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Fulltext scFv antibody: principles and clinical application

Ahmad ZA, Yeap SK, Ali AM, Ho WY, Alitheen NB, Hamid M

Clin. Dev. Immunol., 2012;2012:980250.
PMID: 22474489 DOI: 10.1155/2012/980250

To date, generation of single-chain fragment variable (scFv) has become an established technique used to produce a completely functional antigen-binding fragment in bacterial systems. The advances in antibody engineering have now facilitated a more efficient and generally applicable method to produce Fv fragments. Basically, scFv antibodies produced from phage display can be genetically fused to the marker proteins, such as fluorescent proteins or alkaline phosphatase. These bifunctional proteins having both antigen-binding capacity and marker activity can be obtained from transformed bacteria and used for one-step immunodetection of biological agents. Alternatively, antibody fragments could also be applied in the construction of immunotoxins, therapeutic gene delivery, and anticancer intrabodies for therapeutic purposes. This paper provides an overview of the current studies on the principle, generation, and application of scFv. The potential of scFv in breast cancer research is also discussed in this paper.

Matched MeSH terms: Recombinant Fusion Proteins/immunology
rTES-30USM: cloning via assembly PCR, expression, and evaluation of usefulness in the detection of toxocariasis

Norhaida A, Suharni M, Liza Sharmini AT, Tuda J, Rahmah N

Ann Trop Med Parasitol, 2008 Mar;102(2):151-60.
PMID: 18318937 DOI: 10.1179/136485908X252250

Currently, the laboratory diagnosis of toxocariasis, caused by Toxocara canis or T. cati, mainly relies on serological tests. Unfortunately, however, the specificities of most of the commercial tests that are available for the serodiagnosis of this disease are not very high and this may cause problems, especially in tropical countries where co-infections with other helminths are common. In an effort to develop a serological assay with improved specificity for the detection of Toxocara infection, an IgG(4)-ELISA based on a recombinant version (rTES-30USM) of the 30-kDa Toxocara excretory-secretory antigen (TES-30) has recently been developed. To produce the antigen, the TES-30 gene was cloned via assembly PCR, subcloned into a His-tagged prokaryotic expression vector, and purified by affinity chromatography using Ni(2+)-nitrilotriacetic-acid (Ni-NTA) resin. The performance of the ELISA based on the recombinant antigen was then compared with that of commercial kit, based on an IgG-ELISA, for the serodiagnosis of toxocariasis (Toxocara IgG-ELISA; Cypress Diagnostics, Langdorp, Belgium). Both assays were used to test 338 serum samples, including 26 samples from probable cases of toxocariasis. Assuming that all the probable cases were true cases, the assay based on rTES-30USM demonstrated a sensitivity of 92.3% (24/26) and a specificity of 89.6% (103/115) whereas the commercial kit exhibited a sensitivity of 100% (26/26) but a specificity of only 55.7% (64/115). The high sensitivity and specificity exhibited by the new IgG(4)-ELISA should make the assay a good choice for use in tropical countries and any other area where potentially cross-reactive helminthic infections are common.

Matched MeSH terms: Helminth Proteins/immunology
Fulltext [Study of pathogenicity of Nipah virus and its vaccine development]

Yoneda M

Uirusu, 2014;64(1):105-12.
PMID: 25765986 DOI: 10.2222/jsv.64.105

Nipah virus (NiV), a paramyxovirus, was first discovered in Malaysia in 1998 in an outbreak of infection in pigs and humans, and incurred a high fatality rate in humans. We established a system that enabled the rescue of replicating NiVs from a cloned DNA. Using the system, we analyzed the functions of accessory proteins in infected cells and the implications in in vivo pathogenicity. Further, we have developed a recombinant measles virus (rMV) vaccine expressing NiV envelope glycoproteins, which appeared to be an appropriate to NiV vaccine candidate for use in humans.

