Displaying publications 21 - 40 of 44 in total

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  1. Fulltext Selection of phage-displayed human antibody fragments specific for CD1b presenting the Mycobacterium tuberculosis glycolipid Ac2SGL
    Camacho F, Sarmiento ME, Reyes F, Kim L, Huggett J, Lepore M, et al.
    Int J Mycobacteriol, 2016 06;5(2):120-7.
    PMID: 27242221 DOI: 10.1016/j.ijmyco.2015.12.002
    OBJECTIVE/BACKGROUND: The development of new tools capable of targeting Mycobacterium tuberculosis (Mtb)-infected cells have potential applications in diagnosis, treatment, and prevention of tuberculosis. In Mtb-infected cells, CD1b molecules present Mtb lipids to the immune system (Mtb lipid-CD1b complexes). Because of the lack of CD1b polymorphism, specific Mtb lipid-CD1b complexes could be considered as universal Mtb infection markers. 2-Stearoyl-3-hydroxyphthioceranoyl-2'-sulfate-α-α'-d-trehalose (Ac2SGL) is specific for Mtb, and is not present in other mycobacterial species. The CD1b-Ac2SGL complexes are expressed on the surface of human cells infected with Mtb. The aim of this study was to generate ligands capable of binding these CD1b-Ac2SGL complexes.

    METHODS: A synthetic human scFv phage antibody library was used to select phage-displayed antibody fragments that recognized CD1b-Ac2SGL using CD1b-transfected THP-1 cells loaded with Ac2SGL.

    RESULTS: One clone, D11-a single, light-variable domain (kappa) antibody (dAbκ11)-showed high relative binding to the Ac2SGL-CD1b complex.

    CONCLUSION: A ligand recognizing the Ac2SGL-CD1b complex was obtained, which is a potential candidate to be further tested for diagnostic and therapeutic applications.

    Matched MeSH terms: Single-Chain Antibodies/immunology
  2. Current aspects in immunosensors
    Gopinath SC, Tang TH, Citartan M, Chen Y, Lakshmipriya T
    Biosens Bioelectron, 2014 Jul 15;57:292-302.
    PMID: 24607580 DOI: 10.1016/j.bios.2014.02.029
    Sensing applications can be used to report biomolecular interactions in order to elucidate the functions of molecules. The use of an analyte and a ligand is a common set-up in sensor development. For several decades, antibodies have been considered to be potential analytes or ligands for development of so-called "immunosensors." In an immunosensor, formation of the complex between antibody and antigen transduces the signal, which is measurable in various ways (e.g., both labeled and label-free based detection). Success of an immunosensor depends on various factors, including surface functionalization, antibody orientation, density of the antibody on the sensor platform, and configuration of the immunosensor. Careful optimization of these factors can generate clear-cut results for any immunosensor. Herein, current aspects, involved in the generated immunosensors, are discussed.
    Matched MeSH terms: Antibodies/immunology
  3. Display of the antigenic region of Nipah virus nucleocapsid protein on hepatitis B virus capsid
    Yap WB, Tey BT, Alitheen NB, Tan WS
    J Biosci Bioeng, 2012 Jan;113(1):26-9.
    PMID: 22024533 DOI: 10.1016/j.jbiosc.2011.09.007
    The C-terminal domain of Nipah virus (NiV) nucleocapsid protein (NP₄₀₁₋₅₃₂) was inserted at the N-terminus and the immunodominant loop of hepatitis B core antigen (HBc). The stability of NP₄₀₁₋₅₃₂ increased tremendously when displayed on the HBc particles. These particles reacted specifically with the swine anti-NiV and the human anti-HBc antisera.
    Matched MeSH terms: Hepatitis B Antibodies/immunology
  4. Fulltext Anti-hepatitis A seroprevalence among chronic viral hepatitis patients in Kelantan, Malaysia
    Ahmad F, Hamzah NA, Mustaffa N, Gan SH
    World J Gastroenterol, 2011 Sep 28;17(36):4130-4.
