References 1. Noseworthy JH, Lucchinetti C, Rodriguez M, Weinshenker BG (2000) Multiple sclerosis. N Engl J Med 343: 938–952. 2. Polman CH, Reingold SC, Edan G, Filippi M, Hartung HP, et al. (2005) Diagnostic criteria for multiple sclerosis: 2005 revisions to the ‘‘McDonald Criteria’’. Ann Neurol 58: 840–846. 3. van Walderveen MA, Barkhof F, Hommes OR, Polman CH, Tobi H, et al. (1995) Correlating MRI and clinical disease activity in multiple sclerosis: relevance of hypointense lesions on short-TR/short-TE (T1-weighted) spin-echo images. Neurology 45: 1684–1690. 4. Truyen L, van Waesberghe JH, van Walderveen MA, van Oosten BW, Polman CH, et al. (1996) Accumulation of hypointense lesions (‘‘black holes’’) on T1 spin-echo MRI correlates with disease progression in multiple sclerosis. Neurology 47: 1469–1476. 5. van Walderveen MA, Kamphorst W, Scheltens P, van Waesberghe JH, Ravid R, et al. (1998) Histopathologic correlate of hypointense lesions on T1-weighted spin-echo MRI in multiple sclerosis. Neurology 50: 1282–1288. 6. Barkhof F, Karas GB, van Walderveen MA (2000) T1 hypointensities and axonal loss. Neuroimaging Clin N Am 10: 739–752, ix. 7. Brahic M (2002) Theiler’s virus infection of the mouse, or: of the importance of studying animal models. Virology 301: 1–5. 8. Denic A, Johnson AJ, Bieber AJ, Warrington AE, Rodriguez M, et al. (2011) The relevance of animal models in multiple sclerosis research. Pathophysiology 18: 21–29. 9. Miller SD, Vanderlugt CL, Begolka WS, Pao W, Yauch RL, et al. (1997) Persistent infection with Theiler’s virus leads to CNS autoimmunity via epitope spreading. Nat Med 3: 1133–1136. 10. Pirko I, Nolan TK, Holland SK, Johnson AJ (2008) Multiple sclerosis: pathogenesis and MR imaging features of T1 hypointensities in a [corrected] murine model. Radiology 246: 790–795. 11. McDole JR, Danzer SC, Pun RY, Chen Y, Johnson HL, et al. (2010) Rapid Formation of Extended Processes and Engagement of Theiler’s Virus-Infected Neurons by CNS-Infiltrating CD8 T Cells. Am J Pathol. 12. McDole JR, Danzer SC, Pun RY, Chen Y, Johnson HL, et al. (2010) Rapid formation of extended processes and engagement of Theiler’s virus-infected neurons by CNS-infiltrating CD8 T cells. Am J Pathol 177: 1823–1833. 13. Deb C, Lafrance-Corey RG, Schmalstieg WF, Sauer BM, Wang H, et al. (2010) CD8+ T cells cause disability and axon loss in a mouse model of multiple sclerosis. PLoS ONE 5: e12478. 14. Howe CL, Ure D, Adelson JD, LaFrance-Corey R, Johnson A, et al. (2007) CD8+ T cells directed against a viral peptide contribute to loss of motor function by disrupting axonal transport in a viral model of fulminant demyelination. J Neuroimmunol 188: 13–21. 15. McDole J, Johnson AJ, Pirko I (2006) The role of CD8+ T-cells in lesion formation and axonal dysfunction in multiple sclerosis. Neurol Res 28: 256–261. 16. Tsunoda I, Kuang LQ, Kobayashi-Warren M, Fujinami RS (2005) Central nervous system pathology caused by autoreactive CD8+ T-cell clones following virus infection. J Virol 79: 14640–14646. 17. Myoung J, Hou W, Kang B, Lyman MA, Kang JA, et al. (2007) The immunodominant CD8+ T cell epitope region of Theiler’s virus in resistant C57BL/6 mice is critical for anti-viral immune responses, viral persistence, and binding to the host cells. Virology 360: 159–171. 18. Tsunoda I, Kuang LQ, Fujinami RS (2002) Induction of autoreactive CD8+ cytotoxic T cells during Theiler’s murine encephalomyelitis virus infection: implications for autoimmunity. J Virol 76: 12834–12844. 