CD34 + progenitors from MDS patients are unresponsive to SDF-1, despite high levels of SDF-1 in bone marrow plasma

Fractalkine (CX3CL1) and its receptor CX3CR1 play an important role in natural killer (NK) cell- and cytotoxic T cell-mediated endothelium damage. Here we describe the cytotoxicity of myelodysplastic syndrome (MDS)-derived T cell line, K2-MDS, through the fractalkine–CX3CR1 system. K2-MDS cells induced apoptosis against CD34+ cells from normal bone marrow (BM) in a direct cell contact manner. K2-MDS cells expressed perforin and granzyme B, but they lacked Fas ligand expression. A specific inhibitor for perforin, concanamycin A, blocked K2-MDS-dependent cytotoxicity. Furthermore, a CX3C-chemokine, fractalkine, was expressed in CD34+ cells, and its receptor, CX3CR1, was expressed on K2-MDS cells. The neutralizing monoclonal antibody (MoAb) for fractalkine and soluble fractalkine significantly inhibited K2-MDS-dependent cytotoxicity. K2-MDS cells also induced the cytotoxicity against human umbilical cord endothelial cells (HUVECs) expressing fractalkine. These data indicate that K2-MDS may be a perforin–granzyme-positive T cell line that exerts a cytotoxic effect on CD34+ cells mediated through the fractalkine–CX3CR1 system.

Classical Hodgkin's disease (HD) is characterized by rare neoplastic Hodgkin and Reed-Sternberg (H-RS) cells within abundant reactive cellular backgrounds. In most cases, H-RS cells originate from the B-cell lineage, but their immunophenotypes are unusual. Here we newly found frequent expression of chemokine receptors CXCR6 and CCR10 and their respective ligands CXCL16 and CCL28 in HD-derived cell lines. CCR10 is known to be selectively expressed by plasma cells, whereas CCL28 attracts eosinophils via CCR3 and plasma cells via CCR10 and CCR3. Therefore, we examined their expression in HD tissues by immunohistochemistry. We found that H-RS cells in 15 of 19 cases were positive for CCL28. Among them, seven cases were also positive for CCR10, suggesting a potential autocrine effect. In situ hybridization confirmed the expression of CCL28 mRNA in H-RS cells. The CCL28 positivity in H-RS cells did not significantly correlate with that of LMP-1, CCL17, CCL22, or CCL11. However, it significantly correlated with the background accumulation of eosinophils, plasma cells, and CCR10+ cells. Thus, the production of CCL28 by H-RS cells may play a major role in tissue accumulation of eosinophils and/or plasma cells in classical HD. The frequent expression of CCR10 in H-RS cells themselves also supports their close relationship to plasma cells.

The pattern of bacterial infections and antimicrobial susceptibility has changed significantly during the past 20-30 years. The causative organisms for bacteremia or fungemia identified at Kinki University Hospital in 1985-1996 were compared with the isolates identified during 1997-2002. The prevalence of gram-negative organisms decreased, whereas the prevalence of gram-positive organisms increased. Staphylococcal species predominated in the second period, accounting for 22% of isolates, and methicillin-resistant Staphylococcus aureus (MRSA) increased from 5% to 14% of isolates. Pseudomonas aeruginosa ranked second, although the prevalence decreased in the second period compared with the first. Candida species were also relatively frequent (11%). Enterococcal species had an 8% prevalence. A comparison of all culture isolates showed that gram-negative isolates still predominated among the general patient population, whereas almost equal prevalence was observed in patients with hematological diseases. MRSA was the organism most frequently isolated in the general patient population, followed by P. aeruginosa. Among staphylococcal species, MRSA accounted for as much as 90% of isolates.

Chemokines and chemokine receptors play important roles in migration and tissue localization of various lymphocyte subsets. Here, we report the highly frequent expression of CCR4 in adult T-cell leukemia (ATL) and human T-cell leukemia virus type 1 (HTLV-1)-immortalized T cells. Flow cytometric analysis revealed that ATL and HTLV-1-immortalized T-cell lines consistently expressed CCR4. Inducible expression of HTLV-1 transcriptional activator tax in a human T-cell line Jurkat did not, however, up-regulate CCR4 mRNA. In vitro immortalization of peripheral blood T cells led to preferential outgrowth of CD4(+) T cells expressing CCR4. We further demonstrated highly frequent expression of CCR4 in fresh ATL cells by (1) reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of CCR4 expression in peripheral blood mononuclear cells (PBMCs) from patients with ATL and healthy controls; (2) flow cytometric analysis of CCR4-expressing cells in PBMCs from patients with ATL and healthy controls; (3) CCR4 staining of routine blood smears from patients with ATL; and (4) an efficient migration of fresh ATL cells to the CCR4 ligands, TARC/CCL17 and MDC/CCL22, in chemotaxis assays. Furthermore, we detected strong signals for CCR4, TARC, and MDC in ATL skin lesions by RT-PCR. Collectively, most ATL cases have apparently derived from CD4(+) T cells expressing CCR4. It is now known that circulating CCR4(+) T cells are mostly polarized to Th2 and also contain essentially all skin-seeking memory T cells. Thus, HTLV-1-infected CCR4(+) T cells may have growth advantages by deviating host immune responses to Th2. CCR4 expression may also account for frequent infiltration of ATL into tissues such as skin and lymph nodes.