    PMID: 22039329 DOI: 10.3748/wjg.v17.i36.4130
    To determine the seroprevalence of anti-hepatitis A virus (HAV) antibodies in patients with chronic liver disease (CLD) and to justify the need for hepatitis A vaccination.
    Matched MeSH terms: Hepatitis A Antibodies/immunology
  5. Development and structural characterisation of human scFv targeting MDM2 spliced variant MDM215kDa
    Lim CC, Chan SK, Lim YY, Ishikawa Y, Choong YS, Nagaoka Y, et al.
    Mol Immunol, 2021 07;135:191-203.
    PMID: 33930714 DOI: 10.1016/j.molimm.2021.04.016
    The murine double minute 2 (MDM2) protein is a major negative regulator of the tumour suppressor protein p53. Under normal conditions, MDM2 constantly binds to p53 transactivation domain and/or ubiquinates p53 via its role as E3 ubiquitin ligase to promote p53 degradation as well as nuclear export to maintain p53 levels in cells. Meanwhile, amplification of MDM2 and appearance of MDM2 spliced variants occur in many tumours and normal tissues making it a prognostic indicator for human cancers. The mutation or deletion of p53 protein in half of human cancers inactivates its tumour suppressor activity. However, cancers with wild type p53 have its function effectively inhibited through direct interaction with MDM2 oncoprotein. Here, we described the construction of a MDM2 spliced variant (rMDM215kDa) consisting of SWIB/MDM2 domain and its central region for antibody generation. Biopanning with a human naïve scFv library generated four scFv clones specific to rMDM215kDa. Additionally, the selected scFv clones were able to bind to the recombinant full length MDM2 (rMDM2-FL). Computational prediction showed that the selected scFv clones potentially bind to exon 7-8 of MDM2 while leaving the MDM2/SWIB domain free for p53 interaction. The developed antibodies exhibit good specificity can be further investigated for downstream biomedical and research applications.
    Matched MeSH terms: Single-Chain Antibodies/immunology*
  6. Divalent ion-induced aggregation of gold nanoparticles for voltammetry Immunosensing: comparison of transducer signals in an assay for the squamous cell carcinoma antigen
    Letchumanan I, Gopinath SCB, Arshad MKM
    Mikrochim Acta, 2020 01 14;187(2):128.
    PMID: 31938893 DOI: 10.1007/s00604-020-4115-0
    A method is described for the electrochemical determination of squamous cell carcinoma (SCC) antigen, and by testing the effect of 30 nm gold nanoparticles (GNPs). Three comparative studies were performed in the presence and absence of GNPs, and with agglomerated GNPs. The divalent ion Ca(II) was used to induce a strong agglomeration of GNPs, as confirmed by colorimetry and voltammetry. Herein, colorimetry was used to test the best amount of salt needed to aggregate the GNPs. Despite, voltammetry was used to determine the status of biomolecules on the sensor. The topography of the surface of ZnO-coated interdigitated electrodes was analyzed by using 3D-nano profilometry, scanning electron microscopy, atomic force microscopy and high-power microscopy. The interaction between SCC antigen and antibody trigger vibrations on the sensor and cause dipole moment, which was measured using a picoammeter with a linear sweep from 0 to 2 V at 0.01 V step voltage. The sensitivity level was 10 fM by 3σ calculation for the dispersed GNP-conjugated antigen. This indicates a 100-fold enhancement compared to the condition without GNP conjugation. However, the sensitivity level for agglomerated GNPs conjugated antibody was not significant with 100 fM sensitivity. Specificity was tested for other proteins in serum, namely blood clotting factor IX, C-reactive protein, and serum albumin. The SCC antigen was quantified in spiked serum and gave recoveries that ranged between 80 and 90%. Graphical abstractSchematic representation of SCC (squamous cell carcinoma) antigen determination using divalent ion induced agglomerated GNPs. Sensitivity increment depends on the occurrence of more SCC antigen and antibody binding event via GNPs integration. Notably, lower detection limit was achieved at femto molar with proper orientation of biological molecules.
