Extracorporeal Photopheresis as a Treatment Option for Immune-Related Adverse Events: Two Case Reports and a Prospective Study.

The wide use of immune checkpoint inhibitors has increased the frequency of immune-related adverse events (irAEs). While many are managed with corticosteroids or hormone substitution, up to 14.9% of irAEs are steroid-refractory or steroid-dependent and thus require second-line treatment. These should reduce irAE-related morbidity and mortality and induce a few side effects of their own while maintaining the antitumor response. There is little comparative data on second-line therapies for irAEs. Two cases of irAEs could not be sufficiently managed with corticosteroids and subsequently received treatment with extracorporeal photopheresis (ECP), including one patient with immune-related erosive oral lichen planus and one patient with immune-related colitis. In both cases, the irAE resolved with ECP in combination with immunosuppressive drugs, that is 4 weeks and 10 weeks after the start of ECP, respectively. To investigate this approach, a prospective clinical study that compares ECP and other second-line therapies for the treatment of steroid-refractory and steroid-dependent irAEs with regard to immunophenotype and therapy response has been designed. ECP could be a treatment option for steroid-refractory and steroid-dependent irAEs, given its good safety profile and lack of adverse effects on antitumor response. Comparative prospective studies are needed to generate an evidence base.

Mutation-specific CAR T cells as precision therapy for IGLV3-21R110 expressing high-risk chronic lymphocytic leukemia.

The concept of precision cell therapy targeting tumor-specific mutations is appealing but requires surface-exposed neoepitopes, which is a rarity in cancer. B cell receptors (BCR) of mature lymphoid malignancies are exceptional in that they harbor tumor-specific-stereotyped sequences in the form of point mutations that drive self-engagement of the BCR and autologous signaling. Here, we use a BCR light chain neoepitope defined by a characteristic point mutation (IGLV3-21R110) for selective targeting of a poor-risk subset of chronic lymphocytic leukemia (CLL) with chimeric antigen receptor (CAR) T cells. We develop murine and humanized CAR constructs expressed in T cells from healthy donors and CLL patients that eradicate IGLV3-21R110 expressing cell lines and primary CLL cells, but neither cells expressing the non-pathogenic IGLV3-21G110 light chain nor polyclonal healthy B cells. In vivo experiments confirm epitope-selective cytolysis in xenograft models in female mice using engrafted IGLV3-21R110 expressing cell lines or primary CLL cells. We further demonstrate in two humanized mouse models lack of cytotoxicity towards human B cells. These data provide the basis for advanced approaches of resistance-preventive and biomarker-guided cellular targeting of functionally relevant lymphoma driver mutations sparing normal B cells.

Tumor lysis syndrome induced by tebentafusp.

Tebentafusp, a bispecific T-cell receptor fusion protein directed against gp100 and CD3, can improve survival in patients with metastatic uveal melanoma and was recently approved for the treatment of HLA-A*02:01-positive uveal melanoma patients. Since tebentafusp often induces cytokine-release syndrome, doses must be escalated and patients monitored as inpatients after the first infusions. The occurrence of tumor lysis syndrome, a potentially life-threatening condition, after administration of a single dose of tebentafusp, is reported here. With adequate therapy, including the application of rasburicase, the patient made a full recovery. It is important to raise awareness of the adverse event profile of this new therapeutic approach among healthcare professionals to promptly recognize and treat side effects.

Tebentafusp is a new treatment for a type of eye cancer called uveal melanoma. It helps the body's defense system fight against cancer cells and has shown promise in helping patients live longer. However, not all patients with uveal melanoma can use this treatment. Only those who have a specific gene marker called HLA-A*02:01-positive can benefit from it. Like any new treatment, tebentafusp may have some side effects. One of them is called cytokine-release syndrome, which can cause symptoms like rash, fever and flu-like feelings. Usually, this side effect is not serious and can be treated well. There was a rare but serious case where one patient had a bad reaction after getting only one dose of tebentafusp. This reaction is called tumor lysis syndrome, which happens when cancer cells break down quickly and release harmful substances into the blood. This can be life-threatening. Thankfully, the patient received the right treatment and got better. This information is shared here with doctors and patients, so they know about possible side effects and can use tebentafusp safely.

