Correlation of the tumor escape phenotype with loss of PRELP expression in melanoma.

BACKGROUND: Despite immunotherapies having revolutionized the treatment of advanced cutaneous melanoma, effective and durable responses were only reported in a few patients. A better understanding of the interaction of melanoma cells with the microenvironment, including extracellular matrix (ECM) components, might provide novel therapeutic options. Although the ECM has been linked to several hallmarks of cancer, little information is available regarding the expression and function of the ECM protein purine-arginine-rich and leucine-rich protein (PRELP) in cancer, including melanoma. METHODS: The structural integrity, expression and function of PRELP, its correlation with the expression of immune modulatory molecules, immune cell infiltration and clinical parameters were determined using standard methods and/or bioinformatics. RESULTS: Bioinformatics analysis revealed a heterogeneous, but statistically significant reduced PRELP expression in available datasets of skin cutaneous melanoma when compared to adjacent normal tissues, which was associated with reduced patients' survival, low expression levels of components of the MHC class I antigen processing machinery (APM) and interferon (IFN)-γ signal transduction pathway, but increased expression of the transforming growth factor (TGF)-ß isoform 1 (TFGB1) and TGF-ß receptor 1 (TGFBR1). In addition, a high frequency of intra-tumoral T cells directly correlated with the expression of MHC class I and PRELP as well as the T cell attractant CCL5 in melanoma lesions. Marginal to low PRELP expression levels were found in the 47/49 human melanoma cell lines analysis. Transfection of PRELP into melanoma cell lines restored MHC class I surface expression due to transcriptional upregulation of major MHC class I APM and IFN-γ pathway components. In addition, PRELP overexpression is accompanied by high CCL5 secretion levels in cell supernatant, an impaired TGF-ß signaling as well as a reduced cell proliferation, migration and invasion of melanoma cells. CONCLUSIONS: Our findings suggest that PRELP induces the expression of MHC class I and CCL5 in melanoma, which might be involved in an enhanced T cell recruitment and immunogenicity associated with an improved patients' outcome. Therefore, PRELP might serve as a marker for predicting disease progression and its recovery could revert the tumorigenic phenotype, which represents a novel therapeutic option for melanoma.

Induction of pulmonary HLA-G expression by SARS-CoV-2 infection.

The non-classical human leukocyte antigen (HLA)-G exerts immune-suppressive properties modulating both NK and T cell responses. While it is physiologically expressed at the maternal-fetal interface and in immune-privileged organs, HLA-G expression is found in tumors and in virus-infected cells. So far, there exists little information about the role of HLA-G and its interplay with immune cells in biopsies, surgical specimen or autopsy tissues of lung, kidney and/or heart muscle from SARS-CoV-2-infected patients compared to control tissues. Heterogeneous, but higher HLA-G protein expression levels were detected in lung alveolar epithelial cells of SARS-CoV-2-infected patients compared to lung epithelial cells from influenza-infected patients, but not in other organs or lung epithelia from non-viral-infected patients, which was not accompanied by high levels of SARS-CoV-2 nucleocapsid antigen and spike protein, but inversely correlated to the HLA-G-specific miRNA expression. High HLA-G expression levels not only in SARS-CoV-2-, but also in influenza-infected lung tissues were associated with a high frequency of tissue-infiltrating immune cells, but low numbers of CD8+ cells and an altered expression of hyperactivation and exhaustion markers in the lung epithelia combined with changes in the spatial distribution of macrophages and T cells. Thus, our data provide evidence for an involvement of HLA-G and HLA-G-specific miRNAs in immune escape and as suitable therapeutic targets for the treatment of SARS-CoV-2 infections.

Interferons and Resistance Mechanisms in Tumors and Pathogen-Driven Diseases-Focus on the Major Histocompatibility Complex (MHC) Antigen Processing Pathway.