    Matched MeSH terms: Antibodies/immunology
  7. Fulltext Chronic hepatitis C infection associated with neuromyelitis optica and antinuclear antibodies
    Earnest BS, Men LC, Sukvinder Kaur G, Alias RB, Sunita Devi H
    J Assoc Physicians India, 2010 Feb;58(2):118-20.
    PMID: 20653157
    The neurological manifestations of chronic hepatitis C is most often a peripheral sensory neuropathy characterised by numbness, burning and sensation of "pins and needles". Peripheral motor neuropathy, mononeuropathy, mononeuropathy multiplex and transverse myelitis also occur. Ischemic stroke and transient cerebral ischemia have also been reported. Anterior ischemic optic neuropathy is seen, often following interferon therapy. We report an exceptional case of neuromyelitis optica in chronic hepatitis C infection in the absence of interferon therapy.
    Matched MeSH terms: Hepatitis C Antibodies/immunology*
  8. Fulltext Electrochemical Immunosensor for Detection of Aflatoxin B₁ Based on Indirect Competitive ELISA
    Azri FA, Sukor R, Selamat J, Abu Bakar F, Yusof NA, Hajian R
    Toxins (Basel), 2018 May 11;10(5).
    PMID: 29751668 DOI: 10.3390/toxins10050196
    Mycotoxins are the secondary toxic metabolites produced naturally by fungi. Analysis of mycotoxins is essential to minimize the consumption of contaminated food and feed. In this present work, an ultrasensitive electrochemical immunosensor for the detection of aflatoxin B₁ (AFB₁) was successfully developed based on an indirect competitive enzyme-linked immunosorbent assay (ELISA). Various parameters of ELISA, including antigen⁻antibody concentration, blocking agents, incubation time, temperature and pH of reagents, were first optimized in a 96-well microtiter plate to study the antigen⁻antibody interaction and optimize the optimum parameters of the assay. The optimized assay was transferred onto the multi-walled carbon nanotubes/chitosan/screen-printed carbon electrode (MWCNTs/CS/SPCE) by covalent attachment with the aid of 1-Ethyl-3-(3-dimetylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS). Competition occurred between aflatoxin B₁-bovine serum albumin (AFB₁⁻BSA) and free AFB₁ (in peanut sample and standard) for the binding site of a fixed amount of anti-AFB₁ antibody. Differential pulse voltammetry (DPV) analysis was used for the detection based on the reduction peak of TMB(ox). The developed immunosensor showed a linear range of 0.0001 to 10 ng/mL with detection limit of 0.3 pg/mL. AFB₁ analysis in spiked peanut samples resulted in recoveries between 80% and 127%. The precision of the developed immunosensor was evaluated by RSD values (n = 5) as 4.78% and 2.71% for reproducibility and repeatability, respectively.
    Matched MeSH terms: Antibodies/immunology
  9. Bio-nanogate manipulation on electrode surface as an electrochemical immunosensing strategy for detecting anti-hepatitis B surface antigen
    Syamila N, Syahir A, Sulaiman Y, Ikeno S, Tan WS, Ahmad H, et al.
    Bioelectrochemistry, 2022 Feb;143:107952.
