ovalbumin and Diabetes-Mellitus

Experimental evidence indicates that the relative lack of insulin in an organism results in an overall reduction in inflammatory reactions. This study was planned to determine the inflammatory events in antigen sensitized diabetic guinea pigs. Twenty-five male guinea pigs were categorized into five groups of five each as follows: diabetic, antigen sensitized, antigen sensitized diabetic, insulin-treated antigen sensitized diabetic and control animals. Induction of experimental diabetes and antigen sensitization was performed by injection of streptozotocin and ovalbumin, respectively. Animals were killed by exsanguination and bronchoalveolar lavage was performed. Bronchoalveolar lavage fluid cellular and protein contents were determined. Airway responsiveness to acetylcholine was assessed using isolated tracheal triple-ring. Histopathological examinations were performed on the lungs. Decreases in the airway reactivity in diabetic and antigen sensitized diabetic animals were found compared with antigen sensitized animals. Experimental diabetes also decreased antigen-induced protein leakage into the airspace as well as the accumulation of inflammatory cells (eosinophils, neutrophils, lymphocytes and macrophages) in bronchoalveolar lavage fluid of antigen sensitized animals. Insulin treatment prevented these decreases in protein content and inflammatory cells infiltration in bronchoalveolar lavage fluid observed in the antigen sensitized guinea pigs with diabetes. Histopathological results showed that coinduction of experimental diabetes significantly reduces the number of eosinophils in the lungs of antigen sensitized animals. Again, treatment with insulin increased the number of eosinophils in the antigen sensitized diabetic animals. Experimental diabetes causes were found to decrease the airway reactivity and inflammatory responsiveness induced by antigen sensitization due to a reduction in the insulin levels.

Topics: Acetylcholine; Animals; Antigens; Bronchoalveolar Lavage Fluid; Diabetes Mellitus; Guinea Pigs; Immunization; Leukocytes; Lung; Male; Muscle Contraction; Ovalbumin; Pneumonia

CD4+ helper T (Th) cells play crucial role in priming, expansion and survival of CD8+ cytotoxic T lymphocytes (CTLs). However, how CD4+ Th cell's help is delivered to CD8+ T cells in vivo is still unclear. We previously demonstrated that CD4+ Th cells can acquire ovalbumin (OVA) peptide/major histocompatibility complex (pMHC I) and costimulatory CD80 by OVA-pulsed DC (DC(OVA)) stimulation, and then stimulate OVA-specific CD8+ CTL responses in C57BL/6 mice. In this study, we further investigated CD4+ Th cell's effect on stimulation of CD8 CTL responses in major histocompatibility complex (MHC II) gene knockout (KO) mice and transgenic rat insulin promoter (RIP)-mOVA mice with moderate expression of self OVA by using CD4+ Th cells or Th cells with various gene deficiency. We demonstrated that the in vitro DC(OVA)-activated CD4+ Th cells (3 x 10(6) cells/mouse) can directly stimulate OVA-specific CD8+ T-cell responses in wild-type C57BL/6 mice and MHC II gene KO mice lacking CD4+ T cells. A large amount of CD4+ Th cells (12 x 10(6) cells/mouse) can even overcome OVA-specific immune tolerance in transgenic RIP-mOVA mice, leading to CD8+ CTL-mediated mouse pancreatic islet destruction and diabetes. The stimulatory effect of CD4+ Th cells is mediated by its IL-2 secretion and CD40L and CD80 costimulations, and is specifically delivered to OVA-specific CD8+ T cells in vivo via its acquired pMHC I complexes. Therefore, the above elucidated principles for CD4+ Th cells will have substantial implications in autoimmunity and antitumor immunity, and regulatory T-cell-dependent immune suppression.

Topics: Animals; Autoimmunity; CD8-Positive T-Lymphocytes; Cell Proliferation; Dendritic Cells; Diabetes Mellitus; Genes, MHC Class II; Histocompatibility Antigens Class II; Immune Tolerance; Islets of Langerhans; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Ovalbumin; T-Lymphocytes, Helper-Inducer

CD4(+) helper T (Th) cells play pivotal roles in induction of CD8(+) CTL immunity. However, the mechanism of CD4(+) T cell help delivery to CD8(+) T cells in vivo is still elusive. In this study, we used ovalbumin (OVA)-pulsed dendritic cells (DC(OVA)) to activate OT-II mouse CD4(+) T cells, and then studied the help effect of these CD4(+) T cells on CD8(+) cytotoxic T lymphocyte (CTL) responses. We also examined CTL mediated islet beta cell destruction which led to diabetes in wild-type C57BL/6 mice and transgenic rat insulin promoter (RIP)-mOVA mice expressing beta cell antigen OVA with self OVA-specific tolerance, respectively. In adoptive transfer experiments, we demonstrated that help, in the form of peptide/major histocompatibility complex (pMHC) I acquired from DC(OVA) by DC(OVA) activation, was required for induction of OVA-specific CTL responses in C57BL/6 mice. However, in combination with TCR transgenic OT-I mouse CD8(+) T cells, the tolerogenic dosage of CD4(+) Th cells with acquired pMHC I, but not CD4(+) K(b-/-) Th cells without acquired pMHC I were able to cause diabetes in 8/10 (80%) RIP-mOVA mice. This study thus expands the current knowledge in T cell-mediated autoimmunity and provides insight into the nature of CD4(+) T cell-mediated help in CD8(+) CTL induction.

