Activated granulocytes and inflammatory cytokine signaling drive T-cell lymphoma progression and disease symptoms.

Peripheral T-cell lymphomas (PTCLs), especially angioimmunoblastic and follicular TCLs, have a dismal prognosis because of the lack of efficient therapies, and patients' symptoms are often dominated by an inflammatory phenotype, including fever, night sweats, weight loss, and skin rash. In this study, we investigated the role of inflammatory granulocytes and activated cytokine signaling on T-cell follicular helper-type PTCL (TFH-PTCL) disease progression and symptoms. We showed that ITK-SYK-driven murine PTCLs and primary human TFH-PTCL xenografts both induced inflammation in mice, including murine neutrophil expansion and massive cytokine release. Granulocyte/lymphoma interactions were mediated by positive autoregulatory cytokine loops involving interferon gamma (CD4+ malignant T cells) and interleukin 6 (IL-6; activated granulocytes), ultimately inducing broad JAK activation (JAK1/2/3 and TYK2) in both cell types. Inflammatory granulocyte depletion via antibodies (Ly6G), genetic granulocyte depletion (LyzM-Cre/MCL1flox/flox), or IL-6 deletion within microenvironmental cells blocked inflammatory symptoms, reduced lymphoma infiltration, and enhanced mouse survival. Furthermore, unselective JAK inhibitors (ruxolitinib) inhibited both TCL progression and granulocyte activation in various PTCL mouse models. Our results support the important role of granulocyte-driven inflammation, cytokine-induced granulocyte/CD4+ TCL interactions, and an intact JAK/STAT signaling pathway for TFH-PTCL development and also support broad JAK inhibition as an effective treatment strategy in early disease stages.

Long-term robustness of a T-cell system emerging from somatic rescue of a genetic block in T-cell development.

BACKGOUND: The potential of a single progenitor cell to establish and maintain long-term protective T-cell immunity in humans is unknown. For genetic disorders disabling T-cell immunity, somatic reversion was shown to support limited T-cell development attenuating the clinical phenotype. However, the cases reported so far deteriorated over time leaving unanswered the important question of long-term activity of revertant precursors and the robustness of the resulting T-cell system. METHODS: We applied TCRß-CDR3 sequencing and mass cytometry on serial samples of a now 18 year-old SCIDX1 patient with somatic reversion to analyse the longitudinal diversification and stability of a T-cell system emerging from somatic gene rescue. FINDINGS: We detected close to 105 individual CDR3ß sequences in the patient. Blood samples of equal size contained about 10-fold fewer unique CDR3ß sequences compared to healthy donors, indicating a surprisingly broad repertoire. Despite dramatic expansions and contractions of individual clonotypes representing up to 30% of the repertoire, stable diversity indices revealed that these transient clonal distortions did not cause long-term repertoire imbalance. Phenotypically, the T-cell system did not show evidence for progressive exhaustion. Combined with immunoglobulin substitution, the limited T-cell system in this patient supported an unremarkable clinical course over 18 years. INTERPRETATION: Genetic correction in the appropriate cell type, in our patient most likely in a T-cell biased self-renewing hematopoietic progenitor, can yield a diverse T-cell system that provides long-term repertoire stability, does not show evidence for progressive exhaustion and is capable of providing protective and regulated T-cell immunity for at least two decades. FUNDING: DFG EH 145/9-1, DFG SCHW 432/4-1 and the German Research Foundation under Germany's Excellence Strategy-EXC-2189-Project ID: 390939984.

γδ T-cell Receptors Derived from Breast Cancer-Infiltrating T Lymphocytes Mediate Antitumor Reactivity.