Matched MeSH terms: GTP-Binding Proteins/immunology
Fulltext Worldwide increased prevalence of human adenovirus type 3 (HAdV-3) respiratory infections is well correlated with heterogeneous hypervariable regions (HVRs) of hexon

Haque E, Banik U, Monwar T, Anthony L, Adhikary AK

PLoS One, 2018;13(3):e0194516.
PMID: 29590206 DOI: 10.1371/journal.pone.0194516

Human adenovirus type 3 (HAdV-3) respiratory infections occurs worldwide in both children and adults, leading to severe morbidity and mortality, particularly in the paediatric age group and especially in neonates. During HAdV infection, neutralizing antibodies are formed against the epitopes located in the hyper variable regions (HVRs) of the hexon protein. These neutralizing antibodies provide protection against reinfection by viruses of the same type. Therefore it is reasonable to speculate that variations of HAdV-3 in the HVRs could impair the immunity acquired by previous infection with a different strain with variation in its HVRs. HAdV-3 has recently become the major agent of acute respiratory infection worldwide, being responsible for 15% to 87% of all adenoviral respiratory infections. However, despite the increased prevalence of HAdV-3 as respiratory pathogen, the diversity of hexon proteins in circulating strains remains unexplored. This study was designed to explore the variation in HVRs of hexon among globally distributed strains of HAdV-3 as well as to discover possible relationship among them, thus possibly shedding light on the cause for the increased prevalence of HAdV-3. In this study, for the first time we analysed the hexon proteins of all 248 available strains of HAdV-3 from the NCBI database and compared them with those of the HAdV-3 prototype (GB stain). We found that the HVRs of HAdV-3 strains circulating worldwide were highly heterogeneous and have been mutating continuously since -their original isolation. Based on their immense heterogeneity, the strains can be categorized into 25 hexon variants (3Hv-1 to 3Hv-25), 4 of which (3Hv-1 to 3Hv-4) comprises 80% of the strains. This heterogeneity may explain why HAdV-3 has become the most prevalent HAdVs type worldwide. The heterogeneity of hexon proteins also shows that the development of a vaccine against HAdV-3 might be challenging. The data on hexon variants provided here may be useful for the future epidemiological study of HAdV-3 infection.

Matched MeSH terms: Capsid Proteins/immunology
Fulltext Virus-specific read-through codon preference affects infectivity of chimeric cucumber green mottle mosaic viruses displaying a dengue virus epitope

Teoh PG, Ooi AS, AbuBakar S, Othman RY

J Biomed Biotechnol, 2009;2009:781712.
PMID: 19325913 DOI: 10.1155/2009/781712

A Cucumber green mottle mosaic virus (CGMMV) was used to present a truncated dengue virus type 2 envelope (E) protein binding region from amino acids 379 to 423 (EB4). The EB4 gene was inserted at the terminal end of the CGMMV coat protein (CP) open reading frame (ORF). Read-through sequences of TMV or CGMMV, CAA-UAG-CAA-UUA, or AAA-UAG-CAA-UUA were, respectively, inserted in between the CP and the EB4 genes. The chimeric clones, pRT, pRG, and pCG+FSRTRE, were transcribed into full-length capped recombinant CGMMV transcripts. Only constructs with the wild-type CGMMV read-through sequence yielded infectious viruses following infection of host plant, muskmelon (Cucumis melo) leaves. The ratio of modified to unmodified CP for the read-through expression clone developed was also found to be approximately 1:1, higher than what has been previously reported. It was also observed that infectivity was not affected by differences in pI between the chimera and its wild counterpart. Analysis of recombinant viruses after 21-days-postinculation (dpi) revealed that deletions occurred resulting in partial reversions of the viral population to near wild type and suggesting that this would be the limiting harvest period for obtaining true to type recombinants with this construct.

Matched MeSH terms: Viral Envelope Proteins/immunology
Utility of recombinant LipL41 based IgM and IgG ELISA in diagnosis of canine leptospirosis in an endemic area - a study from Kerala, India

Ambily R, Mini M, Siju J, Vamshikrishna S, Abhinay G, Gleeja VL, et al.

