The immunopathogenesis and immunotherapy of cutaneous T cell lymphoma: Current and future approaches

Effectiveness and safety of interferon α-2a combined with phototherapy for patients with early-stage mycosis fungoides - a single-arm prospective study in 13 patients

Background: Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma.

Objectives: This study was conducted to evaluate efficacy and safety of interferon (IFN) α-2a combined with phototherapy for early-stage MF.

Methods: Thirteen patients with early-stage MF received subcutaneous injections of IFN α-2a at 3 million IU combined with phototherapy three times per week for 6 months. Treatment efficacy was measured by changes in body surface area (BSA) score and modified severity-weighted assessment tool (mSWAT) score at 1, 3, and 6 months after treatment. Histopathologic examinations of skin lesions were performed before and after treatment.

Results: After 3 months of treatment, all 13 patients achieved a partial response, and BSA and mSWAT scores were significantly lower than those at baseline (p < 0.001). After 6 months, BSA and mSWAT scores were significantly lower than those at baseline (p < 0.001) and after 3 months (p < 0.05). Eleven patients achieved complete remission and two patients achieved a partial response (overall response rate, 100%). Histopathologic examination showed a significant decrease in the number of atypical lymphocytes in both epidermis and dermis. No severe adverse effects occurred.

Conclusion: IFN α-2a in combination with phototherapy may be an effective and safe alternative modality for early-stage MF.

Keratinocytes present Staphylococcus aureus enterotoxins and promote malignant and non-malignant T cell proliferation in cutaneous T cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is characterized by malignant T-cells proliferating in a unique tumor microenvironment (TME) dominated by keratinocytes. Skin colonization and infection by Staphylococcus aureus (S. aureus) is a common cause of morbidity and suspected of fueling disease activity. Here we show that expression of HLA-DR, high-affinity receptors for Staphylococcal enterotoxins (SE), by keratinocytes correlates with IFN-γ expression in the TME. Importantly, IFN-γ induces HLA-DR, SE-binding, and SE-presentation by keratinocytes to malignant T-cells from Sézary syndrome (SS) patients, and malignant and non-malignant T-cell lines derived from SS and Mycosis fungoides patients. Likewise, preincubation of keratinocytes with supernatant from patient-derived SE-producing S. aureus triggers proliferation in malignant T-cells and cytokine release (including IL-2), when cultured with non-malignant T-cells. This is inhibited by pre-treatment with engineered bacteriophage S. aureus-specific endolysins. Furthermore, mutations in the HLA-DR binding sites of SE type-A, and siRNA-mediated knockdown of Janus Kinase-3 (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, keratinocytes stimulate IL-2Rγ/JAK3-dependent proliferation of malignant and non-malignant T-cells in an environment with non-malignant T-cells. These findings suggest that keratinocytes in the TME play a key role in S. aureus mediated disease activity in CTCL.

Staphylococcus aureus induces drug resistance in cancer T cells in Sézary syndrome

ABSTRACT

Patients with Sézary syndrome (SS), a leukemic variant of cutaneous T-cell lymphoma (CTCL), are prone to Staphylococcus aureus infections and have a poor prognosis due to treatment resistance. Here, we report that S aureus and staphylococcal enterotoxins (SE) induce drug resistance in malignant T cells against therapeutics commonly used in CTCL. Supernatant from patient-derived, SE-producing S aureus and recombinant SE significantly inhibit cell death induced by histone deacetylase (HDAC) inhibitor romidepsin in primary malignant T cells from patients with SS. Bacterial killing by engineered, bacteriophage-derived, S aureus-specific endolysin (XZ.700) abrogates the effect of S aureus supernatant. Similarly, mutations in major histocompatibility complex (MHC) class II binding sites of SE type A (SEA) and anti-SEA antibody block induction of resistance. Importantly, SE also triggers resistance to other HDAC inhibitors (vorinostat and resminostat) and chemotherapeutic drugs (doxorubicin and etoposide). Multimodal single-cell sequencing indicates T-cell receptor (TCR), NF-κB, and JAK/STAT signaling pathways (previously associated with drug resistance) as putative mediators of SE-induced drug resistance. In support, inhibition of TCR-signaling and Protein kinase C (upstream of NF-κB) counteracts SE-induced rescue from drug-induced cell death. Inversely, SE cannot rescue from cell death induced by the proteasome/NF-κB inhibitor bortezomib. Inhibition of JAK/STAT only blocks rescue in patients whose malignant T-cell survival is dependent on SE-induced cytokines, suggesting 2 distinct ways SE can induce drug resistance. In conclusion, we show that S aureus enterotoxins induce drug resistance in primary malignant T cells. These findings suggest that S aureus enterotoxins cause clinical treatment resistance in patients with SS, and antibacterial measures may improve the outcome of cancer-directed therapy in patients harboring S aureus.

