Immune control in chronic myeloid leukemia

Non peer reviewe

T and NK Cell Mediated Immunity in Chronic Myeloid Leukaemia

Chronic myeloid leukaemia (CML) is caused by a translocation between chromosomes 9 and 22. As a result of the translocation Philadelphia chromosome that contains a malignant oncogene is formed. Tyrosine kinase inhibitors (TKIs) target the malignant oncokinase that is produced from the oncogene and drives the development of CML. The prognosis of CML patients has improved significantly after the emergence of the TKI therapy. Some patients can even stop the treatment without imminent disease relapse. However, it has been shown that patients who stay in remission without any treatment still have leukemic cells left. We hypothesised that the immune system is able to keep these cells under control and studied the mechanisms behind immune surveillance by analysing the immune cell phenotype and function in CML patients. The results of this thesis show that the immune system plays a role in the successful discontinuation of the treatment. The results from 3 separate studies suggested that natural killer cells are important in successful treatment discontinuation in CML, and that they might be capable of activating T cells and adaptive immunity to keep leukaemia under control. We further studied the effects of 2nd generation TKI dasatinib, known to have immunomodulatory effects. We observed that dasatinib treatment increased the number of Granzyme B expressing memory CD4+ helper and CD8+ cytotoxic T-cells, which were highly active by secreting interferon (IFN-. We hypothesise that these cells may have a role in the anti-leukaemia immune activity, as IFN- is known to be important in tumour control. The dasatinib induced antitumour immune effects were confirmed in a B16.OVA mouse melanoma model. We were able to demonstrate that dasatinib treatment increases the amount of tumour-infiltrating CD8+ cytotoxic T cells and induces a tumour size reduction dependent on the presence of functional T cells. Taken together, this thesis work illustrates the significance of an active immune system in successful treatment discontinuation in CML. Based on our results it would be important to combine immune activating agents in the future treatment strategies of CML in order to increase the number of patients who are able to successfully discontinue the treatment and be cured.Krooninen myeloinen leukemia (KML) kehittyy, kun kromosomien 9 ja 22 välillä tapahtuu translokaatio. Translokaation seurauksena syntyy Philadelphia kromosomi, joka sisältää pahanlaatuisen fuusio-onkogeenin. Tyrosiinikinaasiestäjät (TKEt) on kehitetty tämän onkogeenin proteiinituotetta vastaan. KML:n ennuste on parantunut huomattavasti TKE hoidon myötä. Osa potilaista pystyy jopa lopettamaan lääkityksen ilman välitöntä tautisolujen lisääntymistä verenkierrossa. Aiemmat tutkimukset ovat kuitenkin näyttäneet, että näillä potilailla on vielä tautisolukkoa jäljellä. Tutkimuksemme hypoteesi on, että immuunijärjestelmä kykenee hallitsemaan jäljellä olevaa tautisolukkoa ja siksi selvitämme imusolujen ilmiasua ja toimintaa KML potilaissa. Tämän väitöstutkimuksen tulokset osoittavat, että toimivalla immuunijärjestelmällä on merkitystä onnistuneen hoidon lopettamisessa. Kolmen erillisen tutkimuksen tulokset viittaavat siihen, että erityisesti luonnolliset tappajasolut (natural killer cells) ovat merkittävässä osassa ja mahdollisesti aktivoivat T soluja ja opittua immuniteettiä toimimaan leukemiaa vastaan. Tämän lisäksi tutkimme toisen polven TKE:llä dasatinibilla hoidettuja KML potilaita. Dasatinibilla on tunnetusti immuunijärjestelmää muokkaavia vaikutuksia. Havaitsimme, että dasatinibihoito lisää Granzyme B:tä sisältävien auttaja ja tappaja T solujen määrää. Lisäksi nämä solut erittivät paljon interferoni- (IFN-). Soluilla voi olla merkitystä leukemian vastaisessa immuunivasteessa, koska IFN- toimii tunnetusti syöpäkasvainta vastaan. Dasatinibihoidon immunoogiset vaikutukset vahvistettiin hiiren B16.OVA melaanomamallilla. Tulokset näyttivät, että dasatinibihoito lisää kasvaimen sisäisten tappaja T-solujen määrää ja saa aikaan T-soluista riippuvan kasvaimen pienenemisen. Tämä väitöstutkimus kuvastaa aktiivisen immuunijärjestelmän merkitystä onnistuneessa hoidon lopetuksessa KML:ssa. Tutkimustuloksiimme perustuen onnistuneen hoidon lopetuksen ja parantumisen mahdollistamiseksi tulevaisuuden hoidoissa olisi tärkeää yhdistää TKE hoito immuunijärjestelmää aktivoiviin hoitoihin

