Interleukin-13 is overexpressed in cutaneous T-cell lymphoma cells and regulates their proliferation

Real-world study of pegylated interferon α-2a to treat mycosis fungoides/Sézary syndrome using time to next treatment as a measure of clinical benefit: an EORTC CLTG study

BACKGROUND

Mycosis fungoides (MF) and Sézary syndrome (SS) are chronic malignant diseases that typically necessitate diverse strategies to achieve remission. Systemic interferon (IFN)-α (subtypes 2a and 2b) has been used to treat MF/SS since 1984; however, its production was recently stopped. The recombinant pegylated (PEG) form of IFN-α-2a remains the only alternative IFN treatment, although it has not been approved for use in MF/SS.

OBJECTIVES

To assess the effectiveness and safety of PEG-IFN-α-2a in monotherapy and in combination with other treatments using time to next treatment (TTNT) as a measure of clinical therapeutic benefit in a real-world setting.

METHODS

We conducted an international, multicentre retrospective study of patients with MF and SS (of any stage) treated with PEG-IFN-α-2a from July 2012 to February 2022. Patients were included across 11 centres in 10 countries. The primary endpoints were to determine the TTNT of PEG-IFN-α-2a and adverse events (AEs) in MF/SS.

RESULTS

In total, 105 patients were included [mean (SD) age 61 (13.1) years]; 42 (40.0%) had stage IA-IIA and 63 (60.0%) had stage IIB-IVB disease. PEG-IFN-α-2a was combined with other therapies in 67 (63.8%) patients, most commonly with extracorporeal photopheresis (36%) and bexarotene (22%). Patients with stage I-IIA disease achieved an overall response rate (ORR) of 57%; the ORR in those with stage IIB-IVB disease was 51%. Combination treatment resulted in a median TTNT of 10.4 months (range 0.6-50.7) vs. 7.0 months (range 0.7-52.4) for those who received monotherapy (P < 0.01). Overall, the mean (SD) TTNT was 9.2 (10.6) months and the ORR was 53.3% (n = 56). A complete response was seen in 13% of patients and a partial response in 40%. AEs were described in 68.6% (n = 72) of patients. Flu-like symptoms (n = 28; 26.7%), lymphopenia (n = 24; 22.9%) and elevated liver function (n = 10; 9.5%) were the most frequently reported. Grade 3-4 AEs were reported in 23 (21.9%) patients, mostly related to myelosuppression.

CONCLUSIONS

PEG-IFN-α-2a for MF/SS resulted in an ORR of 53.3% and a mean (SD) TTNT of 9.2 (10.6) months. Combination regimens were superior to monotherapy and doses of 180 µg PEG-IFN-α-2a weekly were related to a higher ORR.

Optimization of Interleukin-10 incorporation for dendritic cells embedded in Poly(ethylene glycol) hydrogels

Translational research in biomaterials and immunoengineering is leading to the development of novel advanced therapeutics to treat diseases such as cancer, autoimmunity, and viral infections. Dendritic cells (DCs) are at the center of these therapeutics given that they bridge innate and adaptive immunity. The biomaterial system developed herein uses a hydrogel carrier to deliver immunomodulatory DCs for amelioration of autoimmunity. This biomaterial vehicle is comprised of a poly (ethylene glycol)-4 arm maleimide (PEG-4MAL) hydrogels, conjugated with the immunosuppressive cytokine, interleukin-10, IL-10, and cross-linked with a collagenase-degradable peptide sequence for the injectable delivery of immunosuppressive DCs to an anatomical disease-relevant site of the cervical lymph nodes, for intended application to treat multiple sclerosis. The amount of IL-10 incorporated in the hydrogel was optimized to be 500 ng in vitro, based on immunological endpoints. At this concentration, DCs exhibited the best viability, most immunosuppressive phenotype, and protection against proinflammatory insult as compared with hydrogel-incorporated DCs with lower IL-10 loading amounts. Additionally, the effect of the degradability of the PEG-4MAL hydrogel on the release rate of incorporated IL-10 was assessed by varying the ratio of degradable peptides: VPM (degradable) and DTT (nondegradable) and measuring the IL-10 release rates. This IL-10-conjugated hydrogel delivery system for immunosuppressive DCs is set to be assessed for in vivo functionality as the immunosuppressive cytokine provides a tolerogenic environment that keeps DCs in their immature phenotype, which consequently enhances cell viability and optimizes the system's immunomodulatory functionality.

Keratinocytes Present Staphylococcus aureus Enterotoxins and Promote Malignant and Nonmalignant T Cell Proliferation in Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphoma is characterized by malignant T cells proliferating in a unique tumor microenvironment dominated by keratinocytes (KCs). Skin colonization and infection by Staphylococcus aureus are a common cause of morbidity and are suspected of fueling disease activity. In this study, we show that expression of HLA-DRs, high-affinity receptors for staphylococcal enterotoxins (SEs), by KCs correlates with IFN-γ expression in the tumor microenvironment. Importantly, IFN-γ induces HLA-DR, SE binding, and SE presentation by KCs to malignant T cells from patients with Sézary syndrome and malignant and nonmalignant T-cell lines derived from patients with Sézary syndrome and mycosis fungoides. Likewise, preincubation of KCs with supernatant from patient-derived SE-producing S aureus triggers proliferation in malignant T cells and cytokine release (including IL-2), when cultured with nonmalignant T cells. This is inhibited by pretreatment with engineered bacteriophage S aureus-specific endolysins. Furthermore, alteration in the HLA-DR-binding sites of SE type A and small interfering RNA-mediated knockdown of Jak3 and IL-2Rγ block induction of malignant T-cell proliferation. In conclusion, we show that upon exposure to patient-derived S aureus and SE, KCs stimulate IL-2Rγ/Jak3-dependent proliferation of malignant and nonmalignant T cells in an environment with nonmalignant T cells. These findings suggest that KCs in the tumor microenvironment play a key role in S aureus-mediated disease activity in cutaneous T-cell lymphoma.

The Role of Cytokines in Cutaneous T Cell Lymphoma: A Focus on the State of the Art and Possible Therapeutic Targets

Cutaneous T cell lymphomas (CTCLs), encompassing mycosis fungoides (MF) and Sézary syndrome (SS), present a complex landscape influenced by cytokines and cellular responses. In this work, the intricate relationship between these inflammatory proteins and disease pathogenesis is examined, focusing on what is known at the clinical and therapeutic levels regarding the most well-known inflammatory mediators. An in-depth look is given to their possible alterations caused by novel immunomodulatory drugs and how they may alter disease progression. From this narrative review of the actual scientific landscape, Interferon-gamma (IFN-γ) emerges as a central player, demonstrating a dual role in both promoting and inhibiting cancer immunity, but the work navigates through all the major interleukins known in inflammatory environments. Immunotherapeutic perspectives are elucidated, highlighting the crucial role of the cutaneous microenvironment in shaping dysfunctional cell trafficking, antitumor immunity, and angiogenesis in MF, showcasing advancements in understanding and targeting the immune phenotype in CTCL. In summary, this manuscript aims to comprehensively explore the multifaceted aspects of CTCL, from the immunopathogenesis and cytokine dynamics centred around TNF-α and IFN-γ to evolving therapeutic modalities. Including all the major known and studied cytokines in this analysis broadens our understanding of the intricate interplay influencing CTCL, paving the way for improved management of this complex lymphoma.