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.

Vitamin D in Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphoma (CTCL) is characterized by the proliferation of malignant T cells in inflamed skin lesions. Mycosis fungoides (MF)-the most common variant of CTCL-often presents with skin lesions around the abdomen and buttocks ("bathing suit" distribution), i.e., in skin areas devoid of sun-induced vitamin D. For decades, sunlight and vitamin D have been connected to CTCL. Thus, vitamin D induces apoptosis and inhibits the expression of cytokines in malignant T cells. Furthermore, CTCL patients often display vitamin D deficiency, whereas phototherapy induces vitamin D and has beneficial effects in CTCL, suggesting that light and vitamin D have beneficial/protective effects in CTCL. Inversely, vitamin D promotes T helper 2 (Th2) cell specific cytokine production, regulatory T cells, tolerogenic dendritic cells, as well as the expression of immune checkpoint molecules, all of which may have disease-promoting effects by stimulating malignant T-cell proliferation and inhibiting anticancer immunity. Studies on vitamin D treatment in CTCL patients showed conflicting results. Some studies found positive effects, others negative effects, while the largest study showed no apparent clinical effect. Taken together, vitamin D may have both pro- and anticancer effects in CTCL. The balance between the opposing effects of vitamin D in CTCL is likely influenced by treatment and may change during the disease course. Therefore, it remains to be discovered whether and how the effect of vitamin D can be tilted toward an anticancer response in CTCL.

The effect of UVA light/8-methoxypsoralen exposure used in Extracorporeal Photopheresis treatment on platelets and extracellular vesicles

Extracorporeal Photopheresis (ECP) is a leukapheresis based treatment for Cutaneous T-Cell Lymphoma, which takes advantage of the cellular lethal effects of UVA light in combination with a photoactivated drug, 8-methoxypsoralen. 25% of patients treated with ECP do not respond to treatment, however the underlying mechanisms for this lack of response remain unknown. Platelets, a rich source of extracellular vesicles (EVs) and key mediators in thromboinflammatory oncological progression, as well as leukocytes, are both processed through ECP and are subsequently transfused back into the patient, delivering potent immunomodulation. The effect of exposing platelets and their EVs directly to Ultra Violet A light (UVA)/8-methoxypsoralen is currently unknown. Platelet-rich plasma (PRP) was isolated from healthy donors and exposed to UVA light and/or 8-methoxysporalen in vitro and platelet activation and aggregation was assessed. EV size and concentration were also characterised by Nanoparticle Tracking Analysis and Flow Cytometry. We found that UVA light and 8-methoxypsoralen treatment in vitro does not induce platelet aggregation or significantly alter levels of the platelet activation markers, soluble P-selectin or platelet factor 4, with circulating levels of small and large EV size and concentration remaining constant. Therefore, utilising the combination of UVA light and 8-methoxypsoralen used in ECP in vitro does not activate platelets or alter important circulating EVs. Further studies will be needed to validate if our observations are consistent in vivo.

Targeting CD47-SIRPα axis for Hodgkin and non-Hodgkin lymphoma immunotherapy

The interaction between cluster of differentiation 47 (CD47) and signal regulatory protein α (SIRPα) protects healthy cells from macrophage attack, which is crucial for maintaining immune homeostasis. Overexpression of CD47 occurs widely across various tumor cell types and transmits the "don't eat me" signal to macrophages to avoid phagocytosis through binding to SIRPα. Blockade of the CD47-SIRPα axis is therefore a promising approach for cancer treatment. Lymphoma is the most common hematological malignancy and is an area of unmet clinical need. This review mainly described the current strategies targeting the CD47-SIRPα axis, including antibodies, SIRPα Fc fusion proteins, small molecule inhibitors, and peptides both in preclinical studies and clinical trials with Hodgkin lymphoma and non-Hodgkin lymphoma.

