No abstract

Key Points CLL patients harboring mutated IGHV genes but neither 11q or 17p deletion experience durable remission after frontline FCR.

Monoclonal antibody (MoAb)-based therapies have opened innovative treatment avenues that have impacted on the management of patients with both neoplastic and non-neoplastic hematological diseases. The aim of our study was to evaluate in a large series of cases of acute lymphoblastic leukemia (ALL) the expression of specific antigens, CD19, CD20, CD22, and CD33, for which MoAbs are available for clinical use. For each antigen, evaluation was based on the percentage of positive leukemic cells and the degree of antigen expression by mean fluorescence intensity (MFI) and antibody binding capacity (ABC) that were correlated with age, immunophenotype, and presence/absence of particular molecular markers. We can document that some of the analyzed antigens showed a degree of expression related to the B-cell maturation profile, and that the antigen expression intensity appeared to vary according to the presence of specific genetic markers. These findings suggest that the possible clinical use of a given MoAb in patients with ALL should take into account both the maturation profile of the leukemic cells and the presence of a given molecular transcript. Only clinical studies will conclusively demonstrate whether the differences in antigenic expression truly correlate with the different therapeutic efficacies of the various clinical grade MoAbs.

Background:Epithelial-to-mesenchymal transition (EMT) has a central role in cancer progression and metastatic dissemination and may be induced by local inflammation. We asked whether the inflammation-induced acquisition of mesenchymal phenotype by neoplastic epithelial cells is associated with the onset of mesenchymal stromal cell-like immune-regulatory properties that may enhance tumour immune escape.Methods:Cell lines of lung adenocarcinoma (A549), breast cancer (MCF7) and hepatocellular carcinoma (HepG2) were co-cultured with T, B and NK cells before and after EMT induction by either the supernatant of mixed-lymphocyte reactions or inflammatory cytokines.Results:EMT occurrence following inflammatory priming elicited multiple immune-regulatory effects in cancer cells resulting in NK and T-cell apoptosis, inhibition of lymphocyte proliferation and stimulation of regulatory T and B cells. Indoleamine 2,3-dioxygenase, but not Fas ligand pathway, was involved at least in part in these effects, as shown by the use of specific inhibitors.Conclusions:EMT induced by inflammatory stimuli confers to cancer cells some mesenchymal stromal cell-like immune-modulatory properties, which could be a cue for cancer progression and metastatic dissemination by favouring immune escape.

The role of neutrophils as key players in the regulation of innate and adaptive immune responses is increasingly being recognized. We report that human neutrophils establish a network with both natural killer (NK) cells and 6-sulfo LacNAc ؉ dendritic cells (slanDCs), which ultimately serves to up-regulate NK-derived interferon␥ (IFN␥). This network involves direct reciprocal interactions and positive amplification loops mediated by cellderived cytokines. Accordingly, we show that after lipopolysaccharide ؉ interleu- IntroductionPolymorphonuclear neutrophil leukocytes are known as "professional" phagocytic cells of the innate immune system. However, numerous observations regarding their capacity to respond to and produce a wide variety of cytokines and chemotactic molecules and to change phenotype under specific circumstances also position them as key regulators of various cross talks. 1,2 The outcome(s) of potential interactions between neutrophils and other leukocytes, including macrophages, monocyte-derived dendritic cells (DCs), and T lymphocytes, have been addressed in recent studies [3][4][5][6] and reveal that neutrophils may participate in shaping not only the innate but also the adaptive immune response. 7 For example, activated neutrophils were shown to recruit T-helper 17 (Th17) cells 8 and to trigger T-cell proliferation and strong Th1-cell responses by inducing the maturation of monocyte-derived DCs in in vitro cocultures. 9 Natural killer (NK) cells are effector lymphocytes of the innate immune system endowed with cytotoxic and cytokine-producing capacities, typically recognized for their role in cancer immunosurveillance and pathogen clearance. 10 Although NK cells can directly recognize some pathogens, it is becoming increasingly clear that NK-cell activation requires the presence of accessory cells 11 such as monocytes, 12-14 macrophages, 15,16 and DCs. 17,18 While recent evidence for a potential role of neutrophils in NK-cell activation has been found in mice, 19 it remains unknown whether human neutrophils exert similar effects. Early investigations have focused on a putative inhibitory function of human neutrophils directed toward the cytotoxic activity of cocultured NK cells, 20,21 whereas most subsequent research has delineated the suppressive role of neutrophil-derived reactive oxygen species on NK-cell survival, expression of selected activating receptors, and cytotoxic activity. 22,23 It should also be emphasized that the neutrophil preparations used in most of these studies were not pure (containing approximately 5% of contaminant cells), which might well explain some of the controversial results. 20,21 Based on these premises, we examined whether human neutrophils can activate NK cells either by functioning as and/or modulating the activity of accessory cells. We report that neutrophils potently enhance the release of interferon␥ (IFN␥) by NK cells when cocultured with 6-sulfo LacNAc ϩ dendritic cells (slanDCs), but not CD1c ϩ DCs or plasmacytoid DCs (pDCs), in the presence of lipopoly...

It is increasingly evident that neutrophils are able to cross-talk with other leukocytes to shape ongoing inflammatory and immune responses. In this study, we analyzed whether human NK cells may influence the survival and activation of neutrophils under co-culture conditions. We report that NK cells exposed to either IL-15 or IL-18 alone strongly protect the survival of neutrophils via the release of IFNγ and granulocyte macrophage colony-stimulating factor (GM-CSF) plus IFNγ, respectively, and cause a slight up-regulation of neutrophil CD64 and CD11b expression. In comparison, NK cells exposed to both IL-15 and IL-18 show a lesser ability to increase the survival of neutrophils but can more potently up-regulate CD64 and CD11b expression, as well as induce the de novo surface expression of CD69, in neutrophils. Analysis of the events occurring in neutrophil/NK co-cultures exposed to IL-15 plus IL-18 revealed that (i) neutrophil survival is positively affected by NK-derived GM-CSF but negatively influenced by a CD18-dependent neutrophil/NK contact, (ii) NK-derived IFNγ is almost entirely responsible for the induction of CD64, (iii) both soluble factors (primarily GM-CSF) and direct cell-cell contact up-regulate CD11b and CD69 and (iv) NK-derived GM-CSF induces the expression of biologically active heparin-binding EGF-like growth factor (HB-EGF) in neutrophils. Finally, we demonstrate that NK cells can also express HB-EGF when stimulated with either IL-2 or IL-15, yet independently of endogenous GM-CSF. Altogether, our results define a novel interaction within the innate immune system whereby NK cells, by directly modulating neutrophil functions, might contribute to the pathogenesis of inflammatory diseases.

No abstract

No abstract