Interferons (IFNs), divided into type I, type II, and type III IFNs represent proteins that are secreted from cells in response to various stimuli and provide important information for understanding the evolution, structure, and function of the immune system, as well as the signaling pathways of other cytokines and their receptors. They exert comparable, but also distinct physiologic and pathophysiologic activities accompanied by pleiotropic effects, such as the modulation of host responses against bacterial and viral infections, tumor surveillance, innate and adaptive immune responses. IFNs were the first cytokines used for the treatment of tumor patients including hairy leukemia, renal cell carcinoma, and melanoma. However, tumor cells often develop a transient or permanent resistance to IFNs, which has been linked to the escape of tumor cells and unresponsiveness to immunotherapies. In addition, loss-of-function mutations in IFN signaling components have been associated with susceptibility to infectious diseases, such as COVID-19 and mycobacterial infections. In this review, we summarize general features of the three IFN families and their function, the expression and activity of the different IFN signal transduction pathways, and their role in tumor immune evasion and pathogen clearance, with links to alterations in the major histocompatibility complex (MHC) class I and II antigen processing machinery (APM). In addition, we discuss insights regarding the clinical applications of IFNs alone or in combination with other therapeutic options including immunotherapies as well as strategies reversing the deficient IFN signaling. Therefore, this review provides an overview on the function and clinical relevance of the different IFN family members, with a specific focus on the MHC pathways in cancers and infections and their contribution to immune escape of tumors.

Characterization of the effect of histone deacetylation inhibitors on CD8+ T cells in the context of aging.

BACKGROUND: Posttranslational protein modifications regulate essential cellular processes, including the immune cell activation. Despite known age-related alterations of the phenotype, composition and cytokine profiles of immune cells, the role of acetylation in the aging process of the immune system was not broadly investigated. Therefore, in the current study the effect of acetylation on the protein expression profiles and function of CD8+ T cells from donors of distinct age was analyzed using histone deacetylase inhibitors (HDACi). METHODS: CD8+ T cells isolated from peripheral blood mononuclear cells of 30 young (< 30 years) and 30 old (> 60 years) healthy donors were activated with anti-CD3/anti-CD28 antibodies in the presence and absence of a cocktail of HDACi. The protein expression profiles of untreated and HDACi-treated CD8+ T cells were analyzed using two-dimensional gel electrophoresis. Proteins with a differential expression level (less than 0.66-fold decrease or more than 1.5-fold increase) between CD8+ T cells of young and old donors were identified by matrix-associated laser desorption ionization-time of flight mass spectrometry. Functional enrichment analysis of proteins identified was performed using the online tool STRING. The function of CD8+ T cells was assessed by analyses of cytokine secretion, surface expression of activation markers, proliferative capacity and apoptosis rate. RESULTS: The HDACi treatment of CD8+ T cells increased in an age-independent manner the intracellular acetylation of proteins, in particular cytoskeleton components and chaperones. Despite a strong similarity between the protein expression profiles of both age groups, the functional activity of CD8+ T cells significantly differed with an age-dependent increase in cytokine secretion and expression of activation markers for CD8+ T cells from old donors, which was maintained after HDACi treatment. The proliferation and apoptosis rate of CD8+ T cells after HDACi treatment was equal between both age groups. CONCLUSIONS: Despite a comparable effect of HDACi treatment on the protein signature of CD8+ T cells from donors of different ages, an initial higher functionality of CD8+ T cells from old donors when compared to CD8+ T cells from young donors was detected, which might have clinical relevance.

"Tumor immunology meets oncology (TIMO) XV", April 25th-27th 2019, Halle/Saale, Germany.

Novel insights into basic and translational tumor immunology including immunotherapies were presented by national and international scientists and clinicians at the TIMO XV meeting in Halle.

Immune Escape Mechanisms and Their Clinical Relevance in Head and Neck Squamous Cell Carcinoma.

Immunotherapy has been recently approved for the treatment of relapsed and metastatic human papilloma virus (HPV) positive and negative head and neck squamous cell carcinoma (HNSCC). However, the response of patients is limited and the overall survival remains short with a low rate of long-term survivors. There exists growing evidence that complex and partially redundant immune escape mechanisms play an important role for the low efficacy of immunotherapies in this disease. These are caused by diverse complex processes characterized by (i) changes in the expression of immune modulatory molecules in tumor cells, (ii) alterations in the frequency, composition and clonal expansion of immune cell subpopulations in the tumor microenvironment and peripheral blood leading to reduced innate and adaptive immune responses, (iii) impaired homing of immune cells to the tumor site as well as (iv) the presence of immune suppressive soluble and physical factors in the tumor microenvironment. We here summarize the major immune escape strategies of HNSCC lesions, highlight pathways, and molecular targets that help to attenuate HNSCC-induced immune tolerance, affect the selection and success of immunotherapeutic approaches to overcome resistance to immunotherapy by targeting immune escape mechanisms and thus improve the HNSCC patients' outcome.

