Displaying publications 1 - 20 of 85 in total

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  1. Fulltext Interleukin 6 and Interleukin 17a enhance proliferation and differentiation of murine osteoblast and human foetal osteoblast cell lines
    Shaminea S, Kannan TP, Norazmi MN, Nurul AA
    International Medical Journal Malaysia, 2014;13(2):35-40.
    MyJurnal
    Introduction: Cytokines have been gaining great focus due to their role in enhancing osseointegration as well as their potential in bone reconstruction. Osseointegration often faces complications in its compatibility with the implant due to rejection by the recipients own immune system. Therefore, extensive studies are being carried out to enhance osteoblast development to minimize such complication. The aim of this study was to determine the effect of different concentrations of Interleukin 6 (IL-6) and Interleukin 17a (IL-17A) in the proliferation and differentiation of murine and human osteoblasts.

    Methods: Various concentrations (5, 10, 25 and 50 ng/ml) of rIL-6 and rIL-17A were tested on both murine osteoblast (MC3T3-E1) and human feotal osteoblast (hFOB) cell lines using [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] (MTS) and alkaline phosphatise (ALP) assays. MTS was carried out at 24, 48, 72, 96 and 120 hours while ALP assay was done on day 1, 3, 7, 10 and 14.

    Results: MC3T3-E1 cells showed steadier proliferation and differentiation compared to hFOB. Both cell lines expressed responses in dose-dependent manner. The concentration of 10ng for IL-6 and IL-17A in the case of MC3T3-E1 cell line was found to be the most suitable for further studies.

    Conclusion: IL-6 and IL-17A enhance proliferation and ALP activity of both MC3T3-E1 and hFOB cell lines.
  2. Fulltext Interferon-β controls non-tuberculous mycobacterial infection in mice
    Norazmi MN
    Virulence, 2017 10 03;8(7):1085-1087.
    PMID: 28605283 DOI: 10.1080/21505594.2017.1341035
  3. Immunogenicity of a recombinant Mycobacterium bovis bacille Calmette-Guèrin expressing malarial and tuberculosis epitopes
    Rapeah S, Norazmi MN
    Vaccine, 2006 Apr 24;24(17):3646-53.
    PMID: 16494975 DOI: 10.1016/j.vaccine.2006.01.053
    Recombinant Mycobacterium bovis bacille Calmette-Guèrin (rBCG) expressing the malarial epitopes F2R(II)EBA and (NANP)3 as well as two T cell epitopes of the M. tuberculosis ESAT-6 antigen, generated in favour of mycobacterium codon usage elicited specific immune response against these epitopes. Immunised Balb/c mice demonstrated an increase in almost all of the IgG subclasses against both malarial epitopes and enhanced splenocyte proliferative response against the malarial epitopes as well as selected peptides of ESAT-6. Furthermore, flow cytometric analyses showed elevated numbers of CD4+ lymphocytes expressing IFN-gamma and IL-2 against the ESAT-6 peptides, suggesting a specific Th1-mediated response. This study demonstrated that expressing malarial and TB epitopes in a single rBCG construct induced appropriate humoral and cellular immune response against immunogenic epitopes from both organisms.
  4. Disparity in the percentage of CD4+ T lymphocytes and prognosis of HIV-infected intravenous drug users in Malaysia
    Norazmi MN, Suarn S
    Immunol Lett, 1994 Dec;43(3):177-82.
    PMID: 7721330
    The CD4+ T-lymphocyte absolute count (CD4ac), CD4+ T-lymphocyte percentage (CD4%) and total lymphocyte count (Løac) were assessed in HIV-seropositive intravenous drug users (IVDU) with reference to their correlation with the clinical categories A, B, and C as stipulated by the Centre of Disease Control and Prevention, USA (CDC) and with each other. It was found that while the CD4ac and Løac correlated with the clinical categories, CD4% did not. This may suggest that in our local setting, the CD4% may not necessarily be a suitable alternative marker to CD4ac as proposed by CDC. Furthermore, the CD4% of the normal subjects in this study was found to be relatively lower than the reported Caucasian levels. This may indicate that the use of the cut-off level of less than 14% as an AIDS-defining criteria may not be applicable for our HIV-seropositive IVDU. In addition, unlike the CD4ac which correlated directly with CD4% and Løac, the CD4% did not correlate with Løac. Therefore, due to the observed disparity with clinical status of patients and its possibly lower levels in our normal population, CD4% as a marker for staging HIV disease should be used with caution in our setting. Such findings may also have an impact on the use of established markers for the monitoring and classification of HIV-infected individuals in this region.