    PMID: 34600402 DOI: 10.1016/j.bioelechem.2021.107952
    The diagnosis of hepatitis B virus (HBV) and monitoring of the vaccination efficiency against HBV require real-time analysis. The presence of antibody against hepatitis B virus surface antigen (anti-HBsAg) as a result of HBV infection and/or immunization may indicate individual immune status towards HBV. This study investigated the ability of a bio-nanogate-based displacement immunosensing strategy in detecting anti-HBsAg antibody, via nonspecific-binding between polyamidoamine dendrimers encapsulated gold nanoparticles (PAMAM-Au) and the 'antigenic determinant' region (aD) of HBsAg. For this purpose, maltose binding protein harbouring the aD region (MBP-aD) was synthesized as a bioreceptor and immobilized on the screen-printed carbon electrode (SPCE). Following that, PAMAM-Au was deposited on MBP-aD, forming the 'gate' and was used as a monitoring agent. Under optimal conditions, the high specificity of anti-HBsAg antibody towards MBP-aD displaced PAMAM-Au causing the decrement of anodic peak in differential pulse voltammetry (DPV) analysis. The signal changes were proportionally related to the concentration of anti-HBsAg antibody, in a range of 1 - 1000 mIU/mL with a limit of detection (LOD) of 2.5 mIU/mL. The results also showed high specificity and selectivity of the immunosensor platform in detecting anti-HBsAg antibody both in spiked buffer and human serum samples.
    Matched MeSH terms: Hepatitis B Antibodies/immunology
  10. Effect of colchicine on the murine immune response induced by Aggregatibacter actinomycetemcomitans
    Sosroseno W
    Biomed Pharmacother, 2009 Mar;63(3):221-7.
    PMID: 18534811 DOI: 10.1016/j.biopha.2008.04.004
    The aim of the present study was to test the hypothesis that colchicine may alter Aggregatibacter actinomycetemcomitans-induced immune response and abscess formation in mice. BALB/c mice were either sham-immunized or immunized with heat-killed A. actinomycetemcomitans. Spleen cells were stimulated with heat-killed A. actinomycetemcomitans in the presence or absence of colchicine. Specific IgG subclass antibodies, interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and cell proliferation were determined. The animals were sham-immunized (group I) or immunized with heat-killed A. actinomycetemcomitans (groups II-VII). Colchicine was administered intraperitoneally before (group III), on the same day of (group IV), or after (group V) the primary immunization and on the same day of (group VI) or after (group VII) the secondary immunization. All groups were challenged with viable A. actinomycetemcomitans. The levels of serum-specific IgG subclasses and both IFN-gamma and IL-4 before and after bacterial challenge were assessed. The diameter of skin lesions was assessed. The results showed that colchicine augmented splenic-specific IgG1 and IL-4 as well as cell proliferation but suppressed specific IgG2a and IFN-gamma levels. Enhancement of serum-specific IgG1 and IL-4 levels, suppression of specific IgG2a and IFN-gamma levels as well as DTH response, and delayed healing of the lesions were observed in groups IV and VI, but not in the remaining groups of animals. Therefore, these results suggest that colchicine may induce a T helper 2 (Th2)-like immunity specific to A. actinomycetemcomitans in vitro and that colchicine administered on the same day as the immunization may stimulate a non-protective Th2-like immunity in A. actinomycetemcomitans-induced infections in mice.
    Matched MeSH terms: Antibodies/immunology
  11. HLA-DRB genes and antiribosomal P antibodies in systemic lupus erythematosus
    Teh LS, Doherty DG, Williams BD
    Br J Rheumatol, 1994 Dec;33(12):1125-6.
    PMID: 8000739
    Antibodies to the ribosomal P protein are specific for SLE but their prevalence varies in different ethnic groups. In a group of Chinese SLE patients from Malaysia who have a high prevalence of this antibody, we have found an increased frequency of an uncharacterized HLA-DRB gene allele, DR16X, in patients who are positive for anti-P antibodies compared to antibody negative patients (31.3% vs 3.2%, P < 0.01, Pcorr not significant, relative risk = 13.6). DR16X has only been found in south east Asian populations and may be a genetic factor which influences the high prevalence of anti-P antibodies in Chinese.
    Matched MeSH terms: Antibodies/immunology
  12. L-arginine-dependent nitric oxide production of a murine macrophage-like RAW 264.7 cell line stimulated with Porphyromonas gingivalis lipopolysaccharide
    Sosroseno W, Herminajeng E, Bird PS, Seymour GJ
    Oral Microbiol. Immunol., 2004 Apr;19(2):65-70.
