Chronic lymphocytic leukemia (CLL) is IntroductionThe most common leukemia among white adults, B-cell chronic lymphocytic leukemia (CLL), remains incurable and its pathogenesis poorly defined. 1 Currently no system permits differentiation and long-term growth of CLL cells in vitro; therefore, an in vivo animal model that reproducibly supports engraftment and growth of human CLL cells would help elucidate key features of CLL cell biology and lead to better treatments.Previous attempts to engraft human CLL cells into mice have been hampered for 2 reasons. First, xenogeneic recipients were not sufficiently immune deficient to prevent human cell rejection. [2][3][4][5] Although Dü rig et al 5 successfully transferred CLL cells into nonobese diabetes/severe combined immunodeficiency (NOD/SCID) mice, apparently the level of CLL cell growth was not sufficient to correlate kinetics with essential interactions with different cell subpopulations. Second, optimal engraftment and growth may have been impaired by the inability of a murine microenvironment to support CLL cells in vivo. Indeed, in vitro studies suggest at least 3 cell lineages are involved in CLL survival and growth: lymphoid (T cells 6,7 ), myeloid (monocytes and monocyte-derived nurse-like cells 8 ), and mesenchymal ("stromal cells" 9,10 ).To provide a more physiologic microenvironment for CLL cells within highly immune incompetent recipients, we introduced precursors of human hematopoietic and mesenchymal lineages into NOD/Shi-scid,␥c null (NSG) mice, a NOD/SCID-derived strain that lacks the IL-2 family common cytokine receptor gamma chain gene (␥c), rendering animals completely deficient in lymphocytes, including natural killer (NK) cells. We found activated autologous T cells were essential for leukemia cells to successfully engraft, survive, and proliferate in vivo and to recapitulate cardinal features of human CLL cells: kinetics, CD38 expression, and growth in secondary lymphoid tissues. This adoptive transfer model may facilitate the definition of leukemic and nonleukemic elements involved in the interactions and kinetics of CLL cells in patients. Methods Patients and samplesThe Institutional Review Board and the Institutional Animal Care and Utilization Committee of the North Shore-LIJ Health System sanctioned these studies. After obtaining informed consent, in accordance with the Submitted December 10, 2010; accepted February 17, 2011. Prepublished online as Blood First Edition paper, March 8, 2011 DOI 10.1182 DOI 10. /blood-2010 An Inside Blood analysis of this article appears at the front of this issue.The online version of this article contains a data supplement.The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked ''advertisement'' in accordance with 18 USC section 1734. For personal use only. on June 7, 2019. by guest www.bloodjournal.org From Declaration of Helsinki, we collected blood from 37 CLL patients for whom clinical information, la...

The antibody that we identified was detected in most patients with autoimmune pancreatitis but also in some patients with pancreatic cancer, making it an imperfect test to distinguish between these two conditions.

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Cytotoxic T lymphocyte antigen-4 (CTLA-4) is the major negative regulator of T-cell responses, although growing evidence supports its wider role as an immune attenuator that may also act in other cell lineages. Here, we have analyzed the expression of CTLA-4 in human monocytes and monocyte-derived dendritic cells (DCs), and the effect of its engagement on cytokine production and T-cell stimulatory activity by mature DCs. CTLA-4 was highly expressed on freshly isolated monocytes, then down-modulated upon differentiation toward immature DCs (iDCs) and it was markedly upregulated on mature DCs obtained with different stimulations (lipopolysaccharides [LPS], Poly:IC, cytokines). In line with the functional role of CTLA-4 in T cells, treatment of mDCs with an agonistic anti-CTLA-4 mAb significantly enhanced secretion of regulatory interleukin (IL)-10 but reduced secretion of IL-8/IL-12 pro-inflammatory cytokines, as well as autologous CD4+ T-cell proliferation in response to stimulation with recall antigen purified protein derivative (PPD) loaded-DCs. Neutralization of IL-10 with an anti-IL-10 antibody during the mDCs-CD4+ T-cell co-culture partially restored the ability of anti-CTLA-4-treated mDCs to stimulate T-cell proliferation in response to PPD. Taken together, our data provide the first evidence that CTLA-4 receptor is expressed by human monocyte-derived mDCs upon their full activation and that it exerts immune modulatory effects.