Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Wiskott-Aldrich syndrome (WAS) is an X-linked disorder characterized by immune deficiency, eczema, and microthrombocytopenia. Biochemical evidence indicates that the Wiskott-Aldrich syndrome protein (WASp) is involved in regulating the actin cytoskeleton. Here we report that WAS dendritic cells (DC) have an immunophenotype very similar to normal DC. However, as a consequence of an intrinsically abnormal cytoarchitecture, they are unable to polarize normally and have severely reduced translocational motility in vitro. These findings indicate that WASp is an essential effector for Cdc-42-mediated polarization of primary hematopoietic cells, and suggest that a significant component of the clinical phenotype of WAS could arise from peripheral DC dysmotility and aberrant immune cell trafficking in vivo. Intrinsic dysfunction of the DC population may also have an important role in the pathogenesis of other primary immunodeficiency syndromes, while induced changes in DC cytoskeletal signaling pathways may contribute to the initiation of acquired immunological and inflammatory disorders.
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PMID:Intrinsic dendritic cell abnormalities in Wiskott-Aldrich syndrome. 980 95

The Wiskott-Aldrich syndrome (WAS) is a X-linked hematologic disorder characterized by thrombocytopenia, eczema, and immunodeficiency of variable severity. Reported here are the results of a morphologic, morphometric, and immunophenotypic analysis of splenic lymphoid tissue in 12 WAS patients with documented molecular defect and with different disease severity. Spleens from 29 age-matched patients with different diseases were used as controls. Paraffin-embedded tissue (from all cases) and fresh-frozen samples (from 5 WAS patients and 4 control subjects) were used to study the different white pulp compartments by classic morphologic, immunophenotyping, and image analysis techniques. Data were statistically analyzed by both parametric and nonparametric tests. Spleens from WAS patients showed a significant depletion of the total white pulp (p = 0.0008), T cell (p < 0.05), and B cell (p = 0.0002) areas and marginal zone (MZ) thickness (p < 0.0001). Among WAS patients, a negative correlation was found between the score of severity of the disease and all variables considered (Spearman's rank correlation coefficient, r = -0.79, r = -0.73, r = -0.68, and r = -0.56, respectively). In conclusion, this study shows that in WAS a general depletion of the splenic white pulp occurs, supporting the evidence that WAS is characterized by a combined immune defect. The significant reduction of the MZ may explain the inability of WAS patients to mount a response to T-independent antigens.
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PMID:The spleen in the Wiskott-Aldrich syndrome: histopathologic abnormalities of the white pulp correlate with the clinical phenotype of the disease. 998 45

Cutaneous diseases are common manifestations of infection with human immunodeficiency virus (HIV). Phototherapy with ultraviolet B (UVB) and photochemotherapy with 8-methoxypsoralen plus UVA (PUVA) have been used successfully to treat several of these skin conditions, including psoriasis, folliculitis, pruritus, and eczema. However, in view of the known immunosuppressive effects of UV radiation, concerns have been raised about potential adverse effects of UV on persons infected with HIV. In the following report, we review the effects of UV in HIV-infected cell lines in vitro, in animal models, as well as in human studies. Based on currently available data, UV radiation, as used in phototherapy and photochemotherapy, appears to have no adverse effects in HIV-infected individuals.
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PMID:HIV, UV and immunosuppression. 999 Jun 66

The association between the atopic dermatitis, eczema and T-cell immunodeficiency disorders are well known, thus suggesting that bone marrow T-precursors could use the micro-environment of the skin as an extrathymic site for compensatory ontogenesis. In keeping with this hypothesis, we analyzed the atopic dermatitis skin lymphocytic infiltrate phenotypes to establish their ontogenetic stage of development. Cryostatic sections (4 microns) obtained from acute lesional skin biopsies of six patients with extrinsic atopic dermatitis were processed with indirect immunoperoxidase, using a panel of first-step monoclonal antibodies (mAb) specific to CD104 (integrin beta 4 chain), CD90w (Thy 1 antigen), CD44 (phagocytic glycoprotein-1; Pgp-1), CD1a and the DNA polymerase terminal deoxynucleotidyl transferase (TdT). Within the lymphocytic dermal infiltrate different levels of immunoreactivity were observed with respect to CD104, CD90w and CD1a. A strong, spread staining was also detected for mAb specific to Pgp-1 and TdT. Together, the reported features indicate that the atopic dermatitis skin-homing lymphocytes express immunophenotypes which are distinctive of the early T-ontogeny.
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PMID:Expression of T-lineage early developmental markers by cells establishing atopic dermatitis skin infiltrates. 1002 83

