Expression Of Leukocyte Common Antigen Research Articles

Crosstalk between aldehyde dehydrogenase-1 and chemoresistance in breast cancer: Insights into the role of vitamin D3

AimsAldehyde dehydrogenase-1 (ALDH-1) is considered a signature of breast cancer stem cells and is linked to poor outcomes in breast cancer patients. This study aimed at investigating the effect of vitamin D3 on enhancing the tumor responsiveness to different conventional chemotherapeutic agents, viz., cisplatin, methotrexate, and doxorubicin. Main methodsIn vitro and in vivo experiments were performed using combinations of vitamin D3 and chemotherapeutic agents. Cell cycle analysis and apoptosis assays were performed. Moreover, ALDH-1 expression levels were estimated in cancer cell lines and solid tumors. For solid tumors, tumor volume and histopathological necrotic indices were estimated. Leukocyte presence was also evaluated in tumors using leukocyte common antigen (LCA). Key findingsResults showed a synergistic interaction between vitamin D3 and each of the chemotherapeutic agents on breast cancer cell lines as well as cell cycle arrest at G2/M phase. A decrease in ALDH-1 levels was reported in both breast cancer cells and in tumor tissues. Reductions in tumor volume were also observed in the groups which received the combination therapy. An influence on necrosis rather than apoptosis was also reported, as evidenced by necrotic indices and Bcl-2 expression in tumor sections, respectively. Increased local leukocytes in tumors was also evident, as indicated by increased expression of leukocyte common antigen (LCA). SignificanceOverall, the present study shows that vitamin D3 has an impact on resistance to different chemotherapeutic agents which could be due to the inhibition of ALDH-1, suggesting its use as an adjuvant therapy in cancer patients receiving chemotherapy.

Therapeutic effects of topical netrin-4 in a corneal acute inflammatory model.

To evaluate the therapeutic effect of netrin-4 on the early acute phase of inflammation in the alkali-burned eye. Eye drops containing netrin-4 or phosphate buffered saline (PBS) were administered to a alkali-burn-induced corneal acute inflammatory model four times daily. The clinical evaluations, including fluorescein staining and inflammatory index, were performed on day 1, 4 and 7 using slit lamp microscopy. Global specimens were collected on day 7 and processed for immunofluorescent staining. The levels of inflammatory mediators in the corneas were determined by real-time polymerase chain reaction (PCR). Exogenous netrin-4 administered on rat ocular surfaces showed more improvements in decreasing fluorescein staining on day 4 and 7, and resolved alkali burn-induced corneal inflammation index on day 7 (P<0.01). The levels of IL-1β, IL-6, intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1 (MIP-1) in corneas were decreased in netrin-4-treated groups (P<0.05). In addition, netrin-4 significantly reduced the expression of leukocyte common antigen 45 (CD45) in the alkali-burn cornea (P<0.001). Topical netrin-4 accelerated wound healing and reduced the inflammation on alkali-burn rat model, suggesting a potential as an anti-inflammatory agent in the clinical to treat the acute inflammation.

Bone marrow-derived mesenchymal stromal cells improve vascular regeneration and reduce leukocyte-endothelium activation in critical ischemic murine skin in a dose-dependent manner

Background aimsStem cells participate in vascular regeneration following critical ischemia. However, their angiogenic and remodeling properties, as well as their role in ischemia-related endothelial leukocyte activation, need to be further elucidated. Herein, we investigated the effect of bone marrow–derived mesenchymal stromal cells (BM-MSCs) in a critically ischemic murine skin flap model. MethodsGroups received either 1 × 105, 5 × 105, or 1 × 106 BM-MSCs or cell-free conditioned medium (CM). Controls received sodium chloride. Intravital fluorescence microscopy was performed for morphological and quantitative assessment of micro-hemodynamic parameters over 12 days. ResultsTortuosity and diameter of conduit-arterioles were pronounced in the MSC groups (P < 0.01), whereas vasodilation was shifted to the end arteriolar level in the CM group (P < 0.01). These effects were accompanied by angiopoietin-2 expression. Functional capillary density and red blood cell velocity were enhanced in all treatment groups (P < 0.01). Although a significant reduction of rolling and sticking leukocytes was observed in the MSC groups with a reduction of diameter in postcapillary venules (P < 0.01), animals receiving CM exhibited a leukocyte-endothelium interaction similar to controls. This correlated with leukocyte common antigen expression in tissue sections (P < 0.01) and p38 mitogen-activated protein kinase expression from tissue samples. Cytokine analysis from BM-MSC culture medium revealed a 50% reduction of pro-inflammatory cytokines (interleukin [IL]-1β, IL-6, IL-12, tumor necrosis factor-α, interferon-γ) and chemokines (keratinocyte chemoattractant, granulocyte colony-stimulating factor) under hypoxic conditions. DiscussionWe demonstrated positive effects of BM-MSCs on vascular regeneration and modulation of endothelial leukocyte adhesion in critical ischemic skin. The improvements after MSC application were dose-dependent and superior to the use of CM alone.

