Evidence for the existence of CLL-specific antigens recognized by the immune system can be gathered from the observation that many patients display monoclonal or oligoclonal expansions and skewed ...repertoire of T cells. In vitro functional studies have shown that tumor-specific T-cells are able to lyse the leukemic cells. Antileukemic cellular immunity may be boosted in vivo using dendritic cell-based immunotherapy. Our preclinical studies provide evidence that DC that had endocytosed apoptotic CLL cells (Apo-DC) were superior to fusion hybrids, tumor lysate or RNA in eliciting antileukemic T-cell responses in vitro. We have validated a method for enriching the small number of monocyte precursors present in the peripheral blood of CLL patients and utilize them for generating individualized, Apo-DC cellular vaccines. In most cases, a minimum of 50 × 10
6
Apo-DC could be generated, beginning with immunomagnetically enriched monocytes from a single leukapheresis product containing at least 1% CD14+ cells. Cryopreservation and thawing did not affect the phenotype or the T cell stimulatory function of Apo-DC. A phase I/II, open label clinical trial examining the feasibility, safety and immunogenicity of Apo-DC vaccination has been initiated. CLL patients receive 10
7
Apo-DC for at least five immunizations and monitored clinically and immunologically for 52 weeks. Three cohorts are accrued stepwise. Cohort I receives Apo-DC alone; Cohort II: Apo-DC+ repeated doses of low-dose GM-CSF; Cohort III: low-dose cyclophosphamide followed by Apo-DC + GM-CSF.
T cells are critical in mediating the early control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infection. However, it remains unknown whether memory T cells can ...effectively cross-recognize new SARS-CoV-2 variants with a broad array of mutations, such as the emergent hypermutated BA.2.86 variant. Here, we report in two separate cohorts, including healthy controls and individuals with chronic lymphocytic leukemia, that SARS-CoV-2 spike-specific CD4+ and CD8+ T cells induced by prior infection or vaccination demonstrate resilient immune recognition of BA.2.86. In both cohorts, we found largely preserved SARS-CoV-2 spike-specific CD4+ and CD8+ T cell magnitudes against mutated spike epitopes of BA.2.86. Functional analysis confirmed that both cytokine expression and proliferative capacity of SARS-CoV-2 spike-specific T cells to BA.2.86-mutated spike epitopes are similarly sustained. In summary, our findings indicate that memory CD4+ and CD8+ T cells continue to provide cell-mediated immune recognition to highly mutated emerging variants such as BA.2.86.
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•SARS-CoV-2 spike-specific T cells are profiled in healthy individuals and CLL patients•T cell cross-recognition of mutated BA.2.86 spike epitopes is largely preserved•BA.2.86-reactive T cells display features of high functional capacity
T cells are critical in controlling SARS-CoV-2 infection. The hypermutated BA.2.86 variant exhibits a range of mutations in the spike protein, potentially facilitating evasion from cellular immunity. Müller et al. demonstrate preserved and functional T cell cross-recognition of mutated BA.2.86 epitopes in healthy individuals and patients with chronic lymphocytic leukemia.
Suboptimal immunity to SARS-CoV-2 mRNA vaccination has frequently been observed in individuals with various immunodeficiencies. Given the increased antibody evasion properties of emerging SARS-CoV-2 ...subvariants, it is necessary to assess whether other components of adaptive immunity generate resilient and protective responses against infection. We assessed T cell responses in 279 individuals, covering five different immunodeficiencies and healthy controls, before and after booster mRNA vaccination, as well as after Omicron infection in a subset of patients. We observed robust and persistent Omicron-reactive T cell responses that increased markedly upon booster vaccination and correlated directly with antibody titers across all patient groups. Poor vaccination responsiveness in immunocompromised or elderly individuals was effectively counteracted by the administration of additional vaccine doses. Functionally, Omicron-reactive T cell responses exhibited a pronounced cytotoxic profile and signs of longevity, characterized by CD45RA
effector memory subpopulations with stem cell-like properties and increased proliferative capacity. Regardless of underlying immunodeficiency, booster-vaccinated and Omicron-infected individuals appeared protected against severe disease and exhibited enhanced and diversified T cell responses against conserved and Omicron-specific epitopes. Our findings indicate that T cells retain the ability to generate highly functional responses against newly emerging variants, even after repeated antigen exposure and a robust immunological imprint from ancestral SARS-CoV-2 mRNA vaccination.
Purpose
Patients with cancer frequently experience chemotherapy-induced anaemia (CIA) and iron deficiency. Erythropoiesis-stimulating agents (ESAs), iron supplementation and blood transfusions are ...available therapies. This study evaluated routine practice in CIA management.