19. Pirko I, Suidan GL, Rodriguez M, Johnson AJ (2008) Acute hemorrhagic demyelination in a murine model of multiple sclerosis. J Neuroinflammation 5: 31. 20. Suidan GL, Dickerson JW, Chen Y, McDole JR, Tripathi P, et al. (2010) CD8 T cell-initiated vascular endothelial growth factor expression promotes central nervous system vascular permeability under neuroinflammatory conditions. J Immunol 184: 1031–1040. 21. Suidan GL, McDole JR, Chen Y, Pirko I, Johnson AJ (2008) Induction of blood brain barrier tight junction protein alterations by CD8 T cells. PLoS ONE 3: e3037. 22. Suidan GL, Pirko I, Johnson AJ (2006) A potential role for CD8+ T-cells as regulators of CNS vascular permeability. Neurol Res 28: 250–255. 23. Chitnis T (2007) The role of CD4 T cells in the pathogenesis of multiple sclerosis. Int Rev Neurobiol 79: 43–72. 24. Johnson AJ, Suidan GL, McDole J, Pirko I (2007) The CD8 T cell in multiple sclerosis: suppressor cell or mediator of neuropathology? Int Rev Neurobiol 79: 73–97. 25. McDole JR, Danzer SC, Pun RY, Chen Y, Johnson HL, et al. (2010) Rapid formation of extended processes and engagement of Theiler’s virus-infected neurons by CNS-infiltrating CD8 T cells. Am J Pathol 177: 1823–1833. 26. Johnson AJ, Njenga MK, Hansen MJ, Kuhns ST, Chen L, et al. (1999) Prevalent class I-restricted T-cell response to the Theiler’s virus epitope Db:VP2121-130 in the absence of endogenous CD4 help, tumor necrosis factor alpha, gamma interferon, perforin, or costimulation through CD28. J Virol 73: 3702–3708. 27. Johnson AJ, Upshaw J, Pavelko KD, Rodriguez M, Pease LR (2001) Preservation of motor function by inhibition of CD8+ virus peptide-specific T cells in Theiler’s virus infection. Faseb J 15: 2760–2762. CD4 vs CD8 T-Cells in T1 Black Hole Formation 28. Kang HS, Kim BS (2010) Predominant clonal accumulation of CD8+ T cells with moderate avidity in the central nervous systems of Theiler’s virus-infected C57BL/6 mice. J Virol 84: 2774–2786. 29. Pirko I, Gamez J, Johnson AJ, Macura SI, Rodriguez M (2004) Dynamics of MRI lesion development in an animal model of viral-induced acute progressive CNS demyelination. Neuroimage 21: 576–582. 30. Denic A, Johnson AJ, Bieber AJ, Warrington AE, Rodriguez M, et al. (2011) The relevance of animal models in multiple sclerosis research. Pathophysiology 18: 21–29. 31. Pirko I, Johnson AJ, Lohrey AK, Chen Y, Ying J (2009) Deep gray matter T2 hypointensity correlates with disability in a murine model of MS. J Neurol Sci. 32. Kerkvliet J, Zoecklein L, Papke L, Denic A, Bieber AJ, et al. (2009) Transgenic expression of the 3D polymerase inhibits Theiler’s virus infection and demyelination. J Virol 83: 12279–12289. 33. Pavelko KD, Girtman MA, Mitsunaga Y, Mendez-Fernandez YV, Bell MP, et al. (2011) Theiler’s murine encephalomyelitis virus as a vaccine candidate for immunotherapy. PLoS ONE 6: e20217. 34. Denic A, Macura SI, Mishra P, Gamez JD, Rodriguez M, et al. (2011) MRI in rodent models of brain disorders. Neurotherapeutics 8: 3–18. 35. Robb RA (1999) 3-D visualization in biomedical applications. Annu Rev Biomed Eng 1: 377–399. 36. Robb RA (2001) The biomedical imaging resource at Mayo Clinic. IEEE Trans Med Imaging 20: 854–867. 37. Pirko I, Johnson AJ, Chen Y, Lindquist DM, Lohrey AK, et al. (2011) Brain atrophy correlates with functional outcome in a murine model of multiple sclerosis. Neuroimage 54: 802–806. 38. Losseff NA, Wang L, Miller DH, Thompson AJ (2001) T1 hypointensity of the spinal cord in multiple sclerosis. J Neurol 248: 517–521. 