Charting new frontiers: Co-inhibitory immune checkpoint proteins in therapeutics, biomarkers, and drug delivery systems in cancer care

Cancer remains a major health concern globally. Immune checkpoint inhibitors (ICIs) target co-inhibitory immune checkpoint molecules and have received approval for treating malignancies like melanoma and non-small cell lung cancer. While CTLA-4 and PD-1/PD-L1 are extensively researched, additional targets such as LAG-3, TIGIT, TIM-3, and VISTA have also demonstrated effective in cancer therapy. Combination treatments, which pair ICIs with interventions such as radiation or chemotherapy, amplify therapeutic outcomes. However, ICIs can lead to diverse side effects, and their varies across patients and cancers. Hence, identifying predictive biomarkers to guide therapy is essential. Notably, expression levels of molecules like PD-1, CTLA-4, and LAG-3 have been linked to tumor progression and ICI therapy responsiveness. Recent advancements in drug delivery systems (DDSs) further enhance ICI therapy efficacy. This review explores predominant DDSs for ICI delivery, such as hydrogel, microparticle, and nanoparticle, which offer improved therapeutic effects and reduced toxicity. In summary, we discuss the future of immune therapy focusing on co-inhibitory checkpoint molecules, pinpoint challenges, and suggest avenues for developing efficient, safer DDSs for ICI transport.

Broadening the horizon: potential applications of CAR-T cells beyond current indications

Engineering immune cells to treat hematological malignancies has been a major focus of research since the first resounding successes of CAR-T-cell therapies in B-ALL. Several diseases can now be treated in highly therapy-refractory or relapsed conditions. Currently, a number of CD19- or BCMA-specific CAR-T-cell therapies are approved for acute lymphoblastic leukemia (ALL), diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), multiple myeloma (MM), and follicular lymphoma (FL). The implementation of these therapies has significantly improved patient outcome and survival even in cases with previously very poor prognosis. In this comprehensive review, we present the current state of research, recent innovations, and the applications of CAR-T-cell therapy in a selected group of hematologic malignancies. We focus on B- and T-cell malignancies, including the entities of cutaneous and peripheral T-cell lymphoma (T-ALL, PTCL, CTCL), acute myeloid leukemia (AML), chronic myeloid leukemia (CML), chronic lymphocytic leukemia (CLL), classical Hodgkin-Lymphoma (HL), Burkitt-Lymphoma (BL), hairy cell leukemia (HCL), and Waldenström's macroglobulinemia (WM). While these diseases are highly heterogenous, we highlight several similarly used approaches (combination with established therapeutics, target depletion on healthy cells), targets used in multiple diseases (CD30, CD38, TRBC1/2), and unique features that require individualized approaches. Furthermore, we focus on current limitations of CAR-T-cell therapy in individual diseases and entities such as immunocompromising tumor microenvironment (TME), risk of on-target-off-tumor effects, and differences in the occurrence of adverse events. Finally, we present an outlook into novel innovations in CAR-T-cell engineering like the use of artificial intelligence and the future role of CAR-T cells in therapy regimens in everyday clinical practice.

Role of Tumor Microenvironment in Pituitary Neuroendocrine Tumors: New Approaches in Classification, Diagnosis and Therapy

Adenohypophysal pituitary tumors account for 10-15% of all intracranial tumors, and 25-55% display signs of invasiveness. Nevertheless, oncology still relies on histopathological examination to establish the diagnosis. Considering that the classification of pituitary tumors has changed significantly in recent years, we discuss the definition of aggressive and invasive tumors and the latest molecular criteria used for classifying these entities. The pituitary tumor microenvironment (TME) is essential for neoplastic development and progression. This review aims to reveal the impact of TME characteristics on stratifying these tumors in view of finding appropriate therapeutic approaches. The role of the pituitary tumor microenvironment and its main components, non-tumoral cells and soluble factors, has been addressed. The variable display of different immune cell types, tumor-associated fibroblasts, and folliculostellate cells is discussed in relation to tumor development and aggressiveness. The molecules secreted by both tumoral and non-tumoral cells, such as VEGF, FGF, EGF, IL6, TNFα, and immune checkpoint molecules, contribute to the crosstalk between the tumor and its microenvironment. They could be considered potential biomarkers for diagnosis and the invasiveness of these tumors, together with emerging non-coding RNA molecules. Therefore, assessing this complex network associated with pituitary neuroendocrine tumors could bring a new era in diagnosing and treating this pathology.