Trop Biomed, 2019 Sep 01;36(3):654-663.
PMID: 33597487

A study was undertaken to evaluate the relevance of detecting IgM and IgG antibodies in diagnosis of canine leptospirosis in Kerala, a southern state of India, which is endemic for the disease. A total of 205 blood (35 from healthy vaccinated, 30 from healthy unvaccinated and 140 from diseased dogs) and 151 urine samples (11 from healthy vaccinated and 140 from diseased dogs) were collected from three districts of Kerala, Thrissur, Palakkad and Kozhikode with high incidence of leptospirosis. Recombinant LipL41 protein was used as antigen and IgG and IgM based ELISAs were standardized. The results were compared with the gold standard test, microscopic agglutination test (MAT). The MAT positive samples (146 samples) were divided into those having titre >1:800 and those between 1:100 and 1:400 in view that the former constituted the acute cases. It was found that IgM ELISA was more specific and sensitive in detecting acute cases (MAT >1:800) whereas IgG ELISA was less specific. In case of seroprevalence studies (MAT titre 1:100 to 1: 400), IgG ELISA was found to be more sensitive and specific than IgM ELISA. Receiver operating characteristic curves when plotted, revealed the accuracy of IgM ELISA in acute leptospirosis. Many samples were positive for both IgG and IgM antibodies. Polymerase Chain Reaction (PCR) targeting lipl41 gene was standardized and urine and blood samples from the same dogs were tested. PCR was found to be the specific test for the early detection of leptospires in blood even before seroconversion. However, PCR analysis of the urine samples was found to be insensitive. Hence, it can be concluded that the diagnostic strategies should be modified, and a combination of serological and molecular tests is recommended in endemic areas rather than simple detection of IgM or IgG antibodies, for the early detection of acute clinical cases of leptospirosis.

Matched MeSH terms: Recombinant Proteins/immunology
Fulltext Two Genetically Distinct Plasmodium knowlesi Duffy Binding Protein Alpha Region II (PkDBPαII) Haplotypes Demonstrate Higher Binding Level to Fy(a+b+) Erythrocytes than Fy(a+b--) Erythrocytes

Liew CC, Lau YL, Fong MY, Cheong FW

Am J Trop Med Hyg, 2020 05;102(5):1068-1071.
PMID: 32189613 DOI: 10.4269/ajtmh.19-0836

Invasion of human erythrocytes by merozoites of Plasmodium knowlesi involves interaction between the P. knowlesi Duffy binding protein alpha region II (PkDBPαII) and Duffy antigen receptor for chemokines (DARCs) on the erythrocytes. Information is scarce on the binding level of PkDBPαII to different Duffy antigens, Fya and Fyb. This study aims to measure the binding level of two genetically distinct PkDBPαII haplotypes to Fy(a+b-) and Fy(a+b+) human erythrocytes using erythrocyte-binding assay. The binding level of PkDBPαII of Peninsular Malaysian and Malaysian Borneon haplotypes to erythrocytes was determined by counting the number of rosettes formed in the assay. Overall, the Peninsular Malaysian haplotype displayed higher binding activity than the Malaysian Borneon haplotype. Both haplotypes exhibit the same preference to Fy(a+b+) compared with Fy(a+b-), hence justifying the vital role of Fyb in the binding to PkDBPαII. Further studies are needed to investigate the P. knowlesi susceptibility on individuals with different Duffy blood groups.

Matched MeSH terms: Protozoan Proteins/immunology
Fulltext Transudation of immunoglobulins into duodenal juice of infants with cow's milk protein sensitive enteropathy

Yadav M, Iyngkaran N

Med J Malaysia, 1982 Sep;37(3):239-44.
PMID: 7177005

Eighteen infants clinically suspected to be intolerant of cow's milk were placed on a milk-free formula and six to eight weeks later were orally challenged with cow's milk. Following challenge three groups were recognised. Group A: Four infants tolerated oral feeds ofcow's milk and lacked mucosal abnormality or clinical symptoms. Group B: Seven infants had mucosal deterioration but lacked clinical symptoms and tolerated cow's milk. Group C: Seven infants had mucosal abnormality, developed clinical symptoms and were intolerant of cow's milk. The intestinal transudation of IgA was increased in Group A and unchanged in Group Band C : the IgM levels in the duodenal juice was increased in Group A and B but unchanged in Group C : the IgG levels in the juice were increased in all Groups following challenge. It appears that increased transmission of IgA and IgM or IgM alone in the duodenal juice is associated with lack of development of clinical symptoms. Symptoms are present in infants in whom the IgA and IgM levels in duodenal juice remained unchanged after challenge. It is suggested that patients responding to cow's millt challenge with intestinal production of IgA and IgM (or IgM alone) are able to counter balance the deleterious mechanisms leading to clinical cow's milk intolerance whereas those who, for some unknown reason, do not mount a secretory immune response become ill.