Neomorphic DNA-binding enables tumor-specific therapeutic gene expression in fusion-addicted childhood sarcoma.

Chimeric fusion transcription factors are oncogenic hallmarks of several devastating cancer entities including pediatric sarcomas, such as Ewing sarcoma (EwS) and alveolar rhabdomyosarcoma (ARMS). Despite their exquisite specificity, these driver oncogenes have been considered largely undruggable due to their lack of enzymatic activity.Here, we show in the EwS model that - capitalizing on neomorphic DNA-binding preferences - the addiction to the respective fusion transcription factor EWSR1-FLI1 can be leveraged to express therapeutic genes.We genetically engineered a de novo enhancer-based, synthetic and highly potent expression cassette that can elicit EWSR1-FLI1-dependent expression of a therapeutic payload as evidenced by episomal and CRISPR-edited genomic reporter assays. Combining in silico screens and immunohistochemistry, we identified GPR64 as a highly specific cell surface antigen for targeted transduction strategies in EwS. Functional experiments demonstrated that anti-GPR64-pseudotyped lentivirus harboring our expression cassette can specifically transduce EwS cells to promote the expression of viral thymidine kinase sensitizing EwS for treatment to otherwise relatively non-toxic (Val)ganciclovir and leading to strong anti-tumorigenic, but no adverse effects in vivo. Further, we prove that similar vector designs can be applied in PAX3-FOXO1-driven ARMS, and to express immunomodulatory cytokines, such as IL-15 and XCL1, in tumor entities typically considered to be immunologically 'cold'.Collectively, these results generated in pediatric sarcomas indicate that exploiting, rather than suppressing, the neomorphic functions of chimeric transcription factors may open inroads to innovative and personalized therapies, and that our highly versatile approach may be translatable to other cancers addicted to oncogenic transcription factors with unique DNA-binding properties.

Presence of regulatory T-cells in endometrial cancer predicts poorer overall survival and promotes progression of tumor cells.

PURPOSE: Endometrial cancer (EC) is one of the most common gynaecologic malignancies. Tumor infiltrating regulatory T-cells (Treg) have been reported to have a prognostic impact in many malignancies. Immunotherapeutic strategies are gaining interest for advanced and recurrent EC cases, where treatment options are rare. Our study was aimed at determining the value of Treg in EC progression. METHODS: EC specimens from 275 patients and 28 controls were screened immunohistochemically for the presence of Treg represented by FoxP3. Correlations with clinicopathological and survival parameters were performed. Functional assays were performed using EC cell lines Ishikawa + and RL95-2 after co-culturing with isolated CD4 + CD25 + CD127dim Treg. To assess the influence of EC on the composition of peripheral blood mononuclear cells (PBMC), flow cytometric analyses were performed. RESULTS: We found that an increased infiltration of Treg was associated with high grades and a reduced overall survival. Treg were almost absent in endometrium tissues from healthy control patients. Co-culture of tumor cells with CD4 + CD25 + CD127dim Treg led to functional changes: enhanced invasion, migration and viability indicated that increased levels of Treg in the tumor microenvironment may promote tumor growth. Furthermore, we found that the presence of EC cells led to phenotypic changes in PBMC, showing significantly increased levels of CD25 and FoxP3. CONCLUSION: Our results indicate that the presence of Treg in the EC tumor environment is associated with a poorer outcome. A remarkable impact of Treg on tumor cell behaviour and vice versa of tumor cells on PBMC subpopulations support this notion mechanistically. Our findings provide a basis for focusing on Treg as potential future therapeutic targets in EC.

Beta cell and immune cell interactions in autoimmune type 1 diabetes: How they meet and talk to each other.

BACKGROUND: The highly complex pathogenesis of Type 1 Diabetes is driven by several immune cell types with both effector and regulatory characteristics, which ultimately ends in the destruction of the insulin-producing beta cells. There are multiple layers of interaction between these immune cell populations and the pancreatic islets. SCOPE OF REVIEW: In this review article, we aim to discuss important recent insights into the multiple layers of interaction between immune cell populations and the pancreatic islets. Specifically, we discuss the environment where immune and beta cell interactions occur, the key cell types and molecules involved, and the outcomes of these interactions. MAJOR CONCLUSIONS: Most of the molecular mechanisms underlying aberrant immune cell activation and impaired immune tolerance remain insufficiently understood, which hinders the development of efficient prevention and treatment strategies. In order to overcome this knowledge gap, a better understanding of the complex interactions of immune cells and beta cells, including both the underlying protective and pathogenic mechanisms is urgently required.