Tumor-induced escape mechanisms and their association with resistance to checkpoint inhibitor therapy.

Immunotherapy aims to activate the immune system to fight cancer in a very specific and targeted manner. Despite the success of different immunotherapeutic strategies, in particular antibodies directed against checkpoints as well as adoptive T-cell therapy, the response of patients is limited in different types of cancers. This attributes to escape of the tumor from immune surveillance and development of acquired resistances during therapy. In this review, the different evasion and resistance mechanisms that limit the efficacy of immunotherapies targeting tumor-associated antigens presented by major histocompatibility complex molecules on the surface of the malignant cells are summarized. Overcoming these escape mechanisms is a great challenge, but might lead to a better clinical outcome of patients and is therefore currently a major focus of research.

The tumor microenvironment: Thousand obstacles for effector T cells.

The immune system is endowed with the capability to recognize and destroy transformed cells, but even in the presence of an immune infiltrate many tumors do progress. In the last decades new discoveries have shed light into (some of) the underlying mechanisms. Immune effector cells are not only under the influence of immune suppressive cell subsets, but also intrinsically regulated by immune check point molecules that under physiological condition avoid attach of healthy tissue. Moreover, tumor cells are modifying the surrounding microenvironment through secretion of immune modulators as well as via their own metabolism, thus further impairing the development of immune effector functions. Different approaches are currently being evaluated in the clinic to overcome those regulatory mechanisms and to unleash effector T cells.

Different maturation cocktails provide dendritic cells with different chemoattractive properties.

BACKGROUND: Dendritic cells (DC) are currently implemented as immunotherapeutic strategy for the treatment of tumor patients based on their central role in the immune system. Despite good results were obtained in vitro and in animal models, their clinical use has provided limited success suggesting the requirement to optimise the protocol for their production. METHODS: A cDNA array was performed on FastDC obtained from the differentiation of human peripheral blood monocytes stimulated with the clinical gold standard or with two alternative maturation cocktails combining interferon (IFN)γ and ligands for different toll like receptors (TLR). RESULTS: A stronger modulation of the DC transcriptome with respect to immature DC was found in alternatively stimulated DC when compared to DC stimulated with the clinical gold standard. A major class of molecules differentially expressed using distinct DC stimulation protocols were chemokines. Validation of their differential expression pattern at the mRNA and protein level confirmed the secretion of inflammatory chemokines by the alternative DC. Functional analyses of the chemotactic properties of DC "wash out" supernatants highlighted the ability of alternative, but not of gold standard DC to efficiently recruit immune cells with a prevalence of monocytes. Effector cells belonging to the innate as well as adaptive immunity were also attracted and the interaction with alternative DC resulted in enhanced secretion of IFNγ and induction of cytotoxic activity. Using leukocytes from cancer patients, it was demonstrated that the monocyte-attracting activity targeted cells with an inflammatory phenotype characterised by high levels of HLA-DR expression. CONCLUSIONS: Despite other classes of immune modulatory genes differently expressed in the alternative DC require to be investigated and characterised regarding their functional consequences, the reduced maturation state and chemoattractive properties of the gold standard versus alternative DC clearly promote the necessity to change the clinically used maturation cocktail of DC in order to improve the outcome of patients treated with DC-based vaccines.

Fast dendritic cells stimulated with alternative maturation mixtures induce polyfunctional and long-lasting activation of innate and adaptive effector cells with tumor-killing capabilities.