Role of IL-4 and IL-13 in Cutaneous T Cell Lymphoma

The interleukins IL-4 and IL-13 are increasingly recognized contributors to the pathogenesis of cutaneous T cell lymphomas (CTCLs), and their role in disease-associated pruritus is accepted. The prevailing Th2 profile in advanced CTCL underscores the significance of understanding IL-4/IL-13 expression dynamics from the early stages of disease, as a shift from Th1 to Th2 may explain CTCL progression. Targeted agents blocking key cytokines of type 2 immunity are established therapeutics in atopic disorders and have a promising therapeutic potential in CTCL, given their involvement in cutaneous symptoms and their contribution to the pathogenesis of disease. IL-4, IL-13, and IL-31 are implicated in pruritus, offering therapeutic targets with dupilumab, tralokinumab, lebrikizumab, and nemolizumab. This review analyzes current knowledge on the IL-4/IL-13 axis in mycosis fungoides and Sezary syndrome, the most common types of CTCL, examining existing literature on the pathogenetic implications with a focus on investigational treatments. Clinical trials and case reports are required to shed light on novel uses of medications in various diseases, and ongoing research into the role of IL-4/IL-13 axis blockers in CTCL therapy might not only improve the management of disease-related pruritus but also provide in-depth insights on the pathophysiologic mechanisms of CTCL.

What's New in Cutaneous T-Cell Lymphoma-Associated Pruritus

Cutaneous T-cell lymphomas are a heterogenous group of lymphomas that cause various skin manifestations. Severe pruritus occurs frequently in cutaneous T-cell lymphoma and negatively impacts patients' quality of life. The pathophysiology of cutaneous T-cell lymphoma-associated itch is complex and involves various immune cells, inflammatory cytokines, and neuroimmune interactions. Treating cutaneous T-cell lymphoma pruritus can be challenging, and there have been few randomized controlled studies evaluating the use of antipruritic treatments in these patients. Systemic therapies targeting the disease have also been shown to have some antipruritic effects. Furthermore, although biologic therapy has revolutionized the treatment of other pruritic skin conditions, the use of biologics in cutaneous T-cell lymphoma remains controversial.

Mycosis fungoides and Sézary syndrome following dupilumab treatment: experience of two Italian tertiary care centres

Dupilumab is a monoclonal antibody targeting the interleukin-4 and -13 signalling pathway, and which is proven to be highly effective and safe in atopic dermatitis (AD). Its possible role in treating or inducing cutaneous T-cell lymphomas (CTCLs) has not yet been fully clarified, as several case reports seem to point not only at its beneficial effects but also at a possible pathogenetic role in mycosis fungoides and Sézary syndrome. We present data collected from a cohort of 995 patients with classic or prurigo nodularis-like AD who received dupilumab and were followed longitudinally for a mean period of 25.1 months after first administration to investigate a possible correlation between dupilumab and CTCL development.

Cytokine Profile in Development of Glioblastoma in Relation to Healthy Individuals

Cytokines play an essential role in the control of tumor cell development and multiplication. However, the available literature provides ambiguous data on the involvement of these proteins in the formation and progression of glioblastoma (GBM). This study was designed to evaluate the inflammatory profile and to investigate its potential for the identification of molecular signatures specific to GBM. Fifty patients aged 66.0 ± 10.56 years with newly diagnosed high-grade gliomas and 40 healthy individuals aged 71.7 ± 4.9 years were included in the study. White blood cells were found to fall within the referential ranges and were significantly higher in GBM than in healthy controls. Among immune cells, neutrophils showed the greatest changes, resulting in elevated neutrophil-to-lymphocyte ratio (NLR). The neutrophil count inversely correlated with survival time expressed by Spearman's coefficient rs = -0.359 (p = 0.010). The optimal threshold values corresponded to 2.630 × 103/µL for NLR (the area under the ROC curve AUC = 0.831, specificity 90%, sensitivity 76%, the relative risk RR = 7.875, the confidence intervals 95%CI 3.333-20.148). The most considerable changes were recorded in pro-inflammatory cytokines interleukin IL-1β, IL-6, and IL-8, which were approx. 1.5-2-fold higher, whereas tumor necrosis factor α (TNFα) and high mobility group B1 (HMGB1) were lower in GBM than healthy control (p < 0.001). The results of the ROC, AUC, and RR analysis of IL-1β, IL-6, IL-8, and IL-10 indicate their high diagnostics potential for clinical prognosis. The highest average RR was observed for IL-6 (RR = 2.923) and IL-8 (RR = 3.151), which means there is an approx. three-fold higher probability of GBM development after exceeding the cut-off values of 19.83 pg/mL for IL-6 and 10.86 pg/mL for IL-8. The high values of AUC obtained for the models NLR + IL-1β (AUC = 0.907), NLR + IL-6 (AUC = 0.908), NLR + IL-8 (AUC = 0.896), and NLR + IL-10 (AUC = 0.887) prove excellent discrimination of GBM patients from healthy individuals and may represent GBM-specific molecular signatures.

Advancements in the treatment of mycosis fungoides and Sézary syndrome: monoclonal antibodies, immunotherapies, and Janus kinase inhibitors

Mycosis fungoides (MF) and Sézary syndrome (SS) are forms of cutaneous T cell lymphoma (CTCL) that pose significant challenges in their clinical management, particularly in refractory and advanced-stage disease. With the emergence of novel therapeutic modalities however, there are increasing opportunities to exploit the current understanding of pathophysiologic mechanisms of MF/SS for treatment. This review summarizes recent advances in the treatment of MF/SS, with a focus on monoclonal antibodies, immunotherapies, and Janus kinase (JAK) inhibitors, including ongoing clinical trials.

Dupilumab-Associated Lymphoid Reactions in Patients With Atopic Dermatitis

Importance

Since the increased use of dupilumab for atopic dermatitis (AD) in daily practice, several cases have been reported on the development of cutaneous T-cell lymphomas (CTCL) and lymphoid infiltrates.

