scholarly journals Gut Immune System and the Implications of Oral-Administered Immunoprophylaxis in Finfish Aquaculture

2021 ◽  
Vol 12 ◽  
Author(s):  
Po-Tsang Lee ◽  
Fernando Y. Yamamoto ◽  
Chen-Fei Low ◽  
Jiun-Yan Loh ◽  
Chou-Min Chong
Keyword(s):  
Immune System ◽  
Oral Vaccine ◽  
Vital Role ◽  
Lymphoid Tissues ◽  
Immune Homeostasis ◽  
Intestinal Epithelial ◽  
Molecular Events ◽  
Essential Components ◽  
Intestinal Immune System ◽  
Gut Immunity

The gastrointestinal immune system plays an important role in immune homeostasis regulation. It regulates the symbiotic host-microbiome interactions by training and developing the host’s innate and adaptive immunity. This interaction plays a vital role in host defence mechanisms and at the same time, balancing the endogenous perturbations of the host immune homeostasis. The fish gastrointestinal immune system is armed with intricate diffused gut-associated lymphoid tissues (GALTs) that establish tolerance toward the enormous commensal gut microbiome while preserving immune responses against the intrusion of enteric pathogens. A comprehensive understanding of the intestinal immune system is a prerequisite for developing an oral vaccine and immunostimulants in aquaculture, particularly in cultured fish species. In this review, we outline the remarkable features of gut immunity and the essential components of gut-associated lymphoid tissue. The mechanistic principles underlying the antigen absorption and uptake through the intestinal epithelial, and the subsequent immune activation through a series of molecular events are reviewed. The emphasis is on the significance of gut immunity in oral administration of immunoprophylactics, and the different potential adjuvants that circumvent intestinal immune tolerance. Comprehension of the intestinal immune system is pivotal for developing effective fish vaccines that can be delivered orally, which is less labour-intensive and could improve fish health and facilitate disease management in the aquaculture industry.

scholarly journals Avian gut-associated lymphoid tissues and intestinal immune responses to Eimeria parasites.

1996 ◽  
Vol 9 (3) ◽  
pp. 349-360 ◽  
Author(s):  
H S Lillehoj ◽  
J M Trout
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Minor Role ◽  
Lymphoid Tissues ◽  
Cell Mediated Immunity ◽  
Limited Information ◽  
Effector Cells ◽  
Intestinal Immune System ◽  
Eimeria Spp ◽  
Coccidial Infection

Coccidiosis, an intestinal infection caused by intracellular protozoan parasites belonging to several different species of Eimeria, seriously impairs the growth and feed utilization of livestock and poultry. Host immune responses to coccidial infection are complex. Animals infected with Eimeria spp. produce parasite-specific antibodies in both the circulation and mucosal secretions. However, it appears that antibody-mediated responses play a minor role in protection against coccidiosis. Furthermore, there is increasing evidence that cell-mediated immunity plays a major role in resistance to infection. T lymphocytes appear to respond to coccidial infection through both cytokine production and a direct cytotoxic attack on infected cells. The exact mechanisms by which T cells eliminate the parasites, however, remain unclear. Although limited information is available on the intestinal immune system of chickens, gut lymphoid tissues have evolved specialized features that reflect their role as the first line of defense at mucosal surfaces, including both immunoregulatory cells and effector cells. This review summarizes our current understanding of the avian intestinal immune system and mucosal immune responses to Eimeria spp., providing an overview of the complex cellular and molecular events involved in intestinal immune responses to enteric pathogens.

scholarly journals Entamoeba histolytica Induces Intestinal Cathelicidins but Is Resistant to Cathelicidin-Mediated Killing

2011 ◽  
Vol 80 (1) ◽  
pp. 143-149 ◽  
Author(s):  
Eduardo R. Cobo ◽  
Chen He ◽  
Ken Hirata ◽  
Grace Hwang ◽  
UyenPhuong Tran ◽  
...  
Keyword(s):  
Immune System ◽  
Entamoeba Histolytica ◽  
Cysteine Proteases ◽  
Host Immune System ◽  
Intestinal Epithelial ◽  
Cysteine Proteinases ◽  
Content Type ◽  
Amebic Colitis ◽  
Innate Defense ◽  
Essential Components