γδ T cells in human solid tumors remain poorly defined. Here, we describe molecular and functional analyses of T-cell receptors (TCR) from tumor-infiltrating γδ T lymphocytes (γδ TIL) that were in direct contact with tumor cells in breast cancer lesions from archival material. We observed that the majority of γδ TILs harbored a proinflammatory phenotype and only a minority associated with the expression of IL17. We characterized TCRγ or TCRδ chains of γδ TILs and observed a higher proportion of Vδ2+ T cells compared with other tumor types. By reconstructing matched Vδ2- TCRγ and TCRδ pairs derived from single-cell sequencing, our data suggest that γδ TILs could be active against breast cancer and other tumor types. The reactivity pattern against tumor cells depended on both the TCRγ and TCRδ chains and was independent of additional costimulation through other innate immune receptors. We conclude that γδ TILs can mediate tumor reactivity through their individual γδ TCR pairs and that engineered T cells expressing TCRγ and δ chains derived from γδ TILs display potent antitumor reactivity against different cancer cell types and, thus, may be a valuable tool for engineering immune cells for adoptive cell therapies.

Molecular detection of human T-lymphotropic virus type 1 infection among oncology patients in Germany: A retrospective view.

Human T-cell lymphotropic virus (HTLV) belongs to a larger group of primate T-cell lymphotropic viruses (PTLVs) within the family Retroviridae. It is estimated that 10 to 20 million people worldwide may be infected with HTLV-1. Although most of them are asymptomatic, around 5% of infected individuals may develop either HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) or Adult T-cell Leukaemia/Lymphoma (ATLL). Public Health authorities in many countries have implemented routine blood-donor tests for HTLV-specific antibodies; but this is not the case for Germany since the reported prevalence is very low (7/100,000). With the aim to evaluate retrospectively the presence of HTLV-1 among oncology patients in this country, samples stored at the Universitätsklinikum Freiburg, were analyzed. For this purpose, two different nested-PCR (n-PCR) protocols have been modified and set up for HTLV-1 detection. One positive case was detected by n-PCR among 406 samples (0,25%) in a period of 5 years (2008-2012) corresponding to a T-Cell Lymphoma. Despite the low prevalence, this virus is circulating in Germany, probably due to the increasing numbers of immigrants in these last years. Physicians should consider HTLV-1 infection and suspect it taking in account the ethnic and relation to endemic regions regardless the patient's residence.

Anti-CD3 Fab Fragments Enhance Tumor Killing by Human γδ T Cells Independent of Nck Recruitment to the γδ T Cell Antigen Receptor.

T lymphocytes expressing the γδ T cell receptor (γδ TCR) can recognize antigens expressed by tumor cells and subsequently kill these cells. γδ T cells are indeed used in cancer immunotherapy clinical trials. The anti-CD3ε antibody UCHT1 enhanced the in vitro tumor killing activity of human γδ T cells by an unknown molecular mechanism. Here, we demonstrate that Fab fragments of UCHT1, which only bind monovalently to the γδ TCR, also enhanced tumor killing by expanded human Vγ9Vδ2 γδ T cells or pan-γδ T cells of the peripheral blood. The Fab fragments induced Nck recruitment to the γδ TCR, suggesting that they stabilized the γδ TCR in an active CD3ε conformation. However, blocking the Nck-CD3ε interaction in γδ T cells using the small molecule inhibitor AX-024 neither reduced the γδ T cells' natural nor the Fab-enhanced tumor killing activity. Likewise, Nck recruitment to CD3ε was not required for intracellular signaling, CD69 and CD25 up-regulation, or cytokine secretion by γδ T cells. Thus, the Nck-CD3ε interaction seems to be dispensable in γδ T cells.

Dysregulated CD25 and Cytokine Expression by γδ T Cells of Systemic Sclerosis Patients Stimulated With Cardiolipin and Zoledronate.