Matched MeSH terms: Milk Proteins/immunology*
Toxoplasma gondii: serological characterization and immunogenicity of recombinant surface antigen 2 (SAG2) expressed in the yeast Pichia pastoris

Lau YL, Fong MY

Exp Parasitol, 2008 Jul;119(3):373-8.
PMID: 18457835 DOI: 10.1016/j.exppara.2008.03.016

The full length surface antigen 2 (SAG2) gene of the protozoan parasite Toxoplasma gondii was cloned and intracellularly expressed in the Pichia pastoris expression system. The molecular weight of the expressed recombinant SAG2 (36 kDa) was much larger than the native SAG2 (22 kDa). This discrepancy in size was due to hyperglycosylation, as deglycosylation assay reduced the size of the recombinant SAG2 to 22 kDa. Despite being hyperglycosylated, the recombinant SAG2 reacted strongly with pooled anti-Toxoplasma human serum, pooled anti-Toxoplasma mouse serum and a SAG2-specific monoclonal antibody. The glycosylated recombinant SAG2 was further evaluated in Western blot and in-house enzyme-linked immunosorbent assay (ELISA) using 80 human serum samples, including confirmed early acute (IgM positive, IgG negative; n=20), acute (IgM positive, IgG positive; n=20) and chronic (IgM negative, IgG positive; n=20) toxoplasmosis patients, and toxoplasmosis negative control patients (n=20). Results of the Western blot showed that the recombinant SAG2 reacted with all 60 samples of the toxoplasmosis cases but not with the Toxoplasma-negative samples. The sensitivity of in-house ELISA was 80%, 95% and 100% for early acute, acute and chronic patients' serum samples, respectively. Vaccination study showed that serum from mice immunised with the glycosylated recombinant SAG2 reacted specifically with the native SAG2 of T. gondii. The mice were significantly protected against lethal challenge with live T. gondii RH strain tachyzoites (P<0.01) and their survival time was increased compared to controls. Therefore, the present study shows that the P. pastoris-derived recombinant SAG2 was specific and suitable for use as antigen for detecting anti-Toxoplasma IgG and IgM antibodies. The vaccination study showed that recombinant SAG2 protein was immunoprotective in mice against lethal challenge.

Matched MeSH terms: Recombinant Proteins/immunology*; Protozoan Proteins/immunology*
Tioman virus, a novel paramyxovirus isolated from fruit bats in Malaysia

Chua KB, Wang LF, Lam SK, Crameri G, Yu M, Wise T, et al.

Virology, 2001 May 10;283(2):215-29.
PMID: 11336547

A search for the natural host of Nipah virus has led to the isolation of a previously unknown member of the family Paramyxoviridae. Tioman virus (TiV) was isolated from the urine of fruit bats (Pteropus hypomelanus) found on the island of the same name off the eastern coast of peninsular Malaysia. An electron microscopic study of TiV-infected cells revealed spherical and pleomorphic-enveloped viral particles (100--500 nm in size) with a single fringe of embedded peplomers. Virus morphogenesis occurred at the plasma membrane of infected cells and morphological features of negative-stained ribonucleoprotein complexes were compatible with that of viruses in the family Paramyxoviridae. Serological studies revealed no cross-reactivity with antibodies against a number of known Paramyxoviridae members except for the newly described Menangle virus (MenV), isolated in Australia in 1997. Failure of PCR amplification using MenV-specific primers suggested that this new virus is related to but different from MenV. For molecular characterization of the virus, a cDNA subtraction strategy was employed to isolate virus-specific cDNA from virus-infected cells. Complete gene sequences for the nucleocapsid protein (N) and phosphoprotein (P/V) have been determined and recombinant N and V proteins produced in baculovirus. The recombinant N and V proteins reacted with porcine anti-MenV sera in Western blot, confirming the serological cross-reactivity observed during initial virus characterization. The lack of a C protein-coding region in the P/V gene, the creation of P mRNA by insertion of 2-G residues, and the results of phylogenetic analyses all indicated that TiV is a novel member of the genus Rubulavirus.