ABSTRACTThe enteric protozoan parasiteEntamoeba histolyticais the cause of potentially fatal amebic colitis and liver abscesses.E. histolyticatrophozoites colonize the colon, where they induce inflammation, penetrate the mucosa, and disrupt the host immune system. The early establishment ofE. histolyticain the colon occurs in the presence of antimicrobial human (LL-37) and murine (CRAMP [cathelin-related antimicrobial peptide]) cathelicidins, essential components of the mammalian innate defense system in the intestine. Studying this early step in the pathogenesis of amebic colitis, we demonstrate thatE. histolyticatrophozoites or their released proteinases, including cysteine proteinase 1 (EhCP1), induce intestinal cathelicidins in human intestinal epithelial cell lines and in a mouse model of amebic colitis. Despite induction,E. histolyticatrophozoites were found to be resistant to killing by these antimicrobial peptides, and LL-37 and CRAMP were rapidly cleaved by released amebic cysteine proteases. The cathelicidin fragments however, did maintain their antimicrobial activity against bacteria. Degradation of intestinal cathelicidins is a novel function ofE. histolyticacysteine proteinases in the evasion of the innate immune system in the bowel. Thus, early intestinal epithelial colonization of invasive trophozoites involves a complex interplay in which the ultimate outcome of infection depends in part on the balance between degradation of cathelicidins by amebic released cysteine proteinases and upregulation of proinflammatory mediators which trigger the inflammatory response.

scholarly journals Advances in Oral Subunit Vaccine Design

Vaccines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Hans Van der Weken ◽  
Eric Cox ◽  
Bert Devriendt
Keyword(s):  
Immune Responses ◽  
Immune Cell ◽  
Oral Vaccine ◽  
Vaccine Design ◽  
Secretory Iga ◽  
Lymphoid Tissues ◽  
Oral Vaccines ◽  
Subunit Vaccines ◽  
Vaccine Antigens ◽  
Gut Immunity

Many pathogens invade the host at the intestinal surface. To protect against these enteropathogens, the induction of intestinal secretory IgA (SIgA) responses is paramount. While systemic vaccination provides strong systemic immune responses, oral vaccination is the most efficient way to trigger protective SIgA responses. However, the development of oral vaccines, especially oral subunit vaccines, is challenging due to mechanisms inherent to the gut. Oral vaccines need to survive the harsh environment in the gastrointestinal tract, characterized by low pH and intestinal proteases and need to reach the gut-associated lymphoid tissues, which are protected by chemical and physical barriers that prevent efficient uptake. Furthermore, they need to surmount default tolerogenic responses present in the gut, resulting in suppression of immunity or tolerance. Several strategies have been developed to tackle these hurdles, such as delivery systems that protect vaccine antigens from degradation, strong mucosal adjuvants that induce robust immune responses and targeting approaches that aim to selectively deliver vaccine antigens towards specific immune cell populations. In this review, we discuss recent advances in oral vaccine design to enable the induction of robust gut immunity and highlight that the development of next generation oral subunit vaccines will require approaches that combines these solutions.

MicroRNA Determines the Fate of Intestinal Epithelial Cell Differentiation and Regulates Intestinal Diseases

2019 ◽  
Vol 20 (7) ◽  
pp. 666-673 ◽  
Author(s):  
Sujuan Ding ◽  
Gang Liu ◽  
Hongmei Jiang ◽  
Jun Fang
Keyword(s):  
Target Genes ◽  
Gastrointestinal Disease ◽  
Intestinal Barrier ◽  
Vital Role ◽  
Intestinal Barrier Function ◽  
Intestinal Epithelial ◽  
Intestinal Function ◽  
Cell Fates ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation

The rapid self-renewal of intestinal epithelial cells enhances intestinal function, promotes the nutritional needs of animals and strengthens intestinal barrier function to resist the invasion of foreign pathogens. MicroRNAs (miRNAs) are a class of short-chain, non-coding RNAs that regulate stem cell proliferation and differentiation by down-regulating hundreds of conserved target genes after transcription via seed pairing to the 3' untranslated regions. Numerous studies have shown that miRNAs can improve intestinal function by participating in the proliferation and differentiation of different cell populations in the intestine. In addition, miRNAs also contribute to disease regulation and therefore not only play a vital role in the gastrointestinal disease management but also act as blood or tissue biomarkers of disease. As changes to the levels of miRNAs can change cell fates, miRNA-mediated gene regulation can be used to update therapeutic strategies and approaches to disease treatment.

