Ibrutinib impairs the phagocytosis of rituximab-coated leukemic cells from chronic lymphocytic leukemia patients by human macrophages

We have read with great interest the recent article of Kohrt, H.E. et al1 showing that Ibrutinib prevented NK cell mediated cytotoxicity of antibody-coated CLL cells in vitro. They also found that the concurrent treatment with Ibrutinib and rituximab or trastuzumab reduces the therapeutic efficacy of both anti-CD20 antibodies in a mouse model, while the sequential treatment with Ibrutinib and rituximab restored its anti-lymphoma activity. Since macrophages are the most important effector cells in CD20-directed cytotoxicity in murine models2,3 and they probably play a key role in human anti-CD20 therapy4,5, we determined whether Ibrutinib interferes the capacity of human macrophages to mediate phagocytosis of rituximab-coated CLL cells. To address this issue, macrophages differentiated from healthy peripheral blood monocytes were treated with or without Ibrutinib for 30 minutes and then cultured for 1, 2 or 3 hours with CFSE-labeled CLL cells or rituximab-coated CFSE-labeled CLL cells. Then, cells were tripsinized and the proportion of macrophages that have taken up CFSE-labeled CLL cells (CFSE+ macrophages) were scored by flow cytometry and verified using confocal microscopy, as previously described6. As expected, we found that the cultures with rituximab-coated CLL cells showed the highest percentage of CFSE+ macrophages, which increase in a time dependent manner (open circles in Figure 1A). Ibrutinib was able to reduce these values in all the times evaluated (solid circles in Figure 1A). Low percentages of CFSE+ macrophages were obtained in cultures with uncoated CLL cells, which were not modified by Ibrutinib (open and solid squares in Figure 1A). In addition, we found that Ibrutinib diminishes the percentage of CFSE+ macrophages in the cultures with rituximab-coated cells in a dose dependent manner (Figure 1B), which was not associated to a decreased viability of the macrophages (not shown). Moreover, the inhibitory effect of Ibrutinib was not limited to rituximab since comparable results were obtained when campath-coated CFSE-labeled CLL cells were employed (Figure 1C). Similar results were found when macrophages from CLL patients were used: mean±SE of the % of CFSE+ macrophages: 26.8 ± 2.1 vs, 17.3 ± 2.7 vs 10.8 ± 0.7 for rituximab-coated CFSE-labeled CLL cells alone, with 0.5μM or 5μM of Ibrutinib (n= 6). Representative dot plots are shown in Figure 1D. The results obtained by flow cytometry analysis were validated by confocal microscopy quantifying the number of macrophages that engulfed at least one tumor target cell (Figure 1E). A representative experiment is shown in Figure 1F. In addition, by performing a binding assay at 4oC, we confirmed that Ibrutinib did not reduce the binding of rituximab-coated CFSE-labeled CLL cells to macrophages (Figure 1G). Interestingly, while the presence of Ibrutinib during the assay impairs the phagocytosis of rituximab-coated CLL cells, when Ibrutinib was washed out, macrophages recovered their phagocytic capacity in a time-dependent manner (Figure 1H). In conclusion we found that the presence of Ibrutinib impairs the phagocytosis of rituximab-opsonized CLL cells by human macrophages, which was restored when the inhibitor was removed from the cultures. Our results, and those obtained by Kohrt et al1 suggest that the sequential administration of Ibrutinib followed by rituximab, and not the concurrent treatment of the patients with these agents, might enhance their anti-tumor activity in vivo.Fil: Borge, Mercedes. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Almejún, María Belén. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Cátedra de Microbiología, Parasitología e Inmunología; ArgentinaFil: Podaza, Enrique Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Colado, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fernández Grecco, Horacio. Sanatorio Municipal Dr. Julio Méndez; ArgentinaFil: Cabrejo, María. Sanatorio Municipal Dr. Julio Méndez; ArgentinaFil: Bezares, Raimundo F.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos ; ArgentinaFil: Giordano, Mirta Nilda. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentin

The Savvidy ``ferromagnetic vacuum'' in three-dimensional lattice gauge theory

The vacuum effective potential of three-dimensional SU(2) lattice gauge theory in an applied color-magnetic field is computed over a wide range of field strengths. The background field is induced by an external current, as in continuum field theory. Scaling and finite volume effects are analyzed systematically. The first evidence from lattice simulations is obtained of the existence of a nontrivial minimum in the effective potential. This supports a ``ferromagnetic'' picture of gluon condensation, proposed by Savvidy on the basis of a one-loop calculation in (3+1)-dimensional QCD.Comment: 9pp (REVTEX manuscript). Postscript figures appende

Neutrophils from chronic lymphocytic leukemia patients exhibit an increased capacity to release extracellular traps (NETs)

Chronic lymphocytic leukemia (CLL) is characterized by immune defects that contribute to a high rate of infections and autoimmune cytopenias. Neutrophils are the first line of innate immunity and respond to pathogens through multiple mechanisms, including the release of neutrophil extracellular traps (NETs). These web-like structures composed of DNA, histones, and granular proteins are also produced under sterile conditions and play important roles in thrombosis and autoimmune disorders. Here we show that neutrophils from CLL patients are more prone to release NETs compared to those from age-matched healthy donors (HD). Increased generation of NETs was not due to higher levels of elastase, myeloperoxidase, or reactive oxygen species production. Instead, we found that plasma from CLL patients was able to prime neutrophils from HD to generate higher amounts of NETs upon activation. Plasmatic IL-8 was involved in the priming effect since its depletion reduced plasma capacity to enhance NETs release. Finally, we found that culture with NETs delayed spontaneous apoptosis and increased the expression of activation markers on leukemic B cells. Our study provides new insights into the immune dysregulation in CLL and suggests that the chronic inflammatory environment typical of CLL probably underlies this inappropriate neutrophil priming.Fil: Podaza, Enrique Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Sabbione, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Risnik, Denise Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Borge, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Almejún, María Belén. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Colado, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fernández Grecco, Horacio. Servicio de Hematología, Sanatorio Municipal Dr. Julio Méndez; ArgentinaFil: Cabrejo, María del Rosario. Servicio de Hematología, Sanatorio Municipal Dr. Julio Méndez; ArgentinaFil: Bezares, Raimundo F.. Servicio de Hematología, Hospital Municipal Dr. Teodoro Alvarez; ArgentinaFil: Trevani, Analía Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: 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; Argentin

Nurse-like cells control the activity of chronic lymphocytic leukemia b cells via galectin-1

Accumulation of neoplastic cells in chronic lymphocytic leukemia (CLL) is conditioned by a variety of signals delivered by accompanying cells in lymphoid tissues. Here we examined the relevance of galectin-1 (Gal-1), a glycan-binding protein with immunoregulatory activity, within the CLL microenvironment. We found that monocytes in peripheral blood and stromal and myeloid cells in bone marrow biopsies are the main source of Gal1. Knocking down Gal1 in adherent nurse-like cells differentiated in vitro decreased the expression of activation markers (CD80, CD86, CD25) and mRNA levels of IL10 and CCL3 in CLL cells. The concentration of Gal1 in plasma was increased in CLL patients compared to healthy subjects. Likewise, we found a higher expression of Gal1 in bone marrow biopsies from patients with progressive disease. These results provide the first evidence of a role for Gal-1 in CLL cell differentiation and its expression in accompanying myeloid cells.Fil: Croci Russo, Diego Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Morande, Pablo Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental; ArgentinaFil: Dergan Dylon, Leonardo Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Borge, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental; ArgentinaFil: Toscano, Marta Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Stupirski, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Bezares, R. F.. Hospital General de Agudos "Dr T. Alvarez"; ArgentinaFil: Avalos, J. S.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Narbaitz, M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental; ArgentinaFil: Rabinovich, Gabriel Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental; Argentin