Matched MeSH terms: Recombinant Proteins/immunology; Viral Proteins/immunology; Nucleocapsid Proteins/immunology
Therapeutics and vaccines against chikungunya virus

Ahola T, Couderc T, Courderc T, Ng LF, Hallengärd D, Powers A, et al.

Vector Borne Zoonotic Dis, 2015 Apr;15(4):250-7.
PMID: 25897811 DOI: 10.1089/vbz.2014.1681

Currently, there are no licensed vaccines or therapies available against chikungunya virus (CHIKV), and these were subjects discussed during a CHIKV meeting recently organized in Langkawi, Malaysia. In this review, we chart the approaches taken in both areas. Because of a sharp increase in new data in these fields, the present paper is complementary to previous reviews by Weaver et al. in 2012 and Kaur and Chu in 2013 . The most promising antivirals so far discovered are reviewed, with a special focus on the virus-encoded replication proteins as potential targets. Within the vaccines in development, our review emphasizes the various strategies in parallel development that are unique in the vaccine field against a single disease.

Matched MeSH terms: Viral Proteins/immunology
Fulltext Theoretical investigation on structural, functional and epitope of a 12 kDa excretory-secretory protein from Toxoplasma gondii

Tommy YB, Lim TS, Noordin R, Saadatnia G, Choong YS

BMC Struct Biol, 2012 Nov 27;12:30.
PMID: 23181504 DOI: 10.1186/1472-6807-12-30

BACKGROUND: Toxoplasma gondii is an intracellular coccidian parasite that causes toxoplasmosis. It was estimated that more than one third of the world population is infected by T. gondii, and the disease is critical in fetuses and immunosuppressed patients. Thus, early detection is crucial for disease diagnosis and therapy. However, the current available toxoplasmosis diagnostic tests vary in their accuracy and the better ones are costly.
RESULTS: An earlier published work discovered a highly antigenic 12 kDa excretory-secretory (ES) protein of T. gondii which may potentially be used for the development of an antigen detection test for toxoplasmosis. However, the three-dimensional structure of the protein is unknown. Since epitope identification is important prior to designing of a specific antibody for an antigen-detection based diagnostic test, the structural elucidation of this protein is essential. In this study, we constructed a three dimensional model of the 12 kDa ES protein. The built structure possesses a thioredoxin backbone which consists of four α-helices flanking five β-strands at the center. Three potential epitopes (6-8 residues) which can be combined into one "single" epitope have been identified from the built structure as the most potential antibody binding site.
CONCLUSION: Together with specific antibody design, this work could contribute towards future development of an antigen detection test for toxoplasmosis.

Matched MeSH terms: Protozoan Proteins/immunology*
The use of two-dimension electrophoresis to identify serum biomarkers from patients with dengue haemorrhagic fever

Thayan R, Huat TL, See LL, Tan CP, Khairullah NS, Yusof R, et al.

Trans R Soc Trop Med Hyg, 2009 Apr;103(4):413-9.
PMID: 19203772 DOI: 10.1016/j.trstmh.2008.12.018

Dengue infection is a major public health problem affecting millions of people living in tropical countries. With no suitable vaccines and specific antiviral drugs, treatment for dengue is usually symptomatic and supportive. Early diagnosis and recognition of severe disease is therefore crucial for better management of the patient. Two-dimension electrophoresis was used to identify disease-associated proteins that can be used for diagnosis and as drug targets for treatment. Two markers, identified by mass spectrometry analysis as alpha1-antitrypsin and NS1 proteins were found to be upregulated in dengue fever (DF; n=10) and dengue haemorrhagic fever (DHF; n=10) patients compared with healthy individuals (n=8). Both alpha1-antitrypsin and NS1 proteins were overexpressed two-fold in DHF patients compared with DF patients. Our study suggests that alpha1-antitrypsin and NS1 protein could be used as biomarkers as early indicators of DHF risk among patients with suspected dengue infection.

