Inflammatory events in the central nervous system (CNS) contribute to the disease process in Multiple Sclerosis (MS), Alzheimer's Disease (AD), and Spinal Cord Injury (SCI), and activated macrophages/microglia are central to this response. Immunological activation of these cells leads to the production of a wide array of cytokines, chemokines, matrix metalloproteinases and neurotoxins, and ultimately to glial/neuronal injury and death. The CD40 molecule has an important role in promoting inflammatory responses by macrophages/microglia, since interaction with its cognate ligand, CD 154, leads to secretion of cytokines and neurotoxins. Thus, expression of CD40 on macrophages/microglia in MS and AD brain, and in the injured spinal cord, may be a key determinant of the complex neuroimmunologic cascades that typify these diseases/injury. We hypothesize that aberrant CD40 expression by macrophages/microglia, induced by cytokines such as IFN-gamma and TNF-alpha, contributes to inflammatory responses in the CNS. We also propose that strategies to suppress CD40 expression will attenuate inflammation and neuronal damage within the CNS, which will ultimately be of benefit in MS, AD and SCI. The mediators that regulate expression of CD40 in macrophages/microglia (both induction and inhibition) function at the level of gene transcription, thus it is imperative that we gain a better understanding of the molecular mechanisms involved in these responses. We will elucidate the contribution of the TNF-alpha signaling pathway and subsequent NF-kappaB activation to IFN-gamma induced CD40 gene expression in macrophages/microglia (Aim 1). Next, we will determine the interactions between STAT-1alpha and NF-kappaB transcription factors and the CD40 promoter, and between transcription factors and various co-transactivators including CBP, p300 and CARM1, to fully understand CD40 gene expression (Aim 2). Immunoregulatory cytokines such as IL-4 and IL-10, and neurotrophins such as NGF, inhibit CD40 expression in macrophages/microglia.
In Aim 3, we will determine the molecular mechanism(s) underlying suppression of CD40 expression in these cells. Lastly, we will analyze the expression and function of CD40 and CD154 in vivo, utilizing SCI as a paradigm of neuroinflammation (Aim 4). We will assess CD40 and CD154 expression after SCI, the cell type(s) expressing these proteins and the functional importance of CD40-CD154 interactions in SCI utilizing CD40 and CD154-deficient mice. Our proposed studies will provide a comprehensive assessment of CD40 production and function in macrophages/microglia, thereby setting the foundation for future therapeutic manipulation of this critical immunoregulatory protein.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS045290-03
Application #
6916403
Study Section
Special Emphasis Panel (ZRG1-BDCN-2 (02))
Program Officer
Nunn, Michael
Project Start
2003-07-15
Project End
2008-06-30
Budget Start
2005-07-01
Budget End
2006-06-30
Support Year
3
Fiscal Year
2005
Total Cost
$309,938
Indirect Cost
Name
University of Alabama Birmingham
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
063690705
City
Birmingham
State
AL
Country
United States
Zip Code
35294
Yan, Zhaoqi; Gibson, Sara A; Buckley, Jessica A et al. (2018) Role of the JAK/STAT signaling pathway in regulation of innate immunity in neuroinflammatory diseases. Clin Immunol 189:4-13
Liu, Yudong; Gibson, Sara A; Benveniste, Etty N et al. (2015) Opportunities for Translation from the Bench: Therapeutic Intervention of the JAK/STAT Pathway in Neuroinflammatory Diseases. Crit Rev Immunol 35:505-27
Liu, Yudong; Holdbrooks, Andrew T; Meares, Gordon P et al. (2015) Preferential Recruitment of Neutrophils into the Cerebellum and Brainstem Contributes to the Atypical Experimental Autoimmune Encephalomyelitis Phenotype. J Immunol 195:841-52
Benveniste, Etty N; Liu, Yudong; McFarland, Braden C et al. (2014) Involvement of the janus kinase/signal transducer and activator of transcription signaling pathway in multiple sclerosis and the animal model of experimental autoimmune encephalomyelitis. J Interferon Cytokine Res 34:577-88
Liu, Yudong; Holdbrooks, Andrew T; De Sarno, Patrizia et al. (2014) Therapeutic efficacy of suppressing the Jak/STAT pathway in multiple models of experimental autoimmune encephalomyelitis. J Immunol 192:59-72
Qin, Hongwei; Yeh, Wen-I; De Sarno, Patrizia et al. (2012) Signal transducer and activator of transcription-3/suppressor of cytokine signaling-3 (STAT3/SOCS3) axis in myeloid cells regulates neuroinflammation. Proc Natl Acad Sci U S A 109:5004-9
Park, Keun W; Nozell, Susan E; Benveniste, Etty N (2012) Protective role of STAT3 in NMDA and glutamate-induced neuronal death: negative regulatory effect of SOCS3. PLoS One 7:e50874
Qin, Hongwei; Holdbrooks, Andrew T; Liu, Yudong et al. (2012) SOCS3 deficiency promotes M1 macrophage polarization and inflammation. J Immunol 189:3439-48
Zheng, Ying; Qin, Hongwei; Frank, Stuart J et al. (2011) A CK2-dependent mechanism for activation of the JAK-STAT signaling pathway. Blood 118:156-66
Akhtar, Lisa Nowoslawski; Qin, Hongwei; Muldowney, Michelle T et al. (2010) Suppressor of cytokine signaling 3 inhibits antiviral IFN-beta signaling to enhance HIV-1 replication in macrophages. J Immunol 185:2393-404

Showing the most recent 10 out of 18 publications