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 (DCs) are a heterogeneous population of antigen-presenting cells (APCs) identified in various tissues, including the skin (Langerhans cells), lymph nodes (interdigitating and follicular DCs), spleen, and thymus. Properties of DCs include the ability to (1) capture, process, and present foreign antigens; (2) migrate to lymphoid-rich tissue; and (3) stimulate innate and adaptive antigen-specific immune responses. Until recently, the ability to study DCs has been limited by their absence in most culture systems. It is now known that specific cytokines can be used to expand DCs to numbers sufficient for their in vitro evaluation and for their use in human immunotherapy trials. Human DCs can be derived from hematopoietic progenitors (CD34+-derived DCs) or from adherent peripheral blood monocytes (monocyte-derived DCs). Cultured DCs can be recognized by a typical veiled morphologic appearance and expression of surface markers that include major histocompatibility complex class II, CD86/B7.2, CD80/B7.1, CD83, and CD1a. DCs are susceptible to a variety of gene transfer protocols, which can be used to enhance biological function in vivo. Transduction of DCs with genes for defined tumor antigens results in sustained protein expression and presentation of multiple tumor peptides to host T cells. Alternatively, DCs may be transduced with genes for chemokines or immunostimulatory cytokines. Although the combination of ex vivo DC expansion and gene transfer is relatively new, preliminary studies suggest that injection of genetically modified autologous DCs may be capable of generating anti-tumor immune responses in patients with cancer. Preclinical animal studies showing potent antigen-specific tumor immunity after DC-based vaccination support this hypothesis and provide rationale to further evaluate this approach in patients. Preliminary human studies are now required to evaluate optimal DC dose, schedule of vaccination, route of delivery, and maturational state of cultured cells. Initiation of these phase I/II cell therapy-based studies will occur in collaboration with hospital-based transfusion facilities. Issues relating to cell harvesting, storage, culture methodology, and administration require the collaborative efforts of basic scientists, immunologists, clinical investigators, and transfusion medicine staff to ensure strict quality control of injected cellular products. This review is intended to provide a brief overview of clinical DC-based gene transfer.
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PMID:Genetically modified dendritic cells in cancer therapy: implications for transfusion medicine. 1166 36

True histiocytic lymphoma, as defined by strict criteria, is a very rare neoplasm. We describe three cases occurring as primary tumors in the central nervous system. The patients, two females and one male, ranged in age from 11 to 69 years. The tumors involved the brain in two cases and spinal cord in one, with a size ranging from 7 to 17 mm. Two patients died at 4 months and 8 months, respectively, and one was alive with disease at 5 months. Pathologically, the tumors comprised groups and sheets of noncohesive large cells with pleomorphic vesicular nuclei, distinct nucleoli, and abundant eosinophilic cytoplasm. A dense inflammatory infiltrate consisting of neutrophils, lymphocytes, plasma cells, and histiocytes was present, with multiple foci of necrosis and abscess formation. All three cases demonstrated an identical immunophenotype: positive for CD68 and lysozyme; focally positive for S-100 protein, CD45RB, and CD4; and negative for CD3, CD20, CD21/CD35, CD1a, CD30, ALK1, myeloperoxidase, glial fibrillary acidic protein, and cytokeratin. The proliferative index ranged from 20% to 35%. Ultrastructural examination further confirmed the histiocytic nature of the tumor cells, characterized by irregularly folded or multisegmented nuclei and abundant cytoplasm containing lysosomes; Birbeck granules, interdigitating cell processes, and cell junctions were not found. Although the presence of abundant inflammatory cells could obscure the neoplastic histiocytes, making the distinction from inflammatory conditions difficult, awareness of this unusual histologic feature and the invariable finding of pleomorphic cells in some areas of the lesion permit the correct diagnosis to be made.
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PMID:Primary histiocytic lymphoma of the central nervous system: a neoplasm frequently overshadowed by a prominent inflammatory component. 1168 53