Mode of action, indications and recommendations on extracorporeal photopheresis (ECP)

Extracorporeal photopheresis (ECP) has gained importance in the treatment of several diseases. Initially introduced as a new therapeutic modality for the treatment of patients with cutaneous T-cell lymphoma, the indications for the use of ECP have expanded to include hematology and transplantation immunology. Extracorporeal photopheresis has found its place in the treatment plan of cutaneous T-cell lymphoma, systemic sclerosis, graft-versus-host disease, organ transplantation such as heart and lung, sometimes as first-line therapy and very often in combination with various systemic immunosuppressive therapies. The procedure basically consists of three steps: leukapheresis, photoactivation and reinfusion. The following article presents possible theories about the mechanism of action, which is not yet fully understood, and discusses the five most common indications for ECP treatment with corresponding therapy recommendations.

Wirkweise, Indikationen und Therapieempfehlungen der extrakorporalen Photopherese (ECP)

Die extrakorporale Photopherese (ECP) hat in jüngster Zeit bei der Behandlung verschiedener Krankheiten an Bedeutung gewonnen. Ursprünglich als neue Therapie zur Behandlung von Patienten mit kutanem T‐Zell‐Lymphom vorgestellt, hat sich der Indikationsbereich für die ECP auf Hämatologie und Transplantationsimmunologie erweitert. Die ECP hat ihren festen Platz im Therapieplan bei kutanen T‐Zell‐Lymphomen, systemischer Sklerose, Graft‐versus‐Host‐Erkrankung, Organtransplantationen wie Herz und Lunge, teilweise als Erstlinientherapie und sehr häufig in Kombination mit verschiedenen systemischen immunsuppressiven Therapien. Das Verfahren besteht im Wesentlichen aus drei Schritten: Leukapherese, Photoaktivierung und Reinfusion. Im folgenden Artikel werden die noch nicht vollständig verstandenen Wirkmechanismen dargestellt, die fünf häufigsten Indikationen für die Behandlung mit ECP diskutiert und Therapieempfehlungen für die jeweilige Indikation gegeben.

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.

Autologous, allogeneic hematopoietic cell transplantation and CAR-T/NK therapy: what is their real importance in PTCL?

Peripheral T cell lymphoma (PTCL) is a rare and aggressive type of non-Hodgkin's lymphoma that affects mature T cells. This type of cancer is characterized by the abnormal growth of T cells, which can accumulate in the lymph nodes, spleen, bone marrow, and other organs, leading to a variety of symptoms. PTCLs are often difficult to diagnose and treat, and they have a poorer prognosis than other types of lymphoma. However, recent advancements in treatment options, such as targeted therapies have shown promise in improving outcomes for patients with PTCL. Here, we discuss the use of autologous and allogeneic hematopoietic cell transplantation (HCT) as a treatment strategy for patients with PTCL, as well as the recent treatment approaches based on advanced cellular therapy. The current evidence for the use of HCT in PTCL is mainly derived from registry data, retrospective studies, and expert opinion, as randomized trials are limited due to the low incidence and histological heterogeneity of PTCL subtypes.

Causes of Death in Cutaneous T-Cell Lymphoma Patients

BACKGROUND

The advancing evolution toward a Th2 immune environment confers a progressive immunosuppression in patients with longstanding cutaneous T-cell lymphoma (CTCL). The conjunction of the disease-related immunosuppression as well as the immunosuppressive character of some CTCL treatments increase the risk of infectious and neoplastic diseases, sometimes with fatal outcomes.

OBJECTIVES

The aim of the study was to prospectively study the causes of death in a cohort of CTCL patients, in a tertiary university skin cancer center.

METHODS

All CTCL patients who died between 2008 and 2020 were included. The cause of the death was classified as directly or indirectly related or unrelated to CTCL.

RESULTS

Over the study period, 31 (13F/18m) patients with CTCL died (mean age: 75.2 years), mean delay between diagnosis and death: 3.2 years (min: 1, max: 12 years), 58.1% of death causes were classified as indirect (infection), 12.9% directly related (blastic transformation), 22.5% unrelated, and 6.5% of unknown cause. 51.6% of mycosis fungoides (MF) patients who died had early-stage disease (1A-2A) or were on remission. 45.2% of dead patients had advanced-stage MF (2B-4B). Mean CRP level is increased in patients who died from infection whereas LDH level increased in patients with blastosis. A tertiary center is expected to manage of a higher proportion of CTCL patients with advanced-stage disease.