    PMID: 14871343
    The aim of this study was to determine nitric oxide (NO) production of a murine macrophage cell line (RAW 264.7 cells) when stimulated with Porphyromonas gingivalis lipopolysaccharides (Pg-LPS). RAW 264.7 cells were incubated with i) various concentrations of Pg-LPS or Salmonella typhosa LPS (St-LPS), ii) Pg-LPS with or without L-arginine and/or NG-monomethyl-L-arginine (NMMA), an arginine analog or iii) Pg-LPS and interferon-gamma (IFN-gamma) with or without anti-IFN-gamma antibodies or interleukin-10 (IL-10). Tissue culture supernatants were assayed for NO levels after 24 h in culture. NO was not observed in tissue culture supernatants of RAW 264.7 cells following stimulation with Pg-LPS, but was observed after stimulation with St-LPS. Exogenous L-arginine restored the ability of Pg-LPS to induce NO production; however, the increase in NO levels of cells stimulated with Pg-LPS with exogenous L-arginine was abolished by NMMA. IFN-gamma induced independent NO production by Pg-LPS-stimulated macrophages and this stimulatory effect of IFN-gamma could be completely suppressed by anti-IFN-gamma antibodies and IL-10. These results suggest that Pg-LPS is able to stimulate NO production in the RAW 264.7 macrophage cell model in an L-arginine-dependent mechanism which is itself independent of the action of IFN-gamma.
    Matched MeSH terms: Antibodies/immunology
  13. Fulltext Chimeric Virus-Like Particles of Prawn Nodavirus Displaying Hepatitis B Virus Immunodominant Region: Biophysical Properties and Cytokine Response
    Ninyio NN, Ho KL, Yong CY, Chee HY, Hamid M, Ong HK, et al.
    Int J Mol Sci, 2021 Feb 15;22(4).
    PMID: 33672018 DOI: 10.3390/ijms22041922
    Hepatitis B is a major global health challenge. In the absence of an effective treatment for the disease, hepatitis B vaccines provide protection against the viral infection. However, some individuals do not have positive immune responses after being vaccinated with the hepatitis B vaccines available in the market. Thus, it is important to develop a more protective vaccine. Previously, we showed that hepatitis B virus (HBV) 'a' determinant (aD) displayed on the prawn nodavirus capsid (Nc) and expressed in Spodoptera frugiperda (Sf9) cells (namely, Nc-aD-Sf9) self-assembled into virus-like particles (VLPs). Immunisation of BALB/c mice with the Nc-aD-Sf9 VLPs showed significant induction of humoral, cellular and memory B-cell immunity. In the present study, the biophysical properties of the Nc-aD-Sf9 VLPs were studied using dynamic light scattering (DLS) and circular dichroism (CD) spectroscopy. Enzyme-linked immunosorbent assay (ELISA) was used to determine the antigenicity of the Nc-aD-Sf9 VLPs, and multiplex ELISA was employed to quantify the cytokine response induced by the VLPs administered intramuscularly into BALB/c mice (n = 8). CD spectroscopy of Nc-aD-Sf9 VLPs showed that the secondary structure of the VLPs predominantly consisted of beta (β)-sheets (44.8%), and they were thermally stable up to ~52 °C. ELISA revealed that the aD epitope of the VLPs was significantly antigenic to anti-HBV surface antigen (HBsAg) antibodies. In addition, multiplex ELISA of serum samples from the vaccinated mice showed a significant induction (p < 0.001) of IFN-γ, IL-4, IL-5, IL-6, IL-10, and IL-12p70. This cytokine profile is indicative of natural killer cell, macrophage, dendritic cell and cytotoxic T-lymphocyte activities, which suggests a prophylactic innate and adaptive cellular immune response mediated by Nc-aD-Sf9 VLPs. Interestingly, Nc-aD-Sf9 induced a more robust release of the aforementioned cytokines than that of Nc-aD VLPs produced in Escherichia coli and a commercially used hepatitis B vaccine. Overall, Nc-aD-Sf9 VLPs are thermally stable and significantly antigenic, demonstrating their potential as an HBV vaccine candidate.