39. Pirko I, Nolan TK, Holland SK, Johnson AJ (2008) Multiple sclerosis: pathogenesis and MR imaging features of T1 hypointensities in murine model. Radiology 246: 790–795. 40. Sato F, Tanaka H, Hasanovic F, Tsunoda I (2010) Theiler’s virus infection: Pathophysiology of demyelination and neurodegeneration. Pathophysiology. 41. Tsunoda I, Fujinami RS (2010) Neuropathogenesis of Theiler’s murine encephalomyelitis virus infection, an animal model for multiple sclerosis. J Neuroimmune Pharmacol 5: 355–369. 42. Johnson AJ, Mendez-Fernandez Y, Moyer AM, Sloma CR, Pirko I, et al. (2005) Antigen-specific CD8+ T cells mediate a peptide-induced fatal syndrome. J Immunol 174: 6854–6862. 43. Bitsch A, Kuhlmann T, Stadelmann C, Lassmann H, Lucchinetti C, et al. (2001) A longitudinal MRi study of histopathologically defined hypointense multiple sclerosis lesions. Ann Neurol 49: 793–796. 44. Bitsch A, Schuchardt J, Bunkowski S, Kuhlmann T, Bruck W (2000) Acute axonal injury in multiple sclerosis. Correlation with demyelination and inflammation. Brain 123(Pt 6): 1174–1183. 45. van Waesberghe JH, Kamphorst W, De Groot CJ, van Walderveen MA, Castelijns JA, et al. (1999) Axonal loss in multiple sclerosis lesions: magnetic resonance imaging insights into substrates of disability. Ann Neurol 46: 747–754. 46. Borrow P, Welsh CJ, Nash AA (1993) Study of the mechanisms by which CD4+ T cells contribute to protection in Theiler’s murine encephalomyelitis. Immunology 80: 502–506. 47. Chang JR, Zaczynska E, Katsetos CD, Platsoucas CD, Oleszak EL (2000) Differential expression of TGF-beta, IL-2, and other cytokines in the CNS of Theiler’s murine encephalomyelitis virus-infected susceptible and resistant strains of mice. Virology 278: 346–360. 48. Pullen LC, Miller SD, Dal Canto MC, Van der Meide PH, Kim BS (1994) Alteration in the level of interferon-gamma results in acceleration of Theiler’s virus-induced demyelinating disease. J Neuroimmunol 55: 143–152. 49. Rodriguez M, Zoecklein LJ, Howe CL, Pavelko KD, Gamez JD, et al. (2003) Gamma interferon is critical for neuronal viral clearance and protection in a susceptible mouse strain following early intracranial Theiler’s murine enceph- alomyelitis virus infection. J Virol 77: 12252–12265. 50. Inoue A, Koh CS, Yamazaki M, Yahikozawa H, Ichikawa M, et al. (1998) Suppressive effect on Theiler’s murine encephalomyelitis virus-induced demy- elinating disease by the administration of anti-IL-12 antibody. J Immunol 161: 5586–5593. 51. Hill KE, Pigmans M, Fujinami RS, Rose JW (1998) Gender variations in early Theiler’s virus induced demyelinating disease: differential susceptibility and effects of IL-4, IL-10 and combined IL-4 with IL-10. J Neuroimmunol 85: 44–51. 52. Yamada M, Zurbriggen A, Fujinami RS (1990) Monoclonal antibody to Theiler’s murine encephalomyelitis virus defines a determinant on myelin and oligodendrocytes, and augments demyelination in experimental allergic encephalomyelitis. J Exp Med 171: 1893–1907. 53. Hou W, Kang HS, Kim BS (2009) Th17 cells enhance viral persistence and inhibit T cell cytotoxicity in a model of chronic virus infection. J Exp Med 206: 313–328. 54. Karls KA, Denton PW, Melvold RW (2002) Susceptibility to Theiler’s murine encephalomyelitis virus-induced demyelinating disease in BALB/cAnNCr mice is related to absence of a CD4+ T-cell subset. Mult Scler 8: 469–474. PLoS ONE | www.plosone.org 7 February 2012 | Volume 7 | Issue 2 | e31459