Objectives: γδ T cells, a non-conventional innate lymphocyte subset containing cells that can be activated by lipids and phosphoantigens, are abnormally regulated in systemic sclerosis (SSc). To further evaluate the significance of this dysregulation, we compared how exposure to an autoantigenic lipid, cardiolipin (CL), during co-stimulation with an amino-bisphosphonate (zoledronate, zol), affects the activation and cytokine production of SSc and healthy control (HC) γδ T cells. Methods: Expression of CD25 on Vγ9+, Vδ1+, and total CD3+ T cells in cultured peripheral blood mononuclear cells (PBMCs), their binding of CD1d tetramers, and the effect of monoclonal antibody (mAb) blockade of CD1d were monitored by flow cytometry after 4 days of in vitro culture. Intracellular production of IFNγ and IL-4 was assessed after overnight culture. Results: Percentages of CD25+ among CD3+ and Vδ1+ T cells were elevated significantly in short-term cultured SSc PBMC compared to HC. In SSc but not HC, CL and zol, respectively, suppressed %CD25+ Vγ9+ and Vδ1+ T cells but, when combined, CL + zol significantly activated both subsets in HC and partially reversed inhibition by the individual reagents in SSc. Importantly, Vδ1+ T cells in both SSc and HC were highly reactive with lipid presenting CD1d tetramers, and a CD1d-blocking mAb decreased CL-induced enhancement of %SSc CD25+ Vδ1+ T cells in the presence of zol. %IFNγ+ cells among Vγ9+ T cells of SSc was lower than HC cultured in medium, CL, zol, or CL + zol, whereas %IFNγ+ Vδ1+ T cells was lower only in the presence of CL or CL + zol. %IL-4+ T cells were similar in SSc and HC in all conditions, with the exception of being increased in SSc Vγ9+ T cells in the presence of CL. Conclusion: Abnormal functional responses of γδ T cell subsets to stimulation by CL and phosphoantigens in SSc may contribute to fibrosis and immunosuppression, characteristics of this disease.

Large cell neuroendocrine lung carcinoma induces peripheral T-cell repertoire alterations with predictive and prognostic significance.

OBJECTIVES: This study was performed to evaluate for a potentially important role of T cells in the pathophysiology and treatment sensitivity of large cell neuroendocrine lung carcinoma (LCNEC), an orphan disease with poor prognosis and scarce data to guide novel therapeutic strategies. MATERIALS AND METHODS: We performed T-cell receptor (TCR) ß-chain spectratyping on blood samples of patients treated within the CRAD001KDE37 trial (n = 35) using age-matched current or former (n = 11) and never smokers (n = 10) as controls. The data were analyzed in conjunction with the complete blood counts of the probands as well as the data about response to treatment and overall survival in the clinical trial. RESULTS AND CONCLUSION: Untreated stage IV LCNEC patients had significant T-cell repertoire alterations (p < 0.001) compared to age-matched smokers. These changes correlated positively with blood lymphocyte counts (r = 0.49, p < 0.01), suggesting antigen-induced T-cell proliferation as the causative mechanism. At the same time, LCNEC patients showed mild lymphopenia (1.54 vs. 2.51/nl in median, p < 0.01), which reveals a second, antigen-independent mechanism of systemic immune dysregulation. More pronounced T-cell repertoire alterations and higher blood lymphocyte counts at diagnosis were associated with a better treatment response by RECIST and with a longer overall survival (441 vs. 157 days in median, p = 0.019). A higher degree of T-cell repertoire normalization after 3 months of therapy also distinguished a patient group with more favourable prognosis (median overall survival 617 vs. 316 days, p = 0.036) independent of radiological response. Thus, LCNEC induces clinically relevant changes of the T-cell repertoire, which are measurable in the blood and could be exploited for prognostic, predictive and therapeutic purposes. Their pathogenesis appears to involve antigen-induced oligoclonal T-cell expansions superimposed on TCR-independent lymphopenia.

Morphology of Immunomodulation in Breast Cancer Tumor Draining Lymph Nodes Depends on Stage and Intrinsic Subtype.