Experimental protocols for cancer immunotherapy include the utilization of autologous monocyte-derived dendritic cells (moDC) pulsed with tumor antigens. However, disease can alter the characteristics of monocyte precursors and some patients have increased numbers (up to 40%) of the minor CD16(+) monocyte subpopulation, which in healthy individuals represent 10% of blood monocytes. At the present, the capacity of CD16(+) monocytes to differentiate into DC has not been evaluated. Here, we investigated the ability of CD16(+) monocytes cultured with granulocyte- macrophage colony-stimulating factor, IL-4 and tumor necrosis factor-alpha to generate DC in vitro, and we compared them to DC derived from regular CD16(-) monocytes. Both monocyte subsets gave rise to cells with DC characteristics. They internalized soluble and particulate antigens similarly, and both were able to stimulate T cell proliferation in autologous and allogeneic cultures. Nevertheless, CD16(+) moDC expressed higher levels of CD86, CD11a and CD11c, and showed lower expression of CD1a and CD32 compared to CD16(-) moDC. Lipopolysaccharide-stimulated CD16(-) moDC expressed increased levels of IL-12 p40 mRNA and secreted greater amounts of IL-12 p70 than CD16(+) moDC, whereas levels of transforming growth factor-beta1 mRNA were higher on CD16(+) moDC. Moreover, CD4(+) T cells stimulated with CD16(+) moDC secreted increased amounts of IL-4 compared to those stimulated by CD16(-) moDC. These data demonstrate that both moDC are not equivalent, suggesting either that they reach different stages of maturation during the culture or that the starting monocytes belong to cell lineages with distinct differentiation capabilities.
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PMID:CD16+ and CD16- human blood monocyte subsets differentiate in vitro to dendritic cells with different abilities to stimulate CD4+ T cells. 1171 98

Tumour-derived factors suppress differentiation and function of in vitro generated DC. Here, we investigate the effect of two melanoma clones differing in their invasive and metastatic properties on the generation and/or functional maturation of human epidermal LC. LC were generated from CD34(+) cord blood progenitors under GM-CSF/TNF-alpha/TGF-beta 1. CD34(+) cells were co-cultured with or without melanoma cells using Transwell dishes. After 11 days of co-culture, CD34(+)-derived cells display a non-adherent undifferentiated morphology, a high level of monocytic CD14 marker, a down-regulated expression of LC markers (CD1a, E-cadherin) and DC markers (CD40, CD80, CD54, CD58, CD83, CD86, HLA-DR, HLA-class I). These cells were less potent than control LC in inducing allogeneic T cell proliferation. The generation of the CD14(+) population was correlated with a decrease in the CD1a(+) population, without any statistical differences between the two clones. Melanoma cells diverted the differentiation of CD34(+) cells towards a dominant CD14(+) population only if the progenitors were in an early growth phase. IL-10, TGF-beta 1 and VEGF were not responsible for these effects, as assessed by using blocking antibodies. By contrast, co-culture of fresh epidermal LC with melanoma cells did not affect their phenotype and function. Our data demonstrate that melanoma cells inhibit the earliest steps of LC differentiation, but failed to affect the functional maturation of epidermal LC. This suggests that melanoma cells participate in their own escape from immunosurveillance by preventing LC generation in the local cutaneous microenvironment.
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PMID:Human melanoma cells inhibit the earliest differentiation steps of human Langerhans cell precursors but failed to affect the functional maturation of epidermal Langerhans cells. 1174 38

