast, Foxp3 expression did not significantly change, and IL-36 receptor antagonist (IL-36Ra) was found to be increased. Our findings showed a distinctive immunological profile induction that is dependent on the clinical or commensal EV origin in a mice model of skin-like psoriasis. Characteristically, proteomics analysis showed differences in the EVs protein content, dependent on origin of the isolated EVs. Specifically, in ATCC12228EVs, we found the proteins glutamate dehydrogenase, ornithine carbamoyltransferase, arginine deiminase, carbamate kinase, catalase, superoxide dismutase, phenol-soluble β1/β2 modulin, and polyglycerol phosphate α-glucosyltransferase, which could be involved in the reduction of lesions in the murine imiquimod-induced psoriasis skin. Our results show that the commensal ATCC12228EVs have a greater protective/attenuating effect on the murine imiquimod-induced psoriasis by inducing IL-36Ra expression in comparison with EVs from a clinical isolate of S. epidermidis.

CD38 Correlates with an Immunosuppressive Treg Phenotype in Lupus-Prone Mice

CD38 is a transmembrane glycoprotein expressed by T-cells. It has been reported that patients with systemic lupus erythematosus (SLE) showed increased CD38+CD25+ T-cells correlating with immune activation and clinical signs. Contrariwise, CD38 deficiency in murine models has shown enhanced autoimmunity development. Recent studies have suggested that CD38+ regulatory T-cells are more suppressive than CD38− regulatory T-cells. Thus, we have suggested that CD38 overexpression in SLE patients could play a role in regulating immune activation cells instead of enhancing it. This study found a correlation between CD38 with FoxP3 expression and immunosuppressive molecules (CD69, IL-10, CTLA-4, and PD-1) in T-cells from lupus-prone mice (B6.MRL-Faslpr/J). Additionally, B6.MRL-Faslpr/J mice showed a decreased proportion of CD38+ Treg cells regarding wild-type mice (WT). Furthermore, Regulatory T-Cells (Treg cells) from CD38-/- mice showed impairment in expressing immunosuppressive molecules and proliferation after stimulation through the T-cell receptor (TCR). Finally, we demonstrated an increased ratio of IFN-γ/IL-10 secretion in CD38-/- splenocytes stimulated with anti-CD3 compared with the WT. Altogether, our data suggest that CD38 represents an element in maintaining activated and proliferative Treg cells. Consequently, CD38 could have a crucial role in immune tolerance, preventing SLE development through Treg cells.