Objective

To provide insight in the clinical and histopathologic features of patients with AD clinically suspected for CTCL during dupilumab treatment.

Design, Setting, and Participants

This retrospective observational case series included adult (≥18 years) patients with AD treated with dupilumab between October 2017 and July 2022 at the University Medical Center Utrecht in the Netherlands.

Main outcomes and measures

Relevant patient, disease, and treatment characteristics were evaluated. Skin biopsies before, during, and after treatment were collected and reassessed.

Results

Fourteen patients (54.5% male) with a median (IQR) age of 56 (36-66) years suspected for CTCL with deterioration of symptoms during dupilumab treatment were included. Of 14 patients, 3 were retrospectively diagnosed with preexistent mycosis fungoides (MF). Eleven patients with AD were eventually diagnosed with a lymphoid reaction (LR). These patients showed MF-like symptoms; however, histopathologic findings were different, and included sprinkled distribution of small hyperchromatic lymphocytes in the upper epidermal section, a dysregulated CD4:CD8 ratio, and CD30 overexpression, without loss of CD2/CD3/CD5. The median time to clinical worsening was 4.0 months (IQR, 1.4-10.0). Posttreatment biopsies showed complete clearance of the LR in all patients.

Conclusions and relevance

This study found that dupilumab treatment can cause a reversible and benign LR, which mimics a CTCL, though has distinctive histopathologic features.

Dupilumab-associated mycosis fungoides: a cross-sectional study

Treating atopic dermatitis (AD) with dupilumab, a monoclonal antibody that inhibits interleukin-4 (IL-4) and interleukin-13 (IL-13), may be associated with the progression of mycosis fungoides (MF).This study aims to examine the associations between the length of dupilumab treatment, age and sex, and the onset of MF.An institutional data registry and literature search were used for a retrospective cross-sectional study. Only patients with a diagnosis of MF on dupilumab for the treatment of AD and eczematous dermatitis were included.The primary outcome was the length of dupilumab exposure, age, sex, and the onset of MF. Linear correlations (Pearson) and Cox regression analysis were used to assess the correlation and the risk.A total of 25 patients were included in this study. Five eligible patients were identified at our institution. In addition, a PubMed review identified an additional 20 patients. At the time of MF diagnosis, the median age was 58, with 42% female. Disease history was significant for adult-onset AD in most patients (n = 17, 65.4%) or recent flare of AD previously in remission (n = 3, 11.5%). All patients were diagnosed with MF, and one patient progressed to Sézary syndrome while on dupilumab, with an average duration of 13.5 months of therapy prior to diagnosis. Tumor stage at diagnosis of MF was described in 19 of the cases and ranged from an early-stage disease (IA) to advanced disease (IV). Treatment strategies included narrow-band UVB therapy, topical corticosteroids, brentuximab, pralatrexate, and acitretin. Male gender, advanced-stage disease, and older age correlated significantly with the hazard of MF onset and a shorter time to onset during dupilumab treatment.Our results suggest a correlation between the duration of dupilumab treatment and the diagnosis of MF, the higher MF stage at diagnosis, and the shorter the duration of using dupilumab to MF onset. Furthermore, elderly male patients appeared to be more at risk as both male gender and older age correlated with a hazard of MF diagnosis. The results raise the question as to whether the patients had MF misdiagnosed as AD that was unmasked by dupilumab or if MF truly is an adverse effect of treatment with dupilumab. Close monitoring of these patients and further investigation of the relationship between dupilumab and MF can shed more light on this question .

Microenvironment-dependent growth of Sezary cells in humanized IL-15 mice

Sezary syndrome (SS) is a rare, aggressive leukemic variant of cutaneous T-cell lymphoma (CTCL) that lacks adequate therapeutic options and representative small-animal models. Here, we demonstrate that IL-15 is a critical CTCL growth factor. Importantly, an immunodeficient knock-in mouse model genetically engineered to express human IL-15 uniquely supported the growth of SS patient samples relative to conventional immunodeficient mouse strains. SS patient-derived xenograft (PDX) models recapacitated key pathological features of the human disease, including skin infiltration and spread of leukemic cells to the periphery, and maintained the dependence on human IL-15 upon serial in vivo passaging. Detailed molecular characterization of the engrafted cells by single-cell transcriptomic analysis revealed congruent neoplastic gene expression signatures but distinct clonal engraftment patterns. Overall, we document an important dependence of Sezary cell survival and proliferation on IL-15 signaling and the utility of immunodeficient humanized IL-15 mice as hosts for SS - and potentially other T and NK cell-derived hematologic malignancies - PDX model generation. Furthermore, these studies advocate the thorough molecular understanding of the resultant PDX models to maximize their translational impact.

What Does the Future Hold for Biomarkers of Response to Extracorporeal Photopheresis for Mycosis Fungoides and Sézary Syndrome?

Extracorporeal photopheresis (ECP) is an FDA-approved immunotherapy for cutaneous T-cell lymphoma, which can provide a complete response in some patients. However, it is still being determined who will respond well, and predictive biomarkers are urgently needed to target patients for timely treatment and to monitor their response over time. The aim of this review is to analyze the current state of the diagnostic, prognostic, and disease state-monitoring biomarkers of ECP, and outline the future direction of the ECP biomarker discovery. Specifically, we focus on biomarkers of response to ECP in mycosis fungoides and Sézary syndrome. The review summarizes the current knowledge of ECP biomarkers, including their limitations and potential applications, and identifies key challenges in ECP biomarker discovery. In addition, we discuss emerging technologies that could revolutionize ECP biomarker discovery and accelerate the translation of biomarker research into clinical practice. This review will interest researchers and clinicians seeking to optimize ECP therapy for cutaneous T-cell lymphoma.

Cutaneous T-cell Lymphoma Progression: A Potential Dupilumab Pitfall

Dupilumab is a monoclonal antibody inhibiting key drivers in the inflammatory signaling cascade. It has been considered a saving grace for many patients suffering from severe atopic dermatitis and has quickly become a widespread treatment option for many inflammatory pathologies. However, recent reports have linked dupilumab with exacerbating symptoms and accelerated disease progression of cutaneous T-cell lymphoma (CTCL). This report presents the case of a 60-year-old African American female who was diagnosed with CTCL three months after her initial treatment with dupilumab for presumed atopic dermatitis. An appreciation of this unique relationship, as well as the morphological differences seen in patient presentation, is important for physicians to better guide timely diagnoses while working to uncover the true relationship between dupilumab and CTCL.