Age-associated changes in the immune system may influence the response to anti-PD1 therapy in metastatic melanoma patients

Anti-PD1 treatment has improved the survival of metastatic melanoma patients, yet it is unknown which patients benefit from the treatment. In this exploratory study, we aimed to understand the effects of anti-PD1 therapy on the patients' immune system and discover the characteristics that would result in successful treatment. We collected peripheral blood (PB) samples from 17 immuno-oncology-naive metastatic melanoma patients before and after 1 and 3 months of anti-PD1 therapy. In addition, matching tumor biopsies at the time of diagnosis were collected for tissue microarray. The complete blood counts, PB immunophenotype, serum cytokine profiles, and tumor-infiltrating lymphocytes were analyzed and correlated with the clinical data. Patients were categorized based on their disease control into responders (complete response, partial response, stable disease > 6 months, N = 11) and non-responders (progressive disease, stable diseasePeer reviewe

T and NK cell abundance defines two distinct subgroups of renal cell carcinoma

Renal cell carcinoma (RCC) is considered as an immunogenic cancer. Because not all patients respond to current immunotherapies, we aimed to investigate the immunological heterogeneity of RCC tumors. We analyzedthe immunophenotype of the circulating, tumor, and matching adjacent healthy kidney immune cells from 52 nephrectomy patients with multi-parameter flow cytometry. Additionally, we studied the transcriptomic and mutation profiles of 20 clear cell RCC (ccRCC) tumors with bulk RNA sequencing and a customized pan-cancer gene panel. The tumor samples clustered into two distinct subgroups defined by the abundance of intratumoral CD3+ T cells (CD3(high), 25/52) and NK cells (NKhigh, 27/52). CD3(high) tumors had an overall higher frequency of tumor infiltrating lymphocytes and PD-1 expression on the CD8+ T cells compared to NKhigh tumors. The tumor infiltrating T and NK cells had significantly elevated expression levels of LAG-3, PD-1, and HLA-DR compared to the circulating immune cells. Transcriptomic analysis revealed increased immune signaling (IFN-gamma, TNF-alpha via NF-kappa B, and T cell receptor signaling) and kidney metabolism pathways in the CD3(high) subgroup. Genomic analysis confirmed the typical ccRCC mutation profile including VHL, PBRM1, and SETD2 mutations, and revealed PBRM1 as a uniquely mutated gene in the CD3(high) subgroup. Approximately half of the RCC tumors have a high infiltration of NK cells associated with a lower number of tumor infiltrating lymphocytes, lower PD-1 expression, a distinct transcriptomic and mutation profile, providing insights to the immunological heterogeneity of RCC which may impact treatment responses to immunological therapies.Peer reviewe

Enlarged Memory T-Cell Pool and Enhanced Th1-Type Responses in Chronic Myeloid Leukemia Patients Who Have Successfully Discontinued IFN-alpha Monotherapy

Peer reviewe

beta 2-Integrin Adhesion Regulates Dendritic Cell Epigenetic and Transcriptional Landscapes to Restrict Dendritic Cell Maturation and Tumor Rejection

Dendritic cells (DC), the classic antigen-presenting cells of the immune system, switch from an adhesive, phagocytic phenotype in tissues, to a mature, nonadhesive phenotype that enables migration to lymph nodes to activate T cells and initiate antitumor responses. Monocyte-derived DCs are used in cancer immunotherapy, but their clinical efficacy is limited. Here, we show that cultured bone marrow-derived DCs (BM-DC) expressing dysfunctional beta 2-integrin adhesion receptors displayed enhanced tumor rejection capabilities in B16.OVA and B16-F10 melanoma models. This was associated with an increased CD8(+) T-cell response. BM-DCs expressing dysfunctional beta 2-integrins or manipulated to disrupt integrin adhesion or integrin/actin/nuclear linkages displayed spontaneous maturation in ex vivo cultures (increased costimulatory marker expression, IL12 production, and 3D migration capabilities). This spontaneous maturation was associated with an altered DC epigenetic/transcriptional profile, including a global increase in chromatin accessibility and H3K4me3/H3K27me3 histone methylation. Genome-wide analyses showed that H3K4me3 methylation was increased on DC maturation genes, such as CD86, Il12, Ccr7, and Fscn1, and revealed a role for a transcription factor network involving Ikaros and RelA in the integrin-regulated phenotype of DCs. Manipulation of the integrin-regulated epigenetic landscape in wild-type ex vivo-cultured BM-DCs enhanced their functionality in tumor rejection in vivo. Thus, beta 2-integrin-mediated adhesion to the extracellular environment plays an important role in restricting DC maturation and antitumor responses through regulation of the cellular epigenetic and transcriptional landscape. Targeting beta 2-integrins could therefore be a new strategy to improve the performance of current DC-based cancer immunotherapies.Peer reviewe