  5. Forensic DNA profiling and database
    Panneerchelvam S, Norazmi MN
    Malays J Med Sci, 2003 Jul;10(2):20-6.
    PMID: 23386793 MyJurnal
    The incredible power of DNA technology as an identification tool had brought a tremendous change in crimnal justice . DNA data base is an information resource for the forensic DNA typing community with details on commonly used short tandem repeat (STR) DNA markers. This article discusses the essential steps in compilation of COmbined DNA Index System (CODIS) on validated polymerase chain amplified STRs and their use in crime detection.
  6. Fulltext DNA Profiling in Human Identification: From Past to Present
    Panneerchelvam S, Norazmi MN
    Malays J Med Sci, 2023 Dec;30(6):5-21.
    PMID: 38239252 DOI: 10.21315/mjms2023.30.6.2
    Forensic DNA typing has been widely accepted in the courts all over the world. This is because DNA profiling is a very powerful tool to identify individuals on the basis of their unique genetic makeup. DNA evidence is capable of not only identifying the presence of specific biospecimens in a crime scene, but it is also used to exonerate suspects who are innocent of a crime. Technological advancements in DNA profiling, including the development of validated kits and statistical methods have made this tool to be more precise in forensic investigations. Therefore, validated combined DNA index system (CODIS) short tandem repeats (STRs) kits which require very small amount of DNA, coupled with real-time polymerase chain reaction (PCR) and the statistical strengths are used routinely to identify human remains, establish paternity or to match suspected crime scene biospecimens. The road to modern DNA profiling has been long, and it has taken scientists decades of work and fine tuning to develop highly accurate testing and analyses that are used today. This review will discuss the various DNA polymorphisms and their utility in human identity testing.
  7. Fulltext Pattern recognition receptors and cytokines in Mycobacterium tuberculosis infection--the double-edged sword?
    Hossain MM, Norazmi MN
    Biomed Res Int, 2013;2013:179174.
    PMID: 24350246 DOI: 10.1155/2013/179174
    Tuberculosis, an infectious disease caused by Mycobacterium tuberculosis (Mtb), remains a major cause of human death worldwide. Innate immunity provides host defense against Mtb. Phagocytosis, characterized by recognition of Mtb by macrophages and dendritic cells (DCs), is the first step of the innate immune defense mechanism. The recognition of Mtb is mediated by pattern recognition receptors (PRRs), expressed on innate immune cells, including toll-like receptors (TLRs), complement receptors, nucleotide oligomerization domain like receptors, dendritic cell-specific intercellular adhesion molecule grabbing nonintegrin (DC-SIGN), mannose receptors, CD14 receptors, scavenger receptors, and FCγ receptors. Interaction of mycobacterial ligands with PRRs leads macrophages and DCs to secrete selected cytokines, which in turn induce interferon-γ- (IFNγ-) dominated immunity. IFNγ and other cytokines like tumor necrosis factor-α (TNFα) regulate mycobacterial growth, granuloma formation, and initiation of the adaptive immune response to Mtb and finally provide protection to the host. However, Mtb can evade destruction by antimicrobial defense mechanisms of the innate immune system as some components of the system may promote survival of the bacteria in these cells and facilitate pathogenesis. Thus, although innate immunity components generally play a protective role against Mtb, they may also facilitate Mtb survival. The involvement of selected PRRs and cytokines on these seemingly contradictory roles is discussed.
