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1.
The MRC OX-22- CD4+ T cells that help B cells in secondary immune responses derive from naive precursors with the MRC OX-22+ CD4+ phenotype 总被引:10,自引:4,他引:6 下载免费PDF全文
CD4+ T cells in the rat can be divided into two nonoverlapping subsets by their reactivity with the mAb MRC OX-22, which binds some of the high molecular weight forms of the CD45 antigen. The lineage relationship between subsets of CD4+ T cells expression different forms of CD45 has been a controversial issue for some time. Experiments described in this paper address this question using in vivo assays of T cell reactivity. Analysis of primary antibody responses in vivo show that it is MRC OX-22+ CD4+ T cells that are active in these assays, whereas antigen-primed T cells that provide helper activity for secondary antibody responses in vivo have the MRC OX-22- CD4+ phenotype. It is demonstrated that these memory T cells derive from MRC OX-22+ CD4+ T cell precursors and not from a putative separate lineage. It is concluded that with respect to the provision of help for B cells, MRC OX-22+ CD4+ T cells are precursors of memory cells with the phenotype MRC OX-22- CD4+. 相似文献
2.
MY Mancao LJ Sindel PH Richardson FM Silver 《Acta paediatrica (Oslo, Norway : 1992)》1996,85(1):118-120
Croup is an acute infectious illness usually occurring in children; it is characterized by brassy cough and stridor. The main pathogens include mainly parainfluenza and influenza viruses. Recently there have been reports of prolonged croup caused by the herpes simplex viruses. We report two cases of prolonged croup due to herpes simplex types 1 and 2. We also review and summarize the reported pediatric cases of herpetic croup. 相似文献
3.
CTLA-4 expression on antigen-specific cells but not IL-10 secretion is required for oral tolerance 总被引:7,自引:0,他引:7
CD4(+) T cells play a vital role in mediating the tolerance induced at mucosal sites following exposure to non-pathogenic stimuli, and further understanding of the precise mechanisms by which these cells prevent aberrant responses is required. We have developed a model using transfer of DO11.10 TCR-transgenic bone marrow into irradiated recipients in which it has been possible to track antigen-specific CD4(+) cells in mesenteric lymph nodes (mLN), Peyer's patches (PP) and lamina propria following primary exposure to antigen. Using this model we have demonstrated initial activation in all three gut-associated lymphoid tissue compartments characterized by increases in the frequency of transgenic cells expressing CD69 and CD25. These cells subsequently enter a state of hyporesponsiveness both locally in the mLN and PP and in the periphery following feeding and challenge. Investigating the role of CTLA-4 either using anti-CTLA-4 mAb or by generating chimeras using DO11.10xCTLA-4(-/-) mice as donors we have clearly shown that antigen-specific cells require the expression of this regulatory molecule for oral tolerance. In contrast, oral tolerance was intact in chimeras generated using DO11.10xIL-10(-/-) cells, indicating that secretion of this cytokine by antigen-specific cells is not required. 相似文献
4.
Phenotypically distinct subsets of CD4+ T cells induce or protect from chronic intestinal inflammation in C. B-17 scid mice 总被引:22,自引:0,他引:22
Powrie Fiona; Leach Michael W.; Mauze Smita; Caddie Linda Barcomb; Coffman Robert L. 《International immunology》1993,5(11):1461-1471
CD4+ T cells in the mouse can be subdivided into two fractionsbased on the level of expression of the CD45RB determinant.Previous studies have shown that these subsets are functionallydistinct. We have further characterized the properties of thesesubpopulations in vivo by injecting them into C. B-17 scid mice.The animals restored with the CD45RBhighCD4+ T cell populationdeveloped a lethal wasting disease with severe mononuclear cellinfiltrates into the colon and elevated levels of IFN- mRNA.In contrast, animals restored with the reciprocal CD45RBlowsubset or with unfractionated CD4+ T cells did not develop thewasting or colitis. Importantly, the co-transfer of the CD45RBlowpopulation with the CD45RBhigh population prevented the wastingdisease and colitis. These data indicate that important regulatoryinteractions occur between the CD45RBhigh and CD45RBlowCD4+T cell subsets and that disruption of this mechanism has fatalconsequences. 相似文献
5.
This review correlates the imaging findings and histological appearances seen in chordomas in a series of patients presenting at our institution, together with a published literature review. A parallel presentation of photographs of imaging findings and microscopic histological findings is made, with the aim being to enhance recognition of this uncommon but clinically significant entity. 相似文献
6.
The tetrapeptide Acetyl-N-Ser-Asp-Lys-Pro (AcSDKP, Seraspenide; Ipsen- Biotech, Paris, France), an inhibitor of murine spleen colony-forming units reduces the number and the percentage in DNA synthesis of progenitors from human unfractionated bone marrow. To determine whether AcSDKP may directly affect the growth potential of purified progenitors even at the most primitive level, CD34+HLA-DRhigh and CD34++HLA-DRlow cells were highly purified by cell sorting. Then, CD34+ subsets were stimulated in liquid culture with combinations of growth factors (GFs) and AcSDKP was added for 20 hours or 6 days and cells plated in methylcellulose. After a 20-hour incubation, we show that AcSDKP (at 10(-10) mol/L) significantly inhibits the colony formation of both CD34+ subsets. Moreover, when added daily for 6 days, AcSDKP: (1) reduces the proliferation of both CD34+ cell fractions stimulated by 3 or 7 GFs, and (2) decreases the number of progenitors generated from the CD34+HLA-DRhigh and CD34++HLA-DRlow cell fractions. Furthermore, we show for the first time, using both high proliferative potential cell and long-term culture initiating cell assays, that AcSDKP inhibits the most primitive cells contained in the CD34++HLA-DRlow subpopulation. Finally, by using limiting dilution assays we demonstrated that AcSDKP acts directly at a single cell level and that its inhibitory effect is reversible and dose dependent. 相似文献
7.