The clinical usage of dendritic cells (DC) for tumor immunotherapy still requires improvements. In this study, three alternative maturation mixtures were compared with the cytokine-based gold standard, and the overall interaction of the resulting DC with effector cells from the innate as well as the adaptive immunity was evaluated in healthy donors. Stimulation with the TLR-4 ligand monophosphoryl lipid A together with IFN-γ (alt-2 DC) resulted in DC with the highest levels of costimulatory molecule expression and IL-12p70/IL-10 ratio. Whereas all alternative DC were able to induce NK and γδ T cells to acquire cytotoxic properties and secrete type 1 and proinflammatory cytokines, after both short (20-h)- and long (5-8 d)-time coculture, secretion of IFN-γ by the innate populations was induced in response to alt-2 and alt-1 DC (TNF-α, IFN-α, IFN-γ, IL-1ß, poly IC), but not to alt-3 DC (TNF-α, IFN-γ, IL-1ß, CL097). Regarding CD8(+) T cell-mediated Ag-specific immune responses, a heterogeneous pattern of responses was obtained among the healthy donors, suggesting rather a competition than a synergy among the different effector cells. Our data promote further evaluation of alt-2 fast DC for translatability into clinical immunotherapy trials, while also fostering the need to identify biomarkers for immune cell responsiveness and tumor susceptibility to be able to select for each patient the best possible DC-based therapy.

Combination of multiple omics techniques for a personalized therapy or treatment selection.

Despite targeted therapies and immunotherapies have revolutionized the treatment of cancer patients, only a limited number of patients have long-term responses. Moreover, due to differences within cancer patients in the tumor mutational burden, composition of the tumor microenvironment as well as of the peripheral immune system and microbiome, and in the development of immune escape mechanisms, there is no "one fit all" therapy. Thus, the treatment of patients must be personalized based on the specific molecular, immunologic and/or metabolic landscape of their tumor. In order to identify for each patient the best possible therapy, different approaches should be employed and combined. These include (i) the use of predictive biomarkers identified on large cohorts of patients with the same tumor type and (ii) the evaluation of the individual tumor with "omics"-based analyses as well as its ex vivo characterization for susceptibility to different therapies.

Biglycan as a mediator of proinflammatory response and target for MDS and sAML therapy.

Myelodysplastic syndromes (MDS) and their progression to secondary acute myeloid leukemia (sAML) are associated with an altered protein expression including extracellular matrix (ECM) components thereby promoting an inflammatory environment. Since the role of the proteoglycan biglycan (BGN) as an inflammatory mediator has not yet been investigated in both diseases and might play a role in disease progression, its expression and/or function was determined in cell lines and bone marrow biopsies (BMBs) of MDS and sAML patients and subpopulations of MDS stem cells by Western blot and immunohistochemistry. The bone marrow (BM) microenvironment was analyzed by multispectral imaging, patients' survival by Cox regression. ROC curves were assessed for diagnostic value of BGN. All cell lines showed a strong BGN surface expression in contrast to only marginal expression levels in mononuclear cells and CD34+ cells from healthy donors. In the MDS-L cell line, CD34-CD33+ and CD34+CD33+ blast subpopulations exhibited a differential BGN surface detection. Increased BGN mediated inflammasome activity of CD34-CD33+TLR4+ cells was observed, which was inhibited by direct targeting of BGN or NLRP3. BGN was heterogeneously expressed in BMBs of MDS and sAML, but was not detected in control biopsies. BGN expression in BMBs positively correlated with MUM1+ and CD8+, but negatively with CD33+TLR4+ cell infiltration and was accompanied by a decreased progression-free survival of MDS patients. BGN-mediated inflammasome activation appears to be a crucial mechanism in MDS pathogenesis implicating its use as suitable biomarker and potential therapeutic target. Abbreviations: Ab, antibody; alloSCT, allogenic stem cell transplant; AML, acute myeloid leukemia; BGN, biglycan; BM, bone marrow; BMB, bone marrow biopsy; casp1, caspase 1; CTLA-4, cytotoxic T lymphocyte-associated protein 4; DAMP, danger-associated molecular pattern; ECM, extracellular matrix; FCS, fetal calf serum; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; HD, healthy donor; HSPC, hematopoietic stem and progenitor cell; HSC, hematopoietic stem cell; IFN, interferon; IHC, immunohistochemistry; IL, interleukin; MDS, myelodysplastic syndrome; MPN, myeloproliferative neoplasm; MSI, multispectral imaging; NGS, next-generation sequencing; NLRP3, NLR family pyrin domain containing 3; OS, overall survival; PBMC, peripheral blood mononuclear cell; PD-1, programmed cell death protein 1; PD-L1, programmed death-ligand 1, PFS, progression-free survival; PRR, pattern recognition receptor; SC, stem cell; SLRP, small leucine-rich proteoglycan; TGF, transforming growth factor; TIRAP, toll/interleukin 1 receptor domain-containing adapter protein; TLR, toll-like receptor; Treg, regulatory T cell.