  8. Immunogenicity and in vitro protective efficacy of recombinant Mycobacterium bovis bacille Calmette Guerin (rBCG) expressing the 19 kDa merozoite surface protein-1 (MSP-1(19)) antigen of Plasmodium falciparum
    Nurul AA, Norazmi MN
    Parasitol Res, 2011 Apr;108(4):887-97.
    PMID: 21057812 DOI: 10.1007/s00436-010-2130-5
    Vaccine development against the blood-stage malaria parasite is aimed at reducing the pathology of the disease. We constructed a recombinant Mycobacterium bovis bacille Calmette Guerin (rBCG) expressing the 19 kDa C-terminus of Plasmodium falciparum merozoite surface protein-1 (MSP-1(19)) to evaluate its protective ability against merozoite invasion of red blood cells in vitro. A mutated version of MSP-1(19), previously shown to induce the production of inhibitory but not blocking antibodies, was cloned into a suitable shuttle plasmid and transformed into BCG Japan (designated rBCG016). A native version of the molecule was also cloned into BCG (rBCG026). Recombinant BCG expressing the mutated version of MSP-1(19) (rBCG016) elicited enhanced specific immune response against the epitope in BALB/c mice as compared to rBCG expressing the native version of the epitope (rBCG026). Sera from rBCG016-immunized mice contained significant levels of specific IgG, especially of the IgG2a subclass, against MSP-1(19) as determined by enzyme-linked immunosorbent assay. The sera was reactive with fixed P. falciparum merozoites as demonstrated by indirect immunofluorescence assay (IFA) and inhibited merozoite invasion of erythrocytes in vitro. Furthermore, lymphocytes from rBCG016-immunized mice demonstrated higher proliferative response against the MSP-1(19) antigen as compared to those of rBCG026- and BCG-immunized animals. rBCG expressing the mutated version of MSP-1(19) of P. falciparum induced enhanced humoral and cellular responses against the parasites paving the way for the rational use of rBCG as a blood-stage malaria vaccine candidate.
  9. Influence of 17β-estradiol on 15-deoxy-δ12,14 prostaglandin J2 -induced apoptosis in MCF-7 and MDA-MB-231 cells
    Yaacob NS, Nasir R, Norazmi MN
    Asian Pac J Cancer Prev, 2013;14(11):6761-7.
    PMID: 24377602
    The nuclear receptor, peroxisome proliferator-activated receptor gamma (PPARγ), is expressed in various cancer cells including breast, prostate, colorectal and cervical examples. An endogenous ligand of PPARγ, 15-deoxy-Δ12,14 prostaglandin J2 (PGJ2), is emerging as a potent anticancer agent but the exact mechanism has not been fully elucidated, especially in breast cancer. The present study compared the anticancer effects of PGJ2 on estrogen receptor alpha (ERα)-positive (MCF-7) and ERα-negative (MDA-MB-231) human breast cancer cells. Based on the reported signalling cross-talk between PPARγ and ERα, the effect of the ERα ligand, 17β-estradiol (E2) on the anticancer activities of PGJ2 in both types of cells was also explored. Here we report that PGJ2 inhibited proliferation of both MCF-7 and MDA-MB-231 cells by inducing apoptotic cell death with active involvement of mitochondria. The presence of E2 potentiated PGJ2-induced apoptosis in MCF-7, but not in MDA-MB-231 cells. The PPARγ antagonist, GW9662, failed to block PGJ2-induced activities but potentiated its effects in MCF-7 cells, instead. Interestingly, GW9662 also proved capable of inducing apoptotic cell death. It can be concluded that E2 enhances PPARγ-independent anticancer effects of PGJ2 in the presence of its receptor.
  10. Modulation of cell growth and PPARgamma expression in human colorectal cancer cell lines by ciglitazone
    Yaacob NS, Darus HM, Norazmi MN
    Exp. Toxicol. Pathol., 2008 Sep;60(6):505-12.
