Identification of a Dual-Specific T Cell Epitope of the Hemagglutinin Antigen of an H5 Avian Influenza Virus in Chickens

Avian influenza viruses (AIV) of the H5N1 subtype have caused morbidity and mortality in humans. Although some migratory birds constitute the natural reservoir for this virus, chickens may play a role in transmission of the virus to humans. Despite the importance of avian species in transmission of AIV H5N1 to humans, very little is known about host immune system interactions with this virus in these species. The objective of the present study was to identify putative T cell epitopes of the hemagglutinin (HA) antigen of an H5 AIV in chickens. Using an overlapping peptide library covering the HA protein, we identified a 15-mer peptide, H5246–260, within the HA1 domain which induced activation of T cells in chickens immunized against the HA antigen of an H5 virus. Furthermore, H5246–260 epitope was found to be presented by both major histocompatibility complex (MHC) class I and II molecules, leading to activation of CD4+ and CD8+ T cell subsets, marked by proliferation and expression of interferon (IFN)-γ by both of these cell subsets as well as the expression of granzyme A by CD8+ T cells. This is the first report of a T cell epitope of AIV recognized by chicken T cells. Furthermore, this study extends the previous finding of the existence of dual-specific epitopes in other species to chickens. Taken together, these results elucidate some of the mechanisms of immune response to AIV in chickens and provide a platform for creation of rational vaccines against AIV in this species

Gut hormone changes after jejunoileal (JIB) or biliopancreatic (BPB) bypasssurgery for morbid obesity.

The treatment of obesity by intestinal bypass provides a unique model for the investigation of gut hormone release from the functionally deranged bowel. We have examined the postprandial response of eight circulating gut or pancreatic peptide hormones in 16 preoperative obese patients, 20 patients with jejunoileal bypass, 38 patients with biliopancreatic bypass and 13 age and sex-matched controls. Basal and post-meal hormone concentrations were determined by specific radioimmunoassay methods. Reductions of the upper small intestinal hormones, motilin and gastric inhibitory polypeptide were found in both types of surgery. Conversely, the ileal hormones neurotensin and enteroglucagon were elevated following surgery. This pattern is consistent with the known distribution of these hormones. Variations of response due to surgical differences were noted for gastrin and the enteropancreatic axis, which was more markedly disturbed after biliopancreatic bypass. The alterations of hormone release closely reflect the anatomical changes induced by each particular surgical technique

The effects of ileal transposition and jejunoileal bypass on food intake and GI hormone levels in rats.

Male Wistar rats received three different types of small intestinal surgery. Two groups of rats had either 10 or 20 cm of lower ileum transposed to mid-duodenum. A third comparison group of rats had 85% jejunoileal bypass. All three experimental groups showed a sustained post-operative reduction in food intake and a change in body weight gain. Measurements made 36 days after surgery showed that all experimental groups had a large increase in basal and meal-stimulated enteroglucagon. The total-integrated plasma levels of gastrin, GIP, insulin and blood glucose were significantly reduced. At sacrifice, there were large increases in the wet weight of the small intestine and pancreas. These changes were probably due to the chronic stimulation of the lower ileum with nutrient-rich chyme and may be due to the release of ileal hormones

[Behavior of plasma pancreatic polypeptides and motilin in obese patientssubjected to biliopancreatic bypass].

Biliopancreatic bypass for obesity entails a 2/3 distal gastrectomy with Roux-en-y reconstruction, being the small bowel transected at its midpoint and the enteroenteroanastomosis placed 50 cm proximal to the ileocecal value. Pancreatic polypeptide (PP) and motilin fasting and meal-stimulated plasma concentrations were determined in 13 nonobese healthy volunteers, in 13 nonoperated obese patients, in 9 subjects within two months, in 12 subjects four to twelve months, and in 7 subjects fifteen to twenty months after operation. There were no significant differences in PP fasting levels between either the obese and control groups or between the postoperative groups and the preoperative group. Both meal-stimulated peak and integrated response values were similar in the obese and control groups, and were strikingly and progressively reduced postoperatively, with statistically significant difference between all postoperative groups and preoperative group. Mean plasma motilin fasting and peak values were higher in the obese group than in the control group, and significantly reduced in the 4-12 and 15-20 month group. Despite the huge variability among data, the integrated response in the 0-2 month group was significantly decreased in comparison with the preoperative group, while a subsequent progressive increase was shown by the 4-12 and 15-20 month groups