Comparative Immune Response after Vaccination with SOBERANA® 02 and SOBERANA® plus Heterologous Scheme and Natural Infection in Young Children.

(1) Background: In children, SARS-CoV-2 infection is mostly accompanied by mild COVID-19 symptoms. However, multisystem inflammatory syndrome (MIS-C) and long-term sequelae are often severe complications. Therefore, the protection of the pediatric population against SARS-CoV-2 with effective vaccines is particularly important. Here, we compare the humoral and cellular immune responses elicited in children (n = 15, aged 5-11 years) vaccinated with the RBD-based vaccines SOBERANA® 02 and SOBERANA® Plus combined in a heterologous scheme with those from children (n = 10, aged 4-11 years) who recovered from mild symptomatic COVID-19. (2) Methods: Blood samples were taken 14 days after the last dose for vaccinated children and 45-60 days after the infection diagnosis for COVID-19 recovered children. Anti-RBD IgG and ACE2-RBD inhibition were assessed by ELISA; IgA, cytokines, and cytotoxic-related proteins were determined by multiplex assays. Total B and T cell subpopulations and IFN-γ release were measured by multiparametric flow cytometry using a large panel of antibodies after in vitro stimulation with S1 peptides. (3) Results: Significant higher levels of specific anti-RBD IgG and IgA and ACE2-RBD inhibition capacity were found in vaccinated children in comparison to COVID-19 recovered children. Th1-like and Th2-like CD4+ T cells were also significantly higher in vaccinated subjects. IFN-γ secretion was higher in central memory CD4+ T cells of COVID-19 recovered children, but no differences between both groups were found in the CD4+ and CD8+ T cell effector, terminal effector, and naïve T cell subpopulations. In contrast to low levels of IL-4, high levels of IL-2, IL-6, IFN-γ, and IL-10 suggest a predominant Th1 cell polarization. Cytotoxic-related proteins granzyme A and B, perforin, and granulin were also found in the supernatant after S1 stimulation in both vaccinated and recovered children. (4) Conclusions: Vaccination with the heterologous scheme of SOBERANA® 02/SOBERANA® Plus induces a stronger antibody and cellular immune response compared to natural infections in young children.

Modulation of Lymphocyte Functions in the Microenvironment by Tumor Oncogenic Pathways.

Despite the broad application of different immunotherapeutic strategies for the treatment of solid as well as hematopoietic cancers, the efficacy of these therapies is still limited, with only a minority of patients having a long-term benefit resulting in an improved survival rate. In order to increase the response rates of patients to the currently available immunotherapies, a better understanding of the molecular mechanisms underlying the intrinsic and/or extrinsic resistance to treatment is required. There exist increasing evidences that activation of different oncogenic pathways as well as inactivation of tumor suppressor genes (TSG) in tumor cells inhibit the immune cell recognition and influegnce the composition of the tumor microenvironment (TME), thus leading to an impaired anti-tumoral immune response. A deeper understanding of the link between the tumor milieu and genomic alterations of TSGs and oncogenes is indispensable for the optimization of immunotherapies and to predict the patients' response to these treatments. This review summarizes the role of different cancer-related, oncogene- and TSG-controlled pathways in the context of anti-tumoral immunity and response to different immunotherapies.

Biglycan as a potential regulator of tumorgenicity and immunogenicity in K-RAS-transformed cells.