    PMID: 18579355 DOI: 10.1016/j.etp.2008.05.006
    Studies have shown that ligand activation of peroxisome proliferator-activated receptor gamma (PPARgamma) can induce differentiation and inhibit proliferation of several cancer cells. The present study was performed to investigate the effects of the PPARgamma ligand, ciglitazone, and the involvement of PPARgamma in modulating the growth of human colorectal cancer cells. Lactate dehydrogenase release assay showed that ciglitazone potently inhibited HT-29 (well-differentiated) and COLO-205 (poorly differentiated) colorectal adenocarcinoma cell growth. Measurement of apoptosis by flow cytometry using a fluorescein-conjugated monoclonal antibody against cytokeratin 18 revealed a high induction of apoptosis by ciglitazone in a time-dependent fashion. The expression of PPARgamma1 but not PPARgamma2 mRNA was significantly downregulated as measured by real-time quantitative PCR, and the PPARgamma protein levels were decreased as determined by Western blot analysis. We conclude that ciglitazone treatment suppressed colon cancer cell growth via induction of apoptosis. However, the anticancer effects of ciglitazone may not depend solely on PPARgamma activation.
  11. Influence of recombinant interferon-gamma QN the expression of MHC class I and class II antigens on four human colonic carcinoma cell lines
    Norazmi MN, Hohmann AW, Bradley J
    Malays J Pathol, 1990 Dec;12(2):89-95.
    PMID: 2129402
    The occurrence of MHC class I and class II antigens on four human colonic carcinoma cell lines and the effect of recombinant interferon-gamma (rIFNg) on the expression of these antigens was investigated by immunofluorescent flow cytometry. The concentration of rIFNg which resulted in the largest increase in expression of class I and class II antigens was determined. Changes in the amount of MHC antigen on the membrane were indicated by a shift in the mean fluorescence intensity (MFI) of the cell population. Without addition of rIFNg, the COLO 206, COLO 320F and COLO 397 cell lines were class I positive although the COLO 206 cell line expressed less class I antigen than the other two lines. The HT-29 cell line expressed only a minimal level of class I antigen. Treatment with rIFNg increased the amount of class I antigen on these cell lines 5, 1.4, 2.5 and 20 times respectively. Maximum levels of class I antigen were found two days after treatment. Class I antigen expression returned to pre-treatment levels by day 8 in all but the HT-29 cell line, which maintained its increased level following a single dose of rIFNg. All four cell lines had little or no class II antigens. Following treatment with rIFNg, DR antigen appeared on all four lines whereas DP and DQ antigens could be induced only on the 320F and 397 lines. The amount of class II antigen reached its peak two days after treatment and gradually decreased over the next 6 days of culture.(ABSTRACT TRUNCATED AT 250 WORDS)
  12. Tualang honey induces apoptosis and disrupts the mitochondrial membrane potential of human breast and cervical cancer cell lines
    Fauzi AN, Norazmi MN, Yaacob NS
    Food Chem Toxicol, 2011 Apr;49(4):871-8.
    PMID: 21167897 DOI: 10.1016/j.fct.2010.12.010
    Honey is reported to contain various compounds such as phenols, vitamins and antioxidants. The present study investigates the anticancer potential of Tualang honey (Agromas) (TH) in human breast (MCF-7 and MDA-MB-231) and cervical (HeLa) cancer cell lines; as well as in the normal breast epithelial cell line, MCF-10A. The cells were treated with increasing doses of TH (1-10%) for up to 72 h. Increase in lactate dehydrogenase (LDH) leakage from the cell membranes indicates that TH is cytotoxic to all three cancer cells with effective concentrations (EC(50)) of 2.4-2.8%. TH is however, not cytotoxic to the MCF-10A cells. Reactivity with annexin V fluorescence antibody and propidium iodide as analysed by flow cytometry and fluorescence microscopy shows that apoptosis occurred in these cancer cells. TH also reduced the mitochondrial membrane potential (Δψ(m)) in the cancer cell lines after 24h of treatment. The activation of caspase-3/7 and -9 was observed in all TH-treated cancer cells indicating the involvement of mitochondrial apoptotic pathway. This study shows that TH has significant anticancer activity against human breast and cervical cancer cell lines.