CONCLUSIONS

As infection represented more than 50% of the causes of death in CTCL patients, particular attention should be given to preventive measures such as anti-infective vaccination. Regular surveillance of CRP and LDH levels could be helpful for follow-up of MF patients, respectively, with regards to infection and blastosis.

The Immunotherapeutic Role of Type I and III Interferons in Melanoma and Non-Melanoma Skin Cancers

Interferons (IFNs) have demonstrated therapeutic potential in various skin cancers, specifically squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and melanoma. The precise mechanism through which type I IFNs exert their antitumor effects in skin cancers is still being studied. However, intralesional type I IFN can be used as an alternative to surgery for select patient populations, and high-dose systemic IFN therapy has been shown to be promising in patients with operable high-risk or metastatic melanoma. Despite the therapeutic potential of IFNs in skin cancer treatment, the toxicity profile often prevents the completion of treatment and further expansion of its clinical application. Type I and III IFNs use the same Janus Kinases (JAKs) for signal transduction, which are pathways initiated at a cell surface receptor that mediates the activation of target genes in the nucleus, based on this shared signaling pathway. Due to selective tumor targeting and the ability to generate both innate and adaptive immune responses, we concluded that type III IFNs have minimal side effects compared with established treatments due to selective tumor targeting. While IFN-λ, a type III IFN, shows therapeutic potential as stand-alone or in combination with another IFN, further studies need to be conducted to explore the therapeutic potential of IFN-λ in skin cancer and the underlying physiological roles and mechanisms of action. In this review, we evaluate whether treatment of skin cancer with type III IFN will have minimal side effects compared with established treatments.

Effects of Extracorporeal Photopheresis on Quality of Life and the Course of Diseases in Patients With Mycosis Fungoides and Graft-Versus-Host Disease: A Single-Center Analysis

INTRODUCTION

The aim of the study was to systematically analyze the influence of extracorporeal photopheresis (ECP) on the quality of life (LQ) and the course of the disease in patients with Mycosis Fungoides (MF), as well as with Graft-versus-Host Disease (GvHD).

METHODS

LQ was monitored retrospectively by using the dermatology life quality index (DLQI) and Skindex-29 test before ECP onset and after the last ECP. Disease parameters were assessed by objective criteria i.e. number of associated medical drugs taken, intervals between therapeutic cycles, gradual change of the disease, and eventual side-effects and complications of ECP therapy.

RESULTS

Fifty-one patients were treated with ECP during 2008-19; 19 out of 51 died, and follow-up was not completed in 13 patients. Finally, treatment protocols of 671 ECP procedures were evaluated in 19 patients (10 MF; 9 GvHD). MF and GvHD subpopulations did not differ in the individual scores of LQ questions, either before the outset or after the last ECP. DLQI and Skindex-29 scores were ameliorated by the ECP therapy (p= 0.001 and p< 0.001, respectively) due to improvement of individual scores of feelings, daily/social activities (p< 0.05), and functionality (p≤ 0.05). The median interval between ECP cycles was extended from two to eight weeks (p= 0.001). Needs of GvHD patients for drugs being received for the underlying disease were reduced (p= 0.035). Two of the 10 MF patients worsened from stage IIA to IIIA. Severe or minor side effects leading to a therapy interruption were not recorded.

CONCLUSION

Patients with GvHD experienced a notable decrease in the administration of drugs for their underlying condition, and there were no instances of severe side effects that resulted in the discontinuation of treatment. ECP is safe and effective for the treatment of MF and GvHD.

The immune microenviroment in somatotropinomas: from biology to personalized and target therapy

Pituitary tumors are rare neoplasms, with a heterogeneous biological and clinical behavior, due to their clinical course, local invasive growth, resistance to conventional therapies and the risk of disease progression. Recent studies on tumor microenvironment (TME) provided new knowledge on the biology of these neoplasia, that may explain the different phenotypes of these tumors and suggest new biomarkers able to predict the prognosis and the treatment outcome. The identification of molecular markers that act as targets for biological therapies may open new perspectives in the medical treatments of aggressive pituitary tumors.In this paper, we will review data of TME and target therapies in somatotropinomas.