Unveiling tumor immune evasion mechanisms: abnormal expression of transporters on immune cells in the tumor microenvironment

The tumor microenvironment (TME) is a crucial driving factor for tumor progression and it can hinder the body's immune response by altering the metabolic activity of immune cells. Both tumor and immune cells maintain their proliferative characteristics and physiological functions through transporter-mediated regulation of nutrient acquisition and metabolite efflux. Transporters also play an important role in modulating immune responses in the TME. In this review, we outline the metabolic characteristics of the TME and systematically elaborate on the effects of abundant metabolites on immune cell function and transporter expression. We also discuss the mechanism of tumor immune escape due to transporter dysfunction. Finally, we introduce some transporter-targeted antitumor therapeutic strategies, with the aim of providing new insights into the development of antitumor drugs and rational drug usage for clinical cancer therapy.

Reprogramming of PD-1+ M2-like tumor-associated macrophages with anti-PD-L1 and lenalidomide in cutaneous T cell lymphoma

Cutaneous T cell lymphoma (CTCL) is a disfiguring and incurable disease characterized by skin-homing malignant T cells surrounded by immune cells that promote CTCL growth through an immunosuppressive tumor microenvironment (TME). Preliminary data from our phase I clinical trial of anti-programmed cell death ligand 1 (anti-PD-L1) combined with lenalidomide in patients with relapsed/refractory CTCL demonstrated promising clinical efficacy. In the current study, we analyzed the CTCL TME, which revealed a predominant PD-1+ M2-like tumor-associated macrophage (TAM) subtype with upregulated NF-κB and JAK/STAT signaling pathways and an aberrant cytokine and chemokine profile. Our in vitro studies investigated the effects of anti-PD-L1 and lenalidomide on PD-1+ M2-like TAMs. The combinatorial treatment synergistically induced functional transformation of PD-1+ M2-like TAMs toward a proinflammatory M1-like phenotype that gained phagocytic activity upon NF-κB and JAK/STAT inhibition, altered their migration through chemokine receptor alterations, and stimulated effector T cell proliferation. Lenalidomide was more effective than anti-PD-L1 in downregulation of the immunosuppressive IL-10, leading to decreased expression of both PD-1 and PD-L1. Overall, PD-1+ M2-like TAMs play an immunosuppressive role in CTCL. Anti-PD-L1 combined with lenalidomide provides a therapeutic strategy to enhance antitumor immunity by targeting PD-1+ M2-like TAMs in the CTCL TME.

Transcription factor genetics and biology in predisposition to bone marrow failure and hematological malignancy

Transcription factors (TFs) play a critical role as key mediators of a multitude of developmental pathways, with highly regulated and tightly organized networks crucial for determining both the timing and pattern of tissue development. TFs can act as master regulators of both primitive and definitive hematopoiesis, tightly controlling the behavior of hematopoietic stem and progenitor cells (HSPCs). These networks control the functional regulation of HSPCs including self-renewal, proliferation, and differentiation dynamics, which are essential to normal hematopoiesis. Defining the key players and dynamics of these hematopoietic transcriptional networks is essential to understanding both normal hematopoiesis and how genetic aberrations in TFs and their networks can predispose to hematopoietic disease including bone marrow failure (BMF) and hematological malignancy (HM). Despite their multifaceted and complex involvement in hematological development, advances in genetic screening along with elegant multi-omics and model system studies are shedding light on how hematopoietic TFs interact and network to achieve normal cell fates and their role in disease etiology. This review focuses on TFs which predispose to BMF and HM, identifies potential novel candidate predisposing TF genes, and examines putative biological mechanisms leading to these phenotypes. A better understanding of the genetics and molecular biology of hematopoietic TFs, as well as identifying novel genes and genetic variants predisposing to BMF and HM, will accelerate the development of preventative strategies, improve clinical management and counseling, and help define targeted treatments for these diseases.

Spatially Guided and Single Cell Tools to Map the Microenvironment in Cutaneous T-Cell Lymphoma

Mycosis fungoides (MF) and Sézary syndrome (SS) are two closely related clinical variants of cutaneous T-cell lymphomas (CTCL). Previously demonstrated large patient-to-patient and intra-patient disease heterogeneity underpins the importance of personalized medicine in CTCL. Advanced stages of CTCL are characterized by dismal prognosis, and the early identification of patients who will progress remains a clinical unmet need. While the exact molecular events underlying disease progression are poorly resolved, the tumor microenvironment (TME) has emerged as an important driver. In particular, the Th1-to-Th2 shift in the immune response is now commonly identified across advanced-stage CTCL patients. Herein, we summarize the role of the TME in CTCL evolution and the latest studies in deciphering inter- and intra-patient heterogeneity. We introduce spatially resolved omics as a promising technology to advance immune-oncology efforts in CTCL. We propose the combined implementation of spatially guided and single-cell omics technologies in paired skin and blood samples. Such an approach will mediate in-depth profiling of phenotypic and molecular changes in reactive immune subpopulations and malignant T cells preceding the Th1-to-Th2 shift and reveal mechanisms underlying disease progression from skin-limited to systemic disease that collectively will lead to the discovery of novel biomarkers to improve patient prognostication and the design of personalized treatment strategies.

Dupilumab-associated cutaneous adverse events among adult patients with atopic dermatitis: A retrospective study

Dupilumab, a monoclonal antibody inhibiting interleukin (IL) 4 and IL-13, is approved for the treatment of moderate to severe atopic dermatitis (AD) in children aged ≥6 years, adolescents, and adults. Both clinical trials and real-life data demonstrate its efficacy and safety. However, some cutaneous adverse events (cAEs) have been observed during real-world experiences. The authors' aim was to analyze the spectrum of cAEs in patients receiving dupilumab for the treatment of AD in a real-world setting. A retrospective review of electronic medical records was conducted for 916 patients (475 males and 541 females; mean age, 50.23 ± 19.66 years [range, 18-91 years]) who had received dupilumab for a minimum of 1 month for the treatment of AD from December 2018 to November 2022 at the Department of Dermatology of University Federico II of Naples (Italy). The mean duration of dupilumab treatment was 27.31 ± 21.26 months. A total of 148 of 916 (16.15%) (90 males; mean age, 50.91 ± 15.34 years) patients reported other cAEs apart of AD flare; namely, facial redness (82 of 916; 8.95%), psoriasis (39 of 916; 4.25%), alopecia areata (11 of 916; 1.2%), skin peeling (11 of 916; 1.2%), parapsoriasis (three of 916; 0.32%), and vitiligo (two of 916; 0.21%). Thirty-one of 916 (3.38%) patients discontinued dupilumab because of cAEs (18 of 916; 1.96%) for facial redness, 10 of 916 (1.09%) for psoriasis, and three of 916 (0.32%) for parapsoriasis. In our population, most of the cAEs were mild and did not require discontinuation of dupilumab. These findings would enable dermatologists understand the cutaneous side effects of dupilumab better, resulting in improved treatment plan decisions in clinical practice.