Plasmablastic lymphoma of the right testis

Plasmablastic lymphoma (PBL) is a very rare disease. In 1997 Delecluse et al. reported a series of aggressive nonHodgkin’s lymphomas arising in the oral cavity of HIVpositive patients. In terms of clinical behavior, PBL is highly aggressive with short survival. This is the first report of PBL of the testis in Japan. A 76-year-old man had notable right-side scrotal swelling in September 2009 and underwent a medical examination in our hospital in October of the same year. Ultrasonographic examination demonstrated an enlarged right testis with a heterogeneous echo pattern. Levels of serum testicular tumor markers, including b-human chorionic gonadotrophin, a-fetoprotein and lactate dehydrogenase were all normal. We suspected that it might be a testicular tumor, so right high orchiectomy was performed in October 2009. Macroscopically, the tumor was ash gray in color, and there was no presence of bleeding or necrotic tissue (Fig. 1a). It consisted of diffusely proliferative, relatively uniform large cells with abundant cytoplasm. In particular, the tumor cells were plasmablastic-like and there were almost no mature plasma cells (Fig. 1b). Immunohistochemistry revealed the tumor cells to be positive for CD138, CD56 and epithelial membrane antigen; and negative for CD20, CD79a, CD3, CD10, CD30, cytokeratin and S100 protein. The pathological diagnosis was PBL. There was no evidence of human herpes virus-8 infection (according to polymerase chain reaction analysis), Epstein–Barr virus (according to in situ hybridization) and HIV. Pathologically, PBL is characterized by an immunoblastic or plasmablastic morphology and a plasma cell immunophenotype, and thus, its differentiation from other large B cell lymphomas or plasmablastic plasma cell neoplasms is often problematic. The immunophenotype of PBL tumor cells is almost identical to that of plasma cells; in particular, the expression of leukocyte common antigen and CD20 is absent or weak, but that of plasmacytic markers, such as CD138, is strongly positive. PBL has a well-established association with immunosuppression, and most particularly with HIV infection: approximately 80% of PBL patients are HIV-infected. Cases of PBL have also been reported after solid organ transplantation and in association with steroid therapy for autoimmune disease. PBL typically occurs in the oral cavity. However, PBL of the testis is very rare. Schichman et al. reported the first case. This report documents the third case of PBL of the testis in the world. Although cases of PBL have been reported from countries across the world , there has been only one report from Japan in the English-language published work. This may be because HIV infection is less prevalent in Japan than in other countries. The number of PBL cases in Japan may increase in the future.

Plasmablastic Lymphoma in a Human Immunodeficiency Virus-negative Patient: A Case Report and Review of the Literature

The plasmablastic lymphomas (PBLs) are an aggressive group of non-Hodgkin's lymphomas occurring primarily in human immunodeficiency virus (HIV)-infected individuals with absolute CD4 counts less than 200 per microliter. It was considered to be a diffuse large B-cell lymphoma with a unique im- munophenotype and occurred primarily in the oral cavity. Recent studies report that PBLs also occur in patients without HIV infection. Herein we report an unusual case of plasmablastic lymphoma presenting in nasal cavity in a 74-year-old, HIV-negative woman. Cytologic and histologic examinations demon- strated a large cell lymphoma with plasmacytic differentiation. The tumor cells were positive for CD79a, CD38, however lacked expression of leukocyte common antigen, T-cell, and B-cell markers. Epstein-Barr virus-encoded RNA transcripts were identified by in situ hybridization. To our best knowledge, this is the second case of plasmablastic lymphoma in HIV-negative patient in Korea. (Korean J Hematol 2009;44:122-126.)

Aberrant Leukocyte Common Antigen Expression in Metastatic Small Cell Lung Carcinoma: A Rare Finding and a Potential Diagnostic Pitfall

Aberrant Leukocyte Common Antigen Expression in Metastatic Small Cell Lung Carcinoma: A Rare Finding and a Potential Diagnostic Pitfall

Plasmablastic lymphoma of the cervical lymph nodes in a human immunodeficiency virus-negative patient: a case report and review of the literature.

