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Material complementario: https://www.mdpi.com/article/10.3390/cancers14071676/s1 Clinical and molecular heterogeneity are hallmarks of chronic lymphocytic leukemia (CLL), a neoplasm characterized by accumulation of mature and clonal long-lived CD5 + B-lymphocytes.Mutational status of the IgHV gene of leukemic clones is a powerful prognostic tool in CLL, and it is well established that unmutated CLLs (U-CLLs) have worse evolution than mutated cases. Nevertheless, progression and treatment requirement of patients can evolve independently from the mutational status. Microenvironment signaling or epigenetic changes partially explain this different behavior. Thus, we think that detailed characterization of the miRNAs landscape from patients with different clinical evolution could facilitate the understanding of this heterogeneity. Since miRNAs are key players in leukemia pathogenesis and evolution, we aim to better characterize different CLL behaviors by comparing the miRNome of clinically progressive U-CLLs vs. stable U-CLLs. Our data show up-regulation of miR-26b-5p, miR-106b-5p, and miR-142-5p in progressive cases and indicate a key role for miR-26b-5p during CLL progression. Specifically, up-regulation of miR-26b-5p in CLL cells blocks TGF-B/SMAD pathway by down-modulation of SMAD-4, resulting in lower expression of p21Cip1 kinase inhibitor and higher expression of c-Myc oncogene. This work describes a new molecular mechanism linking CLL progression with TGF-B modulation and proposes an alternative strategy to explore in CLL therapy. ANII: FSGSK_ 1_2017_1_146663

Phosphatidylinositol-3 kinase (PI3K) delta signaling is essential for CLL B cell survival and proliferation. Several PI3K inhibitors are approved for treatment of CLL, but PI3K inhibitor-induced alterations in T cell function have been correlated with immune-related adverse events (irAEs). Zandelisib is a novel selective PI3Kδ inhibitor in clinical development with an intermittent dosing schedule for treatment of B cell malignancies. Here, we investigated the dynamic immunomodulatory properties of zandelisib alone or in combination with BTK inhibitor ibrutinib in normal human T cells, as well as the impact of continuous dosing of zandelisib on effector and regulatory immune cells, irAEs, and survival in a preclinical CLL murine model. Normal human T cells treated ex vivo with zandelisib, ibrutinib, or both were assessed for phenotype and function. A CLL model was initiated by transferring leukemic EμTCL1 splenocytes into syngeneic wildtype recipients. CLL-bearing mice were treated with vehicle or zandelisib (50 mpk bid or 100 mpk qd) for 3 weeks (n=5 per group). Antitumor efficacy, T cell and myeloid subsets in blood, bone marrow and spleen were analyzed. Survival was also observed in a separate cohort of mice treated with zandelisib (100 mpk qd). T cell proliferation was impaired by zandelisib (250nM) and ibrutinib (100 nM) alone, with the combination further reducing T cell proliferation. Zandelisib decreased expression of suppressive markers PD-1, CTLA-4, GITR and CD39 on iTregs; however, no further decrease was observed when zandelisib was combined with ibrutinib. Zandelisib also reduced normal T cell activation and expression of immune checkpoints PD-1 and CTLA-4 on CD4+ T cells and dose dependently inhibited T cell memory differentiation ex vivo, increasing the naïve/central to effector memory ratio. Combination with ibrutinib did not further affect T cell activation, checkpoint expression or memory differentiation. In the CLL murine model, no meaningful difference was seen between bid or qd administration of zandelisib in the reduction of tumor burden (CD19+ CD5+ CLL cells). Zandelisib treatment reduced activated T cells, antigen-experienced T cells, and Tregs. Increased naïve/central to effector memory ratio was observed in treated mice, and PD-1 was downregulated on memory T cells, indicating less T cell exhaustion. Zandelisib decreased macrophages in the spleen but did not impact myeloid-derived suppressor cells. Zandelisib treatment improved survival of CLL-bearing mice significantly when compared to vehicle group (median survival of zandelisib group 140 days vs. 105 days vehicle). In conclusion, zandelisib treatment reduced Tregs, prevented terminal memory differentiation, and T-cell exhaustion—features that have been shown to permit CLL immune evasion—demonstrated antitumor efficacy, and improved overall survival in a preclinical CLL model. Citation Format: Kamira Maharaj, Melanie Mediavilla-Varela, John J. Powers, Sandra Wiley, Angimar Uriepero, Wael Gamal, Kun Jiang, Eva Sahakian, Javier Pinilla-Ibarz. Efficacy and immune profiling of PI3K delta inhibitor zandelisib (ME-401) in a preclinical chronic lymphocytic leukemia (CLL) model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5496.