The study of central nervous system (CNS) leukemia has been hampered by the lack of a suitable animal model. We report that severe combined immunodeficiency (SCID) mice invariably develop rapidly progressive fatal CNS leukemia within 3 weeks after intravenous injection of NALM-6 pre-B acute lymphoblastic leukemia (ALL) cells. Colonization of the dura mater and subarachnoid space, usually of the distal spinal cord with occasional extension into the Virchow-Robin spaces of blood vessels subjacent to the meninges, followed involvement of bone marrow in the skull, vertebrae, and, occasionally, the appendicular skeleton. Occult CNS leukemia was detectable by polymerase chain reaction amplification of human DNA as early as 8 days postinoculation of leukemia cells. We used this in vivo model of human CNS leukemia to examine the therapeutic efficacy and toxicity of intrathecally administered B43 (anti-CD19)-pokeweed antiviral protein (PAP), an anti- B-lineage ALL immunotoxin directed against the pan-B-cell antigen CD19/Bp95. Intrathecal therapy with B43 (anti-CD19)-PAP immunotoxin at nontoxic dose levels significantly improved survival of SCID mice and was superior to intrathecal methotrexate therapy. 相似文献
8.
Fritsch G; Buchinger P; Printz D; Fink FM; Mann G; Peters C; Wagner T; Adler A; Gadner H 《Blood》1993,81(9):2301-2309
Mononuclear cells (MNC) isolated by density centrifugation of cord blood and healthy bone marrow, and of peripheral blood (PB) from patients treated with granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF after chemotherapy, were double-stained with anti CD34 monoclonal antibody (MoAb) (8G12) versus anti CD45, CD45-RB, CD45- RO, and CD45-RA, respectively, and analyzed by flow cytometry. In all specimens, CD34+ MNC co-expressed CD45 at a low level and the expression of CD45-RB was similar or slightly higher. Most CD34+ MNC were negative for CD45-RO, a weak coexpression was only seen in some bone marrow (BM) and blood samples. In contrast, CD45-RA could subdivide the CD34+ population into fractions negative, dim (+), and normal positive (++) for these subgroups, and typical staining patterns were observed for the different sources of hematopoietic cells: in BM, most CD34+ MNC were RA++. In PB, their majority was RA++ after G-CSF but RA+ or RA- after GM-CSF. In cord blood, the hematopoietic progenitors were mainly RA-/RO-. Semisolid culture of sorted CD34+ MNC showed that clusters and dispersed (late) colony-forming unit-GM (CFU- GM) originated from 34+/RA++ cells, while the 34+/RA- MNC formed compact and multicentric, both white and red colonies derived from early progenitors. Addition of 20 ng stem cell factor per milliliter of medium containing 34+/RA- cord blood MNC led to a change of many burst- forming unit-erythrocyte (BFU-E) to CFU-mix which was not, at least to this extent, seen in blood and BM. We conclude that early myeloid CD34+ cells are 45+/RA-. Because this population excludes 34+/19+ B cells and 33+ myeloid cells, both of which are RA++, two-color flow cytometric analysis using CD34 and CD45-RA facilitates the characterization and quantification of early myeloid progenitor cells. 相似文献
9.
Nynke D Scherpbier-de Haan Gerald MM Vervoort Chris van Weel Jozé CC Braspenning Jan Mulder Jack FM Wetzels Wim JC de Grauw 《The British journal of general practice》2013,63(617):e798-e806
Background
Chronic kidney disease (CKD) is highly prevalent in patients with diabetes or hypertension in primary care. A shared care model could improve quality of care in these patientsAim
To assess the effect of a shared care model in managing patients with CKD who also have diabetes or hypertension.Design and setting
A cluster randomised controlled trial in nine general practices in The Netherlands.Method
Five practices were allocated to the shared care model and four practices to usual care for 1 year. Primary outcome was the achievement of blood pressure targets (130/80 mmHg) and lowering of blood pressure in patients with diabetes mellitus or hypertension and an estimated glomerular filtration rate (eGFR)<60ml/min/1.73m2.Results
Data of 90 intervention and 74 control patients could be analysed. Blood pressure in the intervention group decreased with 8.1 (95% CI = 4.8 to 11.3)/1.1 (95% CI = −1.0 to 3.2) compared to −0.2 (95% CI = −3.8 to 3.3)/−0.5 (95% CI = −2.9 to 1.8) in the control group. Use of lipid-lowering drugs, angiotensin-system inhibitors and vitamin D was higher in the intervention group than in the control group (73% versus 51%, 81% versus 64%, and 15% versus 1%, respectively, [P = 0.004, P = 0.01, and P = 0.002]).Conclusion
A shared care model between GP, nurse practitioner and nephrologist is beneficial in reducing systolic blood pressure in patients with CKD in primary care. 相似文献10.