Immunological Phenotypes (immunological + phenotype)

Distribution by Scientific Domains


Selected Abstracts


Autoimmunity, spontaneous tumourigenesis, and IL-15 insufficiency in mice with a targeted disruption of the tumour suppressor gene Fus1,

THE JOURNAL OF PATHOLOGY, Issue 5 2007
AV Ivanova
Abstract The Fus1 gene resides in the critical 3p21.3 human chromosomal region deleted in lung and breast cancers. Recently, the tumour suppressor properties of Fus1 were confirmed experimentally by intra-tumoural administration of Fus1 that suppressed experimental lung metastasis in mice. We generated Fus1 -deficient mice that were viable, fertile, and demonstrated a complex immunological phenotype. Animals with a disrupted Fus1 gene developed signs of autoimmune disease, such as vasculitis, glomerulonephritis, anaemia, circulating autoantibodies, and showed an increased frequency of spontaneous vascular tumours. Preliminary analysis of immune cell populations revealed a consistent defect in NK cell maturation in Fus1 null mice that correlated with changes in the expression of IL-15. Injection of IL-15 into Fus1 knockout mice completely rescued the NK cell maturation defect. Based on these results, we propose the hypothesis that Fus1 deficiency affects NK cell maturation through the reduction of IL-15 production but does not directly alter their developmental capacity. Since acquired immunity was not affected in Fus1 -deficient animals, we suggest a relationship between the Fus1 protein and the regulation of innate immunity via IL-15 production. The increased frequency of spontaneous cancers and the development of an autoimmune syndrome in Fus1 null mice imply that these mice could serve as a model for studying molecular mechanisms of anti-tumour immunity and autoimmunity. Published in 2007 by John Wiley & Sons, Ltd. [source]


Arabidopsis XXT5 gene encodes a putative ,-1,6-xylosyltransferase that is involved in xyloglucan biosynthesis

THE PLANT JOURNAL, Issue 1 2008
Olga A. Zabotina
Summary The function of a putative xyloglucan xylosyltransferase from Arabidopsis thaliana (At1g74380; XXT5) was studied. The XXT5 gene is expressed in all plant tissues, with higher levels of expression in roots, stems and cauline leaves. A T-DNA insertion in the XXT5 gene generates a readily visible root hair phenotype (root hairs are shorter and form bubble-like extrusions at the tip), and also causes the alteration of the main root cellular morphology. Biochemical characterization of cell wall polysaccharides isolated from xxt5 mutant seedlings demonstrated decreased xyloglucan quantity and reduced glucan backbone substitution with xylosyl residues. Immunohistochemical analyses of xxt5 plants revealed a selective decrease in some xyloglucan epitopes, whereas the distribution patterns of epitopes characteristic for other cell wall polysaccharides remained undisturbed. Transformation of xxt5 plants with a 35S::HA-XXT5 construct resulted in complementation of the morphological, biochemical and immunological phenotypes, restoring xyloglucan content and composition to wild-type levels. These data provide evidence that XXT5 is a xyloglucan ,-1,6-xylosyltransferase, and functions in the biosynthesis of xyloglucan. [source]


Recombinase-activating gene 1 immunodeficiency: different immunological phenotypes in three siblings

ACTA PAEDIATRICA, Issue 6 2009
Srdjan Pasic
Abstract We report different immunological phenotypes in three siblings from consanguineous family with recombinase-activating gene 1 (RAG1) gene mutations. Null mutations of RAG genes result in severe combined immunodeficiency (SCID) with absent T and B cells. Hypomorphic mutations with retained activity of RAG genes may lead to a ,leaky' SCID with some features of Omenn syndrome (OS) or typical OS. In our three patients, homozygous, hypomorphic RAG1 gene mutation (g.368,369delAA) was detected. Two patients presented with T,B,SCID phenotype while the youngest patient developed T+B+NK+SCID phenotype with expansion of autologous T-cell receptor (TCR) ,,-positive T cells, increased immunoglobulin levels and retained ability for antibody production. Similar to originally reported patients with this newly recognized immune phenotype, our patient developed disseminated cytomegalovirus (CMV) infection and autoimmune cytopenia. Conclusion: In infants with disseminated cytomegalovirus infection and autoimmune cytopenia, even if basic immunologic investigation appears normal, RAG1 immunodeficiency should be considered. [source]