Gut-Associated Lymphoid Tissue: A Key Tissue Inside the Mucosal Immune System of Hens Immunized with Escherichia coli F4

Abstract

Immunoglobulin Y (IgY) is the predominant antibody found in hen’s (Gallus domesticus) egg yolk. This antibody, developed against several microorganisms in hen egg yolk, has been successfully used as an alternative to immunoglobulins from mammals for use in immunodiagnostics and immunotherapy. Enteropathogenic Escherichia coli (E.coli) F4 is the main etiological agent associated with swine neonatal diarrhea, and it causes notable economic losses in swine production. The aim of the present study was to evaluate the relationship between humoral immune response and the activation of gut-associated lymphoid tissue (GALT) in laying hens intramuscularly immunized with E. coli F4. Adult laying Shaver hens were immunized with a bacterin based on an inactivated lysate E. coli F4 strain that was originally isolated from neonatal piglet diarrhea, following a recommended schedule. The percentage of B lymphocytes in blood and spleen homogenates was determined by flow cytometry. Villi histomorphometry and the size of germinal centers (GC) activated in GALT and the spleen were measured in histological samples either stained with hematoxylin/eosin or through immunofluorescence. Antibody and isotype-specific antibodies in serum and egg yolk were measured using indirect enzyme-linked immunosorbent assay (ELISA). Secretory and serum immunoglobulin A (IgA) were measured by ELISA tests. Laying hen with intramuscular immunization with E. coli F4 lysate, activated both mucosal and systemic protection. Mucosal protection was provided through B lymphocytes, and most of them were activated on Peyer’s patches and esophageal tonsils, in GALT. Furthermore, increased B lymphocyte number in the lamina propria of the gut, and increased intraepithelial plasmatic cell number, produced high levels of mucosal IgA. Activated B lymphocytes interacted with absorptive cells, immune cells, and microbiota in the gut, producing signals that were translated into a powerful physical defense by producing a greater volume of mucin from an increased number of goblet cells. Systemic protection was provided through B lymphocyte activation of spleen GC, which produced hugely specific IgY serum levels. One week later, this specific IgY was deposited in the yolk. This suggests that GALT is a key immunologic tissue inside the mucosal immune system, acting as the “command center” for humoral reaction.

Getting Better Intestinal Health through the Addition of Yeast (Saccharomyces Cerevisiae) Combined with Threonine in Broilers Diets

“…Inside gut, the intestinal epithelium is constantly exposed to microbiota and antigens that are important for the development of immunity. The microbiota interacts with enterocytes, a mucus layer, and mucosal tissue (galt) (Peralta et al, 2017) a dynamic environment, considering the interactions between the enterocytes, leucocytes, goblet cells and the content of the gastrointestinal lumen (non-nutrient dietary factors, nutrients, and microbiota).…”

“…Also, inside mucus layer is found IgA, which regulates the ecological balance of microbiota and has a fundamental role in mucus homeostasis (Peralta, 2016), perhaps the immunoglobulin levels are modify by Sc combinated T, although more research about this item can be necessary to clarify this. In general, increased mucus production (not excesive) can be a great advantage for the animal due to a greater elimination of intestinal pathogens and therefore an improved protection system against intestinal infections (Awad et al, 2009, Brummer et al, 2010Peralta et al, 2017).…”

“…AxioVision V 4.6.3 (Carl Zeiss, Germany), taking a minimum of 20 fields per histological section (Peralta et al, 2017) (Figure 1). …”

Immunomodulation of Avian Dendritic Cells under the Induction of Prebiotics

“…Subsequently, B cells migrate through the lamina propria to the intestinal villi, where DCs and T cells induce in B cells high levels of IgA production. Subsequently, a part of B cells migrates through the bloodstream to the germinal centers of the spleen, where they activate other B cells and stimulate systemic antibody protection [103]. Newcastle disease virus, like other viruses, contains sialic acid-dependent glycans that can be recognized by DCs [104].…”

Stevia (<i>Stevia rebaudiana Bertoni</i>): un aditivo natural efectivo en avicultura?

“…La salud intestinal no solo involucra el aparato digestivo sino también el sistema inmune asociado al intestino y la microbiota intestinal, que interaccionan con distintos mecanismos, tendientes a lograr la homeostasis intestinal. Debido a los numerosos tejidos intervinientes, su interacción es compleja y hay abundantes factores que las modifican, razón por la cual los mecanismos de acción involucrados aún están siendo estudiados (Brandztaeg 2009;Brandztaeg 2011;Deneshyar et al 2011;Maynard et al, 2012;Anastasilakis et al 2013;Huygebraied et al 2011;Peralta et al 2017). Distintas investigaciones coinciden al afirmar que la interacción de estos tres elementos (aparato digestivo, sistema inmune asociado al intestino y microbiota intestinal) tienen una importancia crucial en las primeras semanas de vida de las aves comerciales, momento en que se produce el crecimiento y desarrollo del aparato digestivo, sobre todo el intestino.…”