The development and role of microbialhost interactions in gut mucosal immune development

At birth the piglet＇s immune system is immature and it is dependent upon passive maternal protection until weaning.The piglet＇s mucosal immune system develops over the first few weeks but has not reached maturity at weaning ages which are common on commercial farms. At weaning piglets are presented with a vast and diverse range of microbial and dietary/environmental antigens. Their ability to distinguish between antigens and mount a protective response to potential pathogens and to develop tolerance to dietary antigens is critical to their survival and failure to do so is reflected in the high incidence of morbidity and mortality in the post-weaning period. A growing recognition that the widespread use of antibiotics to control infection during this critical period should be controlled has led to detailed studies of those factors which drive the development of the mucosal immune system, the role of gut microbiota in driving this process, the origin of the bacteria that colonise the young piglet＇s intestine and the impact of rearing environment. This review briefly describes how the mucosal immune system is equipped to respond ＂appropriately＂ to antigenic challenge and the programmed sequence by which it develops. The results of studies on the critical interplay between the host immune system and gut microbiota are discussed along with the effects of rearing environment. By comparing these with results from human studies on the development of allergies in children, an approach to promote an earlier maturation of the piglet immune system to resist the challenges of weaning are outlined.

The Development of Early Life Microbiota in Human Health and Disease

The colonization of the human microbiota in early life has long-lasting health implications.The status of the initial intestinal microbiota determines human growth and development from infancy to adulthood,and thus represents a crucial window in our long-term development.This review aims to summarize the latest findings on the symbiotic gut microbiota early in life and its vital role in metabolic-,allergic-,and auto-immune-disorder-related diseases,including obesity,diabetes,allergy,autism,inflammatory bowel disease,and stunting.It discusses the development process and various factors shaping the gut micro-biota,as well as the crosstalk between the gut microbiota and the host’s physiological systems(especially intestinal immune development and homeostasis,and the central nervous system in the course of neu-rodevelopment),during the early life establishment of the gut microbiota,in order to decipher the mech-anisms of diseases associated with the intestinal microbiome of early life.In addition,it examines microbiota-targeted therapeutic methods that show promising effects in treating these diseases.The true process of gut microbiome maturation,which depends on genetics,nutrition,and environmental factors,must be scrutinized in order to monitor healthy gut microbiome development and potentially correct unwanted courses by means of intervention via methods such as novel probiotics or fecal microbiota transplantation.

Effects of age on immune function in broiler chickens

Background:There are many diseases in poultry,many of which are caused by poor immune function.It is not clear how cytokines and various immune cell functions change with age in modern broilers.The purpose of this study was to explore the patterns of development of the immunity of the broiler chickens in cage.Results:The results showed that there were 3 development patterns of immunity in the broiler chickens.The first pattern was Down-Up.Cytokines and some immune indicators first decreased and then increased,and the lowest levels of immunity basically occurred from d 6 to 13.The second pattern was Up-Down,and from d 30 to 34,the highest levels of non-specific cellular immunity components,such as the peripheral blood mononuclear macrophage ratio,specific cellular immunity components,such as the peripheral blood helper T(Th)cell ratio and T cell and B cell proliferation activity,and mucosal immunity components,such as the ileal CD4,TGF-β1 and IgA mRNA levels,were observed.The third pattern was Up-Up,and the levels of the non-specific cellular immunity components,such as the serum nitric oxide(NO),C3 and C4 levels,the specific cellular immunity components,such as the spleen index,peripheral blood IL-2,IFN-γ/IL-4,cytotoxic T(Tc)cell ratio,and splenic NF-κB mRNA levels,the humoral immunity components,such as the serum IgG level,the mucosal immunity components,such as the ileal MHC-II,CD3d,TCRβsubunit,TCRζsubunit,IFN-γ,pIgR mRNA and ileal mucosa sIgA levels,were continuing to increase from d 1 to 34.Conclusions:It could be concluded that the immune system and its function have not developed well in the broiler chickens d 6 to 13 and that the immune system does not mature until d 30 to 34 in the broiler chickens in cages.It is necessary to enhance the immune function of the broiler chickens through nutritional measures from d 1 to 30.