Matched MeSH terms: Viral Nonstructural Proteins/immunology*
The use of transgenic parasites in malaria vaccine research

Othman AS, Marin-Mogollon C, Salman AM, Franke-Fayard BM, Janse CJ, Khan SM

Expert Rev Vaccines, 2017 Jul;16(7):1-13.
PMID: 28525963 DOI: 10.1080/14760584.2017.1333426

INTRODUCTION: Transgenic malaria parasites expressing foreign genes, for example fluorescent and luminescent proteins, are used extensively to interrogate parasite biology and host-parasite interactions associated with malaria pathology. Increasingly transgenic parasites are also exploited to advance malaria vaccine development. Areas covered: We review how transgenic malaria parasites are used, in vitro and in vivo, to determine protective efficacy of different antigens and vaccination strategies and to determine immunological correlates of protection. We describe how chimeric rodent parasites expressing P. falciparum or P. vivax antigens are being used to directly evaluate and rank order human malaria vaccines before their advancement to clinical testing. In addition, we describe how transgenic human and rodent parasites are used to develop and evaluate live (genetically) attenuated vaccines. Expert commentary: Transgenic rodent and human malaria parasites are being used to both identify vaccine candidate antigens and to evaluate both sub-unit and whole organism vaccines before they are advanced into clinical testing. Transgenic parasites combined with in vivo pre-clinical testing models (e.g. mice) are used to evaluate vaccine safety, potency and the durability of protection as well as to uncover critical protective immune responses and to refine vaccination strategies.

Matched MeSH terms: Protozoan Proteins/immunology
The rubber elongation factor of rubber trees (Hevea brasiliensis) is the major allergen in latex

Czuppon AB, Chen Z, Rennert S, Engelke T, Meyer HE, Heber M, et al.

J Allergy Clin Immunol, 1993 Nov;92(5):690-7.
PMID: 8227860

BACKGROUND: Allergy to latex-containing articles is becoming more and more important because it can result in unexpected life-threatening anaphylactic reactions in sensitized individuals.
METHODS: A protein of 58 kd with an isoelectric point of 8.45 was purified from raw latex and from latex gloves and identified as the major allergen, completely blocking specific IgE antibodies in the serum of latex-sensitized subjects. The allergen is a noncovalent homotetramer molecule, in which the 14.6 kd monomer was identified, by amino acid composition and sequence homologies of tryptic peptides, to be the rubber elongation factor found in natural latex of the Malaysian rubber tree.
RESULTS: Competitive immunoinhibition tests showed that the starch powder covering the finished gloves is the airborne carrier of the allergen, resulting in bronchial asthma on inhalation. The purified allergen can induce allergic reactions in the nanogram range.
CONCLUSION: The identification of the allergen (Hev b I) may help to eliminate it during the production of latex-based articles in the future.

Matched MeSH terms: Proteins/immunology*
The role of CD4+ cells in vivo on the induction of the immune response to Porphyromonas gingivalis in mice

Sosroseno W, Bird PS, Gemmell E, Seymour GJ

J. Periodontol., 2002 Oct;73(10):1133-40.
PMID: 12416770

It has previously been suggested that CD4+ T cells play a pivotal role in regulating the immune response to periodontal pathogens. The aim of the present study therefore was to determine delayed type hypersensitivity (DTH), spleen cell proliferation, serum and splenic anti-Porphyromonas gingivalis antibody levels, and lesion sizes following challenge with viable P. gingivalis in CD4-depleted BALB/c mice immunized with P. gingivalis outer membrane proteins (OMP).

Matched MeSH terms: Bacterial Outer Membrane Proteins/immunology
The manufacture of gloves from natural rubber latex

Yip E, Cacioli P

J Allergy Clin Immunol, 2002 Aug;110(2 Suppl):S3-14.
PMID: 12170237 DOI: 10.1067/mai.2002.124499

Gloves that will provide a barrier of protection from infectious organisms are an essential feature of medical practice for the protection of both patients and medical personnel. Natural rubber latex has consistently been the most satisfactory raw material for the manufacture of gloves. Certain latex proteins, carried over into the finished product by inadequate manufacturing processes, may pose a risk of provoking allergic reactions in some patients and medical workers. As with any allergy, the risk depends on the route of exposure and dose. Hence, the method of manufacture, including the means used to coat gloves to make donning easy, can influence the eventual exposure of sensitive people to latex allergens. In this article, we describe the several processes in use and their effects on latex protein content.