  13. Differential transcriptional expression of PPARalpha, PPARgamma1, and PPARgamma2 in the peritoneal macrophages and T-cell subsets of non-obese diabetic mice
    Yaacob NS, Kaderi MA, Norazmi MN
    J Clin Immunol, 2009 Sep;29(5):595-602.
    PMID: 19472040 DOI: 10.1007/s10875-009-9300-1
    BACKGROUND: The peroxisome proliferator-activated receptors (PPARs) have been implicated in immune regulation. We determined the transcriptional expression of the three isoforms, PPARalpha, PPARgamma1, and PPARgamma2 in the peritoneal macrophages, CD4- and CD8-positive lymphocytes in non-obese diabetic (NOD) mice at 5 and 10 weeks of age as well as at diabetic stage.

    RESULTS: Compared to the non-obese diabetic resistant (NOR) mice, the peritoneal macrophages of NOD mice expressed increased levels of PPARalpha but reduced levels of PPARgamma2, while PPARgamma1 expression was unchanged in all age groups. CD4-positive lymphocytes expressed low levels of PPARalpha in diabetic NOD mice and greatly reduced expression of PPARgamma2 in all age groups. Unlike peritoneal macrophages and CD4-positive cells, the CD8-positive cells expressed low levels of PPARgamma1 in diabetic NOD mice but no difference in PPARalpha and PPARgamma2 expression was observed compared to NOR mice.

    CONCLUSION: The current findings may suggest an important regulatory role of PPARs in the pathogenesis of autoimmune diabetes.

  14. Enhancement of immune response against Mycobacterium tuberculosis HspX antigen by incorporation of combined molecular adjuvant (CASAC)
    Lew MH, Norazmi MN, Tye GJ
    Mol Immunol, 2020 Jan;117:54-64.
    PMID: 31739193 DOI: 10.1016/j.molimm.2019.10.023
    Tuberculosis (TB) is one of the deadliest human diseases worldwide caused by mycobacterial infection in the lung. Bacillus Calmette-Guerin (BCG) vaccine protects against disseminated TB in children, but its effectiveness is still questionable due to highly variable protections in adolescence and elderly individuals. Targeting the latency M.tb antigen is a recent therapeutic approach to eradicate dormant pathogen that could possibly lead to disease activation. In this study, we aimed to potentiate immune responses elicited against 16 kDa α-crystalline (HspX) tuberculosis latency antigen by incorporation of Combined Adjuvant for Synergistic Activation of Cellular immunity (CASAC). Histidine-tagged recombinant HspX protein was initially produced in Escherichia coli and purified using Ni-NTA chromatography. To evaluate its adjuvanticity, C57BL/6 mice (n = 5) were initially primed and intradermally immunised in 2-weeks interval for 4 rounds with recombinant HspX, formulated with and without CASAC. Humoral and cell-mediated immune responses elicited against HspX antigen were evaluated using ELISA and Flow Cytometry. Our findings showed that CASAC improved humoral immunity with increased antigen-specific IgG1 and IgG2a antibody response. Stronger CD8+ and Th1-driven immunity was induced by CASAC formulation as supported by elevated level of IFN-γ, TNF-α, IL-12 and IL-17A; and with low IL-10 secretion. Interestingly, adjuvanted HspX vaccine triggered a higher percentage of effector memory T-cell population than those immunised with unadjuvanted vaccine. In conclusion, CASAC adjuvant has great potential to enhance immunogenicity elicited against HspX antigen, which could be an alternative regimen to improve the efficacy of future therapeutic vaccine against Mycobacterium tuberculosis.
  15. Quantification of human PPARgamma1 gene expression by competitive PCR using an homologous internal standard
    Yaacob NS, Bakar RA, Norazmi MN
    Ann Clin Lab Sci, 2004;34(1):47-56.