Detection of myeloperoxidase gene expression by in situ hybridization in a case of granulocytic sarcoma associated with AML-M0

We have established a T lymphoid cell line, K2-MDS, from the peripheral blood mononuclear cells (PBMC) of a patient with acute myeloblastic leukemia (AML) transformed myelodysplastic syndrome (MDS). K2-MDS cells are positive for the expression of CD4, CD5, CD13, CD25, CD71, CD95, HLA-DR and cytoplasmic CD3. Southern blotting analysis shows T cell receptor (TCR) beta chain genes rearrangements, whereas immunoglobulin heavy chain (IgH) genes are not rearranged. Further, the patient PBMC contains TCR beta chain genes rearrangements in the same manner as K2-MDS cells. The data indicate that K2-MDS is a T lymphoid cell line derived from a myelodysplastic clone in the patient PBMC. This new MDS-derived cell line K2-MDS may be a useful in vitro model for studies on the pathogenetic mechanisms leading to MDS.

Left cervical lymphadenopathy developed in a 50-year-old male who had a history of adult-onset Still's disease for the preceding 18 months. Still's disease is characterized by rash, fever, and leukocytosis. Lymphadenopathy has been reported in about 60% of the patients, and most histopathologic studies have shown non-specific reactive hyperplasia. However, in this case, an open biopsy of the cervical node revealed a histology of diffuse large B-cell lymphoma. The B-cell malignant lymphoma that developed may have resulted from a sequential progression of a previous stage of benign lymphoproliferative lesion. Our case suggests that the pathophysiology of adult-onset Still's disease involves the stimulation of lymphoid systems to the point of progression towards lymphoma. Malignant lymphoma should be added to the list of life-threatening complications which, although rare, are associated with this disease.

Using the suppression subtractive hybridization technique, we isolated a novel kinase, IKK-i, whose message is drastically induced by lipopolysaccharide (LPS) in the mouse macrophage cell line RAW264. 7. The predicted protein contains the kinase domain in its N-terminus, which shares 30% identity to that of IKK-alpha or IKK-beta. The C-terminal portion contains a leucine zipper and a potential helix-loop-helix domain, as in the case of IKK-alpha and IKK-beta. IKK-i is expressed mainly in immune cells, and is induced in response to proinflammatory cytokines such as tumor necrosis factor-alpha, IL-1 and IL-6, in addition to LPS. Overexpression of wild-type IKK-i phosphorylated serine residues Ser32 and Ser36 of IkappaB-alpha (preferentially Ser36), and significantly stimulated NF-kappaB activation. These results suggest that IKK-i is an inducible IkappaB kinase which may play a special role in the immune response.

We analyzed the outcome of 23 patients with hematological diseases who were transplanted with bone marrow cells from unrelated donors in comparison with 46 transplanted from related donors at a single institute during the same time period. Two unrelated donor patients and one related donor patient with CML failed engraftment. The incidence of acute GVHD was higher in unrelated donors than that in related donors(52% vs. 34%). However, there was no difference for the incidence of grade II-IV GVHD between unrelated and related donors (28% vs. 25%). The incidence and severity of acute GVHD decreased after applying HLA DNA typing. Two unrelated donor patients were died of acute GVHD within 100 days, but no one in related donor patient died of acute GVHD. These results show that HLA DNA typing and the management of acute GVHD are important in patients transplanted from unrelated donors.

To identify genes induced in activated macrophages, we screened a cDNA library prepared from the lipopolysaccharide (LPS)-treated cell line, RAW264, using the suppression subtractive hybridization technique. One of the clones isolated was dramatically induced by LPS in macrophages. The predicted protein sequence of this gene contains the domain unique to seven transmembrane receptors, and shows similarity with mouse C-C chemokine receptor 5 (CCR5). Therefore, we designated it LPS inducible C-C chemokine receptor related gene (L-CCR). Northern blot analysis revealed that L-CCR was specifically expressed in differentiated macrophages after LPS stimulation. These results show that L-CCR is a novel C-C chemokine receptor related gene induced by LPS in macrophages and may play an important role in inflammatory responses.

We demonstrated significant growth inhibition by retinoic acid (RA) of HTLV-I (+) T-cell lines (ATL-2 and HUT102), but not HTLV-I (-) T-cell lines (MOLT-4 and Jurkat). We hypothesized that the mechanism of growth inhibition by RA depends on an imbalance in redox potential. To examine the effect of exogenous thiol compounds for the growth of HTLV-I (+) T-cell lines by RA, HTLV-I (+) T-cell lines were cultured with several thiol compounds (thioredoxin, L-cystine, and GSH), following addition of 13-cis RA or ATRA, respectively, in cultured with thiol free medium. Unexpectedly, thiol compounds alone did not restore growth inhibition of HTLV-I (+) T-cell lines. However, when those cells were preincubated with thiol compounds for 24 hours, no growth inhibition by 13-cis RA or ATRA was observed. These results suggest that thiol compounds are associated strongly with sensitivity to RA of HTLV-I (+) T cells, but not of HTLV-I (-) T cells and that thiol compounds serve an important role on HTLV-I (+) T cells.