Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06126 (CD1a)
 2,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dendritic cells (DC) are the main stimulators of primary T cell responses. Very little is known about DC in cord blood (CB), and whether they are involved in the low incidence and severity of GVHD following CB transplantation. Here, CBDC were identified as a HLA-DR+/lineage marker (lin; CD3, CD11b, CD14, CD16, CD19, CD34, CD56 and glycophorin A antigens) negative population, representing 0.3 +/- 0.1% (mean +/- s.d.; n = 15) of CB mononuclear cells. CBDC expressed the CD4, CD11a, CD18, CD45RA, CD50 and CD54 antigens but revealed no expression of the CD1a, CD11c, CD40, CD45R0, CD58, CD83, CD86 and CD102 antigens. Immunomagnetically enriched CBDC showed potent allostimulatory activity for CB T cells. Thus, CBDC are functionally competent and resemble in their immature/resting state CD11c- DC in peripheral blood.
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PMID:Functional competence of dendritic cells in human umbilical cord blood. 971 87

An acute leukemia with an unusual immunophenotype developed in a 17-year-old girl. At the initial presentation, extramedullary involvement was not evident, but with advancing disease, massive splenomegaly and an osteolytic rib tumor developed. The disease was aggressive and refractory to intensive chemotherapeutic regimens for myeloid and lymphoid malignancies, and the patient died 3 months after the initial presentation. The leukemic cells were of irregular shape and variable size; they had deeply indented or bi-lobed nuclei and relatively fine, azurophilic granules in their cytoplasm. They were positive for acid phosphatase and beta-glucuronidase in granular staining, but they were negative for myeloperoxidase. The leukemic cells had a unique immunophenotype: it was positive for T-cell antigens (CD1a, CD2, cytoplasmic CD3, CD4), myeloid antigens (CD13 and CD33), NK-cell antigen (CD56), CD19 and CD30. DNA analysis revealed no gene rearrangement in the T-cell receptor beta, gamma and delta, or immunoglobulin heavy chain genes. The leukemic cells of our patient are thought to have arisen from the transformation of a putative precursor cell common to both the T- and NK-cell lineage in the bone marrow. The current literature on precursor NK-cell malignancy is reviewed, and its clinicopathological feature is discussed.
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PMID:Acute leukemia with the phenotype of a natural killer/T cell bipotential precursor. 1003 70

Dendritic cells (DCs) are pivotal for antigen presentation, T-cell priming and B-cell functions. Few studies have been carried out on DCs in human diseases, partly because the current procedures used for DC preparation include elaborate negative selection with monoclonal antibodies (MoAb) and prolonged culture in cytokine-enriched milieu, which may influence DC functions. Using physical density and their adherent properties, DCs were prepared from the blood of healthy subjects. Approximately 2% of human blood mononuclear cells (MNC) were shown to consist of DCs, yielding DCs of 80-90% purity. They expressed markers related to DCs (CD1a, CD11c, CD32 and CD83), costimulatory molecules (CD40, CD80, CD86), human leucocyte antigen (HLA) class I and II molecules and inducible nitric oxide (NO) synthase (NOS2), and lacked lymphocyte and monocyte markers (CD3, CD19, CD20, CD56 and CD14). Compared with blood MNC and T cells, DCs showed a high level of spontaneous proliferation and nitric oxide production, as well as strong proliferative responses in mixed leucocyte reactions. Enzyme-linked immunospot (ELISPOT) assays revealed higher levels of interleukin (IL)-4-, IL-10- and interferon-gamma (IFN-gamma)-secreting cells among DCs than among MNC or T cells obtained from the same blood specimens, while levels of tumour necrosis factor-alpha (TNF-alpha)- and IL-6-secreting cells did not differ. The results demonstrate that the method used is fast, effective and competitively priced, and should be useful for studies of DCs in disease states.
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PMID:Phenotypic and functional properties of dendritic cells isolated from human peripheral blood in comparison with mononuclear cells and T cells. 1007 22

Dendritic cells (DC) are the main stimulators of primary T-cell responses and, thus, probably play a role in the immune reactions after stem cell transplantation. Very little is known about DC in cord blood (CB) and about their potential involvement in the low incidence and severity of acute graft-versus-host disease after CB transplantation. Here, CBDC were identified as a HLA-DR+ cell population, lacking the CD3, CD11b, CD14, CD16, CD19, CD34, CD56, and glycophorin A lineage markers (lin). This lin-/HLA-DR+ population represented 0.3% +/- 0.1% (mean +/- SD; range, 0.1% to 0. 6%; n = 15) of CB mononuclear cells, and CB contained 5.4 +/- 3.2 x 10(3) CBDC/mL (1.8 to 13.0 x 10(3); n = 15). CBDC expressed CD4, CD11a, CD18, CD45RA, CD50, CD54, and CD123, but showed no expression of CD1a, CD11c, CD33, CD40, CD45R0, CD80, CD83, and CD86 and only limited expression of CD58, CD102, and CD116. Despite this immature phenotype, immunomagnetically lin--enriched CBDC were potent stimulators of allogeneic CB T cells. As few as 266 +/- 107 (193 to 530; n = 10) lin-/HLA-DR+ CBDC stimulated a significant response. However, CBDC failed to take up protein or peptide antigens. Thus, in CB there is a prevalence of a DC subpopulation, resembling the CD11c- DC identified in tonsils, the so-called plasmacytoid T cells, which may exert a function distinct from the CD11c+ DC subpopulation.
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PMID:Identification of cord blood dendritic cells as an immature CD11c- population. 1009 Sep 40