Introduction. Chronic graft-versus-host disease (cGVHD) can manifest as a complication in patients following allogeneic hematopoietic stem cell transplant resulting in morbidity and mortality. Effective treatment strategies for cGVHD are currently lacking. Ibrutinib, an irreversible BTK inhibitor with activity against several other Tec-family kinases, has been clinically developed for cGVHD treatment due to regulation of pathogenetic B cells and T-cell subsets. Vecabrutinib is a more selective, reversible inhibitor of BTK with a distinct kinase domain interaction, which could result in differentiated safety and activity profiles compared to ibrutinib. Vecabrutinib has the capacity to overcome the C481S mutation that mediates resistance to ibrutinib. Vecabrutinib also also demonstrates activity against ITK, which is expressed in T cells. In this study, we investigated the activity and immune modulation of vecabrutinib treatment in a murine model of sclerodermatous cGVHD. Ibrutinib was utilized for comparison. Methods. A murine model of sclerodermatous cGVHD was initiated by adoptive transfer of T-cell depleted bone marrow plus whole splenocytes from B10.D2 donors into BALB/c recipients that were previously subjected to sub-lethal irradiation. Total bone marrow and irradiation only groups were included as controls. Mice with established cGVHD characterized by weight loss and skin irritation symptoms were treated with vecabrutinib once daily at 50mg/kg by oral gavage or ibrutinib at 30mg/kg in drinking water 5 days per week for approximately 3 weeks beginning on day 27 post-adoptive transfer and ending on day 45 (n=10 mice per group). Body weight and clinical symptoms (appearance, activity, skin symptoms, diarrhea, conjunctivitis) were measured throughout the study. Immunophenotyping for B cells and T cells was performed on spleens collected from euthanized mice by flow cytometry at two timepoints (day 40 during treatment and on day 76 post-treatment). Levels of circulating immunoglobulins were measured by multiplex cytokine assay at both timepoints. Results. Clinical symptoms, including appearance, activity, skin irritation, redness, alopecia and diarrhea were significantly reduced in vecabrutinib- and ibrutinib-treated groups. Furthermore, there was a trend toward a more favorable clinical score overall for the vecabrutinib-treated group, however no statistical difference was observed compared to ibrutinib possibly due to small sample size. Weight loss was slightly elevated during vecabrutinib and ibrutinib treatment compared to vehicle (trend), however mice recovered body weight post-treatment and continued to maintain benefit. On day 40 (during treatment) and day 76 (post-treatment) groups of mice were euthanized for immunophenotyping analysis utilizing a 22-color flow cytometry panel. During treatment, both vecabrutinib and ibrutinib-treated mice retained total B cell numbers but exhibited reduced B-cell activation, proliferation, and number of B220+ CD138+ plasma cells. In addition, B cells secreted less IL-10, and IL-4/5. Expression of antigen-presentation molecules CD80 and CD86 on B cells were unchanged. Total CD3+ T cells, activated and proliferating CD4+ and CD8+ T cells, and cytotoxic granzyme-B+ CD8+ T cells were reduced in treated mice. Interestingly, CD4+ CD25+ FoxP3+ Treg number, expression of PD-1 on Tregs and CD4+ CXCR5+ PD-1+ T follicular helper cells were also reduced in both treatment groups. In addition, there were globally reduced numbers of cytokine-secreting CD4+ cells but no differences in Th1/Th2 or Th17/Treg ratios were observed. Post-treatment, proliferation and cytokine secretion of B cells and T cells were still lowered but less impaired than during treatment. Tregs and PD-1 expression were still reduced post-treatment. Finally, circulating levels of IgA were reduced during and post treatment in vecabrutinib-treated mice compared to vehicle, while IgG1, IgG2b were reduced in both treated groups. No changes in IgM levels were observed in either treatment group. In conclusion, vecabrutinib treatment demonstrated efficacy and beneficially regulated B cell and T cell immune subsets in a preclinical murine model of sclerodermatous cGVHD. Studies to further evaluate differences between vecabrutinib and ibrutinib treatment are ongoing. Figure 1 Figure 1. Disclosures Fox: Sunesis Pharmaceuticals: Current Employment. Taverna: Sunesis Pharmaceuticals: Current Employment. Pinilla Ibarz: Sellas: Other: ), patents/royalties/other intellectual property; MEI, Sunesis: Research Funding; AbbVie, Janssen, AstraZeneca, Takeda: Speakers Bureau; AbbVie, Janssen, AstraZeneca, Novartis, TG Therapeutics, Takeda: Consultancy, Other: Advisory.

