Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Insulin-dependent diabetes is a chronic autoimmune disease probably mediated by T cells. We examined the alpha chain of the T-cell antigen receptor in two models of this illness (man and BB rat) to determine any association with autoimmune diabetes. We conducted a population study in man, using a human alpha chain probe, pGA-5, and restriction enzyme Bgl 11. Two allelic forms and three RFLP patterns, 2.8 and 3.0 kb homozygous and 2.8/3.0 heterozygous, were detected. There was no difference in the frequency of these RFLPs among the 50 Type I diabetic patients and 48 controls tested. BB rats develop a spontaneous T-cell mediated autoimmune diabetes. The diabetes has been linked in several breeding studies to an undetermined autosomal recessive gene causing T-cell lymphopenia. We were able to differentiate the T-cell antigen receptor alpha chain of the diabetic BB and control BBN rats using the restriction enzyme EcoR1 and a murine alpha chain probe, TT11. The BB rat had a haplotype characterized by the presence of 4.7 and 5.8 kb bands, and the absence of 1.4, 2.2, 2.6, 3.6, 3.9, 4.1, and 6.1 kb bands. In a breeding study with BB and BBN rats, diabetic animals of the F2 generation demonstrated no linkage with the BBs' alpha chain, nor was lymphopenia linked to the alpha chain of the BB rat. These results suggest that autoimmune diabetes is not linked to the T-cell antigen receptor alpha chain in the BB rat, nor is it associated with alpha chain constant region polymorphisms in Type I diabetes in man.
 ...
PMID:T-cell antigen receptor alpha chain polymorphisms in insulin-dependent diabetes. 290 75

Insulin role in regulating the immunocompetent tissue structure was studied on experimental rats with alloxan diabetes. Tendency to a decrease in the mesenteric lymph node cortical area, accompanied by a fall in the small lymphocyte number, was observed. The lymphatic follicle area markedly diminished. The small lymphocyte and reticular cell content among cellular elements of the clear centers significantly augmented, whereas mitosis number and the percentage of mean and large lymphocytes decreased. Billroth's strand area diminished by one-third comparatively to that of the control. Simultaneously their number of plasma cells and small lymphocytes lowered. Therefore, alloxan diabetes is accompanied by a fall in the parameters of the thymus-dependent structural components of the mesenterial lymph nodes. Insulin deficit induces a decrease in the number of lymphocytes, capable of proliferation and diminishes their mitotic activity.
 ...
PMID:[Reactivity of the lymph nodes of the root of the mesentery in the small intestine of rats with alloxan diabetes]. 634 19

The induction of immunological self-tolerance begins in the thymus during fetal life. The random recombination of gene segments coding for TCR is followed by the negative selection of T cells bearing a TCR directed against self-antigens presented by thymic MHC. Insulin-like growth factor type 2 (IGF-2) is the dominant gene of the insulin family that is transcribed and translated in the thymus of different species. Contrary to the other members of the insulin gene family, IGF-2 gene (IGF2) is not transcribed in the thymus of diabetes-prone BB rats. The absence of thymic IGF2 expression is associated with the diabetogenic autoimmune process in BB rats. This defect could not only contribute to the lymphopenia of BB rats, but also to the absence of central self-tolerance of the insulin family in this animal.
 ...
PMID:[Role of the thymus in the pathophysiology of autoimmune diabetes type 1]. 1130 59