Cancer research of immune-modulating mechanisms mainly addresses the role of tumor-infiltrating immune cells. Mechanisms modulating the adaptive immune system at the primary activation site - the draining lymph node (LN) - are less investigated. Here we present tumor-caused histomorphological changes in tumor draining LNs of breast cancer patients, dependent on the localization (sentinel LN vs. non-sentinel LN), the tumor size, the intrinsic subtype and nodal metastatic status. The quantitative morphological study was conducted in breast cancer patients with at least one sentinel LN and no neoadjuvant therapy. All LNs were annotated considering to their topographical location, stained for IgD/H&E, digitized and quantitatively analyzed. In 206 patients, 394 sentinels and 940 non-sentinel LNs were categorized, comprising 40758 follicles and 7074 germinal centers. Subtype specific immunomorphological patterns were detectable: Follicular density was higher in LNs of Her2 enriched hormone receptor positive and triple-negative breast cancers whereas hormone receptor positive breast cancers showed more macrophage infiltrations in the LN cortex. Follicles are rounder in metastatic LNs and non-sentinel LNs. The identified immunomorphological changes reflect different underlying immunomodulations taking place in the tumor-draining LNs and should therefore be considered as possible prognostic and predictive markers for LN metastasis and therapy associated immunomodulation.

Prognostic relevance of tumor-infiltrating lymphocytes and immune checkpoints in pediatric medulloblastoma.

Pediatric medulloblastomas are the most frequently diagnosed embryonal tumors of the central nervous system. Current therapies cause severe neurological and cognitive side effects including secondary malignancies. Cellular immunotherapy might be key to improve survival and to avoid morbidity. Efficient killing of tumor cells using immunotherapy requires to overcome cancer-associated strategies to evade cytotoxic immune responses. Here, we examined the immune response and immune evasion strategies in pediatric medulloblastomas. Cytotoxic T-cells, infiltrating medulloblastomas with variable activation status, showed no correlation with overall survival of the patients. We found limited numbers of PD1+ T-cells and complete absence of PD-L1 on medulloblastomas. Medulloblastomas downregulated immune recognition molecules MHC-I and CD1 d. Intriguingly, expression of granzyme inhibitors SERPINB1 and SERPINB4 was acquired in 23% and 50% of the tumors, respectively. Concluding, pediatric medulloblastomas exploit multiple immune evasion strategies to overcome immune surveillance. Absence of PD-L1 expression in medulloblastoma suggest limited or no added value for immunotherapy with PD1/PD-L1 blockers.

Immunological considerations underlying heat shock protein-mediated cancer vaccine strategies.

The success of active immunotherapies in the prevention of many infectious diseases over the course of over 200 years has lead scientists to wonder if the same principles could be applied to cancer. Antigen-specific active immunotherapies for the treatment of cancer have been researched for over two decades, however, the overwhelming majority of these studies have failed to stimulate robust clinical responses. It is clear that current active immunotherapy research should incorporate methods to increase the immunostimulatory capacity of these therapies. To directly address this need, we propose the addition of the immunostimulatory heat shock proteins (HSPs) to active immunotherapeutic strategies to augment their efficacy. Heat shock proteins are a family of highly conserved intracellular chaperone proteins, and are the most abundant family proteins inside cells. This ubiquity, and their robust immunostimulatory capacity, points to their importance in regulation of intracellular processes and, therefore, indicators of loss of cellular integrity if found extracellularly. Thus, we emphasize the importance of taking into consideration the location of vaccine-derived HSP/tumor-antigen complexes when designing active immunotheraputic strategies.

Protein-losing pseudomembranous colitis with cap polyposis-like features.

Protein-losing enteropathy (PLE) is characterized by loss of serum proteins into the gastrointestinal tract. It may lead to hypoproteinemia and clinically present as protein deficiency edema, ascites, pleural or pericardial effusion and/or malnutrition. In most cases the site of protein loss is the small intestine. Here we present an unusual case of severe PLE in a 55-year old female with a one-year history of recurrent diarrhea, crampy abdominal pain, and peripheral edema. Endoscopy and MRI showed a diffuse inflammatory thickening of the sigmoid colon and the rectum. Surgical resection of the involved colon was performed and the symptoms were significantly resolved. The final histologic evaluation confirmed a diagnosis of a pseudomembranous colitis with cap polyposis-like features. Such a cause of PLE has never been described before.