Regulatory T Cell Apoptosis during Preeclampsia May Be Prevented by Gal-2.

There are several open questions to be answered regarding the pathophysiology of the development of preeclampsia (PE). Numerous factors are involved in its genesis, such as defective placentation, vascular impairment, and an altered immune response. The activation of the adaptive and innate immune system represents an immunologic, particularity during PE. Proinflammatory cytokines are predominantly produced, whereas immune regulatory and immune suppressive factors are diminished in PE. In the present study, we focused on the recruitment of regulatory T cells (Tregs) which are key players in processes mediating immune tolerance. To identify Tregs in the decidua, an immunohistochemical staining of FoxP3 of 32 PE and 34 control placentas was performed. A clearly reduced number of FoxP3-positive cells in the decidua of preeclamptic women could be shown in our analysis (p = 0.036). Furthermore, CCL22, a well-known Treg chemoattractant, was immunohistochemically evaluated. Interestingly, CCL22 expression was increased at the maternal-fetal interface in PE-affected pregnancies (psyncytiotrophoblast = 0.035, pdecidua = 0.004). Therefore, the hypothesis that Tregs undergo apoptosis at the materno-fetal interface during PE was generated, and verified by FoxP3/TUNEL (TdT-mediated dUTP-biotin nick end labeling) staining. Galectin-2 (Gal-2), a member of the family of carbohydrate-binding proteins, which is known to be downregulated during PE, seems to play a pivotal role in T cell apoptosis. By performing a cell culture experiment with isolated Tregs, we could identify Gal-2 as a factor that seems to prevent the apoptosis of Tregs. Our findings point to a cascade of apoptosis of Tregs at the materno-fetal interface during PE. Gal-2 might be a potential therapeutic target in PE to regulate immune tolerance.

Biliary Cannulation in Endoscopic Retrograde Cholangiography: How to Tackle the Difficult Papilla.

BACKGROUND: In the setting of a naïve papilla, biliary cannulation is a key step in successfully performing endoscopic retrograde cholangiography. Difficult biliary cannulation (DBC) is associated with an increased risk of post-ERCP pancreatitis and failure of the whole procedure. SUMMARY: Recommendations for biliary cannulation can be divided into (a) measures to reduce the likelihood of a difficult papilla situation a priori and (b) rescue techniques in case the endoscopist is actually facing DBC. (a) Careful inspection of the papillary anatomy and optimizing its accessibility by scope positioning is fundamental. A sphincterotome in combination with a soft-tip hydrophilic guidewire rather than a standard catheter with a standard guidewire should be used in most situations. (b) The most important rescue techniques are needle-knife precut, double-guidewire technique, and transpancreatic sphincterotomy. In few cases, anterograde cannulation techniques are needed. To this regard, the EUS-guided biliary drainage followed by rendezvous is increasingly used as an alternative to percutaneous transhepatic biliary drainage. Key Messages: Biliary cannulation can be accomplished with alternative retrograde or less frequently by salvage anterograde techniques, once conventional direct cannulation attempts have failed. Considering recent favorable data for the early use of transpancreatic sphincterotomy, an adopted version of the 2016 European Society for Gastrointestinal Endoscopy (ESGE) algorithm on biliary cannulation is proposed.

[Management of Cystic Lesions of the Pancreas]. / Vorgehen bei Nachweis von zystischen Pankreasraumforderungen.

Cystic pancreatic lesions are a frequent incidental finding on ultrasound or cross sectional imaging. The incidence of pancreatic lesions experience a steady climb in recent years due to an increased number of cross sectional imaging and an increasing life expectancy. The clinical challenge is to identify individuals bearing lesions with potentially malignant or pre-malignant features. Indeed, by far most cystic pancreatic lesions are not associated with an increased risk for the development of cancer. Taking into account the increasing incidence rates of cystic pancreatic lesions a rational and economic use of diagnostics is warranted. This review provides an overview on the different types of cystic lesions, the appropriate use of diagnostics and a clinical management algorithm balancing intervention and surveillance.

