Dentritic Cell Research Articles

Challenge in diagnosis of CD56+ lymphoproliferative disorders: two cases of CD56+CD33+ lymphoma/leukemia.

Two cases of CD56+CD33+ leukemia/lymphoma are reported. The patient in case 1 presented with skin rash, diffuse lymphadenopathy, and hepatosplenomegaly. Blasts with monocytoid and lymphoid features were present in the peripheral blood. The tumor cells expressed HLA-DR, CD4, CD33, CD38, and CD56. Cytogenetic analysis revealed del(2)(p13),del(9)(q22),add(6)(q25),add(12)(p12),-13,-18, and -20. The clinicopathologic features were similar to those of blastic natural killer cell leukemia/lymphoma or type 2 dentritic cell leukemia. The patient in case 2 presented with generalized weakness and skin erythema not responding to antibiotics. Circulating blasts with monocytoid features were seen in the peripheral blood. The tumor cells expressed CD7, CD13, CD33, CD38, and CD56, and cytogenetic analysis revealed -5,add(7)(p22),-8, del(10)(p11.2),-12,der(13; 14)(p10;p10),+14,-16,-18,-19, and del(20)(q13.1). The clinicopathologic features were consistent with a myeloid/ natural killer cell precursor acute leukemia. Both disorders are aggressive hematopoietic malignancies that have similar clinical presentation and morphology but differ in immunophenotype and cytogenetic features.

Of DALIS and DRiPs

CELL BIOLOGY Dendritic cells of the immune system respond to inflammatory signals by undergoing a process of maturation that equips them for antigen processing and presentation. In mature dendritic cells, polyubiquitinated proteins are sorted to intracellular aggregates that have been termed DALIs (for dentritic cell aggresome-like induced structures). DALIs only form when protein synthesis is ongoing; inhibition of protein synthesis leads to their disassembly. Lelouard et al. examined what processes are involved in targeting defective proteins and peptides to DALIs. In the presence of the peptide elongation inhibitor puromycin, incompletely synthesized proteins accumulate. These defective ribosomal products (or DRiPs) were observed to be stored rapidly in DALIs, where they were protected from degradation. Neither an intact microtubule network nor the actin microfilament network was required for this targeting. The DALIs were the sites at which DRiPs appeared to become ubiquitinated. DriPs also form in the absence of puromycin, and the production of these products from self and viral antigens is important in MHC class I restricted antigen presentation. It thus appears that dendritic cells are able to regulate the degradation of DRiPs by producing DALIs and this, in turn, is likely to be important in regulating antigen processing and presentation. — SMH J. Cell Biol. 164 , 667 (2004).

Las células del sistema inmune accesorio

In the reticulo- Endothelial System (RES9, named at present Accesory Inmune System (AIS), two chieff groups of cells can be recognized: 1- Antigen - presnting cells: Dendritic cells 2- Antigen - processing cells: Macrophages (or Histiocytic cell) These cells are wildely disseminated into human organs and tissues: lymphoid organs, blood, liver, endocrine glands, lung, skin, blood vessels, central and peripheral nervous systems (CNS and PNS), placenta. kidney, and soft tissues. Dendritics cells and macrophages can be observed in tissues with silver impregnation technique of Del Río Hortega - Polak, or with multiple specific immunohistochemical stains. The origin of macropage / monocyte is from common pluripoyencial bone marrow progenitor cell, with susequently stages of maturation: Colony - Forming Units (CFU-S), Colony- Forming Units of Granulocyte / Macrophage (CFU-G/M), Colony - Forming Units of Macrophages/ Monocytes. The origin of dentritic cells is heterogenous. Their lineage is from the same bone marrow precursors of macrophages/ monocytes, but there are recent evidences that also may have a lymphoid origin. Macrophages play important roles in: 1- Phagocytosis. 2- Natural Immunity. 3- Secretion of Cytokines. 4- Antigen presentation. The primary function of dentritic cells is the presentation of antigen and activation of T lymphocytes. Nonmalignant reactive disorders and true malignant neoplasms of macrophages and dentritic cells, have been actually reviewed. Between the main entities of these groups there are: 1- Nonmalignant reactive macrophages disorders: Hemophagocytic Syndromes. Sinus Histiocytosis with Massive Lymphadenopathy (Rosai- Dorfman disease) And nonmalignant reactive Langerhans cells disorders: Langehans's - cell Histiocytosis (Histiocytosis X) 2- True malignant Histiocytic Sarcoma (Reticulum cell Sarcoma). Malignant Histiocytosis. Microglioma of CNS 3- True Malignant neoplasm of dentritic cells: Folicular Dentritic Cell Sarcoma and Interdigitating Dentritic Cell Sarcoma. True malignant Langerhans cell neoplasm has not been yet clearly demonstrated. Finally, it is important to note that marcrophages and dentritic cells are commonly observed as reactive cells in numerous malignant tomors (carsinomas, sarcomas, lymphomas, etc) However, their precise role has yet to be determined.