The extracellular matrix component biglycan (BGN) plays an essential role in various physiological and pathophysiological processes. A deficient BGN expression associated with reduced immunogenicity was found in HER-2/neu-overexpressing cells. To determine whether BGN is suppressed by oncogene-driven regulatory networks, the expression and function of BGN was analyzed in murine and human BGNlow/BGNhigh K-RASG12V-transformed model systems as well as in different patients' datasets of colorectal carcinoma (CRC) lesions. K-RAS-mutated CRC tissues expressed low BGN mRNA and protein levels when compared to normal colon epithelial cells, which was associated with a reduced patients' survival. Transfection of BGN in murine and human BGNlow K-RAS-expressing cells resulted in a reduced growth and migration of BGNhigh vs BGNlow K-RAS cells. In addition, increased MHC class I surface antigens as a consequence of an enhanced antigen processing machinery component expression was found upon restoration of BGN, which was confirmed by RNA-sequencing of BGNlow vs. BGNhigh K-RAS models. Furthermore, a reduced tumor formation of BGNhigh versus BGNlow K-RAS-transformed fibroblasts associated with an enhanced MHC class I expression and an increased frequency of tumor-infiltrating lymphocytes in tumor lesions was found. Our data provide for the first time an inverse link between BGN and K-RAS expression in murine and human K-RAS-overexpressing models and CRC lesions associated with altered growth properties, reduced immunogenicity and worse patients' outcome. Therefore, reversion of BGN might be a novel therapeutic option for K-RAS-associated malignancies.

Identification and characterization of novel CD274 (PD-L1) regulating microRNAs and their functional relevance in melanoma.

BACKGROUND: Immune checkpoint inhibitors directed against programmed cell death 1 (PDCD1/PD1) receptor and programmed cell death-ligand 1 (CD274/PD-L1) have been recently successfully implemented for the treatment of many cancers, but the response rate of tumour patients is still limited due to intrinsic and acquired resistances. However, the underlying molecular mechanisms of this limited response have still to be defined in detail. The aim of this study is to uncover processes inhibiting PDCD1/CD274 expression thereby enhancing anti-tumour immune responses. The identification and characterization of microRNAs (miRNAs) targeting the 3'-untranslated region (3'-UTR) as well as the coding sequence (CDS) of CD274 will provide the basis for a new drug development. METHODS: Human melanoma cell lines and tissue samples were subjected to mRNA and/or protein expression analysis using qPCR, Western blot, flow cytometry, and/or immunohistochemistry. The data were correlated to clinical parameters. MiRNA trapping by RNA in vitro affinity purification (miTRAP) technology in combination with small RNA sequencing and different bioinformatics tools were employed to identify CD274-regulating miRNAs. RESULTS: Screening based on miTRAP in combination with RNAseq identified a large number of novel CD274-regulating candidate miRNAs, from which eight selected miRNAs were functionally validated. Five out of eight miRNAs were able to significantly reduce CD274 surface expression indicating that these miRNAs directly bind to the 3'-UTR or CDS of the CD274 gene. The miRNA-mediated inhibition of CD274 expression was accompanied by an increased T cell recognition. Furthermore, an inverse expression of three CD274-regulating miRNAs and CD274 was demonstrated in melanoma lesions. A CD274 miRNA score was generated, which was associated with disease progression and reduced survival of melanoma patients. CONCLUSIONS: These data revealed a novel mechanism that miRNAs targeting the CDS of immune checkpoint genes are functional, have prognostic relevance, and also the potential for the development of novel miRNA-based therapies.

Peripheral Blood Monocyte Abundance Predicts Outcomes in Patients with Breast Cancer.

Biomarkers of response are needed in breast cancer to stratify patients to appropriate therapies and avoid unnecessary toxicity. We used peripheral blood gene expression and cell type abundance to identify biomarkers of response and recurrence in neoadjuvant chemotherapy treated breast cancer patients. We identified a signature of interferon and complement response that was higher in the blood of patients with pathologic complete response. This signature was preferentially expressed by monocytes in single cell RNA sequencing. Monocytes are routinely measured clinically, enabling examination of clinically measured monocytes in multiple independent cohorts. We found that peripheral monocytes were higher in patients with good outcomes in four cohorts of breast cancer patients. Blood gene expression and cell type abundance biomarkers may be useful for prognostication in breast cancer. Significance: Biomarkers are needed in breast cancer to identify patients at risk for recurrence. Blood is an attractive site for biomarker identification due to the relative ease of longitudinal sampling. Our study suggests that blood-based gene expression and cell type abundance biomarkers may have clinical utility in breast cancer.