    Matched MeSH terms: Antibodies/immunology
  14. Delineation of BmSXP antibody V-gene usage from a lymphatic filariasis based immune scFv antibody library
    Rahumatullah A, Ahmad A, Noordin R, Lim TS
    Mol Immunol, 2015 Oct;67(2 Pt B):512-23.
    PMID: 26277276 DOI: 10.1016/j.molimm.2015.07.040
    Phage display technology is an important tool for antibody generation or selection. This study describes the development of a scFv library and the subsequent analysis of identified monoclonal antibodies against BmSXP, a recombinant antigen for lymphatic filariasis. The immune library was generated from blood of lymphatic filariasis infected individuals. A TA based intermediary cloning approach was used to increase cloning efficiency for the library construction process. A diverse immune scFv library of 10(8) was generated. Six unique monoclonal antibodies were identified from the 50 isolated clones against BmSXP. Analysis of the clones showed a bias for the IgHV3 and Vκ1 (45.5%) and IgHV2 and Vκ3 (27.3%) gene family. The most favored J segment for light chain is IgKJ1 (45.5%). The most favored D and J segment for heavy chain are IgHD6-13 (75%) and IgHJ3 (47.7%). The information may suggest a predisposition of certain V genes in antibody responses against lymphatic filariasis.
    Matched MeSH terms: Single-Chain Antibodies/immunology*
  15. Fulltext ABO-Incompatible Living-Donor Kidney Transplantation in a Developing Country: A Multicenter Experience in Malaysia
    Gan CC, Jalalonmuhali M, Nordin NZ, Abdul Wahab MZ, Yahya R, Ng KP, et al.
    Transplant Proc, 2021 Apr;53(3):856-864.
    PMID: 33487455 DOI: 10.1016/j.transproceed.2020.10.038
    Malaysia has a low deceased-donor donation rate and has not embarked on a paired kidney exchange program; therefore, ABO-incompatible and HLA-incompatible transplantation remain the main contributor to the sustainability of the national kidney transplantation (KT) program. There were 26 cases of ABO-incompatible KTs performed from 2011 to 2018 in 3 major transplant centers, namely, Hospital Kuala Lumpur, University Malaya Medical Centre, and Prince Court Medical Centre. We collected perioperative and follow-up data through June 2019. The desensitization protocol varies and is center specific: the localized Japanese protocol and Swedish protocol with a target anti-A/B isoagglutinin titer of 16 or 32 on the day of transplant. The induction and tacrolimus-based maintenance protocol was nearly identical. The median follow-up time was 62.3 months (interquartile range, 37.0-79.7). Fifteen subjects had the highest predesensitization anti-A/B titer of ≥32 (57.7%). The acute cellular rejection and antibody-mediated rejection incidence were 12.5% (3 cases) and 8.3% (2 cases), respectively. Patient, graft, and death-censored graft survival rates were 96.2%, 92.3%, and 96.0%, respectively, 1 year post-living-donor KT (LDKT) and 96.2%, 87.2%, and 90.7%, respectively, 5 years post-LDKT. Our experience shows that ABO-incompatible LDKT using a suitable desensitization technique could be a safe and feasible choice for LDKT even with varied desensitization regimens for recipients with relatively high baseline isoagglutinin titers.
    Matched MeSH terms: Antibodies/immunology
  16. Fulltext Antibody-Based Protective Immunity against Helminth Infections: Antibody Phage Display Derived Antibodies against BmR1 Antigen
    Rahumatullah A, Abdul Karim IZ, Noordin R, Lim TS
    Int J Mol Sci, 2017 Nov 22;18(11).