Novel Coronavirus SARS-CoV-2 (COVID-19) and Pregnancy: A hypothetical view

2020 ◽  
Vol 20 ◽  
Author(s):  
Ahmed RG
Keyword(s):  
Immune System ◽  
Cellular Therapy ◽  
Early Stage ◽  
Control Strategies ◽  
Vital Role ◽  
Healthy Life ◽  
Global Pandemic ◽  
Maternal Immune System ◽  
Perinatal Management ◽  
Novel Coronavirus

Background: The complications of the SARS-CoV-2 infection and its COVID-19 disease on mothers and their offspring are less known. Objective: The aim of this review was to determine the transmission, severity, complications of SARS-CoV-2 infection during the pregnancy. This review showed the influence of COVID-19 disease on the neonatal neurogenesis. Owing to no specific vaccines or medicines that were reported for the treatment of COVID-19 disease, this review suggested some control strategies like treatments (medicinal plants, antiviral therapy, cellular therapy, and immunotherapy), nutrition uptake, prevention, and recommendations. Discussion: This overview showed in severely states that SARS-CoV-2 infection during the early stage of pregnancy might increase the risk of stress, panic, and anxiety. This disorder can disturb the maternal immune system, and thus causing a neurodevelopmental disturbance. This hypothesis may be depending on the severity and intensity of the SARS-CoV-2 infection during pregnancy. However, vertical transmission of SARS-CoV-2 from dams to their fetuses is absent until now. Conclusion: During this global pandemic disease, maintaining safety during pregnancy, vaginal delivery, and breastfeeding may play a vital role in a healthy life for the offspring. Thus, international and national corporations should be continuing for perinatal management, particularly during the next pandemic or disaster time.

scholarly journals The Intestinal Immune System in Obesity and Insulin Resistance

2016 ◽  
Vol 23 (3) ◽  
pp. 413-426 ◽  
Author(s):  
Daniel A. Winer ◽  
Helen Luck ◽  
Sue Tsai ◽  
Shawn Winer
Keyword(s):  
Insulin Resistance ◽  
Immune System ◽  
Intestinal Immune System

scholarly journals The role of gut-associated lymphoid tissues and mucosal defence

2005 ◽  
Vol 93 (S1) ◽  
pp. S41-S48 ◽  
Author(s):  
Maria Luisa Forchielli ◽  
W. Allan Walker
Keyword(s):  
Immune System ◽  
Breast Milk ◽  
Gastrointestinal Disease ◽  
Bacterial Colonization ◽  
Adaptive Immune Response ◽  
Atopic Disease ◽  
Mucosal Immune System ◽  
Bacterial Invasion ◽  
Lymphoid Tissues ◽  
Protective Function

The newborn infant leaves a germ-free intrauterine environment to enter a contaminated extrauterine world and must have adequate intestinal defences to prevent the expression of clinical gastrointestinal disease states. Although the intestinal mucosal immune system is fully developed after a full-term birth, the actual protective function of the gut requires the microbial stimulation of initial bacterial colonization. Breast milk contains prebiotic oligosaccharides, like inulin-type fructans, which are not digested in the small intestine but enter the colon as intact large carbohydrates that are then fermented by the resident bacteria to produce SCFA. The nature of this fermentation and the consequent pH of the intestinal contents dictate proliferation of specific resident bacteria. For example, breast milk-fed infants with prebiotics present in breast milk produce an increased proliferation of bifidobacteria and lactobacilli (probiotics), whereas formula-fed infants produce more enterococci and enterobacteria. Probiotics, stimulated by prebiotic fermentation, are important to the development and sustainment of intestinal defences. For example, probiotics can stimulate the synthesis and secretion of polymeric IgA, the antibody that coats and protects mucosal surfaces against harmful bacterial invasion. In addition, appropriate colonization with probiotics helps to produce a balanced T helper cell response (Th1 = Th2 = Th3/Tr1) and prevent an imbalance (Th1 > Th2 or Th2 > Th1) contributing in part to clinical disease (Th2 imbalance contributes to atopic disease and Th1 imbalance contributes to Crohn's disease andHelicobacter pylori-induced gastritis). Furthermore, a series of pattern recognition receptors, toll-like receptors on gut lymphoid and epithelial cells that interact with bacterial molecular patterns (e.g. endotoxin (lipopolysaccharide), flagellin, etc.), help modulate intestinal innate immunity and an appropriate adaptive immune response. Animal and clinical studies have shown that inulin-type fructans will stimulate an increase in probiotics (commensal bacteria) and these bacteria have been shown to modulate the development and persistence of appropriate mucosal immune responses. However, additional studies are needed to show that prebiotics can directly or indirectly stimulate intestinal host defences. If this can be demonstrated, then prebiotics can be used as a dietary supplement to stimulate a balanced and an appropriately effective mucosal immune system in newborns and infants.

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