Development of Cutaneous T-Cell Lymphoma Following Biologic Treatment: A Systematic Review

BACKGROUND

Cutaneous T-cell lymphoma following biologic therapy is extremely rare.

OBJECTIVE

The aim of this systematic review was to investigate the development of cutaneous T-cell lymphoma (CTCL) following treatment with a biologic agent.

METHODS

A systematic literature review was performed for patients who developed CTCL after exposure to biologic therapy. Works were limited to English language and excluded animal studies, guidelines, and protocols. Potentially eligible titles were identified using controlled vocabulary in tandem with key words. The search strategy was peer-reviewed prior to execution.

RESULTS

Twenty-eight total studies revealed sixty-two patients who developed CTCL following exposure to a biologic agent. Of these, 44% were Caucasian, and the median age at diagnosis was 56 years. Seventy-six percent of patients received biologic therapy for a primary inflammatory skin condition. Dupilumab was the most reported (42%) agent amongst the cohort. The median time from initiation of the biologic agent to diagnosis of CTCL in these cases was 4 months (range: 0-84). Mycosis fungoides (65%) and Sézary syndrome (10%) were the most common subtypes of CTCL diagnosed. Twenty-one (34%) patients were reported to be alive with disease, outcome was not reported in 21 patients (34%), ten patients (16%) were alive and in complete remission, eight patients (13%) died of disease and two patients (3%) died due to other causes.

CONCLUSION

While biologic agents may have a role in the development of CTCL, in order to definitively elucidate their role, more methodologically robust studies (such as those that utilize population databases) would need to occur.

The Robust Tumoricidal Effects of Combined BET/HDAC Inhibition in Cutaneous T-Cell Lymphoma Can Be Reproduced by ΔNp73 Depletion

Combined BET inhibitor/histone deacetylase inhibitor treatment induces marked apoptosis of cutaneous T-cell lymphoma (CTCL) with minimal normal T-cell toxicity. At 96 hours when apoptosis was extensive, a majority of CTCL lines showed ≥2-fold suppression of T-cell survival factors (e.g., AKT1, BCL2 antiapoptotic factors, BIRC5, CD40, CD70, GADD45A, PRKCA, TNFRSF1B, ΔNp73) and ≥2-fold upregulation of proapoptotic factors and tumor suppressors (e.g., ATM, BAK, BIM, multiple caspases, FHIT, HIC1, MGMT, NOD1) (P < 0.05). The largest alterations were in TP73 isoform expression, resulting in increased TAp73/ΔNp73 ratios in CTCL lines and leukemic Sézary cells. Targeted ΔNp73 inhibition by small interfering RNA knockdown resulted in robust CTCL apoptosis comparable with that induced by BET inhibitor/histone deacetylase inhibitor with minimal normal T-cell toxicity. Chromatin immunoprecipitation analysis showed that BET inhibitor/histone deacetylase inhibitor treatment reduced RNA polymerase II binding to ΔNp73, MYC, and AKT1 while increasing its binding to TAp73. CTCL skin lesions expressed both TAp73 and ΔNp73 isoforms in situ. In aggregate, these findings implicate TAp73/ΔNp73 balance as a major factor governing CTCL survival, show that the expression of p73 isoforms can be altered by molecular biological and pharmaceutical means, show that p73 isoforms are expressed across the entire CTCL clinical spectrum, and identify the p73 pathway as a potential target for therapeutics.

Genome-wide identification of alternative splicing associated with histone deacetylase inhibitor in cutaneous T-cell lymphomas