    PMID: 29165352 DOI: 10.3390/ijms18112376
    Helminth parasite infections are significantly impacting global health, with more than two billion infections worldwide with a high morbidity rate. The complex life cycle of the nematodes has made host immune response studies against these parasites extremely difficult. In this study, we utilized two phage antibody libraries; the immune and naïve library were used to identify single chain fragment variable (scFv) clones against a specific filarial antigen (BmR1). The V-gene analysis of isolated scFv clones will help shed light on preferential VDJ gene segment usage against the filarial BmR1 antigen in healthy and infected states. The immune library showed the usage of both lambda and kappa light chains. However, the naïve library showed preferential use of the lambda family with different amino acid distributions. The binding characteristics of the scFv clones identified from this work were analyzed by immunoassay and immunoaffinity pull down of BmR1. The work highlights the antibody gene usage pattern of a naïve and immune antibody library against the same antigen as well as the robust nature of the enriched antibodies for downstream applications.
    Matched MeSH terms: Single-Chain Antibodies/immunology
  17. Fulltext Development of a Phage Display Panning Strategy Utilizing Crude Antigens: Isolation of MERS-CoV Nucleoprotein human antibodies
    Lim CC, Woo PCY, Lim TS
    Sci Rep, 2019 Apr 15;9(1):6088.
    PMID: 30988390 DOI: 10.1038/s41598-019-42628-6
    Antibody phage display has been pivotal in the quest to generate human monoclonal antibodies for biomedical and research applications. Target antigen preparation is a main bottleneck associated with the panning process. This includes production complexity, downstream purification, quality and yield. In many instances, purified antigens are preferred for panning but this may not be possible for certain difficult target antigens. Here, we describe an improved procedure of affinity selection against crude or non-purified antigen by saturation of non-binders with blocking agents to promote positive binder enrichment termed as Yin-Yang panning. A naïve human scFv library with kappa light chain repertoire with a library size of 109 was developed. The improved Yin-Yang biopanning process was able to enrich monoclonal antibodies specific to the MERS-CoV nucleoprotein. Three unique monoclonal antibodies were isolated in the process. The Yin-Yang biopanning method highlights the possibility of utilizing crude antigens for the isolation of monoclonal antibodies by phage display.
    Matched MeSH terms: Single-Chain Antibodies/immunology
  18. Development of monoclonal antibodies against recombinant LipL21 protein of pathogenic Leptospira through phage display technology
    Mohd Ali MR, Sum JS, Aminuddin Baki NN, Choong YS, Nor Amdan NA, Amran F, et al.
    Int J Biol Macromol, 2021 Jan 31;168:289-300.
    PMID: 33310091 DOI: 10.1016/j.ijbiomac.2020.12.062
    Leptospirosis is a potentially fatal zoonosis that is caused by spirochete Leptospira. The signs and symptoms of leptospirosis are usually varied, allowing it to be mistaken for other causes of acute febrile syndromes. Thus, early diagnosis and identification of a specific agent in clinical samples is crucial for effective treatment. This study was aimed to develop specific monoclonal antibodies against LipL21 antigen for future use in leptospirosis rapid and accurate immunoassay. A recombinant LipL21 (rLipL21) antigen was optimized for expression and evaluated for immunogenicity. Then, a naïve phage antibody library was utilized to identify single chain fragment variable (scFv) clones against the rLipL21 antigen. A total of 47 clones were analysed through monoclonal phage ELISA. However, after taking into consideration the background OD405 values, only 4 clones were sent for sequencing to determine human germline sequences. The sequence analysis showed that all 4 clones are identical. The in silico analysis of scFv-lip-1 complex indicated that the charged residues of scFv CDRs are responsible for the recognition with rLipL21 epitopes. The generated monoclonal antibody against rLipL21 will be evaluated as a detection reagent for the diagnosis of human leptospirosis in a future study.