Integrated transcriptome and trajectory analysis of cutaneous T-cell lymphoma identifies putative precancer populations

The incidence of cutaneous T-cell lymphoma (CTCL) increases with age, and blood involvement portends a worse prognosis. To advance our understanding of the development of CTCL and identify potential therapeutic targets, we performed integrative analyses of paired single-cell RNA and T-cell receptor (TCR) sequencing of peripheral blood CD4+ T cells from patients with CTCL to reveal disease-unifying features. The malignant CD4+ T cells of CTCL showed highly diverse transcriptomic profiles across patients, with most displaying a mature Th2 differentiation and T-cell exhaustion phenotype. TCR-CDR3 peptide prediction analysis suggested limited diversity between CTCL samples, consistent with a role for a common antigenic stimulus. Potential of heat diffusion for affinity-based trajectory embedding transition analysis identified putative precancerous circulating populations characterized by an intermediate stage of gene expression and mutation level between the normal CD4+ T cells and malignant CTCL cells. We further revealed the therapeutic potential of targeting CD82 and JAK that endow the malignant CTCL cells with survival and proliferation advantages.

CD30 Regulation of IL-13-STAT6 Pathway in Breast Implant-Associated Anaplastic Large Cell Lymphoma

BACKGROUND

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare, usually indolent CD30+ T-cell lymphoma with tumor cells, often surrounded by eosinophils, expressing IL-13 and pSTAT6.

OBJECTIVES

The aim of this study was to understand the unique tumor pathology and growth regulation of BIA-ALCL, leading to potential targeted therapies.

METHODS

We silenced CD30 and analyzed its effect on IL-13 signaling and tumor cell viability. IL-13 signaling receptors of BIA-ALCL cell lines were evaluated by flow cytometry and pSTAT6 detected by immunohistochemistry. CD30 was deleted by CRISPR/Cas9 editing. Effects of CD30 deletion on transcription of IL-13 and IL-4, and phosphorylation of STAT6 were determined by real-time polymerase chain reaction and western blotting. The effect of CD30 deletion on p38 mitogen-activated protein kinase (MAPK) phosphorylation was determined. Suppression of IL-13 transcription by a p38 MAPK inhibitor was tested. Tumor cell viability following CD30 deletion and treatment with a pSTAT6 inhibitor were measured in cytotoxicity assays.

RESULTS

BIA-ALCL lines TLBR1 and TLBR2 displayed signaling receptors IL-4Rα, IL-13Rα1 and downstream pSTAT6. Deletion of CD30 by CRISPR/Cas9 editing significantly decreased transcription of IL-13, less so Th2 cytokine IL-4, and phosphorylation of STAT6. Mechanistically, we found CD30 expression is required for p38 MAPK phosphorylation and activation, and IL-13-STAT6 signaling was reduced by an inhibitor of p38 MAPK in BIA-ALCL tumor cells. Tumor cell viability was decreased by silencing of CD30, and a specific inhibitor of STAT6, indicating STAT6 inhibition is cytotoxic to BIA-ALCL tumor cells.

CONCLUSIONS

These findings suggest reagents targeting the IL-13 pathway, pSTAT6 and p38 MAPK, may become useful for treating BIA-ALCL patients.

Interleukin-13 inhibition by tralokinumab reduces inducible T-cell costimulator-positive innate lymphoid cells in skin lesions of atopic dermatitis

Despite the low frequency of skin ILCs and the limited number of samples analyzed in this study, our data indicate that ICOS+ ILCs express IL-13Rα1 and that the density of ICOS+ ILCs decreased four weeks after initiation of treatment with tralokinumab.

Malignant T cells induce skin barrier defects through cytokine-mediated JAK/STAT signaling in cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is a devastating lymphoid malignancy characterized by the accumulation of malignant T cells in the dermis and epidermis. Skin lesions cause serious symptoms that hamper quality of life and are entry sites for bacterial infection, a major cause of morbidity and mortality in advanced diseases. The mechanism driving the pathological processes that compromise the skin barrier remains unknown. Here, we report increased transepidermal water loss and compromised expression of the skin barrier proteins filaggrin and filaggrin-2 in areas adjacent to TOX-positive T cells in CTCL skin lesions. Malignant T cells secrete mediators (including cytokines such as interleukin 13 [IL-13], IL-22, and oncostatin M) that activate STAT3 signaling and downregulate filaggrin and filaggrin-2 expression in human keratinocytes and reconstructed human epithelium. Consequently, the repression of filaggrins can be counteracted by a cocktail of antibodies targeting these cytokines/receptors, small interfering RNA-mediated knockdown of JAK1/STAT3, and JAK1 inhibitors. Notably, we show that treatment with a clinically approved JAK inhibitor, tofacitinib, increases filaggrin expression in lesional skin from patients with mycosis fungoides. Taken together, these findings indicate that malignant T cells secrete cytokines that induce skin barrier defects via a JAK1/STAT3-dependent mechanism. As clinical grade JAK inhibitors largely abrogate the negative effect of malignant T cells on skin barrier proteins, our findings suggest that such inhibitors provide novel treatment options for patients with CTCL with advanced disease and a compromised skin barrier.

Cytokine/Chemokine assessment as a complementary diagnostic tool for inflammatory skin diseases

Inflammatory skin conditions are the 4th leading cause of non-fatal health burden in the general population worldwide. The diagnosis of skin lesions due to systemic drug reactions, viral or bacterial exanthems, or in patients with psoriasis, atopic dermatitis or contact dermatitis is often difficult and relies heavily upon conventional histopathologic examination. Conversely, it is widely accepted that the cutaneous profile of inflammatory markers, or 'inflammatory signature', is differentially expressed in various skin conditions. In this pilot study, we investigated the possibility of inflammatory skin disease diagnosis from an immunological perspective in small punch biopsies. We collected lesional and perilesional punch biopsies from 139 patients suffering from a variety of inflammatory skin conditions and attending the Dermatology Department at the Princess Alexandra Hospital in Brisbane, Australia. Using bead-based immunoassays we were able to measure 13 out of 17 inflammatory markers from a pre-selected multi-analyte panel and to detect significant differences between lesional and perilesional biopsies from each individual patient. Hierarchical and unbiased clustering methods based on inflammatory signatures grouped psoriasis and atopic dermatitis lesions into individual clusters in contrast to other skin conditions, highlighting the potential of inflammatory signatures to be used as diagnostic differentiators and to inform alternative targets in anti-inflammatory treatment strategies.