Constitutive Expression of CCL22 Is Mediated by T Cell-Derived GM-CSF.

CCL22 is a key mediator of leukocyte trafficking in inflammatory immune responses, allergy, and cancer. It acts by attracting regulatory T cells and Th2 cells via their receptor CCR type 4 (CCR4). Beyond its role in inflammation, CCL22 is constitutively expressed at high levels in lymphoid organs during homeostasis, where it controls immunity by recruiting regulatory T cells to dendritic cells (DCs). In this study, we aimed to identify the mechanisms responsible for constitutive CCL22 expression. We confirmed that CD11c+ DCs are the exclusive producers of CCL22 in secondary lymphatic organs during homeostasis. We show that in vitro both murine splenocytes and human PBMCs secrete CCL22 spontaneously without any further stimulation. Interestingly, isolated DCs alone, however, are unable to produce CCL22, but instead require T cell help. In vitro, only the coculture of DCs with T cells or their supernatants resulted in CCL22 secretion, and we identified T cell-derived GM-CSF as the major inducer of DC-derived CCL22 expression. In vivo, Rag1 -/- mice, which lack functional T cells, have low CCL22 levels in lymphoid organs, and this can be restored by adoptive transfer of wild-type T cells or administration of GM-CSF. Taken together, we uncover T cell-derived GM-CSF as a key inducer of the chemokine CCL22 and thus, to our knowledge, identify a novel role for this cytokine as a central regulator of immunity in lymphatic organs. This knowledge could contribute to the development of new therapeutic interventions in cancer and autoimmunity.

CCL22 Signaling in the Tumor Environment.

T cell-mediated elimination of malignant cells is one cornerstone of endogenous and therapeutically induced antitumor immunity. Tumors exploit numerous regulatory mechanisms to suppress T cell immunity. Regulatory T cells (T regs) play a crucial role in this process due to their ability to inhibit antitumoral immune responses and they are known to accumulate in various cancer entities. The chemokine CCL22, predominately produced by dendritic cells (DCs), regulates T reg migration via binding to its receptor CCR4. CCL22 controls T cell immunity, both by recruiting T regs to the tumor tissue and by promoting the formation of DC-T reg contacts in the lymph node. Here, we review the current knowledge on the role of CCL22 in cancer immunity. After revising the principal mechanisms of CCL22-induced immune suppression, we address the factors leading to CCL22 expression and ways of targeting this chemokine therapeutically. Therapeutic interventions to the CCL22-CCR4 axis may represent a promising strategy in cancer immunotherapy.

Peritumoural CCL1 and CCL22 expressing cells in hepatocellular carcinomas shape the tumour immune infiltrate.

Development, course of disease and prognosis of hepatocellular carcinomas (HCC) are strongly influenced by the immune system. Immunosuppressive regulatory T cells (Treg) have been shown to negatively impact disease progression and survival. To further understand the mechanisms of Treg attraction to HCC lesions, this study provides an analysis of Treg attracting chemokines in human HCC tissues. We analysed the expression of the Treg attracting chemokines CCL1 and CCL22 as well as the infiltration of FoxP3+ Treg and CD8+ T cells in paraffin-embedded tissue sections of 62 HCC patients. Expression of both chemokines was detected in 47 of 62 tissue slides. Chemokine expression was generally higher in tumour stroma and peritumoural liver tissue than in the tumour tissue itself. CD8+ T cells and FoxP3+ Treg were found at high levels in many tumour tissues. Intratumoural infiltration of Treg positively correlated with CCL22 levels in peritumoural liver tissue. In contrast, no correlation of Treg numbers and expression of CCL1 was detected. In summary, we describe here that the chemokines CCL1 and CCL22 are expressed in HCC tissues and, to a higher extent, in the stroma and peritumoural liver tissue. CCL22 may contribute to Treg recruitment and immunosuppression, whereas the role of CCL1 remains to be defined. It will be interesting to investigate the potential of these chemokines as drug targets for cancer therapy.

CCL22 controls immunity by promoting regulatory T cell communication with dendritic cells in lymph nodes.

