Niannian Ji

University of Texas at San Antonio, San Antonio, Texas, United States

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Publications (6)23.13 Total impact

  • Niannian Ji, Thomas G Forsthuber
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    ABSTRACT: The enzyme-linked immunospot (ELISPOT) assay is a widely used method for enumerating antigen-specific cytokine-producing or antibody-secreting immune cells. It is one of the most effective immunological and diagnostic approaches to detect and quantify low-frequency cytokine- or antibody-producing cells in human and animal tissues, such as peripheral blood, lymph nodes, and spleen. Detection and quantification of specific cytokine-producing cells by the ELISPOT assay is based on the formation of visible spots at the site of cytokine release by the cells under investigation (e.g., T cells) using pairs of different capture and detection antibodies under optimized conditions.Here we focus mainly on practical, optimized protocols for cytokine ELISPOT assays for detection of mouse and human cytokine-producing immune cells (e.g., peripheral blood mononuclear cells, PBMC), including suggestions for trouble-shooting and optimizing steps for problematic tissue samples.
    Methods in molecular biology (Clifton, N.J.) 08/2014; · 1.29 Impact Factor
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    ABSTRACT: Induction of experimental autoimmune encephalomyelitis (EAE) in susceptible animals requires reactivation of encephalitogenic CD4(+) T cells by APCs in the CNS. However, it has remained unresolved from where APCs in the CNS acquire myelin Ag for T cell activation and under which conditions, that is, whether only during EAE or also in the naive CNS. In this study, we investigated the kinetics of myelin Ag uptake by CNS APCs during EAE and in the naive CNS. Our results show that during EAE CX3CR1(+)CD11b(+) microglia were the first APCs in the CNS to contain myelin Ag upon induction of disease, albeit in very small numbers. Dendritic cells (DCs) arrived in the CNS in sizable numbers significantly later (day 5 postimmunization), without detectable myelin Ag, but acquired it by day 7 postimmunization. Furthermore, a sharp increase in neuroantigen-containing DCs coincided with the onset of EAE symptoms. Importantly, in naive mice a low but consistent number of microglia contained myelin Ag, suggesting release by oligodendrocytes under steady state conditions. Although microglia isolated from naive brain and spinal cord did not elicit a strong CD4(+) T cell response in vitro, myelin Ag-containing microglia may still play a local role in modulating encephalitogenic CD4(+) T cell responses in early EAE prior to the arrival of other professional APCs, such as DCs. Finally, newly arriving DCs in the CNS not yet loaded with myelin Ag before the onset of EAE may be a potential therapeutic target.
    The Journal of Immunology 11/2013; · 5.52 Impact Factor
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    ABSTRACT: The strong association of HLA-DR2b (DRB1*1501) with multiple sclerosis (MS) suggests this molecule as prime target for specific immunotherapy. Inhibition of HLA-DR2b-restricted myelin-specific T cells has the potential to selectively prevent CNS pathology mediated by these MHC molecules without undesired global immunosuppression. In this study, we report development of a highly selective small molecule inhibitor of peptide binding and presentation by HLA-DR2b. PV-267, the candidate molecule used in these studies, inhibited cytokine production and proliferation of myelin-specific HLA-DR2b-restricted T cells. PV-267 had no significant effect on T cell responses mediated by other MHC class II molecules, including HLA-DR1, -DR4, or -DR9. Importantly, PV-267 did not induce nonspecific immune activation of human PBMC. Lastly, PV-267 showed treatment efficacy both in preventing experimental autoimmune encephalomyelitis and in treating established disease. The results suggest that blocking the MS-associated HLA-DR2b allele with small molecule inhibitors may be a promising therapeutic strategy for the treatment of MS.
    The Journal of Immunology 10/2013; · 5.52 Impact Factor
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    ABSTRACT: T-bet was initially described as a T-box transcription factor with an essential role in orchestrating Th1 cell differentiation. Subsequently, it was determined that T-bet controls the expression of numerous cytokines and their receptors, adhesion molecules and chemokine receptors, and therefore determines the differentiation and development status of many types of immune cells. The critical role of T-bet in autoimmune diseases, particularly multiple sclerosis and its animal model experimental autoimmune encephalomyelitis, implicates it as a potential biomarker for pathogenic T cells as well as a therapeutic drug target.
    Immunotherapy 03/2011; 3(3):435-41. · 2.39 Impact Factor
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    ABSTRACT: Ab-mediated blockade of the adhesion molecule VLA-4 has been shown to ameliorate disease in human multiple sclerosis patients and experimental autoimmune encephalomyelitis (EAE) animal models. We wanted to determine whether anti-VLA-4 Ab treatment affected the function and persistence of autoreactive T cells in mice with EAE. Unexpectedly, we observed a high level of mortality in anti-VLA-4 mAb (PS/2)-treated mice with actively induced EAE despite decreased disease severity. Investigation of the underlying mechanism showed that injection of PS/2 mAb in combination with pertussis toxin resulted in anaphylaxis and mortality. Furthermore, the data showed that CD4(+) T cells were required for this effect and suggested a role for IL-1β and TNF-α in the underlying pathology. The results reveal a previously not appreciated deleterious effect of anti-VLA-4 Ab treatment in combination with exposure to pertussis toxin.
    The Journal of Immunology 03/2011; 186(5):2750-6. · 5.52 Impact Factor
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    Thomas G Forsthuber, Niannian Ji
    Expert Review of Clinical Immunology 05/2007; 3(3):251-4. · 2.89 Impact Factor