Molecular pathogenesis of Cutaneous T cell Lymphoma: Role of chemokines, cytokines, and dysregulated signaling pathways

Cutaneous T cell lymphomas (CTCLs) are a heterogeneous group of lymphoproliferative neoplasms that exhibit a wide spectrum of immune-phenotypical, clinical, and histopathological features. The biology of CTCL is complex and remains elusive. In recent years, the application of next-generation sequencing (NGS) has evolved our understanding of the pathogenetic mechanisms, including genetic aberrations and epigenetic abnormalities that shape the mutational landscape of CTCL and represent one of the important pro-tumorigenic principles in CTCL initiation and progression. Still, identification of the major pathophysiological pathways including genetic and epigenetic components that mediate malignant clonal T cell expansion has not been achieved. This is of prime importance given the role of malignant T cell clones in fostering T helper 2 (Th2)-bias tumor microenvironment and fueling progressive immune dysregulation and tumor cell growth in CTCL patients, manifested by the secretion of Th2-associated cytokines and chemokines. Alterations in malignant cytokine and chemokine expression patterns orchestrate the inflammatory milieu and influence the migration dynamics of malignant clonal T cells. Here, we highlight recent insights about the molecular mechanisms of CTCL pathogenesis, emphasizing the role of cytokines, chemokines, and associated downstream signaling networks in driving immune defects, malignant transformation, and disease progression. In-depth characterization of the CTCL immunophenotype and tumoral microenvironment offers a facile opportunity to expand the therapeutic armamentarium of CTCL, an intractable malignant skin disease with poor prognosis and in dire need of curative treatment approaches.

[New insights into the pathogenesis and molecular understanding of cutaneous T-cell lymphomas]

The pathogenesis of cutaneous T‑cell lymphomas (CTCL) is still an enigma. Therefore, extensive translational research efforts have been undertaken in recent years to gain further clinical and molecular insights. There is increasing evidence that the different clinical appearance of the CTCL subtypes derives from the assumption that they develop from different skin subpopulations of T cells. Detection and quantification of the malignant T‑cell clones is crucial for the diagnosis and prognosis of CTCL. Numerous recurrent mutant cellular signalling pathways have been found in recent years. This includes the JAK-STAT, NFκB, T‑cell receptor and MAP kinase signalling pathways, as well as cell cycle control and epigenetics. The most recent analyses imply a tumour evolution model with initial copy number variation, like amplification or deletions of specific DNA fragments (CNVs) and only subsequent later single nucleotide variations (SNVs). The crucial question, however, is which CNVs are sufficient to initiate general tumourigenesis? The challenge is to identify possible driver genes. Increasing molecular understanding in CTCL will include new breakthrough therapeutic options in the near future.

Interleukin 13 receptor alpha 2 (IL13Rα2): Expression, signaling pathways and therapeutic applications in cancer

Interleukin 13 receptor alpha 2 (IL13Rα2) is increasingly recognized as a relevant player in cancer invasion and metastasis. Despite being initially considered a decoy receptor for dampening the levels of interleukin 13 (IL-13) in diverse inflammatory conditions, accumulating evidences in the last decades indicate the capacity of IL13Rα2 for mediating IL-13 signaling in cancer cells. The biological reasons behind the expression of this receptor with such extremely high affinity for IL-13 in cancer cells remain unclear. Elevated expression of IL13Rα2 is commonly associated with invasion, late stage and cancer metastasis that results in poor prognosis for glioblastoma, colorectal or breast cancer, among others. The discovery of new mediators and effectors of IL13Rα2 signaling has been critical for deciphering its underlying molecular mechanisms in cancer progression. Still, many questions about the effects of inflammation, the cancer type and the tumor degree in the expression of IL13Rα2 remain largely uncharacterized. Here, we review and discuss the current status of the IL13Rα2 biology in cancer, with particular emphasis in the role of inflammation-driven expression and the regulation of different signaling pathways. As IL13Rα2 implications in cancer continue to grow exponentially, we highlight new targeted therapies recently developed for glioblastoma, colorectal cancer and other IL13Rα2-positive tumors.

T Cell Extracellular Traps: Tipping the Balance Between Skin Health and Disease

The role of extracellular traps (ETs) in the innate immune response against pathogens is well established. ETs were first identified in neutrophils and have since been identified in several other immune cells. Although the mechanistic details are not yet fully understood, recent reports have described antigen-specific T cells producing T cell extracellular traps (TETs). Depending on their location within the cutaneous environment, TETs may be beneficial to the host by their ability to limit the spread of pathogens and provide protection against damage to body tissues, and promote early wound healing and degradation of inflammatory mediators, leading to the resolution of inflammatory responses within the skin. However, ETs have also been associated with worse disease outcomes. Here, we consider host-microbe ET interactions by highlighting how cutaneous T cell-derived ETs aid in orchestrating host immune responses against Cutibacterium acnes (C. acnes), a commensal skin bacterium that contributes to skin health, but is also associated with acne vulgaris and surgical infections following joint-replacement procedures. Insights on the role of the skin microbes in regulating T cell ET formation have broad implications not only in novel probiotic design for acne treatment, but also in the treatment for other chronic inflammatory skin disorders and autoimmune diseases.

Discordant lymphomas of classic Hodgkin lymphoma and peripheral T-cell lymphoma following dupilumab treatment for atopic dermatitis

There have recently been a few case reports of cutaneous T-cell lymphomas following treatment of atopic dermatitis with dupilumab, which works binding to the interleukin (IL)-4 receptor and inhibiting the JAK/ STAT cascade located downstream of both IL-4 and IL-13. Here, we report the first case of Hodgkin lymphoma (HL) in a patient treated with dupilumab for one year. Based on multiple biopsies, this case was diagnosed as a rare combination of discordant lymphomas of HL and peripheral T-cell lymphoma. As both lymphomas are known to overexpress IL-13, future studies should carefully evaluate the effect of anti-IL-13 therapy. A literature review showed that dermatitis persisted or worsened in all reported lymphoma cases following dupilumab and cutaneous T-cell lymphoma was diagnosed within 2 years of the start of treatment with dupilumab. In these cases, with the addition of our own, the median interval was 12 months, and 31% needed multiple biopsies for diagnosis of lymphomas. Our results demonstrate a need to be alert to potential development of lymphomas associated with the IL-13 and IL-4 pathways in patients with poorly responsive atopic dermatitis receiving dupilumab, and to consider the possibility of composite or discordant lymphomas in diagnosis and treatment of lymphomas.