T-cell prolymphocytic leukemia (T-PLL) is a postthymic T-cell neoplasm with a characteristic morphology and heterogeneous immunophenotype. Most cases of T-PLL express membrane T-cell receptors (TCRs) of the alphabeta phenotype. We experienced a 30-year-old man suffering from TCRgammadelta T-cell leukemia with morphology compatible to T-PLL with a postthymic phenotype. He was admitted with skin eruption and pancytopenia. Peripheral blood and bone marrow were occupied with medium-sized lymphocytes, which had moderately condensed chromatin with a single nucleolus and sparse, nongranular basophilic cytoplasm. The immunophenotype was CD1a-, CD2-, CD3+, CD4-, CD5+, CD7+, CD8-, and terminal deoxynucleotidyl transferase negative. Hepatosplenomegaly was absent. He was diagnosed as having T-PLL and was treated with combination chemotherapy. Six months later the leukemic cell became chemoresistant. Although the patient showed transient improvement in response to pentostatin, he died 13 months after the diagnosis. To our knowledge, this is the first case of T-PLL with a TCRgammadelta phenotype.
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PMID:T-cell receptor gammadelta T-cell leukemia with the morphology of T-cell prolymphocytic leukemia and a postthymic immunophenotype. 1179 17

P-glycoprotein (Pgp) and vaults are associated with multidrug resistance in tumor cells, but their physiological functions are not yet clear. Pgp, the prototypical transmembrane transporter molecule, may also facilitate the migration of skin dendritic cells (DC). Vaults--ribonucleoprotein cell organelles, frequently overexpressed in Pgp-negative drug-resistant tumor cells--have also been associated with intracellular transport processes. Given the pivotal role of DC in dealing with exposure to potentially harmful substances, the present study was set out to examine the expression of Pgp and vaults during differentiation and maturation of DC. DC were obtained from different sources, including blood-derived monocytes, CD34(+) mononuclear cells, and chronic myeloid leukemia cells. Whereas flow cytometric and immunocytochemical analyses showed slightly augmented levels of Pgp, up-regulation of vault expression during DC culturing was strong, readily confirmed by Western blotting, and independent of the source of DC. In further exploring the functional significance of vault expression, it was found that supplementing DC cultures with polyclonal or mAbs against the major vault protein led to lower viabilities of LPS- or TNF-alpha-matured monocytes-DC. Moreover, expression of critical differentiation, maturation, and costimulatory molecules, including CD1a and CD83, was reduced and their capacity to induce Ag-specific T cell proliferative and IFN-gamma release responses was impaired. These data point to a role for vaults in both DC survival and functioning as APC.
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PMID:Up-regulation of drug resistance-related vaults during dendritic cell development. 1182 84

We analyzed the clinicopathologic and molecular findings in 26 adults (age 16-72 years) with T-cell acute lymphoblastic leukemia (T-ALL) and observed features that correlated with age. Patients older than 60 years (n = 5) had a low frequency of hepatosplenomegaly (0 [0%]), anterior mediastinal mass (1 [20%]), and lymphadenopathy (2 [40%]), and completely responded to chemotherapy (4 of 4). The T-ALL in this group commonly expressed myeloid antigens (4 [80%]), had lineage-inappropriate gene rearrangements (2/3 [67%]) and chromosome 2 deletion (3/4 [75%]), and exclusively used the V(III) or V(IV) families of the T-cell receptor (TCR) gamma gene. In comparison, patients 16 to 60 years old (n = 21) more commonly had an anterior mediastinal mass (8 [38%]), hepatosplenomegaly (10 [48%]), and lymphadenopathy (16 [76%]). The tumors in these patients commonly used the TCR gamma gene VI or V(II) families (17/25 total rearrangements [68%]). Myeloid antigen expression (5 [24%]) and lineage inappropriate gene rearrangements (4/15 [27%]) were uncommon. Within this group, CD1a expression correlated with age 28 to 60 years. These results illustrate considerable age-related heterogeneity in adult T-ALL, which may reflect differences in tumor cell maturation.
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PMID:Precursor T-cell acute lymphoblastic leukemia in adults: age-related immunophenotypic, cytogenetic, and molecular subsets. 1186 21