Cutaneous T-cell lymphomas (CTCLs) are a kind of non-Hodgkin lymphoma that originates from skin, which is difficult to treat with traditional drugs. Human histone deacetylase inhibitors (HDACi) targeted therapy has become a promising treatment strategy in recent years, but some patients can develop resistance to the drug, leading to treatment failure. There are no public reports on whether alternative splicing (AS) and RNA binding proteins (RBP) affect the efficacy of targeted therapy. Using data from the Gene Expression Omnibus (GEO) database, we established a co-change network of AS events and RBP in CTCLs for the first time, and analyzed the potential regulatory effects of RBP on HDACi-related AS events. The dataset GSE132053, which contained the RNA sequence data for 17 HDACi samples, was downloaded and clean reads were aligned to the human GRCh38 genome by hierarchical indexing for spliced alignment of the transcripts, allowing four mismatches. Gene expression levels were evaluated using exons per million fragments mapped for each gene. Student’s t-tests were performed to evaluate the significance of changes in ratios for AS events, and regulated alternative splicing events (RASEs) were defined as events with p values less than 0.05. To sort the differentially expressed genes functional categories, Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways were identified using the KOBAS 2.0 server. The regulatory mechanisms of the RASEs and RBPs were evaluated using Pearson’s correlation coefficient. Seven indirect events of HDACi resistance or sensitivity were identified: NIR_5151_RP11-977G19.10, NIR_4557_IRAG2, NIR_11870_SUMO1, NIR_5347_ING4, NIR_17935_DNAJC2, NIR_17974_CBLL1, and NIR_422_SLC50A1. The potential regulatory relationships between RBPs and HDACi-sensitive RASEs were also analyzed. LEPR and HNRNPAO significantly affected NIR_11870_SUMO1, suggesting a potential regulatory relationship. Additionally, CNN1 may regulate NIR_5347_ING4, CNOT3 may regulate NIR_17935_DNAJC2, and DQX1 and LENG9 may regulate NIR_422_SLC5A1. Overall, our findings establish a theoretical foundation for the precise targeted treatment of CTCLs with HDACi.

The role of immune checkpoint receptors in the malignant phenotype of cutaneous T cell lymphoma

Immune checkpoint receptors (ICR) modulate the immune response and are critical hubs for immunotherapy. However, data on their role in T lymphoid malignancies, such as cutaneous T cell lymphoma (CTCL), is sparse. We aimed to explore the role of ICR in the malignant features of transformed T lymphocytes and evaluate the effect of ICR-targeting monoclonal antibodies, often used as immunotherapy for solid tumors. We used the CTCL cell line HH and the Sézary cell line Hut78 to examine ICR expression and the effects of ICR inhibition on cell viability and proliferation. Despite their shared T cell progeny, the different CTCL cell lines exhibit markedly different ICR expression profiles. Programmed cell death-ligand 1 (PD-L1) was expressed by both cell lines, while programmed death-1 (PD-1) was expressed only by the HH cell line. Common to all malignant T cells was an autonomous hyper-proliferative state that did not require T cell receptor stimulation. A monoclonal antibody blocking PD-1 had a small but statistically significant augmenting effect on T cell proliferation. Of note, when the cells were exposed to ionizing radiation, healthy lymphocytes and those derived from the HH cell line were salvaged by anti-PD-L1. We show a regulatory role of ICR, mainly PD-1 and its ligand PD-L1, on cutaneous T cell malignancy.

Impact of Mogamulizumab in Real-Life Advanced Cutaneous T-Cell Lymphomas: A Multicentric Retrospective Cohort Study

Simple Summary

Mogamulizumab is a recent monoclonal antibody prescribed in the second line to treat advanced mycosis fungoides and Sézary syndromes. We collected data from all patients who used mogamulizumab in six French university hospitals until 1 September 2021. Our primary objective was to determine the median progression free survival (PFS). Secondary objectives were to consider tolerance regarding side effect occurrence and severity. Twenty-one patients were included, with a median time of follow-up of 11.6 months, and progression-free survival was estimated at 22 months. Twenty patients presented adverse events, of which 10 were severe. The median time between the introduction of mogamulizumab and the first adverse event was 21 days. Our study suggests that mogamulizumab is a significant treatment option to extend PFS in patients with advanced refractory cutaneous T-cell lymphomas (CTCL). The long-term safety of mogamulizumab was determined to be acceptable since we reported few grade III–IV adverse events (AEs) compared to other systemic treatments.