Activation-induced cytidine deaminase (AID) initiates somatic hypermutation and class switch recombination of the immunoglobulin genes. As a trade-off for its physiological function, AID also contributes to tumor development through its mutagenic activity. In chronic lymphocytic leukemia (CLL), AID is overexpressed in the proliferative fractions (PFs) of the malignant B lymphocytes, and its anomalous expression has been associated with a clinical poor outcome. Recent preclinical data suggested that ibrutinib and idelalisib, 2 clinically approved kinase inhibitors, increase AID expression and genomic instability in normal and neoplastic B cells. These results raise concerns about a potential mutagenic risk in patients receiving long-term therapy. To corroborate these findings in the clinical setting, we analyzed AID expression and PFs in a CLL cohort before and during ibrutinib treatment. We found that ibrutinib decreases the CLL PFs and, interestingly, also reduces AID expression, which correlates with dampened AKT and Janus Kinase 1 signaling. Moreover, although ibrutinib increases AID expression in a CLL cell line, it is unable to do so in primary CLL samples. Our results uncover a differential response to ibrutinib between cell lines and the CLL clone and imply that ibrutinib could differ from idelalisib in their potential to induce AID in treated patients. Possible reasons for the discrepancy between preclinical and clinical findings, and their effect on treatment safety, are discussed. Fil: Morande, Pablo Elías. Instituto Pasteur de Montevideo; Uruguay. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Sivina, Mariela. University of Texas Health Science Center at Houston. University of Texas Md Anderson Cancer Center; Estados Unidos Fil: Uriepero, Angimar. Instituto Pasteur de Montevideo; Uruguay Fil: Seija, Noé. Instituto Pasteur de Montevideo; Uruguay Fil: Berca, Catalina. Instituto Pasteur de Montevideo; Uruguay Fil: Fresia, Pablo. Instituto Pasteur de Montevideo; Uruguay Fil: Landoni, Ana Inés. Ministerio de Salud.Hospital Maciel. Administración de los Servicios de Salud del Estado; Uruguay Fil: Di Noia, Javier M.. University of Montreal; Canadá. Cliniques de Montreal. Institut de Recherches. Division of Immunity and Viral Infections; Canadá Fil: Burger, Jan A.. University of Texas Health Science Center at Houston. University of Texas Md Anderson Cancer Center; Estados Unidos Fil: Oppezzo, Pablo. Instituto Pasteur de Montevideo; Uruguay

Lipoprotein lipase (LPL) mRNA expression in chronic lymphocytic leukaemia (CLL) is associated with an unmutated immunoglobulin profile and poor clinical outcome. We evaluated the subcellular localization of LPL protein in CLL cells that did or did not express LPL mRNA. Our results show that LPL protein is differently located in CLL cells depending on whether it is incorporated from the extracellular medium in mutated CLL or generated de novo by leukaemic cells of unmutated patients. The specific quantification of endogenous LPL protein correlates with mRNA expression levels and mutational IGHV status, suggesting LPL protein as a possible reliable prognostic marker in CLL. Fil: Prieto, Daniel. Instituto Pasteur de Montevideo; Uruguay. Instituto de Investigaciones Biológicas "Clemente Estable"; Uruguay Fil: Seija, Noé. Universidad de la República; Uruguay. Instituto Pasteur de Montevideo; Uruguay Fil: Uriepero, Angimar. Instituto Pasteur de Montevideo; Uruguay Fil: Souto-Padron, Thais. Universidade Federal do Rio de Janeiro; Brasil Fil: Oliver, Carolina. Universidad de la República; Uruguay Fil: Irigoin, Victoria. Universidad de la República; Uruguay Fil: Guillermo, Cecilia. Universidad de la República; Uruguay Fil: Navarrete, Marcelo A.. Universidad de Magallanes; Chile Fil: Inés Landoni, Ana. Ministerio de Salud. Administración Servicios de Salud del Estado. Hospital Maciel; Uruguay Fil: Dighiero, Guillermo. Ministerio de Salud. Administración Servicios de Salud del Estado. Hospital Maciel; Uruguay Fil: Gabus, Raúl. Ministerio de Salud. Administración Servicios de Salud del Estado. Hospital Maciel; Uruguay Fil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina Fil: Oppezzo, Pablo. Instituto Pasteur de Montevideo; Uruguay

Contains fulltext : 170058.pdf (Publisher’s version ) (Open Access) OBJECTIVES: Acceptance of childhood vaccination varies between societies, affecting worldwide vaccination coverage. Low coverage rates are common in indigenous populations where parents often choose not to vaccinate their children. We aimed to gain insight into reasons for vaccine acceptance or rejection among Warao Amerindians in Venezuela. METHODS: Based on records of vaccine acceptance or refusal, in-depth interviews with 20 vaccine-accepting and 11 vaccine-declining caregivers were performed. Parents' attitudes were explored using a qualitative approach. RESULTS: Although Warao caregivers were generally in favor of vaccination, fear of side effects and the idea that young and sick children are too vulnerable to be vaccinated negatively affected vaccine acceptance. The importance assigned to side effects was related to the perception that these resembled symptoms/diseases of another origin and could thus harm the child. Religious beliefs or traditional healers did not influence the decision-making process. CONCLUSIONS: Parental vaccine acceptance requires educational programs on the preventive nature of vaccines in relation to local beliefs about health and disease. Attention needs to be directed at population-specific concerns, including explanation on the nature of and therapeutic options for side effects.