Improved analysis of TCRγδ variable region expression in humans.

Deeper understanding of γδ Τ cell increases in various clinical situations requires the assessment of TCRγ and δ variable (V) region gene expression and junctional diversity. Here we describe an improved TCRγ and δ spectratyping method used to study the γδ T-cell expansions in two patients with thymoma and immunodeficiency. One of these patients also suffered from chronic CMV infection and pure red cell aplasia and the other from chronic visceral leishmaniasis and myasthenia gravis. Analyses of the junctional diversity of the TCRγ and δ chains, flow cytometry with a panel of non-commercially available anti-TCRγδ V region monoclonal antibodies and functional studies were performed. The results clearly distinguished an expansion of oligoclonal, most likely antigen-driven, cytotoxic γδ T cells in the first patient from a naive pattern of polyclonal γδ T-cell proliferation in the second. These findings demonstrate the diversity of γδ T-cell expansions in immunodeficient patients and highlight the value of spectratyping as a tool for their characterization and understanding of the underlying mechanisms.

B-cell signaling in persistent polyclonal B lymphocytosis (PPBL).

Persistent polyclonal B lymphocytosis (PPBL) is a benign hematological disorder characterized by a selective expansion of circulating polyclonal marginal zone (MZ)-like B cells. Previous reports demonstrated that cases of PPBL showed poor activation, proliferation and survival of B cells in vitro, yet the underlying defect remains unknown. Here we report for the first time an attenuated activation of the canonical NF-κB (nuclear factor of kappa light polypeptide gene enhancer in B cells) and mitogen-activated protein kinase/extracellular signal-regulated kinase pathway after CD40 stimulation. This defect was selective, as alternative NF-κB signaling after CD40 stimulation and both B-cell receptor- and Toll-like receptor 9-mediated activation remained unaffected. Reduced canonical NF-κB activation resulted in decreased IκBα and CD40 expression in resting cells. In PPBL patients, expression of Bcl-xL in MZ-like B cells did not increase upon activation, consistent with the high apoptosis rates of PPBL-derived B cells that were observed in vitro. The B-cell phenotype of mice with selective knockouts of early components of the CD40 signaling pathway resembles PPBL, but sequencing corresponding genes in sorted MZ-like B cells of PPBL patients did not reveal relevant genetic alterations. Nevertheless, the frequently observed mutations in early signaling components of the NF-κB pathway in MZ lymphomas underline the relevance of our findings for the pathogenesis of PPBL.

Pediatric Primitive Neuroectodermal Tumors of the Central Nervous System Differentially Express Granzyme Inhibitors.

BACKGROUND: Central nervous system (CNS) primitive neuroectodermal tumors (PNETs) are malignant primary brain tumors that occur in young infants. Using current standard therapy, up to 80% of the children still dies from recurrent disease. Cellular immunotherapy might be key to improve overall survival. To achieve efficient killing of tumor cells, however, immunotherapy has to overcome cancer-associated strategies to evade the cytotoxic immune response. Whether CNS-PNETs can evade the immune response remains unknown. METHODS: We examined by immunohistochemistry the immune response and immune evasion strategies in pediatric CNS-PNETs. RESULTS: Here, we show that CD4+, CD8+, γδ-T-cells, and Tregs can infiltrate pediatric CNS-PNETs, although the activation status of cytotoxic cells is variable. Pediatric CNS-PNETs evade immune recognition by downregulating cell surface MHC-I and CD1d expression. Intriguingly, expression of SERPINB9, SERPINB1, and SERPINB4 is acquired during tumorigenesis in 29%, 29%, and 57% of the tumors, respectively. CONCLUSION: We show for the first time that brain tumors express direct granzyme inhibitors (serpins) as a potential mechanism to overcome cellular cytotoxicity, which may have consequences for cellular immunotherapy.

