Dendritic cells (DCs) are the most potent antigen presenting cells and have long been recognized as key regulators of the immune system, linking both stimulatory and inhibitory components of normal immunity. While DCs are well characterized with respect to primary and secondary immune responses, their unique role in coordinating central and peripheral tolerance is not fully delineated. It is increasingly evident that the failure of DCs’ ability to maintain tolerance can lead to autoimmune and/or inflammatory diseases. For the past few years our efforts have been focused on exploring the role of DCs in chronic viral infections especially those related to HTLV-1, HIV-1 and HCV as well as in neuroinflammatory diseases such as MS/EAE, HAM/TSP, Glioblastoma, and fairly recently Autism. Currently three different projects are underway to investigate DC biology with respect to aforementioned disease pathogenesis.
Project 1: Define the role of dendritic cells in HIV-1/HCV co-infection
Within the United States, approximately 1 million people are infected with HIV-1 and approximately 4 million people are infected with HCV. Globally, the prevalence of HIV-1/HCV co-infection is substantial with significant overlap in geographical areas and types of populations affected. Both HIV-1 and HCV share similar routes of transmission, where intravenous drug use (IDU) is possibly the main cause of high rates of HIV-1/HCV coinfection (up to 90% within the specific IDU population). Additionally, many individuals who received repetitive blood transfusions prior to mandatory HIV-1 and HCV screening were found to be co-infected. It is becoming increasingly evident that there is an acceleration of HCV-mediated liver disease as well as cirrhosis, liver failure, and hepatocellular carcinoma in HIV-infected individuals. HIV-1 has been shown to advance the course of HCV infection through increases in the rate of HCV viral persistence, RNA levels, progression to liver fibrosis and shortens survival in those with de-compensated cirrhosis. Similarly, infection with HCV has been shown to hinder immunological reconstitution after the initiation of antiretroviral therapy, and it contributes to liver toxicity in HIV-infected patients. However, little is known about the pathophysiology of HIV-1/HCV co-infection that results in advanced/accelerated hepatic diseases. It remains unknown whether immune activation or deficiencies due to HIV-1 infection are associated with the acceleration of liver disease in the co-infected individuals due to the lack of comprehensive immune profiling studies. Additionally, very limited serum proteomic profiling data has been available for the HCV mono-infected patients with no proteomics or glycoproteomics data reported so far from patients with HIV-1/HCV co-infection. To address these knowledge gaps, we propose to investigate a well-defined cohort of HIV-1 and HCV mono- and co-infected individuals and monitor patients’ immunological, transcriptome, and proteome profiling in response to the interferon therapy.
Luminex analyses of plasma cytokine and chemokine expression in HIV-1/HCV mono- and co-infected patients. Left, the absolute concentrations of various cytokines and chemokines were normalized to healthy donor plasma and a pattern analysis was performed using a core developed software suite specific for Luminex® analysis. Results are presented as the mean plasma cytokine value for the sample (S) over the concentration from normal donor plasma (D) for that cytokine ({S/n)}/(D)) and arranged as an unsupervised distance clustered intensity plot. Right, the individual and median concentrations of various chemokines from HIV mono, HIV-1/HCV co-infected, and HCV mono-infected individuals (n=3 for each condition and are represented by diamond, circle and square symbols, respectively). The median value is represented by a bar.
Project 2: Dendritic cell trafficking into the CNS during neuroinflammation
The molecular mechanisms of how circulating DCs gain access to the central nervous system have not been investigated so far. Increase in immune cell infiltration across the blood-brain barrier (BBB) is influenced by chemokines. Monocyte chemotactic protein 1 (MCP-1) is one such potent chemoattractant known to be secreted by the astrocytes at the BBB. In order to understand the influence of MCP-1 on DC trafficking, both in vivo and in vitro imaging studies were undertaken in conjunction with transmigration assays. Near Infra-Red imaging of DCs’ CNS transmigration correlated with the severity of inflammation during experimental autoimmune encephalomyelitis (EAE). Histology confirmed MCP-1 presence in EAE lesions in concurrence with DCs emerging from perivascular spaces. DCs exhibited a better transmigration pattern as compared to T cells in BBB model studies. These observations correlated with those obtained by transwell imaging that has also indicated a paracellular versus transcellular pattern of migration by DCs and T cells, respectively. At the molecular level, MCP-1 seems to facilitate DC transmigration in an ERK1/2-dependent manner. These comprehensive continued studies provide state-of-the-art view of DCs
In vitro imaging showing movement of DCs across the endothelium in response to MCP-1. Human brain microvascular cells were grown to confluence on a collagen-coated PET membrane transwell inserts with 3 μm pores. Primary peripheral blood lymphocytes (PBLs) and monocyte-derived dendritic cells (MDDCs) were labeled with DAPI and added to the upper chamber of the transwell. At 30 minute after immune cell addition the transwells were washed, stained for ICAM-1 (green) or Caveolin-1 (red) and viewed at 100X to determine paracellular versus transcellular migration patterns.