Potential role of PRKCSH in lung cancer: bioinformatics analysis and a case study of Nano ZnO

PRKCSH, also known as glucosidase II beta, functions as a contributor to lung tumorigenesis by regulating the cell cycle in a p53-dependent manner under severe environmental stress. However, the prognostic value and molecular mechanisms by which the level of PRKCSH is significantly increased in cancer cells are not clearly understood. Here, we first generated a biological profile of PRKCSH expression changes in cancers by analysing bioinformatic data from cancer databases. We found that higher PRKCSH expression was correlated with a poorer prognosis and greater infiltration of most immune cell types in patients with lung cancer. In particular, PRKCSH expression showed significant negative correlations with the level of STAT6 (r = -0.31, p < 0.001) in lung cancer tissues. We further found that PRKCSH deficiency promoted G2/M arrest in response to zinc oxide nanoparticle (Nano ZnO) treatment in A549 cells. With regard to the mechanism, PRKCSH deficiency may induce STAT6 translocation to the nucleus to activate p53 expression through binding to the p53 promoter region from -365 bp to +126 bp. Eventually, activated p53 contributed to Nano-ZnO-induced G2/M arrest in lung cancer cells. Taken together, our data provide new insights into immunotherapy target choices and the prognostic value of PRKCSH. Since the G2/M cell cycle checkpoint is crucial for lung cancer prognosis, targeting PRKCSH expression to suppress the activation of the STAT6/p53 pathway is a potential therapeutic strategy for managing lung cancer.

Elevated serum IL-13 level is associated with increased Treg cells in tumor microenvironment and disease progression of Diffuse large B-cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common aggressive lymphoid malignancy, with an immunosuppressive microenvironment affecting clinical outcome. Interleukin (IL)-13 overexpression is observed in multiple solid tumors and contributes to tumor progression. This study aims to investigate pretreatment serum IL-13 levels and their relationship with the prognosis of DLBCL patients. One hundred and sixty-six patients with newly diagnosed DLBCL from June 2015 to July 2017 were included. Patients with elevated pretreatment serum IL-13 levels (IL-13≥1.63pg/ml) were classified into the high IL-13 group and they had significantly lower complete remission rate (60% vs. 74%, p=0.0059), higher progression rate (43% vs. 23%, p=0.0051), and poor progression-free survival (2-yr PFS, 63% vs. 78%，p=0.0078) and overall survival (2-yr OS, 75% vs. 92%, p=0.0027), when compared to those in the low IL-13 group (IL-13<1.63pg/ml). Meanwhile, increased Treg cell ratio in peripheral blood (p=0.0147) and elevated serum IL-2 levels (p=0.0272) were observed in the high IL-13 group. Moreover, RNA sequencing data showed that patients in the high IL-13 group had significantly elevated expression of chemokines and chemokine receptors (CCR4, CCL19, CCL21, CXCL2) related to Treg activation and recruitment. Consistent with the chemokine profile, tumor immunophenotyping analysis revealed that higher Treg cells recruitment in the high IL-13 group than the low IL-13 group (p=0.0116). In vitro, when lymphoma cells co-cultured with peripheral blood monocytes of healthy controls, metformin down-regulated both IL-13 level and Treg cell ratio, in consistent with the decreased serum IL-13 levels of patients after 6 months of metformin maintenance therapy in the high IL-13 group. Taken together, pretreatment serum IL-13 level is related to the immunosuppressive microenvironment and poor clinical outcome of DLBCL patients and could be targeted by metformin, thus providing a new therapeutic strategy in treating DLBCL with high serum IL-13 levels. This article is protected by copyright. All rights reserved.

Emerging drugs for the treatment of cutaneous T-cell lymphoma

INTRODUCTION

Cutaneous T cell lymphoma (CTCL) is a rare and incurable group of non-Hodgkin lymphomas that manifests as patches, plaques, tumors, and/or erythroderma in the skin. Standard skin-directed therapies for CTCL are effective in patients with indolent early-stage disease but more advanced/refractory stage patients require systemic therapies. However, none of the treatments are considered curative and most patients suffer from relapses. Biologic therapies and immunotherapy provide novel treatment options for patients with advanced or refractory disease.

AREAS COVERED

This review provides a discussion of recently approved biological and novel therapeutics that are actively developed for the management of the heterogenous group of CTCL.

EXPERT OPINION

Mogamulizumab and brentuximab vedotin have reached the market and are approved for the treatment of CTCL, providing valuable options. Additionally, therapies utilizing immune checkpoint inhibitors, miRNA inhibitors, and peptide inhibitors show promising results in clinical trials. Durvalumab, pembrolizumab, TTI-621, BNZ-1, and MRG-106 are several of the emerging treatments still in trials. Further combinatorial studies are needed as none of the treatments have demonstrated long term remissions.

T cells in the skin: lymphoma and inflammatory skin disease

T cells are established contributors to the pathogenesis of atopic dermatitis (AD) and psoriasis, yet whether they are the key drivers or simply unwitting participants remains incompletely understood. Conversely, malignant T cells are the undisputed culprits of cutaneous T cell lymphoma (CTCL), a group of diseases that share key clinical, histopathological and molecular features with inflammatory skin disease (ISD). Here, we compare the pathogenesis of ISD and CTCL and discuss the resulting insights. Recurrent, skin-limited disease implicates skin-resident T cells (T_RM) in both ISD and CTCL. In CTCL, malignant T cells recruit benign T cells into inflammatory skin lesions, a disease-amplifying function also proposed for pathogenic T cells in ISD. Mechanistically, cytokines produced by malignant T cells in CTCL and by pathogenic T cells in ISD, respectively, are likely both necessary and sufficient to drive skin inflammation and pruritus, which in turn promotes skin barrier dysfunction and dysbiosis. Therapies for ISD target T cell effector functions but do not address the chronicity of disease while treatments for CTCL target malignant T cells but not primarily the symptoms of the disease. By integrating our understanding of ISD and CTCL, important insights into pathogenesis and therapy can be made which may improve the lives of sufferers of both disease groups.

The Role of Tumor Microenvironment in the Pathogenesis of Sézary Syndrome

Sézary syndrome is an aggressive leukemic variant of cutaneous T-cell lymphomas, characterized by erythroderma, lymphadenopathy, and peripheral blood involvement by CD4+ malignant T-cells. The pathogenesis of Sézary syndrome is not fully understood. However, the course of the disease is strongly influenced by the tumor microenvironment, which is altered by a combination of cytokines, chemokines, and growth factors. The crosstalk between malignant and reactive cells affects the immunologic response against tumor cells causing immune dysregulation. This review focuses on the interaction of malignant Sézary cells and the tumor microenvironment.

Challenging Cutaneous T-Cell Lymphoma: What Animal Models Tell us So Far

Cutaneous T-cell lymphomas are characterized by heterogeneity of clinical variants, further complicated by genomic and microenvironmental variables. Furthermore, in vitro experiments are hampered by the low culture efficiency of these malignant cells. Animal models are essential for understanding the pathogenetic mechanisms underlying malignancy and for discovering new anticancer treatments. They are divided into two main categories: those in which tumors arise in the host owing to genetic modifications and those that use tumor cell transplantation. In this review, we summarize the attempts to decipher the complexity of the pathogenesis of cutaneous T-cell lymphoma by exploiting genetically modified and xenograft models.

