Efficient tumor antigen loading of dendritic antigen presenting cells by transimmunization

A simplified extracorporeal photopheresis procedure based on single high-dose ultraviolet A light irradiation shows similar in vitro efficacy

BACKGROUND

Extracorporeal photopheresis (ECP) is one of the most widely used and effective cell-based therapies for the treatment of T-cell-mediated diseases. The patients' white blood cells (WBCs) are collected by apheresis and exposed to the photosensitizer 8-methoxypsoralen (8-MOP) and ultraviolet A (UVA) light before retransfusion. The UVA/8-MOP combination has been in use in ECP for more than 4 decades; however, whether ECP can be simplified by UVA light irradiation only has never been analyzed.

STUDY DESIGN AND METHODS

Peripheral blood mononuclear cells were treated with classical ECP or different UVA light doses only (UVA^only ). Treatment efficacy was investigated by apoptosis induction in WBC subsets, inhibition of T-cell proliferation, and the ability of monocytes to induce allogeneic T-cell expansion and to respond to lipopolysaccharide and interferon-γ stimulation in vitro.

RESULTS

High-dose UVA^only treatment (5 J/cm² ) was as efficient as ECP to induce apoptosis within 48 hours. UVA^only treatment modulated the composition of the surviving cells by improving monocyte survival and promoting CD8⁺ T-cell apoptosis. Both ECP and UVA^only treatment inhibited anti-CD3/anti-CD28 triggered T-cell proliferation. Interestingly, whereas ECP-treated monocytes exhibited a markedly reduced capacity to respond to stimulation and to induce allogeneic T-cell proliferation, UVA^only treatment preserved monocyte functionality to some degree.

CONCLUSIONS

High-dose UVA^only and standard ECP showed comparable efficacy in inducing apoptosis and inhibiting direct T-cell proliferation. Hence, UVA^only treatment can be a simplified alternative to ECP therapy. Furthermore, increased monocyte survival with partially preserved functionality after UVA^only treatment may provide a novel method for immunoregulation.

European dermatology forum - updated guidelines on the use of extracorporeal photopheresis 2020 - part 1

Background

Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T‐cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multi‐disciplinary setting. It has confirmed recognition in well‐known documented conditions such as graft‐versus‐host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease.

Materials and methods

In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added.

Results and conclusion

These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines are divided in two parts: PART I covers cutaneous T‐cell lymphoma, chronic graft‐versus‐host disease and acute graft‐versus‐host disease while PART II will cover scleroderma, solid organ transplantation, Crohn's disease, use of ECP in paediatrics practice, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

Transimmunization restores immune surveillance and prevents recurrence in a syngeneic mouse model of ovarian cancer

Ovarian cancer accounts for most deaths from gynecologic malignancies. Although more than 80% of patients respond to first-line standard of care, most of these responders present with recurrence and eventually succumb to carcinomatosis and chemotherapy-resistant disease. To improve patient survival, new modalities must, therefore, target or prevent recurrent disease. Here we describe for the first time a novel syngeneic mouse model of recurrent high-grade serous ovarian cancer (HGSOC), which allows immunotherapeutic interventions in a time course relevant to human carcinomatosis and disease course. Using this model, we demonstrate the efficacy of Transimmunization (TI), a dendritic cell (DC) vaccination strategy that uses autologous and physiologically derived DC loaded with autologous whole tumor antigens. TI has been proven successful in the treatment of human cutaneous T cell lymphoma and we report for the first time its in vivo efficacy against an intra-peritoneal solid tumor. Given as a single therapy, TI is able to elicit an effective anti-tumor immune response and inhibit immune-suppressive crosstalks with sufficient power to curtail tumor progression and establishment of carcinomatosis and recurrent disease. Specifically, TI is able to inhibit the expansion of tumor-associated macrophages as well as myeloid-derived suppressive cells consequently restoring T cell immune-surveillance. These results demonstrate the possible value of TI in the management of ovarian cancer and other intra-peritoneal tumors.

Depletion of M2-like tumor-associated macrophages delays cutaneous T-cell lymphoma development in vivo

Macrophages have key roles in tumor development and invasion in several human cancers, but little is known about their pathogenic role in cutaneous T-cell lymphoma (CTCL). Herein, we used PCR arrays to profile the expression of inflammatory cytokines in 12 patients with mycosis fungoides (MF), the most common variant of CTCL. Compared with normal controls, MF skin displayed increased mRNA levels of macrophage-related cytokines. Moreover, we detected CD163, a reliable marker of tumor-associated macrophages, in the tumor microenvironment of MF biopsies. To demonstrate that macrophages had a role in CTCL tumorigenesis, we xenografted human CTCL tumor cells in immunocompromised mice and compared tumor development using clodronate-containing liposomes to deplete macrophages in mice. Mice treated with clodronate-containing liposomes show markedly less tumor growth compared with mice treated with phosphate-buffered saline-containing liposomes (P<0.001). We also noted a strong correlation between macrophage depletion and decreased expression of vascular marker, CD31, and lymphatic marker, podoplanin, suggesting a role for macrophages in angiogenesis. In vitro, clodronate-containing liposomes killed activated murine M2 macrophages, but not Hut78 cells, demonstrating selective ability to induce apoptosis in macrophages. Our data indicate that macrophages have a critical role in the progression of Hut78 cell tumor formation in skin, thus providing a new therapeutic strategy for CTCL.