The Wiskott-Aldrich syndrome (WAS) is an X-linked disorder characterized by immunodeficiency, eczema and thrombocytopenia. The gene responsible for WAS was identified through positional cloning, and the function of the encoded protein (WASP) is still the subject of much speculation. WASP is currently thought to be involved in the regulation of actin polymerization in hematopoietic cells. To study the elements that regulate the WASP gene, we have identified the sites for transcription initiation. We found that two promoters were responsible for controlling WASP expression. Multiple transcription initiation sites were found immediately adjacent to the translation start site, however an alternate exon with a second promoter region was identified 6 kb upstream. Examination of the 5' sequence adjacent to the initiation sites in both promoters failed to reveal a TATA or CCAAT box, but numerous putative transcription factor binding sites including Sp1, Ets, c-Myb and PU.1 were apparent. Reporter constructs generated from each promoter showed functional activity in the Jurkat T-cell and HEL erythro-megakaryocytic cell lines. Although the alternate exon sequence was extremely GC rich and contained several potential binding elements, the primary promoter was stronger than the upstream promoter in the cell lines assayed. The transcription factor binding site profiles within each promoter suggested that they may play different roles in regulating WASP expression depending on the stage of differentiation and development, and the cell lineage. In this study we have also reported the complete nucleotide sequence of the coding and intervening sequences for the WASP gene. A comprehensive knowledge of the genomic structure and the further characterization of WASP gene expression will facilitate the continued investigation of mutations in WAS patients, and the eventual prospect of gene therapy.
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PMID:The identification and characterization of two promoters and the complete genomic sequence for the Wiskott-Aldrich syndrome gene. 1006 31

The Wiskott-Aldrich Syndrome (WAS) is a rare X-linked primary immunodeficiency that is characterized by recurrent infections, hematopoietic malignancies, eczema, and thrombocytopenia. A variety of hematopoietic cells are affected by the genetic defect, including lymphocytes, neutrophils, monocytes, and platelets. Early studies noted both signaling and cytoskeletal abnormalities in lymphocytes from WAS patients. Following the identification of WASP, the gene mutated in patients with this syndrome, and the more generally expressed WASP homologue N-WASP, studies have demonstrated that WASP-family molecules associate with numerous signaling molecules known to alter the actin cytoskeleton. WASP/N-WASP may depolymerize actin directly and/or serve as an adaptor or scaffold for these signaling molecules in a complex cascade that regulates the cytoskeleton.
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PMID:The Wiskott-Aldrich syndrome protein (WASP): roles in signaling and cytoskeletal organization. 1035 77

The Rho-family GTP-hydrolysing proteins (GTPases), Cdc42, Rac and Rho, act as molecular switches in signalling pathways that regulate cytoskeletal architecture, gene expression and progression of the cell cycle. Cdc42 and Rac transmit many signals through GTP-dependent binding to effector proteins containing a Cdc42/Rac-interactive-binding (CRIB) motif. One such effector, the Wiskott-Aldrich syndrome protein (WASP), is postulated to link activation of Cdc42 directly to the rearrangement of actin. Human mutations in WASP cause severe defects in haematopoletic cell function, leading to clinical symptoms of thrombocytopenia, immunodeficiency and eczema. Here we report the solution structure of a complex between activated Cdc42 and a minimal GTPase-binding domain (GBD) from WASP. An extended amino-terminal GBD peptide that includes the CRIB motif contacts the switch I, beta2 and alpha5 regions of Cdc42. A carboxy-terminal beta-hairpin and alpha-helix pack against switch II. The Phe-X-His-X2-His portion of the CRIB motif and the alpha-helix appear to mediate sensitivity to the nucleotide switch through contacts to residues 36-40 of Cdc42. Discrimination between the Rho-family members is likely to be governed by GBD contacts to the switch I and alpha5 regions of the GTPases. Structural and biochemical data suggest that GBD-sequence divergence outside the CRIB motif may reflect additional regulatory interactions with functional domains that are specific to individual effectors.
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PMID:Structure of Cdc42 in complex with the GTPase-binding domain of the 'Wiskott-Aldrich syndrome' protein. 1036 May 78

