Lymphoplasmacyte-rich meningioma with hematologic signs and PD-L1 over-expression

Lymphoplasmacyte-rich meningioma (LPRM) is one of the rarest variants of grade I meningiomas. It can be clinically associated with prominent peripheral blood abnormalities, anemia, and/or various gammopathy, which usually disappear after surgical removal of the tumor. We document a case of right frontal LPRM in a 72-year-old male who presented general cognitive decadence. The patient suffered from mild anemia. The LPRM is a rare variant of meningioma, with only a few cases globally reported in the literature. It has been categorized as a grade I tumor in the 2021 World Health Organization (WHO) classification central nervous system. Due to the rarity, this meningioma variant origin and biological behavior are still not clear. Immunohistochemistry profile showed prominent PD-L1 expression, leading to additional interrogation on LPRM immunomorphological characteristics, the significance of the inflammatory tumoral microenvironment and its correlation with the immune-checkpoints

Antibodies to adhesion molecules inhibit the lytic function of MHC-unrestricted cytotoxic cells by preventing their activation.

We evaluated the effect of the antibodies to adhesion molecules CD2, CD11a/CD18 (LFA-1), and CD56 (N-CAM) on MHC-unrestricted cytotoxicity mediated by polyclonal NK cells and LAK cells or by CD3+ or CD3- cytolytic cell clones against a panel of tumor cell targets selected according to expression or absence of the corresponding ligands. We show that (i) antibodies to CD11a/CD18 and, to a lesser extent, antibodies to CD2 inhibit target cell lysis, whereas anti-CD56 antibodies exert little if any effect; (ii) in a model system using polyclonal NK/LAK cells as effectors and K562 or HL60-R (NK-resistant) cells as targets, inhibition of cytotoxicity occurs without a significant impairment of effector to target cell binding; (iii) the cytotoxic function of CD3+ or CD3- cytotoxic cell clones is inhibited differentially by antibodies to adhesion molecules; (iv) conjugates formed in the presence of antibodies which inhibit target cell lysis display a significant reduction of target to effector cell contact surface; and (v) this may lead to defective activation of effector cells, as indicated by lack of redistribution of the microtubular apparatus. We conclude that (i) MHC-unrestricted cytotoxicity is regulated by a number of molecular interactions that span far beyond our present knowledge and that it is strictly dependent on the surface phenotype of the effector cell and of the target cell; (ii) in certain types of effector/target cell interactions, antibodies to adhesion molecules do not prevent conjugate formation but reduce the extent of cell-to-cell surface contact which, in turn, leads to defective activation of the effector cell and, therefore, to inhibition of target cell lysis

MiR-146b-5p regulates IL-23 receptor complex expression in chronic lymphocytic leukemia cells

Chronic lymphocytic leukemia (CLL) cells express the interleukin-23 receptor (IL-23R) chain, but the expression of the complementary IL-12R(31 chain requires cell stimulation via surface CD40 molecules (and not via the B-cell receptor [BCR]). This stimulation induces the expression of a heterodimeric functional IL-23R complex and the secretion of IL-23, initiating an autocrine loop that drives leukemic cell expansion. Based on the observation in 224 untreated Binet stage A patients that the cases with the lowest miR-146b-5p concentrations had the shortest time to first treatment (TTFT), we hypothesized that miR-146b-5p could negatively regulate IL-12R(31 side chain expression and clonal expansion. Indeed, miR-146b-5p significantly bound to the 3 '-UTR region of the IL-12R(31 mRNA in an in vitro luciferase assay. Downregulation of miR-146b-5p with specific miRNA inhibitors in vitro led to the upregulation of the IL-12R(31 side chain and expression of a functional IL-23R complex similar to that observed after stimulation of the CLL cell through the surface CD40 molecules. Expression of miR-146b-5p with miRNA mimics in vitro inhibited the expression of the IL-23R complex after stimulation with CD40L. Administration of a miR-146b-5p mimic to NSG mice, successfully engrafted with CLL cells, caused tumor shrinkage, with a reduction of leukemic nodules and of IL-12R(31-positive CLL cells in the spleen. Our findings indicate that IL-12R(31 expression, a crucial checkpoint for the functioning of the IL-23 and IL-23R complex loop, is under the control of miR-146b-5p, which may represent a potential target for therapy since it contributes to the CLL pathogenesis. This trial is registered at www.clinicaltrials.gov as NCT00917540

Microenvironmental regulation of the IL-23R/IL-23 axis overrides chronic lymphocytic leukemia indolence

reserved36noAlthough the progression of chronic lymphocytic leukemia (CLL) requires the cooperation of the microenvironment, the exact cellular and molecular mechanisms involved are still unclear. We investigated the interleukin (IL)-23 receptor (IL-23R)/IL-23 axis and found that circulating cells from early-stage CLL patients with shorter time-to-treatment, but not of those with a more benign course, expressed a defective form of the IL-23R complex lacking the IL-12Rb1 chain. However, cells from both patient groups expressed the complete IL-23R complex in tissue infiltrates and could be induced to express the IL-12Rb1 chain when cocultured with activated T cells or CD40L+cells. CLL cells activated in vitro in this context produced IL-23, a finding that, together with the presence of IL-23 in CLL lymphoid tissues, suggests the existence of an autocrine/paracrine loop inducing CLL cell proliferation. Interference with the IL-23R/IL-23 axis using an anti-IL-23p19 antibody proved effective in controlling disease onset and expansion in xenografted mice, suggesting potential therapeutic strategies.mixedCutrona, Giovanna*; Tripodo, Claudio; Matis, Serena; Recchia, Anna Grazia; Massucco, Carlotta; Fabbi, Marina; Colombo, Monica; Emionite, Laura; Sangaletti, Sabina; Gulino, Alessandro; Reverberi, Daniele; Massara, Rosanna; Boccardo, Simona; De Totero, Daniela; Salvi, Sandra; Cilli, Michele; Pellicanò, Mariavaleria; Manzoni, Martina; Fabris, Sonia; Airoldi, Irma; Valdora, Francesca; Ferrini, Silvano; Gentile, Massimo; Vigna, Ernesto; Bossio, Sabrina; De Stefano, Laura; Palummo, Angela; Iaquinta, Giovanni; Cardillo, Martina; Zupo, Simonetta; Cerruti, Giannamaria; Ibatici, Adalberto; Neri, Antonino; Fais, Franco; Ferrarini, Manlio; Morabito, FortunatoCutrona, Giovanna; Tripodo, Claudio; Matis, Serena; Recchia, Anna Grazia; Massucco, Carlotta; Fabbi, Marina; Colombo, Monica; Emionite, Laura; Sangaletti, Sabina; Gulino, Alessandro; Reverberi, Daniele; Massara, Rosanna; Boccardo, Simona; De Totero, Daniela; Salvi, Sandra; Cilli, Michele; Pellicanò, Mariavaleria; Manzoni, Martina; Fabris, Sonia; Airoldi, Irma; Valdora, Francesca; Ferrini, Silvano; Gentile, Massimo; Vigna, Ernesto; Bossio, Sabrina; De Stefano, Laura; Palummo, Angela; Iaquinta, Giovanni; Cardillo, Martina; Zupo, Simonetta; Cerruti, Giannamaria; Ibatici, Adalberto; Neri, Antonino; Fais, Franco; Ferrarini, Manlio; Morabito, Fortunat