Project 3: Mechanistic aspects of DC:T cell interaction during HTLV-1-associated cancer and neuroinflammatory disease. HTLV-1 is the etiologic agent of two immunologically distinct diseases; adult T cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a chronic debilitating neuroinflammatory disease with similarities to MS. The humoral and cellular immune responses during HAM/TSP are directed to the HTLV-1 transactivator protein Tax that is oncogenic in nature. The molecular mimicry exhibited by anti-Tax antibodies to neuronal antigen (hnRNAP A1) and intense proliferation of chronically activated Tax-specific cytotoxic CD8+ T lymphocytes support the autoimmune nature of the disease. Therefore, HAM/TSP demonstrates a clear link between chronic viral infection and autoimmune disease of the CNS and allows for the direct comparison of the infecting agent with host antigens providing important insights into the pathogenesis of MS and other neuroinflammatory diseases. This project deals with defining the role of various DC subsets (myeloid and plasmacytoid) in regulating Tax-specific CTL response and associated neuroinflammation under three different experimental settings: in vitro using primary DC culture systems, ex vivo in HAM/TSP patients, and in vivo in a mouse model of neuroinflammation. Ultimate goal of this project is to determine how DC biology can be harnessed to enhance or silence its function in a disease-specific manner.
proposed model to explain the early interaction between htlv-1 and dendritic cells.the model shown here attempts to explain some of the early steps in dc activation following infection with htlv-1. the upregulation of antiviral genes by the dcs and the viral mediated selective downregulation of key signaling molecules demonstrates the constant struggle for power between the dendritic cell and the virus.
Selected Publications:
"HTLV-1 Tax mediated downregulation 1 of miRNAs associated with chromatin remodeling factors in T cells with stably integrated viral promoter"
Rahman S, Quanna K, Khan Z.K, Pandya D, Wigdahl B. and Jain P.
PLoS One, in press, 2012.
"Unique and differential protein signatures for HIV-1 and HCV mono-infection versus co-infection"
Boukli N.V, Shetty J, Reis L, Cubano M, Ricaurte, P, Shah Z, Nickens A, Talal R, Philip and Jain P.
Clinical Proteomics, in press, 2012.
Mechanisms of dendritic cell trafficking across the blood-brain barrier"
Sagar, D., Foss, C., Baz, R., Martin, G., Khan, Z. K., and P. Jain.
Journal of Neuroimmune Pharmacology, 7:74-94, 2012.
"Co-transcriptional chromatin remodeling by small RNA species: A HTLV-1 perspective"
Aliya N, Rahman S,Khan Z.K, and Jain P.
Leukemia Research and Treatment, 2012: 1-15, 2012.
"Investigation of plasma biomarkers in HIV-1/HCV mono- and coinfected individuals by multiplex iTRAQ quantitative proteomics."
Shetty V, Jain P, Z Nickens, Gomathinayagam S, Mehta A, and Philip R.
A Journal of Integrative Biology, 15(10): 705-711, 2011.
"Dendritic cell mediated early immune responses are critical to controlling cell-free HTLV-1 infection."
Rahman S, Khan Z.K, Wigdahl B, Jennings S, Tangy F, and Jain P.
Journal of Immunology, 186 (1): 390-402, 2011.
"Unique cytokine/chemokine signatures for HIV-1 and HCV mono- infection versus co-infection as determined by the Luminex® analyses."
Rahman S, Connolly J, Manuel S, Chehimi J, Montaner L, and Jain P.
Journal of Clinical & Cellular Immunology, 2(1): 1000104-1000108, 2011.
"A novel high throughput screening assay to identify inhibitor of HIV-1 gp120 interaction with DC-SIGN."
Tran T, El Baz R, Cuconati A, Arthos J, Jain P, and Z.K Khan.
Journal of Antivirals and Antiretrovirals, 3: 49-54, 2011.
"The tug-of-war between dendritic cells and human chronic viruses"
Rahman S, Khan ZK, and Jain P
International Reviews of Immunology, in press, 2011.
"α4β1-integrin mediates the recruitment of immature dendritic cells across the blood-brain barrier during experimental autoimmune encephalomyelitis"
Jain P*, Coisne C, Enzmann G, Rottapel R, and Engelhardt B
Journal of Immunology, 184 (12): 7196-7206, 2010.
"Presentation of HTLV-1 Tax protein by dendritic cells: the underlying mechanism of HTLV-1 associated neuroinflammatory disease,"
Manuel S, . Schell T, Acheampong E, Rahman S, Khan Z.K, and Jain P.
Journal of Leukocyte Biology, 86: 1205-1216, 2009.
"DC-SIGN mediates cell-free infection and transmission of human T cell leukemia virus type 1."
Jain P, Manuel S, Khan Z.K., Ahuja J, and Wigdahl B.
Journal of Virology, 83: 10908-10921, 2009.
"Identification of HTLV-1 Tax amino acid signals and cellular factors involved in secretion of the viral oncoprotein"
Jain P, Mostoller K, Flaig KE, Ahuja J, Alefantis T, Khan ZK, and Wigdahl B
Journal of Biological Chemistry, 282: 34581-34593, 2007.
"Modulation of dendritic cell maturation and function by the Tax protein of human T cell leukemia virus type 1"
Jain P, Ahuja J, Khan ZK, Shimizu S, Meucci O, Jennings S, and. Wigdahl B
Journal of Leukocyte Biology, 82: 44-56, 2007.
Patent:
"Isolation of bivittoside D from sea cucumber and activity thereof"
Lakshmi V, Pandey K, Saxena A, Madhusudanan KP, Srivastava MN, Khan ZK, Jain P, Gupta G, and Dhar JD (2004).
US patent no. U015092-8. |