Methods
Medical oncologists and/or haematologists from nine European countries (
n
= 375) were surveyed on their last five cancer patients treated for CIA (
n
= 1,730). Information was collected on tests performed at diagnosis of anaemia, levels of haemoglobin (Hb), serum ferritin and transferrin saturation (TSAT), as well as applied anaemia therapies.
Results
Diagnostic tests and therapies for CIA varied across Europe. Anaemia and iron status were mainly assessed by Hb (94 %) and ferritin (48 %) measurements. TSAT was only tested in 14 %. At anaemia diagnosis, 74 % of patients had Hb ≤10 g/dL, including 15 % with severe anaemia (Hb <8 g/dL). Low-iron levels (ferritin ≤100 ng/mL) were detected in 42 % of evaluated patients. ESA was used in 63 % of patients, blood transfusions in 52 % and iron supplementation in 31 % (74 % oral, 26 % intravenous iron). Only 30 % of ESA-treated patients received a combination of ESA and iron supplementation. Blood transfusions formed part of a regular anaemia treatment regimen in 76 % of transfused patients. Management practices were similar in 2009 and 2011.
Conclusion
Management of anaemia and iron status in patients treated for CIA varies substantially across Europe. Iron status is only assessed in half of the patients. In contrast to clinical evidence, iron treatment is underutilised and mainly based on oral iron supplementation. Implementation of guidelines needs to be increased to minimize the use of blood transfusions.
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent activator of the cell death pathway and exerts tumoricidal activity in vivo with minimal toxicity. In order to investigate ...the therapeutic potential of TRAIL in B chronic lymphocytic leukemia (B-CLL) we have analyzed the expression of TRAIL receptors (TRAIL-Rs) in leukemic cells from B-CLL patients and their in vitro sensitivity to apoptosis induced by recombinant human TRAIL. We have found TRAIL-R1 and -R2 death receptor, and TRAIL-R3 and -R4 decoy receptor mRNA expression in most of the 57 B-CLL patients studied (R1 82%, R2 100%, R3 96% and R4 82%). TRAIL-R1 and R2 proteins were expressed on the surface and within the cells, whereas R3 and R4 decoy receptors were almost exclusively expressed in the cytoplasm. Despite TRAIL death receptor expression, B-CLL cells were relatively resistant to induction of apoptosis by recombinant human TRAIL (300 ng/ml). However, the susceptibility to TRAIL-induced apoptosis was increased by treatment of B-CLL cells with actinomycin D (Act D). Western blot analysis showed higher constitutive expression of the long form of FLICE-inhibitory protein (FLIP(L)) in B-CLL as compared to normal tonsillar B cells. Act D treatment down-regulated both long and short FLIP expression, which was correlated with the increase in B-CLL sensitivity to TRAIL. Although the surface TRAIL death receptor expression was up-regulated both by cell culture and by Act D treatment, the changes were not correlated with a gain in susceptibility to TRAIL. In addition, neither decoy receptors nor Bcl-2 expression were affected by Act D. Our findings suggest the possible involvement of FLIP in regulating TRAIL-mediated apoptosis in B-CLL.
The expression patterns of stimulator of interferon genes (STING) were investigated in a cohort of 158 T- and natural killer (NK)-cell and 265 B-cell non-Hodgkin lymphomas (NHLs), as well as in ...control reactive lymph nodes and tonsils. STING expression was assessed by immunohistochemical methods using diagnostic biopsy specimens obtained prior to treatment. Using an arbitrary 10% cutoff, STING was differentially expressed among T/NK-cell NHLs; positive in 36 out of 38 (95%) cases of ALK+ anaplastic large cell lymphoma (ALCL), 23 out of 37 (62%) ALK-ALCLs, 1 out of 13 (7.7%) angioimmunoblastic T-cell lymphomas, 15 out of 19 (79%) peripheral T-cell lymphomas, not otherwise specified, 20 out of 36 (56%) extranodal NK/T-cell lymphomas of nasal type, 6 out of 7 (86%) T-cell lymphoblastic lymphomas, and 3 out of 4 (75%) mycosis fungoides. STING expression did not correlate with clinicopathological parameters or outcome in these patients with T/NK-cell lymphoma. By contrast, all 265 B-cell NHLs of various types were STING-negative. In addition, STING mRNA levels were very high in 6 out of 7 T-cell NHL cell lines, namely, ALK+ and ALK-ALCL cell lines, and very low or undetectable in 7 B-cell NHL cell lines, suggesting transcriptional downregulation of STING in neoplastic B-cells. At the protein level, using Western blot analysis and immunohistochemistry performed on cell blocks, STING expression was found to be restricted to T-cell NHL cell lines. Taken together, STING expression represents a novel biomarker and therapeutic target in T- and NK-cell lymphomas with direct immunotherapeutic implications since modulators of cGAS-STING activity are already available for clinical use.