Combined immunodeficiency and hypoglycemia associated with mutations in hypoxia upregulated 1

Non peer reviewe

Immune profiles in acute myeloid leukemia bone marrow associate with patient age, T-cell receptor clonality, and survival

The immunologic microenvironment in various solid tumors is aberrant and correlates with clinical survival. Here, we present a comprehensive analysis of the immune environment of acute myeloid leukemia (AML) bone marrow (BM) at diagnosis. We compared the immunologic landscape of formalin-fixed paraffin-embedded BM trephine samples from AML (n = 69), chronic myeloid leukemia (CML; n = 56), and B-cell acute lymphoblastic leukemia (B-ALL) patients (n 5 52) at diagnosis to controls (n = 12) with 30 immunophenotype markers using multiplex immunohistochemistry and computerized image analysis. We identified distinct immunologic profiles specific for leukemia subtypes and controls enabling accurate classification of AML (area under the curve [AUC] = 1.0), CML (AUC = 0.99), B-ALL (AUC = 0.96), and control subjects (AUC = 1.0). Interestingly, 2 major immunologic AML clusters differing in age, T-cell receptor clonality, and survival were discovered. A low proportion of regulatory T cells and pSTAT(+)cMAF(-) monocytes were identified as novel biomarkers of superior event-free survival in intensively treated AML patients. Moreover, we demonstrated that AML BM and peripheral blood samples are dissimilar in terms of immune cell phenotypes. To conclude, our study shows that the immunologic landscape considerably varies by leukemia subtype suggesting disease-specific immunoregulation. Furthermore, the association of the AML immune microenvironment with clinical parameters suggests a rationale for including immunologic parameters to improve disease classification or even patient risk stratification.Peer reviewe

Divergent roles for antigenic drive in the aetiology of primary versus dasatinib-associated CD8(+) TCR-Vβ(+) expansions

CD8(+) T-cell expansions are the primary manifestation of T-cell large granular lymphocytic leukemia (T-LGLL), which is frequently accompanied by neutropenia and rheumatoid arthritis, and also occur as a secondary phenomenon in leukemia patients treated with dasatinib, notably in association with various drug-induced side-effects. However, the mechanisms that underlie the genesis and maintenance of expanded CD8(+) T-cell receptor (TCR)-V beta(+) populations in these patient groups have yet to be fully defined. In this study, we performed a comprehensive phenotypic and clonotypic assessment of expanded (TCR-V beta(+)) and residual (TCR-V beta(-)) CD8(+) T-cell populations in T-LGLL and dasatinib-treated chronic myelogenous leukemia (CML) patients. The dominant CD8(+) TCR-V beta(+) expansions in T-LGLL patients were largely monoclonal and highly differentiated, whereas the dominant CD8(+) TCR-V beta(+) expansions in dasatinib-treated CML patients were oligoclonal or polyclonal, and displayed a broad range of memory phenotypes. These contrasting features suggest divergent roles for antigenic drive in the immunopathogenesis of primary versus dasatinib-associated CD8(+) TCR-V beta(+) expansions.Peer reviewe

Novel TMEM173 Mutation and the Role of Disease Modifying Alleles

Upon binding to pathogen or self-derived cytosolic nucleic acids cyclic GMP-AMP synthase (cGAS) triggers the production of cGAMP that further activates transmembrane protein STING. Upon activation STING translocates from ER via Golgi to vesicles. Monogenic STING gain-of-function mutations cause early-onset type I interferonopathy, with disease presentation ranging from fatal vasculopathy to mild chilblain lupus. Molecular mechanisms underlying the variable phenotype-genotype correlation are presently unclear. Here, we report a novel gain-of-function G207E STING mutation causing a distinct phenotype with alopecia, photosensitivity, thyroid dysfunction, and features of STING-associated vasculopathy with onset in infancy (SAVI), such as livedo reticularis, skin vasculitis, nasal septum perforation, facial erythema, and bacterial infections. Polymorphism in TMEM173 and IFIH1 showed variable penetrance in the affected family, implying contribution to varying phenotype spectrum. The G207E mutation constitutively activates inflammation-related pathways in vitro, and causes aberrant interferon signature and inflammasome activation in patient PBMCs. Treatment with Janus kinase 1 and 2 (JAK1/2) inhibitor baricitinib was beneficiary for a vasculitic ulcer, induced hair regrowth and improved overall well-being in one patient. Protein-protein interactions propose impaired cellular trafficking of G207E mutant. These findings reveal the molecular landscape of STING and propose common polymorphisms in TMEM173 and IFIH1 as likely modifiers of the phenotype.Peer reviewe