muramidase and Leukemia--Lymphocytic--Chronic--B-Cell

Chronic lymphocytic leukemia (CLL) is a common B-cell malignancy characterized by a highly variable course and outcome. The disease is believed to be driven by B-cell receptor (BCR) signals generated by external antigens and/or cell-autonomous BCR interactions, but direct in vivo evidence for this is still lacking. To further define the role of the BCR pathway in the development and progression of CLL, we evaluated the capacity of different types of antigen/BCR interactions to induce leukemia in the Eμ-TCL1 transgenic mouse model. We show that cell autonomous signaling capacity is a uniform characteristic of the leukemia-derived BCRs and represents a prerequisite for CLL development. Low-affinity BCR interactions with autoantigens generated during apoptosis are also positively selected, suggesting that they contribute to the pathogenesis of the disease. In contrast, high-affinity BCR interactions are not selected, regardless of antigen form or presentation. We also show that the capacity of the leukemic cells to respond to cognate antigen correlates inversely with time to leukemia development, suggesting that signals induced by external antigen increase the aggressiveness of the disease. Collectively, these findings provide in vivo evidence that the BCR pathway drives the development and can influence the clinical course of CLL.

Topics: Amino Acid Sequence; Animals; Antigen Presentation; Autoantigens; Disease Progression; Gene Rearrangement, B-Lymphocyte, Heavy Chain; Gene Rearrangement, B-Lymphocyte, Light Chain; Humans; Leukemia, Experimental; Leukemia, Lymphocytic, Chronic, B-Cell; Mice; Mice, Inbred C57BL; Mice, Transgenic; Molecular Sequence Data; Muramidase; Proto-Oncogene Proteins; Receptors, Antigen, B-Cell; Signal Transduction; snRNP Core Proteins

Chronic lymphocytic leukaemia (CLL) cells convert CD14(+) cells from patients into 'nurse-like' cells (NLCs). CLL cells can also convert CD14(+) peripheral blood mononuclear cells (PBMCs) from healthy donors into cells with morphological similarities to NLCs (CD14(CLL) -cells). However it is unclear whether only CLL cells induce this conversion process. This study showed that CD14(+) PBMCs from healthy donors could also be converted into differentiated cells (CD14(B) -cells) by non-malignant B-cells. In order to identify changes specifically induced by CLL cells, we compared gene expression profiles of NLCs, CD14(CLL) -cells and CD14(B) -cells. CD14(+) cells cultured with CLL cells were more similar to NLCs than those cultured with non-malignant B-cells. The most significant changes induced by CLL cells were deregulation of the antigen presentation pathway and of genes related to immunity. NLCs had reduced levels of lysozyme activity, CD74 and HLA-DR in-vitro while expression of inhibitory FCGR2B was increased. These findings suggest an impaired immunocompetence of NLCs which, if found in-vivo, could contribute to the immunodeficiency in CLL patients.

Topics: Adaptive Immunity; B-Lymphocytes; Cell Differentiation; Coculture Techniques; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; HLA Antigens; Humans; Immunity, Innate; Immunocompetence; Leukemia, Lymphocytic, Chronic, B-Cell; Leukocytes, Mononuclear; Lipopolysaccharide Receptors; Muramidase; Reverse Transcriptase Polymerase Chain Reaction; Tumor Cells, Cultured

We present a case of proliferative fasciitis arising adjacent to an operative scar of the right lower leg of a patient with chronic lymphatic leukemia, diabetes mellitus, and multiple subcutaneous angiolipomas. A 61-year old man had a hard mass in his right lower leg that had rapidly increased in size in the past 10 days. The mass was microscopically composed of a dense proliferation of spindle cells forming interlacing fascicles admixed with an inflammatory infiltrate of lymphocytes and eosionphils, focal hemorrhage, and myxomatous change as typically seen in nodular fasciitis as well as many characteristic ganglion cell-like giant cells. Immunohistochemically, most of the spindle-shaped cells were positive for vimentin and alpha-actin, whereas the ganglion cell-like giant cells were positive for vimentin and negative for alpha-actin and lysozyme. We suggest that the main component cells of proliferative fasciitis are fibroblastic in nature, many of which are myofibroblasts in large part, whereas the ganglion cell-like giant cells are related more closely to fibroblasts rather than histiocytes or pericytes. Additionally, proliferating cell nuclear antigen (PCNA) stain revealed that many of the fibroblastic cells showed high proliferative activity, especially in the hypercellular areas, although there was no significant difference in PCNA staining between the focus traumatized by the needle biopsy and the nontraumatized areas.

Topics: Actins; Angiolipoma; Biopsy, Needle; Cell Division; Cicatrix; Coloring Agents; Diabetes Mellitus; Eosinophils; Fasciitis; Fibroblasts; Giant Cells; Hemorrhage; Histiocytes; Humans; Immunohistochemistry; Leg Dermatoses; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphocytes; Male; Middle Aged; Muramidase; Neoplasms, Multiple Primary; Proliferating Cell Nuclear Antigen; Skin Neoplasms; Vimentin

A grave prognosis is usually associated with leukemic skin infiltrates (leukemia cutis). However, some leukemic skin infiltrates are clinically similar to reactive non-leukemic infiltrates in patients with leukemia; thus it is of great importance to distinguish them. Fifty-four cases which were thought clinically to be leukemia cutis underwent immunophenotyping with a panel of nine T, B, monocytic, and macrophage markers using paraffin sections. Immunohistochemistry helped identify 44 cases with leukemia cutis and 10 with reactive infiltrates. In all cases of leukemia cutis, the staining patterns of skin infiltrates were concordant with cell type in the bone marrow. Furthermore, the panel of markers was usually helpful in distinguishing reactive from leukemia infiltrates, especially in cases with chronic lymphatic leukemia. Immunohistochemistry is a valuable adjunct in histopathologic differentiation of skin infiltrates in most cases of leukemia. With formalin-fixed, paraffin-embedded biopsies, we recommend that CD45 (LCA), CD45RO (UCHL-1), CD3, CD20 (L-26), CD43 (Leu-22), CD68 (KP-1), lysozyme, and chloroacetate esterase be considered in cases of systemic leukemia with cutaneous papules and nodules that prove difficult to interpret with routine section.

