Characterization and functional analyses of novel chicken leukocyte immunoglobulin-like receptor subfamily B members 4 and 5.

The inhibitory leukocyte immuno-globulin-like receptors (LILRBs) play an important role in innate immunity. Currently, no data exist regarding the role of LILRB4 and LILRB5 in the activation of immune signaling pathways in mammalian and avian species. Here, we report for the first time, the cloning and structural and functional analyses of chicken LILRB4-5 genes identified from 2 genetically disparate chicken lines.

Chicken novel leukocyte immunoglobulin-like receptor subfamilies B1 and B3 are transcriptional regulators of major histocompatibility complex class I genes and signaling pathways.

Objective: The inhibitory leukocyte immunoglobulin-like receptors (LILRBs) play an important role in innate immunity. The present study represents the first description of the cloning and structural and functional analysis of LILRB1 and LILRB3 isolated from two genetically disparate chicken lines.

Methods: Chicken LILRB1-3 genes were identified by bioinformatics approach.

Leukocyte Immunoglobulin-Like Receptors A2 and A6 are Expressed in Avian Macrophages and Modulate Cytokine Production by Activating Multiple Signaling Pathways.

The activating leukocyte immunoglobulin-like receptors (LILRAs) play an important role in innate immunity. However, most of the LILRA members have not been characterized in avian species including chickens. The present study is the first attempt at cloning, structural analysis and functional characterization of two LILRAs (LILRA2 and LILRA6) in chickens.

Development of a blocking latex agglutination test for the detection of antibodies to chicken anemia virus.

A blocking latex agglutination test (b-LAT) developed in this study was evaluated for the detection of antibodies against chicken anemia virus (CAV) in chickens. Polystyrene latex beads were coupled with a neutralizing monoclonal antibody (mAb) to CAV (mAb-beads). When mAb-beads were mixed with antigens prepared from the lysate of MDCC-MSB1 cells infected with CAV, agglutination occurred.

Diagnostic value of the recombinant tandem repeat antigen TeGM6-4r for surra in water buffaloes.

Trypanosoma evansi infection, or surra, is currently affecting various species of animals, especially water buffaloes. Since diagnosis is an important aspect of surra control, development of novel diagnostic antigens is of interest to implement and improve the currently utilized methods. Our study evaluated the tandem repeat antigen TeGM6-4r in T.

Protection of piglets against Edema disease by maternal immunization with Stx2e toxoid.

Edema disease (ED) in piglets is caused by Shiga toxin Stx2e-producing Escherichia coli. We show that a genetically disarmed Stx2e toxoid is a safe antigen that generates antiserum protecting piglets against the Stx2e toxin. Immunization of suckling piglets with the Stx2e toxoid was safe, had no adverse effects on growth of the piglets, and resulted in effective prevention of edema disease clinical symptoms after challenge with the Stx2e toxin.

Escherichia coli strains causing edema disease in northern Vietnam share an identical verotoxin 2e.

Edema disease (ED) is a common fatal disease in newly weaned piglets. To develop an effective control program for ED, we carried out a study to better understand the incidence and spread of the disease and the characteristics of the causative agent. In our study, 69 Escherichia coli strains, isolated from 92 piglets showing clinical signs of ED from 13 provinces in northern Vietnam, were positive for both the VT2e toxin and the F18 major fimbrial subunit gene fedA.

Acute febrile myalgia in Vietnam due to trichinellosis following the consumption of raw pork.

Trichinellosis outbreaks occur occasionally in Vietnam following the consumption of undercooked pork. Diagnosing trichinella can be problematic because fever and myalgia are nonspecific, and diagnosis may be delayed. We describe 5 Vietnamese patients in whom trichinellosis was diagnosed after several weeks of illness.

Prevalence, intensity and risk factors for clonorchiasis and possible use of questionnaires to detect individuals at risk in northern Vietnam.

A high prevalence of the liver flukes Clonorchis sinensis and Opisthorchis viverrini has been reported in a number of provinces in Vietnam. Knowledge about C. sinensis infection gained from Thailand over the past decade suggests that the habit of eating raw freshwater fish is a major risk factor for infection.

Heavy-chain-only antibody expression and B-cell development in the mouse.

Antibodies expressed in mice, humans, and most mammals consist of paired heavy (H) and light (L) chains. Cellular release of single H-chains without L-chains is prevented by chaperone association and retention in the endoplasmic reticulum. Consequently, H-chain-only antibodies are absent, except in pathological conditions known as Heavy Chain Disease, where they occur in mutated form.

Human tapeworms in north Vietnam.

Sixty-five Taenia samples were collected from patients in a referral hospital in Hanoi, north Vietnam, for species identification by morphological and molecular techniques. PCR-RFLP of a mitochondrial 12S rDNA fragment, developed for this study, allowed direct differentiation between all Taenia spp., overcoming the disadvantages of classical morphological examination, which failed on disintegrated samples.

Expression of a dromedary heavy chain-only antibody and B cell development in the mouse.

In mature B cells of mice and most mammals, cellular release of single H chain Abs without L chains is prevented by H chain association with Ig-specific chaperons in the endoplasmic reticulum. In precursor B cells, however, surface expression of mu-H chain in the absence of surrogate and conventional L chain has been identified. Despite this, Ag-specific single H chain Ig repertoires, using mu-, gamma-, epsilon-, or alpha-H chains found in conventional Abs, are not produced.

Heavy-chain only antibodies derived from dromedary are secreted and displayed by mouse B cells.

Whereas functional heavy (H)-chain antibodies devoid of light (L)- chains account for about half of the circulating immunoglobulins in Camelidae, H-chain only antibodies (HCAbs) are not produced in other healthy mammals including rodents and humans. To test the feasibility of expressing single chain antibodies in the mouse, which on account of their small size and antigen-recognition properties would have a major impact on antibody engineering strategies, we constructed a rearranged dromedary H-chain gene encoding the immunoglobulin G2a (IgG2a) isotype with specificity for hen-egg lysozyme (HEL). This IgG2a H-chain gene was introduced into mouse myeloma cells not expressing endogenous immunoglobulin H- or L-chains.

Heavy-chain antibodies in Camelidae; a case of evolutionary innovation.

The emergence in Camelidae species of functional antibodies devoid of light chains (referred to as heavy-chain antibodies or HCAbs) is an intriguing evolutionary event. Homodimeric HCAbs have also been documented in spotted ratfish ( Cos5-Abs) and nurse shark (NAR). To reveal the evolutionary history of HCAbs, we evaluated the phylogenetic and phenotypic relationships among HCAbs and conventional antibodies across taxa and confirmed the current viewpoint that different groups of HCAbs have evolved independently in the three lineages.

Adaptive evolution of variable region genes encoding an unusual type of immunoglobulin in camelids.

A typical immunoglobulin (Ig) molecule is composed of four polypeptide chains: two identical heavy (H) chains and two identical light (L) chains. This tetrameric structure is conserved in almost all jawed vertebrate species. However, it has been discovered that camels and llamas (family: Camelidae) possess a type of dimeric Ig that consists of two H chains only.