Home About us Contact
|
Home About us Contact | ||
|
|
||
Mononuclear Leucocytes (mononuclear + leucocyte)
Selected AbstractsA carbohydrate neoepitope that is up-regulated on human mononuclear leucocytes by neuraminidase treatment or by cellular activationIMMUNOLOGY, Issue 2 2001Mark T. Quinn Summary The expression of cell-surface antigens can delineate specific leucocyte developmental or functional stages. For example, certain membrane glycoproteins are expressed selectively on leucocyte subsets only after activation. Leucocyte activation can also induce changes in carbohydrate epitopes expressed on surface antigens. In the present studies, we report on a novel monoclonal immunoglobulin M antibody (mAb 13.22) that recognizes a unique carbohydrate epitope expressed on human leucocyte membrane proteins. Characterization of mAb 13.22 specificity by immunoblotting showed that it recognized proteins of MW ,95 000 and 150 000, including both CD18 and CD11b. The mAb 13.22 epitope was removed by N -glycosidase F but not by endoglycosidase H or fucosidase, demonstrating that it is an N-linked carbohydrate antigen. Interestingly, immunoblot staining was enhanced after neuraminidase treatment, suggesting that the antibody epitope might also be partially masked by sialic acid. In resting leucocytes, the mAb 13.22 antigen was expressed strongly on neutrophils, while dull staining was present on monocytes, and no lymphocyte staining was observed. In marked contrast, treatment of leucocytes with neuraminidase resulted in exposure of a mAb 13.22 neoepitope on a subset of lymphocytes (primarily T lymphocytes and natural killer cells) as well as up-regulated staining more than 18-fold on monocytes. Activation of lymphocytes in culture with phytohaemagglutinin or concanavalin A also unmasked the mAb 13.22 neoepitope on ,37% of the CD45RO+ lymphocytes. Furthermore, analysis of leucocytes collected from the synovial fluid of patients with rheumatoid arthritis showed that ,18% of the lymphocytes present expressed the mAb 13.22 neoepitope. Taken together, our results suggest that the mAb 13.22 carbohydrate neoepitope could represent a physiologically relevant marker that is up-regulated on leucocyte subsets during the inflammatory response. [source] MicroRNA-21 expression in neonatal blood associated with antenatal immunoglobulin E production and development of allergic rhinitisCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2010R.-F. Chen Summary Background The prevalence of allergic diseases has increased in the past decades. It is unknown whether expression of certain microRNAs (miRNAs) in neonatal leucocytes is correlated to IgE production and/or allergic diseases. Objective This study investigated the association of miRNA expression in neonatal leucocytes with cord blood IgE (CBIgE) elevation and development of allergic disease. Methods We screened for the expression of a panel of 157 miRNAs in mononuclear leucocytes from human umbilical cord blood (CB) samples with elevated CBIgE and tracked the association of down-regulated miRNA expression to the miRNA-targeted gene expression and to children with allergic rhinitis (AR). Results Among the initial screen of 10 CB samples with elevated CBIgE, expression of eight of the 157 miRNAs was low. Of these eight down-expressed miRNAs, three remained down-regulation in a validation with other 20 CB samples, and two of the three miRNAs, miR-21 and miR-126, were significantly lower in monocytes from AR children. Further analysis of mRNA expression of the miR-21-targeted genes identified that TGFBR2 expression on monocytes was significantly up-regulated in CB with elevated CBIgE, and in AR patients. Transfection of miR-21 precursor into monocytes from patients with AR increased miR-21 expression and decreased TGFBR2 expression. Conclusion This study demonstrated the first in the literature that lower miR-21 expression in CB and increased TGFBR2 expression is associated with antenatal IgE production and development of AR. Cite this as: R.-F. Chen, H.-C. Huang, C.-Y. Ou, T.-Y. Hsu, H. Chuang, J.-C. Chang, L. Wang, H.-C. Kuo and K. D. Yang, Clinical & Experimental Allergy, 2010 (40) 1482,1490. [source] Diminished cytokine signalling against bacterial components in mononuclear leucocytes from ulcerative colitis patients after leukocytapheresisCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2005K. Mitsuyama Summary Infiltration by circulating inflammatory cells is a prominent local inflammatory feature of ulcerative colitis (UC). Several trials have suggested that leukocytapheresis by filtration can benefit patients with active UC. We investigated how this therapy might modulate the inflammatory response. Patients with active UC who were beginning repeated filtration leukocytapheresis were studied. Mononuclear cell preparations were obtained from blood before and after the first treatment, and expression of cytokine signalling components and the cell-proliferative response were analysed in vitro. Leukocytapheresis reduced lipopolysaccharide-induced production of proinflammatory cytokines (interleukin-1, -6, -8 and tumour necrosis factor-,, P < 0·05 for all) and activation of intracellular signalling components (nuclear factor-,B, mitogen-activated protein kinases, and signal transducer and activator of transcription-3), as well as surface expression of toll-like receptor-4 (P < 0·05) in mononuclear cells. The therapy also reduced the cell-proliferative response by mononuclear cells stimulated with sonicated bacterial preparations from autologous intestine (P < 0·05). These results indicate that activated mononuclear cells in the peripheral blood of patients with active UC are removed by leukocytapheresis and replaced by cells with a lower activation status. This replacement may partly explain the therapeutic benefit. [source] Identification of wild type and variants of oestrogen receptors in polymorphonuclear and mononuclear leucocytesCLINICAL ENDOCRINOLOGY, Issue 1 2006Denis Stygar Summary Objective, ,Leucocytes play an important role in the pathogenesis of autoimmune and cardiovascular diseases. Clinical and epidemiological observations indicate that the sex steroid hormones, particularly oestrogens, may regulate leucocyte functions. The assumption that oestrogens have a direct effect on leucocytes has to be supported by identification of functional oestrogen receptors (ER) in leucocytes. This study aimed at investigating the presence of ER subtypes in different types of leucocytes isolated from peripheral blood of female and male donors. Design and patients, ,A total of nine men (age range 18,43 years) and nine women (age range 19,42 years) all healthy blood donors, were recruited for the study. The donors did not receive any medication or hormonal contraceptives for the last three months. Ten millilitres of peripheral blood was collected from each donor. Polymorphonuclear leucocytes (PMN) and peripheral blood mononuclear cells (PBMC) were purified by density gradient centrifugation. Measurements, ,ER, and ER, mRNA expression was measured by real-time reverse transcriptase,polymerase chain reaction (RT-PCR), and ER proteins were analysed by Western blot in the PBMC and PMN leucocyte populations. In addition, expression profiles of ER variant isoforms were characterized by conventional PCR using the splice-targeted primer approach. Results, ,Although we detected wild-type ER, and ER, mRNAs in PBMC but not in PMN cells, the ER, and ER, proteins were found in both cell types using Western blot. We observed that both ER, and ER, proteins differ in size between PMN and PBMC, suggesting that the two leucocyte populations contain diverse variant isoforms of ER, and ER,. RT-PCR analysis of exon-deleted ER splice variants revealed that PBMC express several exon-deleted variants of ER, and ER,, along with wild-type receptor, whereas the PMN cells only express exon-deleted variant isoforms and no wild-type ER, or ER,. Conclusions, ,Our study demonstrates the presence of ER, and ER, in PBMC and PMN cells from female and male donors. The ER, and ER, genes have complex transcriptional profiles, with many receptor variant isoforms being expressed. Considering the diversity of ER isoforms in leucocyte subtypes, we conclude that the expected effect of oestrogen would be highly cell type-specific. Further studies are needed to test the functional activity of ER isoforms and their relation to disease. [source] | ||||||||||