    Matched MeSH terms: Single-Chain Antibodies/immunology
  19. Fulltext Broad specificity of immune helminth scFv library to identify monoclonal antibodies targeting Strongyloides
    Rahumatullah A, Balachandra D, Noordin R, Baharudeen Z, Lim YY, Choong YS, et al.
    Sci Rep, 2021 01 28;11(1):2502.
    PMID: 33510342 DOI: 10.1038/s41598-021-82125-3
    Antibodies have different chemical properties capable of targeting a diverse nature of antigens. Traditionally, immune antibody libraries are perceived to be disease-specific with a skewed repertoire. The complexity during the generation of a combinatorial antibody library allows for a skewed but diverse repertoire to be generated. Strongyloides stercoralis is a parasite that causes strongyloidiasis, a potentially life-threatening disease with a complex diagnosis that impedes effective control and treatment of the disease. This study describes the isolation of monoclonal antibodies against S. stercoralis NIE recombinant protein using an immune antibody phage display library derived from lymphatic filaria-infected individuals. The isolated antibody clones showed both lambda and kappa light chains gene usage, with diverse amino acid distributions. Structural analysis showed that electropositivity and the interface area could determine the binding affinity of the clones with NIE. The successful identification of S. stercoralis antibodies from the filarial immune library highlights the breadth of antibody gene diversification in an immune antibody library that can be applied for closely related infections.
    Matched MeSH terms: Single-Chain Antibodies/immunology*
  20. One-Year Outcomes of Living Related Kidney Transplant in Patients With Preformed HLA Donor-Specific Antibodies: A Single-Center Experience in Malaysia
    Jalalonmuhali M, Ng KP, Mohd Shariff NH, Lee YW, Wong AH, Gan CC, et al.
    Transplant Proc, 2020 05 21;52(6):1718-1722.
    PMID: 32448671 DOI: 10.1016/j.transproceed.2020.02.140
    The shortage of deceased donors led to an increase of living related renal transplant performed in the presence of donor-specific antibodies (DSAs) or ABO incompatibilities. There are various desensitization protocols that have been proposed. Here, we describe the outcome of these sensitized patients. This is a prospective cohort study recruiting all kidney transplant recipients from August 2016 until June 2018. Deceased donations, ABO incompatible patients, and sensitized patients who were not prescribed on our desensitization protocol were excluded. Recipients were screened for the presence of HLA-antibodies 1 month before transplant. Those with positive DSA will undergo flow cytometry (risk stratification). We are using a protocol that consisted of intravenous rituximab 200 mg (day -14), intravenous antithymocyte globulin 5mg/kg (day 0-4), plasma exchange post transplant for patients with mean fluorescent intensity (MFI) < 3000, and negative flow cytometry. Those patients with MFI ≥ 3000 or positive flow cytometry need extra cycles pretransplant. A total of 40 patients were recruited, and 20 were sensitized patients. Among the sensitized group 4 of 20 had flow cytometry crossmatch positive, while all had preformed HLA-DSA. A total of 8 of 20 had class I HLA-DSA, 11 of 20 had class II HLA-DSA, and 1of 20 was positive for both class I and II HLA-DSA. Mean immunodominant MFI was 2133.4 (standard deviation [SD], 4451.24) and 1383.7 (SD, 2979.02) for class I and class II, respectively. At 1 year, mean serum creatinine was 108.90 (SD, 25.95) and 118.42 (SD, 31.68) in sensitized and unsensitized patients, respectively. One of 20 unsensitized patients had Banff 1B rejection at 3 months, and there was no significant rejection in sensitized patients at 6 months and 1 year. There was no difference in the occurrence of de novo HLA-DSA between the groups. Desensitization protocols may help to overcome incompatibility barriers in living donor renal transplant. The combination of low-dose rituximab, antithymocyte globulin, and judicious use of plasma exchange has worked well for our cohort.
    Matched MeSH terms: Antibodies/immunology
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