Expression and function of cathelicidin hCAP18/LL-37 in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of clonal Bcellsin peripheral blood and lymphoid tissues 1. Circulating CLL cells are non-dividing Blymphocytes, but a significant fraction of the clone proliferates in lymphoid tissues wherethey receive a plethora of signals from the microenvironment that promote their survivaland expansion 2. Cathelicidins are a family of proteins with antibacterial functions mainlyexpressed by neutrophils, macrophages and epithelial cells 3. In humans, the only memberof this family, hCAP18, is encoded by the gene CAMP. The cleavage of hCAP18 generatesthe antimicrobial peptide LL-37, which has been recently implicated in the promotion oftumor growth, through direct stimulation of malignant cells, initiation of angiogenesis andrecruitment of immune cells 4. In this study, we investigated the role of hCAP18/LL-37 inCLL.Fil: Podaza, Enrique Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Palacios, Florencia. The Feinstein Institute for Medical Research. Karches Center for Oncology Research; Estados UnidosFil: Croci Russo, Diego Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Risnik, Denise Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Yan, Xiao J.. The Feinstein Institute for Medical Research. Karches Center for Oncology Research; Estados UnidosFil: Almejún, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Colado, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Elías, Esteban Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Borge, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Morande, Pablo Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Bezares, Raimundo F.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Fernández Grecco, Horacio. Sanatorio Municipal Dr. Julio Méndez. Servicio de Hematología; ArgentinaFil: Rabinovich, Gabriel Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Chiorazzi, Nicholas. The Feinstein Institute for Medical Research. Karches Center for Oncology Research; Estados UnidosFil: 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; Argentin

Venetoclax resistance induced by activated T cells can be counteracted by sphingosine kinase inhibitors in chronic lymphocytic leukemia

The treatment of chronic lymphocytic leukemia (CLL) patients with venetoclax-based regimens has demonstrated efficacy and a safety profile, but the emergence of resistant cells and disease progression is a current complication. Therapeutic target of sphingosine kinases (SPHK) 1 and 2 has opened new opportunities in the treatment combinations of cancer patients. We previously reported that the dual SPHK1/2 inhibitor, SKI-II enhanced the in vitro cell death triggered by fludarabine, bendamustine or ibrutinib and reduced the activation and proliferation of chronic lymphocytic leukemia (CLL) cells. Since we previously showed that autologous activated T cells from CLL patients favor the activation of CLL cells and the generation of venetoclax resistance due to the upregulation of BCL-XL and MCL-1, we here aim to determine whether SPHK inhibitors affect this process. To this aim we employed the dual SPHK1/2 inhibitor SKI-II and opaganib, a SPHK2 inhibitor that is being studied in clinical trials. We found that SPHK inhibitors reduce the activation of CLL cells and the generation of venetoclax resistance induced by activated T cells mainly due to a reduced upregulation of BCL-XL. We also found that SPHK2 expression was enhanced in CLL cells by activated T cells of the same patient and the presence of venetoclax selects resistant cells with high levels of SPHK2. Of note, SPHK inhibitors were able to re-sensitize already resistant CLL cells to a second venetoclax treatment. Our results highlight the therapeutic potential of SPHK inhibitors in combination with venetoclax as a promising treatment option for the patients

Work ethics and general work attitudes in adolescents are related to quality of life, sense of coherence and subjective health – a Swedish questionnaire study

BACKGROUND: Working life is an important arena in most people's lives, and the working line concept is important for the development of welfare in a society. For young people, the period before permanent establishment in working life has become longer during the last two decades. Knowledge about attitudes towards work can help us to understand young people's transition to the labour market. Adolescents are the future workforce, so it seems especially important to notice their attitudes towards work, including attitudes towards the welfare system. The aim of this study was to describe and analyse upper secondary school students' work attitudes, and to explore factors related to these attitudes. METHODS: The sample consisted of 606 upper secondary school students. They all received a questionnaire including questions about quality of life (QOL), sense of coherence (SOC), subjective health and attitudes towards work. The response rate was 91%. A factor analysis established two dimensions of work attitudes. Multivariate analyses were carried out by means of logistic regression models. RESULTS: Work ethics (WE) and general work attitudes (GWA) were found to be two separate dimensions of attitudes towards work. Concerning WE the picture was similar regardless of gender or study programme. Males in theoretical programmes appeared to have more unfavourable GWA than others. Multivariate analyses revealed that good QOL, high SOC and good health were significantly related to positive WE, and high SOC was positively related to GWA. Being female was positively connected to WE and GWA, while studying on a practical programme was positively related to GWA only. Among those who received good parental support, GWA seemed more favourable. CONCLUSION: Assuming that attitudes towards work are important to the working line concept, this study points out positive factors of importance for the future welfare of the society. Individual factors such as female gender, good QOL, high SOC and good health as well as support from both parents, positive experience of school and work contacts related positively to attitudes towards work. Further planning and supportive work have to take these factors into account

New Procedures to Make Active, Fractal-Like Surfaces on Thin pd Wires

n/