Disturbed B-lymphocyte selection in autoimmune lymphoproliferative syndrome.

Fas is a transmembrane receptor involved in the maintenance of tolerance and immune homeostasis. In murine models, it has been shown to be essential for deletion of autoreactive B cells in the germinal center. The role of Fas in human B-cell selection and in development of autoimmunity in patients carrying FAS mutations is unclear. We analyzed patients with either a somatic FAS mutation or a germline FAS mutation and somatic loss-of-heterozygosity, which allows comparing the fate of B cells with impaired vs normal Fas signaling within the same individual. Class-switched memory B cells showed: accumulation of FAS-mutated B cells; failure to enrich single V, D, J genes and single V-D, D-J gene combinations of the B-cell receptor variable region; increased frequency of variable regions with higher content of positively charged amino acids; and longer CDR3 and maintenance of polyreactive specificities. Importantly, Fas-deficient switched memory B cells showed increased rates of somatic hypermutation. Our data uncover a defect in B-cell selection in patients with FAS mutations, which has implications for the understanding of the pathogenesis of autoimmunity and lymphomagenesis of autoimmune lymphoproliferative syndrome.

Acquired T-Cell Immunodeficiency in Thymoma Patients.

Acquired T-cell immunodeficiency can occur in thymoma patients with or without hypogammaglobulinemia (Good's syndrome), but it has received little attention to date. It appears predominantly associated with lymphocyte-rich (i.e., cortical or mixed) thymomas and frequently coexists with autoimmune manifestations. The main abnormalities are an increase in circulating naive T cells, cutaneous T-cell anergy, TCR hyporesponsiveness in vitro as well as a numerical and functional impairment of regulatory T cells. All of these probably result from an abnormal T-cell maturation in the neoplastic thymic microenvironment. A better understanding of thymoma-related acquired T-cell immunodeficiency will be important for immunotherapy of this orphan disease as well as for the prevention and treatment of opportunistic infections, autoimmune complications and secondary malignancies that contribute to the morbidity and mortality of thymoma patients.

DCLRE1C (ARTEMIS) mutations causing phenotypes ranging from atypical severe combined immunodeficiency to mere antibody deficiency.

Null mutations in genes involved in V(D)J recombination cause a block in B- and T-cell development, clinically presenting as severe combined immunodeficiency (SCID). Hypomorphic mutations in the non-homologous end-joining gene DCLRE1C (encoding ARTEMIS) have been described to cause atypical SCID, Omenn syndrome, Hyper IgM syndrome and inflammatory bowel disease-all with severely impaired T-cell immunity. By whole-exome sequencing, we investigated the molecular defect in a consanguineous family with three children clinically diagnosed with antibody deficiency. We identified perfectly segregating homozygous variants in DCLRE1C in three index patients with recurrent respiratory tract infections, very low B-cell numbers and serum IgA levels. In patients, decreased colony survival after irradiation, impaired proliferative response and reduced counts of naïve T cells were observed in addition to a restricted T-cell receptor repertoire, increased palindromic nucleotides in the complementarity determining regions 3 and long stretches of microhomology at switch junctions. Defective V(D)J recombination was complemented by wild-type ARTEMIS protein in vitro. Subsequently, homozygous or compound heterozygous DCLRE1C mutations were identified in nine patients from the same geographic region. We demonstrate that DCLRE1C mutations can cause a phenotype presenting as only antibody deficiency. This novel association broadens the clinical spectrum associated with ARTEMIS mutations. Clinicians should consider the possibility that an immunodeficiency with a clinically mild initial presentation could be a combined immunodeficiency, so as to provide appropriate care for affected patients.