Chemokines have crucial roles in organ development and orchestration of leukocyte migration. The chemokine CCL22 is expressed constitutively at high levels in the lymph node, but the functional significance of this expression is so far unknown. Studying a newly established CCL22-deficient mouse, we demonstrate that CCL22 expression by dendritic cells (DCs) promotes the formation of cell-cell contacts and interaction with regulatory T cells (T reg) through their CCR4 receptor. Vaccination of CCL22-deficient mice led to excessive T cell responses that were also observed when wild-type mice were vaccinated using CCL22-deficient DCs. Tumor-bearing mice with CCL22 deficiency showed prolonged survival upon vaccination, and further, CCL22-deficient mice had increased susceptibility to inflammatory disease. In conclusion, we identify the CCL22-CCR4 axis as an immune checkpoint that is crucial for the control of T cell immunity.

CCL1 is a major regulatory T cell attracting factor in human breast cancer.

BACKGROUND: Regulatory T cells (Treg) suppress cytotoxic T cell anti-tumoral immune responses and thereby promote tumor progression. Prevention of intratumoral Treg accumulation by inhibition of their migration to the tumor microenvironment is a promising therapeutic strategy. The aim of this study was to identify the role of the two major Treg-attracting chemokines CCL1 and CCL22 in human breast cancer. METHODS: One hundred ninety-nine tissue samples of patients with invasive breast cancer were stained for CCL1 and CCL22 by immunohistochemistry. Chemokine expression and tumor infiltration by regulatory T cells, determined by expression of the transcription factor FoxP3, were quantified and their correlation to clinical features was statistically analyzed. RESULTS: Both CCL1 and CCL22 were expressed in most breast cancer tissues. CCL1 was significantly over-expressed in invasive breast cancer as compared to normal breast tissue. CCL1, but surprisingly not CCL22, showed a significant correlation with the number of tumor-infiltrating FoxP3+ Treg (p< 0.001). High numbers of intratumoral CCL1 expressing cells were related to high grade tumors (G4) and a positive estrogen receptor (ER) status whereas high CCL22 expression was generally seen in lower grade tumors. The median survival of 88 patients with high intratumoral CCL1 expression was 37 months compared to 50 months for the 87 patients with low CCL1 levels, this trend was however not statistically significant. CONCLUSIONS: We found a high expression of CCL1 in human breast cancer. CCL1 significantly correlated with the infiltration of immunosuppressive FoxP3+ Treg, that are known to negatively affect survival. Thus, CCL1 may serve as prognostic marker and novel therapeutic target in breast cancer.

Cancer cell-derived IL-1α induces CCL22 and the recruitment of regulatory T cells.

In cancer patients, immunosuppression through regulatory T cells (Treg) is a crucial component of tumor immune evasion and contributes to disease progression. Tumor-infiltrating Treg in particular suppress local effector T cell responses and are associated with poor prognosis in tumors such as human pancreatic cancer or hepatocellular carcinoma (HCC). The chemokine CCL22 is known to recruit Treg into the tumor tissue and many types of human tumors are known to express high levels of CCL22. The mechanisms leading to intratumoral secretion of CCL22 are so far unknown. We demonstrate here that intratumoral CCL22 is induced in tumor-infiltrating immune cells through cancer cell-derived interleukin-1 (IL-1α). In pancreatic cancer and HCC, CCL22 is produced by intratumoral dendritic cells, while the cancer cells themselves do not secrete CCL22 in vitro and in vivo. Incubation of human peripheral blood mononuclear cells (PBMC) or murine splenocytes with tumor cells or tumor cell supernatants strongly induced CCL22 secretion in vitro. Tumor cell supernatants contained IL-1 and CCL22 induction in PBMC could be specifically prevented by the IL-1 receptor antagonist anakinra or by transfection of tumor cell lines with IL-1 siRNA, leading to a suppression of Treg migration. In conclusion, we identify here tumor cell-derived IL-1α as a major inducer of the Treg attracting chemokine CCL22 in human cancer cells. Therapeutic blockade of the IL-1 pathway could represent a promising strategy to inhibit tumor-induced immunosuppression.

FOXP3+ Cells Recruited by CCL22 into Breast Cancer Correlates with Less Tumor Nodal Infiltration.