Extracorporeal photopheresis reverses experimental graft-versus-host disease through regulatory T cells

Extracorporeal photopheresis (ECP), a technique that exposes isolated white blood cells to photoactivatable 8-methoxypsoralen and ultraviolet A radiation, is used clinically to treat cutaneous T-cell lymphoma and immune-mediated diseases such as graft-versus-host disease (GVHD). ECP is thought to control these diseases in part through direct induction of lymphocyte apoptosis, but its effects on the immune system beyond apoptosis remain poorly characterized. We have developed a novel method for incorporating ECP treatment into well-established and clinically relevant murine models of GVHD to examine its effects during an ongoing immune response. We demonstrate that the transfer of cells treated with ECP reverses established GVHD by increasing donor regulatory T cells and indirectly reducing the number of donor effector lymphocytes that themselves had never been exposed to psoralen and ultraviolet A radiation.

Efficacy and tolerability of currently available therapies for the mycosis fungoides and Sezary syndrome variants of cutaneous T-cell lymphoma

Primary cutaneous T-cell lymphomas are a heterogenous group of non-Hodgkin lymphomas. The characteristic clinicopathologic and immunophenotypic features and prognoses of the various cutaneous lymphomas have been recently described by the World Health Organization and European Organization for Research and Treatment of Cancer. Cutaneous T-cell lymphoma variants include mycosis fungoides and Sezary syndrome, which are generally associated, respectively, with indolent and aggressive clinical courses and are the subject of this review. Currently utilized treatments for cutaneous T-cell lymphoma include skin-directed therapies (topical agents such as corticosteroids, mechlorethamine, carmustine, and retinoids, phototherapy, superficial radiotherapy, and total skin electron beam therapy), systemic therapies (photophoresis, retinoids, denileukin diftitox, interferons, and chemotherapy), and stem cell transplantation (autologous and allogeneic). This review will describe recent advances in our understanding of the biology (immunologic, cytogenetic, and genetic) of cutaneous T-cell lymphomas and discuss the efficacy and tolerability of the current therapeutic options for cutaneous T-cell lymphomas. Disease progression in over 20% of patients with early stages of disease and the current lack of a definitive treatment which produces durable responses in advanced stages of disease indicates a critical unmet need in CTCL. New insights into the molecular and immunologic changes associated with cutaneous T-cell lymphomas should ultimately lead to the identification of novel therapeutic targets and the development of improved therapeutic options for patients with these malignancies.

Clinical and laboratory experience of vorinostat (suberoylanilide hydroxamic acid) in the treatment of cutaneous T-cell lymphoma

The most common cutaneous T-cell lymphomas (CTCLs) – mycosis fungoides (MF) and Sézary Syndrome – are characterised by the presence of clonally expanded, skin-homing helper-memory T cells exhibiting abnormal apoptotic control mechanisms. Epigenetic modulation of genes that induce apoptosis and differentiation of malignant T cells may therefore represent an attractive new strategy for targeted therapy for T-cell lymphomas. In vitro studies show that vorinostat (suberoylanilide hydroxamic acid or SAHA), an oral inhibitor of class I and II histone deacetylases, induces selective apoptosis of malignant CTCL cell lines and peripheral blood lymphocytes from CTCL patients at clinically achievable doses. In a Phase IIa clinical trial, vorinostat therapy achieved a meaningful partial response (>50% reduction in disease burden) in eight out of 33 (24%) patients with heavily pretreated, advanced refractory CTCL. The most common major toxicities of oral vorinostat therapy were fatigue and gastrointestinal symptoms (diarrhoea, altered taste, nausea, and dehydration from not eating). Thrombocytopenia was dose limiting in patients receiving oral vorinostat at the higher dose induction levels of 300 mg twice daily for 14 days. These studies suggest that vorinostat represents a promising new agent in the treatment of CTCL patients. Additional studies are underway to define the exact mechanism (s) of by which vorinostat induces selective apoptosis in CTCL cells and to further evaluate the antitumour efficacy of vorinostat in a Phase IIb study in CTCL patients.

Mycosis fungoides and the Sézary syndrome

PURPOSE OF REVIEW

Mycosis fungoides and the Sézary syndrome represent a heterogeneous group of good-to-intermediate-risk non-Hodgkin lymphomas that have recently been identified as distinct histopathologic and clinical entities by the World Health Organization and European Organization for Research on the Treatment of Cancer lymphoma classification systems. Significant progress has been made in identifying and categorizing patients based on clinical prognostic factors, but there is little information regarding the etiology, molecular biology, and molecular genetics of these diseases. This review outlines recent advances in clinical diagnosis and prognosis as well as novel therapeutic approaches.

RECENT FINDINGS

A number of reports have further defined clinical prognostic subgroups among early-stage patients and those with circulating Sézary cells. The recent availability and demonstrated efficacy of the oral RXR retinoid, bexarotene, has altered the treatment paradigm of early-stage patients who would not otherwise be exposed to systemic therapies. Novel targeted agents and receptor-directed therapies, including the fusion toxin, denileukin diftitox, histone deacetylase inhibitors, and novel nucleoside analog therapies, have demonstrated promising activity and are undergoing further clinical evaluation. The evolution of immunotherapy has been augmented by studies demonstrating the efficacy of peptide-loaded dendritic cells as well as the use of photopheresis to generate an anti-idiotype cytotoxic T-cell response.

SUMMARY

This review will enumerate the most recent findings with respect to clinical staging, prognosis, and treatment of patients with mycosis fungoides and the Sézary syndrome. Novel treatment options will be reviewed and treatment paradigms will be outlined.