Università della Svizzera italiana

Dependence of immunoglobulin class switch recombination in B Cells on vesicular release of ATP and CD73 ectonucleotidase activity

Schena, Francesca ; Volpi, Stefano ; Faliti, Caterina Elisa ; Penco, Federica ; Santi, Spartaco ; Proietti, Michele ; Schenk, Ursula ; Damonte, Gianluca ; Salis, Annalisa ; Bellotti, Marta ; Fais, Franco ; Tenca, Claudya ; Gattorno, Marco ; Eibel, Hermann ; Rizzi, Marta ; Warnatz, Klaus ; Idzko, Marco ; Ayata, Cemil Korcan ; Rakhmanov, Mirzokhid ; Galli, Thierry ; Martini, Alberto ; Canossa, Marco ; Grassi, Fabio ; Traggiai, Elisabetta

In: Cell report, 2013, vol. 3, no. 6, p. 1824-1831

Immunoglobulin (Ig) isotype diversification by class switch recombination (CSR) is an essential process for mounting a protective humoral immune response. Ig CSR deficiencies in humans can result from an intrinsic B cell defect; however, most of these deficiencies are still molecularly undefined and diagnosed as common variable immunodeficiency (CVID). Here, we show that extracellular...

Università della Svizzera italiana

Selective preservation of bone marrow mature recirculating but not marginal zone B cells in murine models of chronic inflammation

Traggiai, Elisabetta ; Casati, Anna ; Frascoli, Michela ; Porcellini, Simona ; Ponzoni, Maurilio ; Sanvito, Francesca ; Leng, Lin ; Bucala, Richard ; Moretta, Lorenzo ; Grassi, Fabio

In: Plos one, 2010, vol. 5, no. 6, p. e11262

Inflammation promotes granulopoiesis over B lymphopoiesis in the bone marrow (BM). We studied B cell homeostasis in two murine models of T cell mediated chronic inflammation, namely calreticulin-deficient fetal liver chimeras (FLC), which develop severe blepharitis and alopecia due to T cell hyper responsiveness, and inflammatory bowel disease (IBD) caused by injection of CD4+ naïve T cells...

Università della Svizzera italiana

Homeostatic expansion of autoreactive immunoglobulin-secreting cells in the Rag2 mouse model of Omenn syndrome

Cassani, Barbara ; Poliani, Pietro Luigi ; Marrella, Veronica ; Schena, Francesca ; Sauer, Aisha V. ; Ravanini, Maria ; Strina, Dario ; Busse, Christian E. ; Regenass, Stephan ; Wardemann, Hedda ; Martini, Alberto ; Facchetti, Fabio ; Burg, Mirjam van der ; Rolink, Antonius G. ; Vezzoni, Paolo ; Grassi, Fabio ; Traggiai, Elisabetta ; Villa, Anna

In: Journal of experimental medicine, 2010, vol. 207, no. 7, p. 1525-1540

Hypomorphic RAG mutations, leading to limited V(D)J rearrangements, cause Omenn syndrome (OS), a peculiar severe combined immunodeficiency associated with autoimmune-like manifestations. Whether B cells play a role in OS pathogenesis is so far unexplored. Here we report the detection of plasma cells in lymphoid organs of OS patients, in which circulating B cells are undetectable. Hypomorphic...

Università della Svizzera italiana

P2X7 receptor restrains pathogenic Tfh cell generation in systemic lupus erythematosus

Faliti, Caterina E. ; Gualtierotti, Roberta ; Rottoli, Elsa ; Gerosa, Maria ; Perruzza, Lisa ; Romagnani, Andrea ; Pellegrini, Giovanni ; De Ponte Conti, Benedetta ; Rossi, Riccardo L. ; Idzko, Marco ; Mazza, Emilia M.C. ; Bicciato, Silvio ; Traggiai, Elisabetta ; Meroni, Pier Luigi ; Grassi, Fabio

In: Journal of Experimental Medicine, 2019, vol. 216, no. 2, p. 317-336

Altered control of T follicular helper (Tfh) cells can lead to generation of autoantibodies and autoimmune manifestations. Signaling pathways that selectively limit pathogenic responses without affecting the protective function of Tfh cells are unknown. Here we show that the ATP-gated ionotropic P2X7 receptor restricts the expansion of aberrant Tfh cells and the generation of self-reactive...