Topics: Animals; CD8-Positive T-Lymphocytes; Cell Proliferation; Dendritic Cells; Diabetes Mellitus; Histocompatibility Antigens Class I; Insulin; Insulin-Secreting Cells; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; Peptides; Phenotype; Promoter Regions, Genetic; Rats; T-Lymphocytes, Helper-Inducer

Administration of antigens via mucosal routes, such as orally or intranasally, can induce specific immunological tolerance and has been used as a rational basis for the treatment of autoimmune diseases, including type 1 diabetes. Recently, however, orally delivered antigens were shown to induce CD8 cytotoxic T-lymphocytes (CTLs) capable of causing autoimmune diabetes. In this report, we have examined several mucosal routes for their ability to induce CTLs and autoimmune diabetes, with the aim of identifying approaches that would maximize tolerance and minimize CTL generation. In normal C57BL/6 mice, ovalbumin (OVA) delivered by either the oral or nasal routes or by aerosol inhalation was able to prime CTL immunity in both high- and low-dose regimens. To address the relevance of these CTLs to autoimmune disease, OVA was given to mice that transgenically expressed this antigen in their pancreatic beta-cells. Irrespective of antigen dose or the route of delivery, mucosal OVA triggered diabetes, particularly after intranasal administration. These findings suggest that CTL immunity is likely to be a consequence of mucosal antigen delivery, regardless of the regimen, and should be considered in the clinical application of mucosal tolerance to autoimmune disease prevention.

Topics: Administration, Intranasal; Administration, Oral; Aerosols; Animals; Antigens; Diabetes Mellitus; Dose-Response Relationship, Drug; Immunity; Mice; Mice, Inbred C57BL; Nasal Mucosa; Ovalbumin; T-Lymphocytes, Cytotoxic

An antigen administered orally can induce immunological tolerance to a subsequent challenge with the same antigen. Evidence has been provided for the efficacy of this approach in the treatment of human autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. However, oral administration of autoantigen in mice was found to induce a cytotoxic T lymphocyte response that could lead to the onset of autoimmune diabetes. Thus, feeding autoantigen can cause autoimmunity, which suggests that caution should be used when applying this approach to the treatment of human autoimmune diseases.

Topics: Administration, Oral; Animals; Autoantigens; Autoimmune Diseases; CD4-Positive T-Lymphocytes; Chimera; Diabetes Mellitus; Dose-Response Relationship, Immunologic; Mice; Mice, Inbred C57BL; Mice, Transgenic; Ovalbumin; T-Lymphocytes, Cytotoxic

The potential value of eight commercial available polymer-based reversed-phase (RP) columns for peptide and protein separations was evaluated using crude acetic acid extracts of normal and diabetic human pancreata and mixtures of pure polypeptides as samples. All columns were characterized with acetic acid gradients in water as mobile phase, and different chromatographic profiles were obtained depending on the type of polymer column (bare or derivatized) and the type of ligand. Some of the columns were virtually free from effects related to the polymer skeleton whereas in others the separation was influenced by both the ligand and the polymeric backbone. Two selected polymeric RP columns were, together with a silica-based C4 column, further characterized with acetonitrile gradients in trifluoroacetic acid (TFA), and the separation temperature was found to have a drastic effect on the separation efficiency for proteins with mol. wt. greater than 6000 dalton. No such effect was seen for polypeptides with mol. wt. less than 6000 dalton. Mixtures of pure peptides and proteins were separated using acetic acid gradients in water, acetonitrile or isopropanol, and normally the highest efficiency was found with the use of acetonitrile as mobile phase modifier. Isopropanol was less suitable as an organic modifier. The separation of the beta-lactoglobulin A- and B-chains may be used to give a rapid estimate of the chromatographic usability of polymer-based RP-columns for peptide and protein separations in acetic acid gradients in water and in acetonitrile gradients. Recoveries for insulin, proinsulin, growth hormone, ovalbumin and human serum albumin were measured for several polymer-based RP columns eluted with acetic acid gradients in water and with acetonitrile-based mobile phases. The highest recoveries of serum albumin and ovalbumin were found after elution with acetic acid gradients in water.

Topics: Acetates; Acetic Acid; Acetonitriles; Chromatography, High Pressure Liquid; Diabetes Mellitus; Humans; Insulin; Lactoglobulins; Muramidase; Ovalbumin; Pancreas; Peptides; Polymers; Serum Albumin; Trifluoroacetic Acid

The non-enzymic glycosylation of proteins has been implicated as a contributing pathogenia in the secondary complications of diabetes mellitus. The reversible acetylation of proteins by aspirin could slow down the advance of the biochemical lesion in well-controlled patients. The rate of acetylation of albumin by aspirin at 37 degrees C and pH = 7.30 was found to proceed two orders of magnitude faster than the glycosylation, providing a basis for therapeutic possibilities for the complications of diabetes mellitus.

Topics: Acetylation; Aspirin; Diabetes Complications; Diabetes Mellitus; Glycosylation; Humans; In Vitro Techniques; Ovalbumin; Serum Albumin

Topics: Adolescent; Adult; Albumins; Animals; Antibodies; Antigen-Antibody Reactions; Cardiovascular Diseases; Cattle; Child; Collagen Diseases; Communicable Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 1; Female; gamma-Globulins; Gastrointestinal Diseases; Hematologic Diseases; Humans; Hypersensitivity; Infant; Infant, Newborn; Insulin; Iodine Isotopes; Lactalbumin; Maternal-Fetal Exchange; Milk; Nervous System Diseases; Ovalbumin; Pregnancy; Respiratory Tract Diseases; Serum Albumin; Serum Albumin, Bovine; Skin Tests; Viral Vaccines