Translational analysis and final efficacy of the AVETUX trial - Avelumab, cetuximab and FOLFOX in metastatic colorectal cancer.

Introduction: In metastatic colorectal cancer (mCRC), the efficacy of immune checkpoint blockade (ICB) has so far been limited to patients with microsatellite instability high tumors (MSI-H). Unfortunately, most mCRC patients suffer from non-immunogenic microsatellite stable (MSS) tumors. Therefore, new combinatorial strategies are urgently needed to enhance the immunogenicity of MSS tumors to finally increase the number of patients benefiting from ICB. Methods: The AVETUX trial aimed to combine the PD-L1 antibody avelumab with the standard of care chemotherapy combination FOLFOX and the anti-EGFR antibody cetuximab. Furthermore, we performed a central radiological review of the pre- and on-treatment computed tomography scans to better define the individual response to treatment. Results and Discussion: In total, 43 patients were treated of which 39 patients were confirmed as RAS/BRAF wildtype in central tissue review and finally response evaluated. A final progression-free survival (PFS) of 11.1 (range: 0.8 to 22.3 months) and a herein updated final overall survival (OS) of 32.9 months (range: 0.8 to 47.1 months) was reached. We observed a strong median depth of response of 67.5% tumor shrinkage and deepness of response correlated significantly with survival. On the other hand, early tumor shrinkage was not an indicator of better outcome at a cut-off of 20% (median values). In a next step, we correlated the individual best radiological response with potential ICB response biomarkers and found that the clonality and diversity, but not frequency of tumor infiltrating lymphocytes (TiLs) and peripheral blood mononuclear cells (PBMCs), strongly correlated with response. In summary, we report the final overall survival of the AVETUX trial and propose T cell clonality and diversity as a potential marker to predict response to chemo-immunotherapy combinations in MSS mCRC by performing a central radiological review. Clinical Trial Registration: ClinicalTrials.gov, identifier (NCT03174405).

Update Breast Cancer 2022 Part 1 - Early Stage Breast Cancer.

Evidence relating to the treatment of breast cancer patients with early-stage disease has increased significantly in the past year. Abemaciclib, olaparib, and pembrolizumab are new drugs with good efficacy in the relevant patient groups. However, some questions remain unanswered. In particular, it remains unclear which premenopausal patients with hormone receptor-positive breast cancer should be spared unnecessary treatment. The question of the degree to which chemotherapy exerts a direct cytotoxic effect on the tumor or reduces ovarian function through chemotherapy could be of key importance. This group of patients could potentially be spared chemotherapy. New, previously experimental biomarker analysis methods, such as spatial analysis of gene expression (spatial transcriptomics) are gradually finding their way into large randomized phase III trials, such as the NeoTRIP trial. This in turn leads to a better understanding of the predictive factors of new therapies, for example immunotherapy. This review summarizes the scientific innovations from recent congresses such as the San Antonio Breast Cancer Symposium 2021 but also from recent publications.

Identification and characterization of human leukocyte antigen class I ligands in renal cell carcinoma cells.

The presentation of tumor antigen-derived peptides by human leukocyte antigen (HLA) class I surface antigens on tumor cells is a key prerequisite to trigger effective T-cell responses in cancer patients. Multiple complementary strategies like cDNA and serological expression cloning, reverse immunology and different 'ome'-based methods have been employed to identify potential T-cell targets. This report focuses on a ligandomic profiling approach leading to the identification of 49 naturally processed HLA class I peptide ligands presented on the cell surface of renal cell carcinoma (RCC) cells. The source proteins of the defined HLA ligands are classified according to their biological function and subcellular localization. Previously established cDNA microarray data of paired tissue specimen of RCC and renal epithelium assessed the transcriptional regulation for 28 source proteins. In addition, HLA-A2-restricted, peptide-specific T cells directed against a HLA ligand derived from sulfiredoxin-1 (SRXN1) were generated, which were able to recognize and lyse ligand-presenting target cells in a HLA class I-restricted manner. Furthermore, tumor-infiltrating T cells isolated from a RCC patient were also able to kill SRXN1 expressing tumor cells. Thus, this experimental strategy might be suited to define potential candidate biomarkers and novel targets for T-cell-based immunotherapies of this disease.