CD200 is a transmembrane molecule with an important immunoregulatory role that is overexpressed on most chronic lymphocytic leukemia (CLL) cells. In this study, we characterized a previously unknown soluble form of this molecule in human plasma termed sCD200. Levels of sCD200 were elevated in the plasma of patients with CLL as compared with healthy controls, and there was a significant correlation with CLL disease stage. Infusion of sCD200hi CLL plasma into severely immunocompromised NOD.SCIDγcnull (NSG) mice enhanced the engraftment of CLL splenocytes as compared with mice receiving sCD200lo normal plasma. CLL cells were detected in both the spleen and peritoneal cavity of animals for up to 75 days. Engraftment of CLL cells did not occur after infusion of CLL plasma depleted of sCD200 and was abolished in mice treated with anti-CD200 or OKT3 monoclonal antibody (mAb), suggesting a role for both sCD200 and T cells in CLL engraftment. Notably, anti-CD200 mAb was as effective as rituximab in eliminating engrafted CLL cells when administered 21 days after engraftment. Taken together, our findings point to sCD200 as a novel prognostic marker and therapeutic target for CLL. Furthermore, the humanized mouse model described here may prove valuable to preclinically assess new treatment regimens for CLL. Cancer Res; 72(19); 4931–43. ©2012 AACR.

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Progress in whole-genome sequencing using short-read (e.g., <150 bp), next-generation sequencing technologies has reinvigorated interest in high-resolution physical mapping to fill technical gaps that are not well addressed by sequencing. Here, we report two technical advances in DNA nanotechnology and single-molecule genomics: (1) we describe a labeling technique (CRISPR-Cas9 nanoparticles) for high-speed AFM-based physical mapping of DNA and (2) the first successful demonstration of using DVD optics to image DNA molecules with high-speed AFM. As a proof of principle, we used this new “nanomapping” method to detect and map precisely BCL2–IGH translocations present in lymph node biopsies of follicular lymphoma patents. This HS-AFM “nanomapping” technique can be complementary to both sequencing and other physical mapping approaches.

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Bone marrow examination has become increasingly important for the diagnosis and treatment of hematologic and other illnesses. Morphologic evaluation of the bone marrow aspirate and biopsy has recently been supplemented by increasingly sophisticated ancillary assays, including immunocytochemistry, cytogenetic analysis, flow cytometry, and molecular assays. With our rapidly expanding knowledge of the clinical and biologic diversity of leukemia and other hematologic neoplasms, and an increasing variety of therapeutic options, the bone marrow examination has became more critical for therapeutic monitoring and planning optimal therapy. Sensitive molecular techniques, in vitro drug sensitivity testing, and a number of other special assays are available to provide valuable data to assist these endeavors. Fortunately, improvements in bone marrow aspirate and needle technology has made the procurement of adequate specimens more reliable and efficient, while the use of conscious sedation has improved patient comfort. The procurement of bone marrow specimens was reviewed in the first part of this series. This paper specifically addresses the diagnostic interpretation of bone marrow specimens and the use of ancillary techniques.

Killer immunoglobulin-like receptor (KIR) and KIR-ligand (KIRL) interactions play an important role in natural killer (NK) cell mediated graft versus leukemia effect following hematopoietic cell transplantation (HCT). However, there is considerable heterogeneity in the KIR gene and KIRL content in individuals, making it difficult to estimate the full clinical impact of NK cell reconstitution following HCT.Herein a novel mathematical model designed to quantify these interactions is presented to better assess the influence of NK cell-mediated alloreactivity on transplant outcomes. Ninety-eight HLA matched unrelated donor (URD) HCT recipients were retrospectively studied. The KIR-KIRL interactions were quantified using a system of matrix equations. Unit values were ascribed to each KIR-KIRL interaction and directionality of interactions was denoted by, either a positive (activating) or negative symbol (inhibition); these interactions were then summed. The absolute values of both the missing KIRL as well as inhibitory KIR-KIRL interactions were significantly associated with overall survival and relapse. These score components were initially used to develop a weighted (w-KIR Score) and subsequently a simplified, non-weighted KIR-KIRL interaction scores (IM-KIR Score). Increased w-KIR Score and IM-KIR Score were both predictive of all-cause mortality and relapse; w-KIR score HR of 0.37 (P=0.001) and 0.44 (P=0.044) respectively; IM-KIR score HR of 0.5 (P=0.049) and 0.44 (P=0.002) respectively. IM-KIR score was also associated with NK cell reconstitution post HCT. KIR-KIRL interactions as reflected by the w-KIR and IM-KIR scores influence both relapse risk and survival in recipients of HLA matched URD HCT with hematological malignancies..

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