Gamma/delta T-cell lymphoma is a rare neoplasm that is not well characterized and is associated with a poor prognosis. We report a case of gamma/delta peripheral T-cell lymphoma that appeared as a breast lump in a 35-yr-old woman. The patient was examined for a 2-mo history of a right-sided breast mass with associated hepatosplenomegaly 2 yr in duration. A fine-needle aspiration biopsy (FNAB) was performed, and the diagnosis of lymphoma was rendered. The patient received two cycles of CHOP and is alive with persistent disease. FNAB showed evidence of polymorphous lymphoma, consisting of medium-size to large cells with immature chromatin. Flow cytometric immunophenotyping showed expression of CD2, CD3, and CD7 with lack of expression of CD1a, CD4, CD5, CD8, and CD56. Flow cytometry also showed predominant expression of the gamma/delta T-cell receptor. Cytogenetic analysis showed 48XX+i7(q11.2),+7(3). Our case indicates that gamma/delta peripheral T-cell lymphoma can be diagnosed by FNAB. This rare entity requires further investigation.
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PMID:gamma/delta peripheral T-cell lymphoma of the breast diagnosed by fine-needle aspiration biopsy. 1189 23

Interdigitating dendritic cell sarcoma is an extremely rare neoplasm that mainly occurs in the lymph nodes. We report a case of interdigitating dendritic cell sarcoma arising from the spleen, a previously unreported site for interdigitating dendritic cell sarcoma. An 87-year-old woman, visiting Ashigara Hospital with complaints of palpitation and dyspnea, was found to have pancytopenia and low proteinemia. Abdominal ultrasonography and CT scanning demonstrated severe splenomegaly with heterogeneous enhancement. She received a splenectomy under the clinical diagnosis of a splenic tumor. Grossly, the spleen was markedly enlarged, with confluent massive nodules. Microscopically, the normal architecture was effaced with diffuse proliferation of large pleomorphic cells arrayed in a somewhat sheet-like pattern. Erythrophagocytosis was commonly observed. Immunohistochemical studies showed that the tumor cells were positive for S-100 protein, fascin, vimentin, and CD68, but uniformly negative for CD45, B- and T-cell markers, CD1a, CD30, complement receptors, CD34, Factor VIII, HMB-45, and lysozyme. Ultrastructurally, the tumor cells possessed complex interdigitating cytoplasmic dendritic processes. Birbeck granules were absent. Based on these findings, the present case was diagnosed as interdigitating dendritic cell sarcoma. The patient died of multiple liver metastases 3 months postoperatively.
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PMID:Interdigitating dendritic cell sarcoma of the spleen: report of a case with a review of the literature. 1191 34

Production of immunosuppressive factors is one of the mechanisms by which tumors evade immunosurveillance. Soluble factors hampering dendritic cell (DC) development have recently been identified in culture supernatants derived from tumor cell lines. In this study, we investigated the presence of such factors in 24-h culture supernatants from freshly excised solid human tumors (colon, breast, renal cell carcinoma, and melanoma). While primary tumor-derived supernatant (TDSN) profoundly hampered the in vitro DC differentiation from CD14(+) plastic-adherent monocytes or CD34(+) precursors (based on morphology and CD1a/CD14 phenotype), the effects of tested tumor cell line-derived supernatants were minor. Cyclooxygenase (COX)-1- and COX-2-regulated prostanoids present in the primary TDSN were found to be solely responsible for the observed hampered differentiation of monocyte-derived DC (MoDC). In contrast, both prostanoids and IL-6 were found to contribute to the TDSN-induced inhibition of DC differentiation from CD34(+) precursor cells. While the addition of TDSN during differentiation interfered with the ability of CD34-derived DC to stimulate a primary allogeneic T cell response, it actually increased this ability of MoDC. These opposite effects were correlated to different effects of the TDSN on the expression levels of CD86 and HLA-DR on the DC from the different precursor origins. Although TDSN increased the T cell-stimulatory capacity of MoDC, TDSN inhibited the IL-12 production and increased the IL-10 production of MoDC, thus skewing them to a type-2 T cell-inducing phenotype. In conclusion, this study demonstrates that primary tumors negatively impact DC development and function through COX-1 and -2 regulated factors, whereas tumor-derived cell lines may lose this ability upon in vitro propagation.
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PMID:Prostanoids play a major role in the primary tumor-induced inhibition of dendritic cell differentiation. 1197 Sep 75


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