The ROR1 receptor tyrosine kinase is expressed in embryonic tissues but is absent in normal adult tissues. ROR1 is of importance in oncogenesis and is overexpressed in several cancers, such as NSCLC. ...In this study, we evaluated ROR1 expression in NSCLC patients (N = 287) and the cytotoxic effects of a small molecule ROR1 inhibitor (KAN0441571C) in NSCLC cell lines. ROR1 expression in tumor cells was more frequent in non-squamous (87%) than in squamous (57%) carcinomas patients, while 21% of neuroendocrine tumors expressed ROR1 (
= 0.0001). A significantly higher proportion of p53 negative patients in the ROR1
group than in the p53 positive non-squamous NSCLC patients (
= 0.03) was noted. KAN0441571C dephosphorylated ROR1 and induced apoptosis (Annexin V/PI) in a time- and dose-dependent manner in five ROR1
NSCLC cell lines and was superior compared to erlotinib (EGFR inhibitor). Apoptosis was confirmed by the downregulation of MCL-1 and BCL-2, as well as PARP and caspase 3 cleavage. The non-canonical Wnt pathway was involved. The combination of KAN0441571C and erlotinib showed a synergistic apoptotic effect. KAN0441571C also inhibited proliferative (cell cycle analyses, colony formation assay) and migratory (scratch wound healing assay) functions. Targeting NSCLC cells by a combination of ROR1 and EGFR inhibitors may represent a novel promising approach for the treatment of NSCLC patients.
Interleukin 4 (IL‐4) is a pleiotropic type II cytokine which has been shown to have a direct killing effect on lymphoma and B‐cell chronic lymphocytic leukaemia (B‐CLL) cells in vitro. The clinical ...effects and toxicity of IL‐4 treatment in patients with B‐CLL were evaluated. Fourteen patients with B‐CLL who were in partial remission after chemotherapy received one, two or three 8‐week cycles of escalating doses (2, 4 or 6 µg/kg/d s.c.) of IL‐4 for 3 d/week. Clinical response was analysed after each treatment cycle and toxicity was monitored continuously. Ten patients (71%) had progressive disease (PD) during IL‐4 treatment. This was mainly attributable to an increase (two‐ to fourfold) of the blood lymphocyte count during IL‐4 therapy. After cessation of IL‐4 treatment, the lymphocytosis decreased spontaneously in 8 out of 12 evaluable patients. Splenomegaly remained unchanged in 7/7 patients, whereas enlarged lymph nodes were reduced by > 50% in 1/13 patients and by 25–50% in 4/13 patients. None of the patients achieved an objective tumour regression (complete or partial remission). A temporary increase (16–60%) of the platelet count was observed during IL‐4 treatment. The platelet count decreased in 8/11 patients after the end of IL‐4 therapy. World Health Organization (WHO) grade I/II fever, arthralgia and fatigue was observed in one‐third of the patients and was more commonly seen with the highest dose (6 µg/kg/d). One patient developed pulmonary oedema and WHO grade III neutropenia was recorded in three patients. IL‐4 was well tolerated by most patients in an outpatient setting. The anti‐tumour activity observed in previous in vitro studies was not verified by the present in vivo trial which showed that IL‐4 may instead increase the number of CLL cells in blood, indicating that IL‐4 may have induced a stimulatory or antiapoptotic effect on the CLL cells in blood. These results may have important implications for the development of immunotherapy of CLL. In addition, the potential platelet‐stimulatory effect of IL‐4 warrants further studies.
The humanized CD52 monoclonal antibody Campath-1H was used as first-line therapy in nine patients with progressive chronic lymphocytic leukaemia (CLL). Intravenous (n = 5) or subcutaneous (n = 4) ...injections (up to 30 mg/inj.) were given three times a week for a maximum of 18 weeks. Three patients achieved a complete remission (CR) and five patients a partial remission (PR) (response rate 89%). CLL cells were cleared from blood in all patients and from the bone marrow in seven patients. The response duration time was 8 + -24+ months. Adverse events were mild except for one patient who developed CMV pneumonitis. All patients developed lymphocytopenia (B and T cells) but other haematological toxicities were negligible. Campath-1H is a highly effective and well-tolerated agent in patients with previously untreated CLL and further studies are warranted.
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