    PMID: 15038667
    The polymerase chain reaction (PCR) is useful for amplifying specific mRNAs, particularly those present in low copy numbers. However, due to the exponential nature of the amplification process, PCR cannot readily be used to quantify gene expression. A competitive PCR technique was developed to address this shortcoming. An internal standard that is 100% homologous to, but shorter than, the target gene was constructed. The practicality of the method was demonstrated by determining the expression levels of a human transcription factor, peroxisome proliferator-activated receptor gamma 1 (hPPARgamma1) which is normally present in low copy numbers in selected cells. A mock system was used to test the accuracy and sensitivity of the method, which was subsequently used to determine the expression of this receptor in lipopolysaccharide (LPS)-activated monocytes, which are known to express hPPARgamma1 differentially during cellular activation. Densitometric analysis showed that the competitive PCR method reliably estimated the expression levels of hPPARgamma1 at the attomole (10(-18)) level in monocytes.
  16. Fulltext Immunogenicity of recombinant BCG-based vaccine expressing the 22 kDa of serine repeat antigen (SE22) of Plasmodium falciparum
    Teo WH, Nurul AA, Norazmi MN
    Trop Biomed, 2012 Jun;29(2):239-53.
    PMID: 22735846 MyJurnal
    The Plasmodium falciparum serine repeat antigen (SERA) is one of the promising blood-stage malarial vaccine candidates. In this study, recombinant Mycobacterium bovis bacille Calmette-Guerin (rBCG) expressing the 22 kDa protein (SE22) from the 47 kDa Nterminal domain of serine repeat antigen (SERA), generated in favour of mycobacterium codon usage, elicited specific immune response in BALB/c mice with a mixed Th1/Th2 profile. Immunized sera containing high levels of specific IgG1 and IgG2a against the epitope (as determined by ELISA) were reactive with fixed P. falciparum merozoites as demonstrated by indirect immunofluorescence assay (IFA). Furthermore, the lymphocyte proliferative response to SE22 antigen from rBCG-immunized mice was higher than that of controls. The expression of intracellular cytokines (IL-2, IL-4 and IFNγ) in CD4+- and CD8+-cells was also enhanced following in-vitro stimulation with SE22. These findings indicate that a rBCG-based vaccine candidate expressing a blood-stage antigen of P. falciparum could enhance both humoral and cellular immune responses, thus paving the way for the rational use of rBCG as a vaccine candidate against malaria.
  17. Fulltext Plasmodium falciparum 19 kDa of merozoite surface protein-1 (MSP-1(19)) expressed in Mycobacterium bovis bacille Calmette Guerin (BCG) is reactive with an inhibitory but not a blocking monoclonal antibody
    Nurul AA, Rapeah S, Norazmi MN
    Trop Biomed, 2010 Apr;27(1):60-7.
    PMID: 20562815
    Proteins on the surface of Plasmodium falciparum merozoites are good targets for vaccine development against malaria because they are accessible to antibodies in the plasma. The 19 kDa C-terminus of merozoite surface protein-1 (MSP-1(19)) has been shown to induce both inhibitory as well as blocking antibodies, the latter blocking the protective effects of the former. Inhibitory antibodies bind to MSP-1(19) and inhibit merozoite invasion of red blood cells (RBC) but the binding of blocking antibodies can prevent binding of inhibitory antibodies thereby allowing the parasite to invade RBC. We constructed a synthetic version of the MSP-1(19) of the P. falciparum using mycobacterium codon usage by assembly PCR. The synthetic MSP-1(19) was mutated at various sites to promote the production of inhibitory but not blocking antibodies as previously reported. The native and mutated MSP-1(19) were cloned and expressed in Mycobacterium bovis bacille Calmette-Guerin (BCG) and the expressions of the recombinant proteins were detected by specific monoclonal antibodies (mAbs) namely, 12.10 and 1E1 against MSP-1(19) using Western blotting. The mutated MSP-1(19) protein reacted with the inhibitory mAb, 12.10, but not the blocking mAb, 1E1, paving the way for the construction of a potential recombinant BCG (rBCG) blood stage vaccine against malaria.