The cutaneous lymphocyte-associated antigen (CLA), recognized by the monoclonal antibody HECA-452, is a cell surface glycoprotein that binds specifically to E-selectin. CLA is present on most T cells at sites of cutaneous immune response and has been shown to be important in lymphocyte homing to the skin. It is expressed only by a minor subset of peripheral T cells and is absent on thymocytes. We have analysed (using a FACScan flow cytometer) the expression of CLA on human lymph cells derived from normal skin, from ultraviolet (UV)-irradiated skin and from allergic contact dermatitis. Whereas in the peripheral blood CLA was expressed on < 20% of CD4 +, CD8 + and CD56 + cells (natural killer cells), > 60% of CD4 +, CD8 + and CD56 + cells isolated from skin-derived lymph expressed CLA. Furthermore, > 90% of CD1a + dendritic lymph cells were positive for CLA. UV irradiation of the skin and induction of an allergic contact dermatitis did not change CLA expression on lymph cells, although lymph flow and cell output increased. These results provide further evidence for an important role of CLA in cell homing to the skin.
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PMID:The HECA-452 epitope is highly expressed on lymph cells derived from human skin. 1058 71

Cytologic, immunologic, and cytogenetic studies were performed on the blast cells of a newborn with Down syndrome and transient myeloproliferative disease. This hematologic disorder is uncommon, and occurs primarily in infants with Down syndrome. This boy presented with a high white blood cell count and a high percentage of blast cells, without anemia or thrombocytopenia. Chromosome analysis showed a constitutional trisomy 21 without any other clonal abnormality. A three-color flow cytometric analysis was performed and revealed two different CD45 dim, CD34(+), CD117(+), CD56(+) immature subpopulations: the normal immature myeloid precursor and an immature blast cell population that expressed CD41, CD42, CD61, CD36, CD13, CD1a, and CD2. We postulate that this population could be the leukemic precursor involved in the acute megakaryoblastic leukemia frequently observed in children with Down syndrome.
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PMID:Immunophenotype of a transient myeloproliferative disorder in a newborn with trisomy 21. 1079 50

We report here a case of nonhepatosplenic gammadelta T-cell lymphoma with undescribed initial localization in testis, without hepatosplenomegaly or adenopathies, and subsequent development in the maxillary sinus. The maxillar mass biopsy revealed a T-cell infiltration, and its immunologic characterization by flow cytometry showed a gammadelta T-cell phenotype (CD45+, CD3+, CD2+, TCR gammadelta+), without expression of CD7, CD5, CD1a, TdT, CD4, CD8, TCR alphabeta, or NK antigens (CD16, CD56, and CD57). Clonal gamma-chain gene rearrangement by polymerase chain reaction (PCR) was detected in testicular and maxillar biopsies. Epstein-Barr virus type 1 (EBV) sequences were detected by molecular biology in the biopsy material, suggesting that this oncogenic virus may play a role in the genesis of the clonal expansion of gammadelta T-cells. The patient was initially treated with standard chemotherapeutic protocols, with poor response and aggressive course.
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PMID:Nonhepatosplenic gamma delta T-cell lymphoma with initial testicular compromise. 1107 46