We report a case of plasmablastic lymphoma presenting in cervical lymph nodes in an 82-year-old, human immunodeficiency virus-negative man. Cytologic and histologic examinations demonstrated a large cell lymphoma with plasmacytic differentiation. The tumor cells were positive for CD138, CD38, epithelial membrane antigen, CD30, and lysozyme, but lacked expression of leukocyte common antigen, T-cell, and B-cell markers. Abundant Epstein-Barr virus-encoded RNA transcripts were identified by in situ hybridization. A monoclonal rearrangement of kappa-light- chain gene was demonstrated. The cytologic, histologic, immunohistochemical, and molecular features of plasmablastic lymphoma are reviewed. The potential diagnostic pitfalls and differential diagnoses, especially in a fine-needle aspiration specimen, are addressed.

Differential expression of leukocyte common antigen in human fetal lymphoid organs.

To investigate the differential expression of various types of leukocyte common antigen (LCA) isoforms during development, we analyzed human fetal lymphoid organs, including the thymus, liver, spleen, and bone marrow from 14 weeks to 29 weeks of gestational age by immunohistochemical and flow cytometric methods. In fetal thymus, over 90% of thymocytes throughout the entire fetal life expressed CD45RO and CD45RB, while CD45RA was expressed only in less than 5% of thymocytes. This expression pattern of LCA isoforms was established by a gestational age of 14 weeks or earlier, and persisted throughout the fetal period. The tissue distribution was different from each isoform; CD45RO-positive thymocytes were found in both the cortex and medulla at the 14th week with low intensity, but was localized in the cortex with increasing fetal age. CD45RB-positive thymocytes distributed mainly in the medulla from early gestational age. Among extrathymic lymphoid organs, a small portion of lymphoid cells expressing leukocyte common antigens appeared first in the liver at 10-12 weeks of gestational age and was followed by a small number in the spleen and bone marrow by 13-15 weeks. All lymphoid cells in these extrathymic lymphoid organs at this stage were CD19+ B cells. The number of these CD19+ cells increased abruptly during the early period of mid-gestational age. The pattern of tissue distribution of each LCA isoform in the fetal liver and spleen correlated well with the patterns of quantitative analysis by flow cytometry. In summary we found that different LCA isoforms expressed in cell-type-specific pattern and showed different tissue distribution during the period of fetal development, and that LCA was the earliest antigen expressed by lymphocytes in the thymus and extrathymic lymphoid organs in our series.

Immunophenotypic analysis of infiltrating leukocytes and microglia in an experimental rat glioma.

The appearance and cellular distribution of major histocompatibility complex (MHC), as well as lymphocytic and macrophage antigens has been studied in a fully developed experimental rat forebrain glioma. Activated microglial cells and microglia-derived macrophages expressing CR3 complement receptor molecules and MHC class II (Ia) antigen were found throughout the tumor, and with increased density along the tumor's periphery. MHC class I antigen expression was entirely absent from tumor cells, and found only occasionally on microglia. The expression of leukocyte common antigen, and CD4 and CD8 antigens was conspicuous throughout the tumor, and associated with lymphocytes, perivascular cells, and microglia. Cells expressing the ED2 macrophage epitope were almost exclusively of the perivascular type and revealed a distribution dissimilar to that of cells positive for Ia antigen. The ED2 epitope was found sporadically on ramified microglial cells. The results show that despite heavy infiltration with blood mononuclear and CNS microglial cells, the tumor showed no evidence of destruction caused by inflammatory cells. Possible mechanisms of tumor immunosuppressive activity preventing the full immunological activation of microglia and blood mononuclear cells are discussed.

Expression of leukocyte common antigen in lymphoblastic lymphoma and small noncleaved undifferentiated non‐Burkitt's lymphoma: An immunohistochemical study

Nine cases of lymphoblastic lymphoma and eight cases of small, noncleaved undifferentiated non-Burkitt's lymphoma were studied. All cases were stained with monoclonal antibodies, directed to the leukocyte common antigen (LCA), B- and T-cell markers as well as Calla. Small noncleaved, undifferentiated non-Burkitt's lymphomas were LCA positive and expressed one or more B-cell markers. Three cases of lymphoblastic lymphoma were LCA positive and showed reactivity with antibodies OKT4, OKT6 and OKT8. The six remaining cases of lymphoblastic lymphoma were LCA negative, except for only one case that was weakly LCA positive using more sensitive detection methods. Two of the LCA negative cases expressed Calla, and four cases did not show any reactivity with the monoclonal antibodies used. In all LCA negative cases, small residual non-neoplastic nodules representing remnants of lymphoid follicles, could be detected. Since five out of nine cases of lymphoblastic lymphoma were LCA negative, lack of staining for LCA does not preclude the diagnosis of lymphoma.