Human TNF Receptor-Associated Factor 5 (TRAF5): cDNA Cloning, Expression and Assignment of the TRAF5 Gene to Chromosome 1q32

Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) are signal transducers for members of the TNF receptor superfamily. We previously identified murine TRAF5 (mTRAF5) and showed that it specifically interacts with the lymphotoxin-β receptor (LT-βR) and activates the transcription factor NF-κB. Here we have cloned the human TRAF5 homologue (hTRAF5) by cross hybridization with mTRAF5 cDNA. hTRAF5 cDNA is composed of 2894 nucleotides with a 557-amino-acid open reading frame that exhibits 77.5 and 80% identity to mTRAF5 at the nucleotide and amino acid levels, respectively. Northern blot analysis revealed that hTRAF5 mRNA is expressed in all visceral organs. Western blotting revealed that hTRAF5 protein was abundantly expressed in the human follicular dentritic cell line, FDC-1, and to a much lesser degree in several tumor cell lines. Interspecific backcross mapping revealed thatTraf5is located in the distal region of mouse chromosome 1, which shares a region of homology with human chromosome 1q. Fluorescencein situhybridization confirmed regional localization to human chromosome 1q32.

Infiltration by immunocompetent cells in early stage invasive carcinoma of the uterine cervix: a prognostic study

In various tumor types dentritic cell, infiltration and the presence of tumor-infiltrating lymphocytes have been associated with an improved clinical outcome. In the uterine cervix these immunocompetent cells have been associated with improved prognosis in high stage disease. The current study examines the significance of stromal and tumor T-lymphocyte infiltration together with S-100 positive dendritic cell infiltration in a series of 73 women with low stage (FIGO 1b) invasive squamous and adenosquamous cervical carcinoma. Thirty four percent of cases contained S-100 positive dendritic cells. These were under-represented in cases showing pelvic recurrence or distant disease (1 of 11 compared to 24 of 62 free of recurrence, P = 0.05) and over-represented in cases showing lymphatic/capillary space involvement (12 of 23 compared to 13 of 46 without vascular space invasion, P = 0.05). The women were followed up for an average of 5.2 years and the five-year survival for women whose tumors contained S-100 positive dendritic cells was 92% compared to 73% for negative cases (P = 0.04). There was a significant association between a low density of tumor infiltrating T-cells and risk of pelvic lymph node spread and subsequent local or distant disease control failure (P = 0.008). A five year survival advantage was seen with five or more CD 3 positive tumor infiltrating T-lymphocytes per high power field (90%) compared to a lower count (68%) (P = 0.04). A similar advantage could not be demonstrated for a high stromal infiltrate of T-cells. As yet neither the specific mechanisms that induce these cells to infiltrate some cervical carcinomas nor the nature of the immunological injury that the cells co-ordinate in tumor tissue are well understood.