The diagnosis of T-cell lymphomas by fine-needle aspiration biopsies (FNAB) is extremely difficult. This is mainly due to the rarity of the disease, the morphologic similarity to reactive lymphadenopathy, and the difficulty in identifying abnormal T-cell antigen expression. We studied FNAB of histologically proven T-cell lymphomas in an attempt to identify the salient cytomorphologic features as well as the surface marker attributes of the disease. Twenty cases were reviewed. The smears were evaluated for overall cytologic pattern and percentage of abnormal cells. A critical review of flow cytometric (FCM) antigen expression of the lymphomas was also performed. There were 6 female and 14 male patients, with an age range of 9-84 yr (median, 36 yr). Fourteen cases (70%) showed polymorphous smears, and 6 cases (30%) showed monomorphous smears. Abnormal cells ranged from 10-100% (median, 60%). Abnormal T-cell antigen expression by FCM analysis was seen in 17 cases (85%). The most common aberrant T-cell antigen pattern was loss of 3 or more pan-T-cell antigens (n = 10). The most common individual T-cell antigen loss was that of CD7 (n = 10), followed by loss of CD5 (n = 5). There was also loss of CD4 and CD8 (n = 5), loss of CD5 and CD7 (n = 5), complete loss of CD3 (n = 4), coexpression of CD4 and CD8 (n = 1), and partial loss of CD3 (n = 1). CD56 was expressed in 2 cases. CD1a was tested in one case and was positive. CD4/CD8 ratio was elevated (>2.5) in 9 cases (53%), with a range of 3/1-57/1 (median, 12/1). TCR gene rearrangement using PCR was positive in 7 of 9 tested cases. Our findings suggest that the diagnosis of peripheral T-cell lymphomas can be achieved by FNAB in the majority of cases through close analysis of the morphology. This can be supported by a critical analysis of the phenotype using two or three-color flow cytometry with an attempt at identification of one or more abnormal T-cell antigen expression and/or loss. This can be supplemented by CD4/CD8 ratios and T-cell receptor gene rearrangement analysis.
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PMID:Diagnosis of peripheral T-cell lymphoma by fine-needle aspiration biopsy: a cytomorphologic and immunophenotypic approach. 1107 40

Chronic (histiocytic) intervillositis (CHIV), defined for the purposes of this study as diffuse histiocytic infiltration of the intervillous space without villitis, is an idiopathic lesion seen in the chorionic sacs of some spontaneous abortion specimens and placentas. In this retrospective study, we evaluated all patients diagnosed with CHIV from 2 hospitals between 1993 and 2000, plus 1 additional patient from 1977. Histopathology, phenotype of the leukocytic infiltrate, perinatal outcome, and other associated clinical features were assessed by review of clinical records and all available pathology specimens plus immunohistochemical staining. CHIV was found in 31 of 45 specimens examined from 21 patients (23 of 31 first trimester, 3 of 5 second trimester, and 5 of 9 third trimester). Recurrence rate was 67% for patients with more than one specimen reviewed. Overall perinatal mortality rate was 77%, and only 18% of pregnancies reached 37 weeks. Eight of 19 patients with 3 or more pregnancies had recurrent spontaneous abortion (RSA); 5 with primary RSA (> or = 3 consecutive spontaneous abortions (SAB) with no living children) and 3 with secondary RSA (> or = 3 consecutive SAB with 1 or more living children). Severe intrauterine growth restriction was seen in 5 of 8 second- and third-trimester placentas with CHIV. Patients were generally not of advanced maternal age (mean, 29.8 +/- 6.2 years), and there was no obvious racial predisposition. Autoimmune or allergic phenomena were identified in 11 patients. Immunohistochemical staining of the intervillous infiltrate showed a near uniform population of monocyte-macrophages at varying stages of maturity and activation: more than 90% CD45Rb and CD68 positive, 30% to 40% MAC387 positive, less than 5% CD3 positive, and CD1a, CD20, CD30, and CD56 negative. We conclude that CHIV is an uncommon but important cause of recurrent spontaneous abortion and, in some cases, loss at later gestational ages. HUM PATHOL 31:1389-1396.
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PMID:Chronic histiocytic intervillositis: a placental lesion associated with recurrent reproductive loss. 1156 35

T/NK progenitors are present in the thymus; however, the thymus predominantly promotes T cell development. In this study, we demonstrated that human thymic epithelial cells (TEC) inhibit NK cell development. Most ex vivo human thymocytes express CD1a, indicating that thymic progenitors are predominantly committed to the T cell lineage. In contrast, the CD1a(-)CD3(-)CD56(+) NK population comprises only 0.2% (n = 7) of thymocytes. However, we observed increases in the percentage (20- to 25-fold) and absolute number (13- to 71-fold) of NK cells when thymocytes were cultured with mixtures of either IL-2, IL-7, and stem cell factor or IL-15, IL-7, and stem cell factor. TEC, when present in the cultures, inhibited the increases in the percentage (3- to 10-fold) and absolute number (3- to 25-fold) of NK cells. Furthermore, we show that TEC-derived soluble factors inhibit generation of NK-CFU and inhibit IL15- or IL2-driven NK cell differentiation from thymic CD34(+) triple-negative thymocytes. The inhibitory activity was found to be associated with a 8,000- to 30,000 Da fraction. Thus, our data demonstrate that TEC inhibit NK cell development from T/NK CD34(+) triple negative progenitors via soluble factor(s), suggesting that the human thymic microenvironment not only actively promotes T cell maturation but also controls the development of non-T lineage cells such as the NK lineage.
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PMID:Human thymic epithelial cells inhibit IL-15- and IL-2-driven differentiation of NK cells from the early human thymic progenitors. 1116 Feb 72


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