Investigation of the immune effects of Scutellaria baicalensis on blood leukocytes and selected organs of the chicken＇s lymphatic system

Background： The health of chickens and the welfare of poultry industry are central to the efforts of addressing global food security. Therefore, it is essential to study chicken immunology to maintain and improve its health and to find novel and sustainable solutions. This paper presents a study on investigation of the effect of Scutellaria baicalensis root（SBR） on the immune response of broiler chicken, especially on lymphocytes and heterophils reactivity, regarding their contribution to the development of immunity of the chickens.Methods： The 121-day-old Hubbard Hi-Y male broiler hybrids were randomly assigned to four treatment groups,three SBR supplemented groups（0.5, 1.0, and 1.5% of SBR） and one control group. Each treatment was replicated five times with six birds per replicate pen in a battery brooder. Blood was collected after 3-（rd） and 6-（th）wk of the experiment, and hemoglobin and hematocrit values were determined, as well as total leukocyte count and differential count were performed. Nitroblue tetrazolium test and phagocytosis assay as nonspecific immune parameters and humoral immune responses to the antigenic challenge by sheep red blood cells were performed.Moreover, the ability of peripheral blood lymphocytes to form radial segmentation（RS） of their nuclei was analyzed.Body weight and relative weight of spleen, liver, and bursa of Fabricius were recorded.Results： Results showed that mean heterophile/lymphocyte ratio increased in the SBR groups compared to the control group and the blood of the chickens showed lymphocytic depletion. The results also demonstrated that the relative weight of bursa of Fabricius and spleen in groups fed with SBR significantly decreased compared to the control group. This study also showed that the addition of SBR significantly inhibited the formation of RS of nuclei compared to some cytotoxic substances.Conclusion： We found that SBR supplementation should be carefully evaluated when given to poultry. The excess intake of SBR supplementation may cause immunologic inhibition and may negatively affect the development of immune organs. SBR has inhibited the formation of radial segmentation nuclei showing antimetastatic properties and also the phagocytosis of chicken heterophils.

Transcriptome analysis of hsp18.3 functions and regulatory systems using RNA-sequencing in the red flour beetle,Tribolium castaneum

The red flour beetle, Tribolium castaneum, is a major agriculture pest of stored grain, cereal products and peanuts for human consumption. It is reported that heat shock protein 18.3 of T. castaneum（Tchsp18.3） plays a significant role in stress resistance, development and reproduction. However, the regulatory systems of Tchsp18.3 remain unknown. Therefore, we compared the global transcriptome profiles of RNA interference（RNAi）-treated larvae（ds-Tchsp18.3） and control larvae of T. castaneum using RNA sequencing. Overall, we obtained 14 154 435 sequence reads aligned with 13 299 genes. Additionally, 569 differentially expressed genes（DEGs） were identified from the ds-Tchsp18.3 and control groups, of which 246 DEGs were annotated in the 47 Gene Ontology（GO） functional groups and 282 DEGs were assigned to 147 Kyoto Encyclopedia of Genes and Genomes（KEGG） biological signaling pathways. The DEGs encoding viperin, dorsal, Hdd11, PGRP2, defensin1 and defensin2 were simultaneously related to immunity and stress responses, which suggests that cross-talk might exist between the immunity and stress responses of T. castaneum. The knockdown of Tchsp18.3 gene expression suppressed the antioxidant activity process, which most likely modulated the effects of Tchsp18.3 on development and reproduction. Furthermore, the DEGs, including Blimp-1, Gld, Drm, Kinesin-14, Pthr2, Delta（11）-like and EGF-like domain protein 2, were also associated with the development and reproduction of ds-Tchsp18.3 insects. Additionally, knockdown of Tchsp18.3 amplified the serine protease（SP） signaling pathway to further regulate stress responses and innate immunity as well as development and reproduction of the red flour beetles. These results provide valuable insight into the molecular regulatory mechanism of Tchsp18.3 involved in insect physiology and further facilitate the research of suitable and sustainable management for pest control.

Differential requirement of BAK1 C-terminal tail in development and immunity

Summary BRI1-ASSOCIATED RECEPTOR KINASE 1 （BAK1） plays critical roles in plant developmental and immune signaling pathways. BAKI and a large number of leucine-rich repeat receptor-like kinases （LRR-RLKs） harbor a mysterious carboxyl-terminal tail （CT） beyond their kinase domain. In this study we analyzed the biological significance of this CT region using a unique bak~ mutant allele which causes deletion of the CT region. We showed that BAKt CT promotes its kinase activity and is required for pathogen-associated molec- ular pattern （PAMP）-triggered immunity, but it is dispensable for brassinosteroid responses and BAK1/ BKKl-inhibited cell death signaling. Therefore the BAK1 C-terminal tail is differentially required for its functions in development and immunity.