Abstract

Background: Advanced mycosis fungoides (MF) and Sézary syndrome (SS) are rare, aggressive cutaneous T-cell lymphomas that may be difficult to treat. Mogamulizumab is a recent monoclonal antibody targeting the CCR4 receptor expressed on the surface of Sézary cells. It can be prescribed in MF/SS stages III to IV in the second line after systemic therapy or in stages IB-II after two unsuccessful systemic therapies. We lack data on long-term efficiency and potential side effects in real-life conditions. Our study aims to determine efficacy considering the median PFS of advanced CTCL with mogamulizumab. Secondary objectives were to consider tolerance and estimate delay until side effects appeared. Methods: Data on patients with advanced cutaneous T-cell lymphomas were collected since French Authorization, in six French university hospitals. Patients were followed until they stopped mogamulizumab because of relapse or toxicity. For those still treated by mogamulizumab, the end point was 1 September 2021. We excluded 3 patients as they had already been included in the MAVORIC study and data was not available. Results: The median time of follow-up was 11.6 months. Of the 21 patients included, we reported four full-response patients, eight in partial response, one in stability, three in progression, and five were deceased. One patient had visceral progression, and seven had new lymphadenopathy. Progression-free survival was estimated at 22 months. Twenty patients presented adverse events, of which 10 were severe, i.e., grade III-IV. The median time between the introduction of mogamulizumab and the first adverse event was 21 days. Conclusions: Our study suggests that mogamulizumab can give patients with advanced refractory CTCL a consequent PFS, estimated at 22 months. The long-term safety of mogamulizumab was determined to be acceptable since we reported few grade III–IV AEs, comparable with other studies. No other study using real-life data has been performed to investigate the AEs of mogamulizumab.

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.

How to Sequence Therapies in Mycosis Fungoides

OPINION STATEMENT

Choice of therapy in mycosis fungoides is based on both patient- and lymphoma-specific factors, such as disease characteristics, comorbidities, symptoms and effect on quality of life, potential associated toxicities of therapy, response and tolerance to prior lines of therapy, and convenience and practicality. Generally, we sequence therapies from least toxic, targeted, nonimmunosuppressive to more toxic, immunosuppressive and from single agent to multiple agents, as necessary. If more toxic, immunosuppressive agents are required to alleviate disease burden or symptoms, we generally use them just long enough to control the disease, then transition to a maintenance regimen with less toxic, less immunosuppressive agents.

Research advances on the immune research and prospect of immunotherapy in pituitary adenomas

Background

Pituitary adenomas are one type of intracranial tumor, which can be divided into microadenoma (≤ 1 cm), macroadenoma (> 1 cm), and giant adenoma (≥ 4 cm) according to their diametral sizes. They are benign, typically slow-progressing, whereas the biological behavior of some of them is invasive, which presents a major clinical challenge. Treatment of some pituitary adenomas is still difficult due to drug resistance or multiple relapses, usually after surgery, medication, and radiation. At present, no clear prediction and treatment biomarkers have been found in pituitary adenomas and some of them do not cause clinical symptoms, so patients are often found to be ill through physical examination, and some are even found through autopsy. With the development of research on pituitary adenomas, the immune response has become a hot spot and may serve as a novel disease marker and therapeutic target.

The distribution and function of immune cells and their secreted molecules in pituitary adenomas are extremely complex. Researchers found that infiltration of immune cells may have a positive effect on the treatment and prognosis of pituitary adenomas. In this review, we summarized the advance of tumor immunity in pituitary adenomas, revealing the immunity molecules as potential biomarkers as well as therapeutic agents for pituitary adenomas.

Conclusion

The immune studies related to pituitary adenomas may help us find relevant immune markers. At the same time, the exploration of immunotherapy also provides new options for the treatment of pituitary adenomas.

CD4-Targeted T Cells Rapidly Induce Remissions in Mice with T Cell Lymphoma

OBJECTIVE

To explore the immune cell therapy for T cell lymphoma, we developed CD4-specific chimeric antigen receptor- (CAR-) engineered T cells (CD4CART), and the cytotoxic effects of CD4CART cells were determined in vitro and in vivo.

METHODS

CD4CART cells were obtained by transduction of lentiviral vector encoding a single-chain antibody fragment (scFv) specific for CD4 antigen, costimulatory factor CD28 fragment, and intracellular signal transduction domain of CD3 fragments. Control T cells were obtained by transduction of reporter lentiviral vector. The cytotoxicity, tumor growth, and survival rate of mice with T cell lymphoma were analyzed after adoptive T cell transfer in vivo.

RESULTS

CD4CART cells had potent cytotoxic activity against CD4+ T1301 tumor T cells in a concentration-dependent manner. In addition, adoptive CD4CART cell transfer significantly suppressed tumor growth and improved animal survival with T cell lymphoma, compared to the mice who received control T cells and PBS.

CONCLUSION

CD4CART cells have potent cytotoxic effects on T cell lymphoma. The study provided an experimental basis for CD4CART-mediated therapy of T cell lymphoma.