Topics: Acute Disease; Adolescent; Adult; Aged; Antigens, CD; Antigens, CD20; Antigens, Differentiation, B-Lymphocyte; Antigens, Differentiation, Myelomonocytic; Biomarkers, Tumor; Biopsy; Bone Marrow; CD3 Complex; Cell Movement; Dermatitis; Female; Humans; Immunohistochemistry; Leukemia; Leukemia, Lymphocytic, Chronic, B-Cell; Leukemic Infiltration; Leukocyte Common Antigens; Leukosialin; Lymphocytes, Tumor-Infiltrating; Macrophages; Male; Middle Aged; Muramidase; Paraffin; Sialoglycoproteins; Skin; Staining and Labeling

An in vitro model was used to investigate the potential for different structural forms of endogenous antigen to be processed and presented by major histocompatibility complex class II molecules. For this purpose the class II-restricted presentation of an immunodominant epitope of hen egg lysozyme [HEL-(46-61)] was studied in class II-positive B-lymphoma cells (M12.C3) transfected with genes encoding HEL molecules either (i) secreted in high (hi) or low (lo) amounts as soluble antigen [sHEL(hi/lo)], (ii) localized within the endoplasmic reticulum (ER)/salvage compartment (ER-HEL), or (iii) anchored on the cell surface as an integral membrane protein (mHEL). The corresponding sHEL, ER-HEL, and mHEL gene products were expressed as predicted except that HEL determinants accumulated in the culture supernatant as well as on the cell membrane of mHEL-transfected cells. Class II-positive cells endogenously expressing all three forms of HEL antigen constitutively presented the immunodominant HEL-(46-61) determinant with differential efficiency (mHEL, sHEL greater than ERHEL) to a class II-restricted T hybridoma. A second T hybridoma recognized endogenous HEL-(46-61) determinants constitutively presented on sHEL(hi) and mHEL transfectants but not on sHEL(lo) or ERHEL transfectants. The formation of HEL-(46-61)/I-Ak complexes in the ERHEL and sHEL(lo) transfectants was therefore limiting. Mixing experiments with different antigen-presenting cells indicated that the HEL-(46-61) determinant was derived from endogenous antigen rather than by reuptake of shed or secreted HEL determinants. We conclude that MHC class II molecules can present some antigenic determinants derived from endogenous proteins that are sequestered in the ER/salvage compartment as well as distally transported in the form of secretory or membrane antigens.

Topics: Animals; Antigen-Presenting Cells; Autoantigens; B-Lymphocytes; Cloning, Molecular; Endoplasmic Reticulum; Epitopes; Histocompatibility Antigens Class II; In Vitro Techniques; Leukemia, Lymphocytic, Chronic, B-Cell; Membrane Proteins; Mice; Muramidase; Recombinant Proteins; Solubility; T-Lymphocytes; Transfection; Tumor Cells, Cultured

A comparative study of large cell lymphoma (LCL) (ten B and ten T), Hodgkin's disease (15 cases), and true histiocytic lymphoma (two cases) was undertaken, using formalin-fixed paraffin-embedded tissue sections, a panel of eight antibodies, and one lectin to determine if any particular antibody or immunologic profile could reliably distinguish between these entities. The antibodies used were against Leu-M1, alpha-1-anti-chymotrypsin (alpha-ACT), alpha-anti-trypsin (alpha-AT), lysozyme, kappa, lambda, leukocyte common antigen (LCA), and S-100 protein. The lectin used was peanut agglutinin (PNA). Although Leu-M1 staining was positive in 11 of 15 cases (73%) of Hodgkin's disease, it was also positive in 4 of 10 cases (40%) of T-cell lymphoma, 2 of 10 cases (20%) of B-cell lymphoma, and 1 of 2 cases (50%) of true histiocytic lymphoma. Peanut-agglutinin staining results were similar to Leu-M1. The only staining profile that emerged was the presence of Leu-M1, PNA-, alpha-ACT, and alpha-AT staining in Reed-Sternberg (RS) cells in 11 of 15 cases of Hodgkin's disease. Leu-M1 and its staining pattern is characteristic, but not entirely specific for RS cells, and it was not positive in at least 25% of the cases of Hodgkin's disease in formalin-fixed, paraffin-embedded tissues. The limitations of this antibody and others should be recognized.

Topics: alpha 1-Antichymotrypsin; alpha 1-Antitrypsin; Antigens, Neoplasm; Histocompatibility Antigens; Hodgkin Disease; Humans; Immunoenzyme Techniques; Lectins; Leukemia, Lymphocytic, Chronic, B-Cell; Leukocyte Common Antigens; Lymphoma, Large B-Cell, Diffuse; Muramidase; Peanut Agglutinin; S100 Proteins