Safety and Danger Considerations of Novel Treatments for Atopic Dermatitis in Context of Primary Cutaneous Lymphomas

The impact of new and emerging therapies on the microenvironment of primary cutaneous lymphomas (PCLs) has been recently raised in the literature. Concomitantly, novel treatments are already used or registered (dupilumab, upadacitinib) and others seem to be added to the armamentarium against atopic dermatitis. Our aim was to review the literature on interleukins 4, 13, 22, and 31, and JAK/STAT pathways in PCLs to elucidate the safety of using biologics (dupilumab, tralokinumab, fezakinumab, nemolizumab) and small molecule inhibitors (upadacitinib, baricitinib, abrocitinib, ruxolitinib, tofacitinib) in the treatment of atopic dermatitis. We summarized the current state of knowledge on this topic based on the search of the PubMed database and related references published before 21 October 2021. Our analysis suggests that some of the mentioned agents (dupilumab, ruxolitinib) and others may have a direct impact on the progression of cutaneous lymphomas. This issue requires further study and meticulous monitoring of patients receiving these drugs to ensure their safety, especially in light of the FDA warning on tofacitinib. In conclusion, in the case of the rapid progression of atopic dermatitis/eczema, especially in patients older than 40 years old, there is a necessity to perform a biopsy followed by a very careful pathological examination.

Clinical Response to Anti-CD47 Immunotherapy Is Associated with Rapid Reduction of Exhausted Bystander CD4+ BTLA+ T Cells in Tumor Microenvironment of Mycosis Fungoides

Simple Summary

The identification of the events that accompany cancer progression is essential for developing new therapies. We have used mycosis fungoides, the most common type of cutaneous lymphoma, as a model for our study. We have shown that cancer progression is accompanied by the expansion of exhausted immune cells around malignant cells. Those exhausted cells prevent immune activation, blocking cancer clearance by the immune system. Furthermore, we have demonstrated that novel anti-CD47 immunotherapy with mycosis fungoides leads to the reduction of exhausted T cells accompanied by the expansion of NK and CD8⁺ T cells. These therapeutic benefits of CD47 blockade were further facilitated by interferon-α, which stimulates cytotoxic cells. Thus, we showed that CD47 might serve as an effective therapeutic target in treating mycosis fungoides.

Abstract

Cancer progression in mycosis fungoides, the most common form of cutaneous T-cell lymphoma, occurs in a predictable, sequential pattern that starts from patches and that evolves to plaques and later to tumors. Therefore, unlocking the relationship between the microarchitecture of mycosis fungoides and the clinical counterparts of that microstructure represents important steps for the design of targeted therapies. Using multispectral fluorescent imaging, we show that the progression of mycosis fungoides from plaque to tumor parallels the cutaneous expansion of the malignant CD4⁺ T cells that express TOX. The density of exhausted BTLA⁺ CD4⁺ T cells around malignant CD4⁺TOX⁺ cells was higher in tumors than it was in plaques, suggesting that undesired safeguards are in place within the tumor microenvironment that prevent immune activation and subsequent cancer eradication. Overriding the CD47 checkpoint with an intralesional SIRPαFc fusion decoy receptor induced the resolution of mycosis fungoides in patients that paralleled an amplified expansion of NK and CD8⁺ T cells in addition to a reduction of the exhausted BTLA⁺ CD4⁺ T cells that were engaged in promiscuous intercellular interactions. These therapeutic benefits of the CD47 blockade were further unleashed by adjuvant interferon-α, which stimulates cytotoxic cells, underscoring the importance of an inflamed microenvironment in facilitating the response to immunotherapy. Collectively, these findings support CD47 as a therapeutic target in treating mycosis fungoides and demonstrate a synergistic role of interferon-α in exploiting these clinical benefits.

STAT6 and phosphorylated STAT6 are differentially expressed in lymphomas

BACKGROUND

The STAT6 pathway is implicated in the pathogenesis of various lymphomas; however, its immunohistochemical expression has not been fully investigated. Thus, the aim of this study was to investigate the immunohistochemical expression of the two forms of STAT6, phosphorylated or not, in a series of systemic lymphomas.

MATERIALS AND METHODS

Immunohistochemical expression of two antibodies, STAT6 (clone YE361) and pSTAT6 (clone Y641), which recognise the phosphorylated form of the molecule was studied in 60 lymphomas.

RESULTS

STAT6^YE361 expression was cytoplasmic, with 23.3% of the cases showing high expression. pSTAT6^Y641 expression was mostly nuclear and found in 45% of the cases. pSTAT6^Y641 nuclear expression was associated with the lymphoma type (p < 0.0001), as it was seen mostly in follicular, Hodgkin and angioimmunoblastic T cell lymphomas. STAT6^YE361 cytoplasmic expression was also associated with lymphoma type (p = 0.001), as it was mostly found in diffuse large B cell and marginal B cell lymphomas. No association with PD-L1 expression, other clinicopathological data or prognosis was found.

CONCLUSION

The two STAT6 clones are differentially expressed between lymphoma types.

CCR7 in Blood Cancers - Review of Its Pathophysiological Roles and the Potential as a Therapeutic Target

According to the classical paradigm, CCR7 is a homing chemokine receptor that grants normal lymphocytes access to secondary lymphoid tissues such as lymph nodes or spleen. As such, in most lymphoproliferative disorders, CCR7 expression correlates with nodal or spleen involvement. Nonetheless, recent evidence suggests that CCR7 is more than a facilitator of lymphatic spread of tumor cells. Here, we review published data to catalogue CCR7 expression across blood cancers and appraise which classical and novel roles are attributed to this receptor in the pathogenesis of specific hematologic neoplasms. We outline why novel therapeutic strategies targeting CCR7 might provide clinical benefits to patients with CCR7-positive hematopoietic tumors.

The Microenvironment's Role in Mycosis Fungoides and Sézary Syndrome: From Progression to Therapeutic Implications

BACKGROUND

Mycosis fungoides (MF) and Sezary Syndrome (SS) are the most common cutaneous T-cell lymphomas. It has been hypothesized that the interaction between the immune system, cutaneous cells, and neoplastic elements may play a role in MF/SS pathogenesis and progression.

METHODS

This paper aims to revise in a narrative way our current knowledge of the microenvironment's role in MF/SS.

RESULTS AND CONCLUSIONS

Literature data support a possible implication of microenvironment cells in MF/SS pathogenesis and progression, opening up new therapeutic avenues.