Recurrent acyclovir (ACV)-resistant (ACV-r) herpes simplex virus type 1 (HSV-1) infections occurred in a patient with Wiskott-Aldrich syndrome, an X-linked recessive immunodeficiency syndrome composed of three clinical characteristics of immunodeficiency, thrombocytopenia, and an eczematous dermatitis. The patient had severe and recurrent ACV-r herpes simplex and was treated with vidarabine in a satisfactory manner from 1993 to 1997. During the 4-year observation period, two ACV-sensitive (ACV-s) HSV-1 isolates and five ACV-r HSV-1 isolates were recovered. The nucleotide sequence of the thymidine kinase (TK) gene from these sequential ACV-r isolates was compared with the ACV-s isolates. A single nucleotide deletion of cytosine (C) from homopolymer stretch of four C residues between nucleotide 1061 and 1064 of the open reading frame was found in all ACV-r isolates. No other differences were observed in the TK nucleotide sequence between ACV-s and ACV-r isolates. The TK nucleotide sequences of the two ACV-s isolates were identical to each other and those of the five ACV-r isolates were identical to one another. These results suggest that the ACV-r HSV-1 might have derived from the ACV-s strain in the patient body and that TK-associated ACV-r HSV-1 can reactivate from latency.
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PMID:Nucleotide sequence of thymidine kinase gene of sequential acyclovir-resistant herpes simplex virus type 1 isolates recovered from a child with Wiskott-Aldrich syndrome: evidence for reactivation of acyclovir-resistant herpes simplex virus. 1042 6

Wiskott-Aldrich syndrome (WAS) is an X-linked recessive immunodeficiency characterized by thrombocytopenia, eczema, and recurrent infections, and caused by mutations in the WAS protein (WASP) gene. WASP contains several functional domains through which it interacts with proteins involved in intracellular signaling and regulation of the actin cytoskeleton. In this report, 17 WASP gene mutations were identified, 12 of which are novel. DNA of affected males and obligate carriers was PCR amplified and analyzed by SSCA, heteroduplex analysis, and direct sequencing. The effects of the mutations at the mRNA and protein level were ascertained by RT-PCR and Western blot analyses. All missense mutations were located in exons 1-4. Most of the nonsense, frameshift and splice site mutations were found in exons 6-11. Mutations that alter splice sites led to the synthesis of several types of mRNAs, a fraction of which represented the normally spliced product. The presence of normally spliced transcripts was correlated with a milder phenotype. When one such case was studied by Western blotting, reduced amounts of normal-size WASP were present. In other cases as well, a correlation was found between the amount of normal or mutant WASP present and the phenotypes of the affected individuals. No protein was detected in two individuals with severe WAS. Reduced levels of a normal-size WASP with a missense mutation were seen in two individuals with XLT. It is concluded that mutation analysis at the DNA level is not sufficient for predicting clinical course. Studies at the transcript and protein level are needed for a better assessment.
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PMID:Novel mutations in the Wiskott-Aldrich syndrome protein gene and their effects on transcriptional, translational, and clinical phenotypes. 1044 59

Wiskott-Aldrich syndrome (WAS) is a rare X-linked recessive trait, characterized by thrombocytopenia, eczema, immunodeficiency and a high risk of malignancy, usually leukaemia or lymphoma. Until recently, most patients died before the age of 10 years. A patient with WAS who developed extranodal non-Hodgkin's lymphoma at the age of 16 years is reported. Despite thrombocytopenia at presentation, chemotherapy was well tolerated. There was disease progression after first line chemotherapy and radiotherapy, but the patient responded to second line chemotherapy with cisplatin, vincristine and etoposide. He remains disease free 9 years after completing treatment.
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PMID:Long-term survival following non-Hodgkin's lymphoma arising in Wiskott-Aldrich syndrome. 1047 30


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