Matched MeSH terms: Plant Proteins/immunology
The full-length clone of cucumber green mottle mosaic virus and its application as an expression system for Hepatitis B surface antigen

Ooi A, Tan S, Mohamed R, Rahman NA, Othman RY

J Biotechnol, 2006 Feb 24;121(4):471-81.
PMID: 16271415

A cucumber green mosaic mottle virus (CGMMV) full-length clone was developed for the expression of Hepatitis B surface antigen (HBsAg). The expression of the surface displayed HBsAg by the chimeric virus was confirmed through a double antibody sandwich ELISA. Assessment of the coat protein composition of the chimeric virus particles by SDS-PAGE analysis showed that 50% of the coat proteins were fused to the HBsAg. Biological activity of the expressed HBsAg was assessed through the stimulation of in vitro antibody production by cultured peripheral blood mononuclear cells (PBMC). PBMC that were cultured in the presence of the chimeric virus showed up to an approximately three-fold increase in the level of anti HBsAg immunoglobulin thus suggesting the possible use of this new chimeric virus as an effective Hepatitis B vaccine.

Matched MeSH terms: Recombinant Proteins/immunology
The detection of house dust mite Dermatophagoides farinae, Der f 2 and Zen-1 allergen-specific immunoglobulin E antibodies in dogs with atopic Dermatitis in Malaysia

Chan WY, Selvarajah GT, Ajat M, Suzuki R, Tsukui T

Vet Immunol Immunopathol, 2019 Jun;212:43-49.
PMID: 31213251 DOI: 10.1016/j.vetimm.2019.05.002

Canine atopic dermatitis (AD) is a chronic, inflammatory and pruritic allergic skin disease in dogs. House dust mites such as Dermatophagoides farinae are one of the known causative agents for the induction of canine AD worldwide. D. farinae protein Der f 2 is known as an important allergen involved in canine AD and recently, Zen-1 has also been identified as an allergenic protein. There is limited information on the prevalence and role of allergen sensitization to crude D. farinae extract (CDF), Der f 2 and Zen-1 among dogs diagnosed with AD in Malaysia. The aim of this study was to determine the proportion of CDF-, Der f 2- and Zen-1-specific reactive sera among dogs diagnosed with AD in Malaysia using an enzyme-linked immunosorbent assay (ELISA). Serum samples were collected from dogs diagnosed with AD from several veterinary clinics in Malaysia. The canine case records were retrieved and information on signalment, dermatological and non-dermatological histories, clinical presentation, food allergies, and exclusion of ectoparasitic, microbial and fungal skin infections were obtained through a survey form. All serum samples were evaluated to quantify the CDF-, Der f 2- and Zen-1-specific immunoglobulin E (IgE) levels. A total of 24.6%, 48.4% and 29.8% of dogs diagnosed with AD were positive for CDF-, Der f 2- and Zen-1-specific IgE, respectively. These results suggest that CDF-, Der f 2- and Zen-1 are important allergens that can contribute to AD in dogs in Malaysia, and serological testing can be performed to provide additional treatment options involving specific immunotherapies.

Matched MeSH terms: Arthropod Proteins/immunology*
Fulltext The detection and characterization of pathogenic Leptospira and the use of OMPs as potential antigens and immunogens

Gebriel AM, Subramaniam G, Sekaran SD

Trop Biomed, 2006 Dec;23(2):194-207.
PMID: 17322822 MyJurnal

The detection of leptospires in patient blood in the first week of the disease using PCR provides an early diagnostic tool. PCR using two sets of primers (G1/G2 and B64-I/B64-II) tested with samples seeded with 23 leptospiral strains from pathogenic and non-pathogenic strains was able to amplify leptospiral DNA from pathogenic strains only. Of the 39 antibody negative samples collected from patients suspected for leptospirosis, only 1 sample (2.6%) was PCR positive. Using LSSP-PCR, the G2 primers allowed the characterization of Leptopira species to 10 different genetic signatures which may have epidemiological value in determining species involved in outbreaks. Leptospiral outer membrane proteins from three strains were purified and reacted against patients sera and gave rise to different profiles for pathogenic and non-pathogenic strains. Lymphocytes of mice injected with OMPs proliferated and released IFN(-3) when stimulated in vitro using Leptospira OMP as antigens. This suggests that an immune response could be established using leptospiral OMPs as a putative vaccine. OMPs were also used in a Dot-ELISA to detect antibodies against Leptospira pathogens in humans.

Matched MeSH terms: Bacterial Outer Membrane Proteins/immunology*

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