BACKGROUND: Regulatory T-cells (Tregs) are a T-cell subpopulation with suppressive capacities, which are specifically attracted by C-C motif chemokine 22 (CCL22). Treg infiltration of tumors is associated with a poor prognosis in many patients. We aimed to investigate whether CCL22 is expressed in human breast cancer and whether its presence is associated with Treg infiltration. MATERIALS AND METHODS: Eighty paraffin-embedded human breast cancer samples were stained for CCL22 and for the Treg-specific transcription factor forkhead box P3 (FOXP3). Expression was evaluated in a semi-quantitative manner. RESULTS: FOXP3(+) cells infiltrated 50% of the breast tumors. Moreover, Treg infiltrated 93% of the tertiary lymphoid structures. CCL22 expression positively correlated with FOXP3(+) cell infiltration into the tertiary lymphoid structures. CONCLUSION: Our results demonstrate that CCL22 expression correlates with infiltration by FOXP3(+) cells. Interestingly, Treg presence negatively correlated with positive nodal status. In addition to their unfavorable role as mediators of evasion from antitumor immune response, Tregs might also have a beneficial role by reducing inflammation thereby limiting early tumor growth and spreading.

C-C chemokine receptor type-4 transduction of T cells enhances interaction with dendritic cells, tumor infiltration and therapeutic efficacy of adoptive T cell transfer.

T cell infiltration at the tumor site has been identified as a major predictor for the efficacy of adoptive T cell therapy. The chemokine C-C motif ligand 22 (CCL22) is highly expressed by immune cells in murine and human pancreatic cancer. Expression of its corresponding receptor, C-C chemokine receptor type 4 (CCR4), is restricted to regulatory T cells (Treg). We show that transduction of cytotoxic T cells (CTL) with CCR4 enhances their immigration into a pancreatic cancer model. Further, we show that binding of CCR4 with CCL22 strengthens the binding of T cell LFA-1 to dendritic cell (DC) ICAM-1 and increases CTL activation. In vivo, in a model of subcutaneous pancreatic cancer, treatment of tumor-bearing mice with CCR4-transduced CTL led to the eradication of established tumors in 40% of the mice. In conclusion, CCR4 overexpression in CTL is a promising therapeutic strategy to enhance the efficacy of adoptive T cell transfer (ACT).

Suppression of intratumoral CCL22 by type i interferon inhibits migration of regulatory T cells and blocks cancer progression.

The chemokine CCL22 is abundantly expressed in many types of cancer and is instrumental for intratumoral recruitment of regulatory T cells (Treg), an important subset of immunosuppressive and tumor-promoting lymphocytes. In this study, we offer evidence for a generalized strategy to blunt Treg activity that can limit immune escape and promote tumor rejection. Activation of innate immunity with Toll-like receptor (TLR) or RIG-I-like receptor (RLR) ligands prevented accumulation of Treg in tumors by blocking their immigration. Mechanistic investigations indicated that Treg blockade was a consequence of reduced intratumoral CCL22 levels caused by type I IFN. Notably, stable expression of CCL22 abrogated the antitumor effects of treatment with RLR or TLR ligands. Taken together, our findings argue that type I IFN blocks the Treg-attracting chemokine CCL22 and thus helps limit the recruitment of Treg to tumors, a finding with implications for cancer immunotherapy.

Expression of CCL22 and Infiltration by Regulatory T Cells are Increased in the Decidua of Human Miscarriage Placentas.

PROBLEM: Regulatory T cells (Treg) are a T-cell subpopulation with suppressive capacities, specifically attracted by CCL22. We aimed to investigate whether CCL22 is expressed in human placentas and whether its presence, together with Treg infiltration, is associated with miscarriage conditions. METHOD OF STUDY: Paraffin samples were stained for CCL22 and for the Treg-specific transcription factor FoxP3. Expression levels were evaluated in a semi-quantitative manner. Double immunofluorescence was used for the identification of CCL22-producing cells. RESULTS: In all placentas, trophoblasts expressed CCL22. Interestingly, expression in the decidua was only observed in miscarriage conditions. Maternal stromal cells expressed CCL22. Correlation with a higher presence of Treg in the decidua of abortive tissues was observed. CONCLUSION: Our results demonstrate that CCL22 is expressed in human placenta. Decidual expression was only observed in miscarriage conditions and correlates with Treg infiltration. Thus, CCL22 plays a role in human pregnancy and may occur as a negative feedback response to pro-inflammatory events during miscarriage conditions.