  18. Fulltext Phagocytic activity and pro-inflammatory cytokines production by the murine macrophage cell line J774A.1 stimulated by a recombinant BCG (rBCG) expressing the MSP1-C of Plasmodium falciparum
    Rapeah S, Dhaniah M, Nurul AA, Norazmi MN
    Trop Biomed, 2010 Dec;27(3):461-9.
    PMID: 21399587 MyJurnal
    Macrophages are involved in innate immunity against malaria due to their ability to phagocytose infected erythrocytes and produce inflammatory cytokines, which are important for controlling parasite growth during malaria infection. In this study, the ability of a recombinant BCG (rBCG) vaccine expressing the 19-kDa C-terminus of merozoite surface protein-1 (MSP1-C) of Plasmodium falciparum, to stimulate the phagocytic activity and secretion of pro-inflammatory cytokines by the macrophage cell line J774A.1 was measured at varying times. The results demonstrate the ability of the rBCG construct to activate the inflammatory action of macrophages, which is important as a first-line of defence in clearing malaria infections.
  19. The expression of cytokine genes in the peritoneal macrophages and splenic CD4- and CD8-positive lymphocytes of the nonobese diabetic mice
    Yaacob NS, Kaderi MA, Norazmi MN
    J Clin Immunol, 2004 Mar;24(2):177-84.
    PMID: 15024185 DOI: 10.1023/B:JOCI.0000019783.61674.1d
    Type 1 diabetes is an autoimmune disease that results from the destruction of the insulin-producing pancreatic beta islet cells, probably via the influence of cytokines. However, direct correlation between the expression of selected cytokines by various immune cells at different time points during the progression of the disease has not yet been clearly demonstrated. In this study, we showed that the mRNA expression of the pro-inflammatory cytokines, TNF-alpha, IL-1 beta, IL-6, and GM-CSF, were increased while the anti-inflammatory cytokine, TGF-beta, decreased in the peritoneal macrophages of nonobese diabetic (NOD) mice. IL-6 expression however decreased when the mice became diabetic. Surprisingly the expression of IFN-gamma and IL-2 by splenic CD4+ cells were lower in 5-week-old NOD mice as compared to the nonobese diabetic resistant (NOR) control mice, but their expression was higher in older NOD mice. The expression of IL-4 and IL-10 decreased in splenic CD4-positive lymphocytes. Splenic CD8-positive lymphocytes expressed increased levels of IFN-gamma and IL-10 but the latter decreased sharply when diabetes occurred. The relevance of these findings to the pathogenesis of type 1 diabetes is discussed.
  20. Fulltext Immunogenicity mechanism of mRNA vaccines and their limitations in promoting adaptive protection against SARS-CoV-2
    Salleh MZ, Norazmi MN, Deris ZZ
    PeerJ, 2022;10:e13083.
    PMID: 35287350 DOI: 10.7717/peerj.13083
    Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19) in late 2019, hundreds of millions of people have been infected worldwide. There have been unprecedented efforts in acquiring effective vaccines to confer protection against the disease. mRNA vaccines have emerged as promising alternatives to conventional vaccines due to their high potency with the capacity for rapid development and low manufacturing costs. In this review, we summarize the currently available vaccines against SARS-CoV-2 in development, with the focus on the concepts of mRNA vaccines, their antigen selection, delivery and optimization to increase the immunostimulatory capability of mRNA as well as its stability and translatability. We also discuss the host immune responses to the SARS-CoV-2 infection and expound in detail, the adaptive immune response upon immunization with mRNA vaccines, in which high levels of spike-specific IgG and neutralizing antibodies were detected after two-dose vaccination. mRNA vaccines have been shown to induce a robust CD8+T cell response, with a balanced CD4+ TH1/TH2 response. We further discuss the challenges and limitations of COVID-19 mRNA vaccines, where newly emerging variants of SARS-CoV-2 may render currently deployed vaccines less effective. Imbalanced and inappropriate inflammatory responses, resulting from hyper-activation of pro-inflammatory cytokines, which may lead to vaccine-associated enhanced respiratory disease (VAERD) and rare cases of myocarditis and pericarditis also are discussed.
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