Leuenberger T, Paterka M, Reuter E, Herz J, Niesner RA, Radbruch H, Bopp T, Zipp F, Siffrin V. The Role of CD8+ T Cells and Their Local Interaction with CD4+ T Cells in Myelin Oligodendrocyte Glycoprotein35-55-Induced Experimental Autoimmune Encephalomyelitis. J Immunol. 2013 Oct. [Epub ahead of print]T cells have an essential role in the induction of multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE). Although for CD4+ T cells it is well established that they contribute to the disease, less is known about the role of CD8+ T cells. Our aim was to determine the individual contribution of CD4+ and CD8+ T cells in myelin oligodendrocyte glycoprotein (MOG)35-55-induced EAE. We investigated MOG35-55-activated CD8+ T cells to clarify their potential to induce or attenuate EAE. We monitored the behaviour of CD8+ T cells and their interaction with CD4+T cells directly at the site of inflammation in the CNS using intravital imaging of the brainstem of EAE-affected living anesthetized mice. We found that mice without CD4+ T cells did not develop relevant clinical signs of disease, although CD8+ T cells were present in the CNS of these mice. These CD8+ T cells displayed reduced motility compared with those in the presence of CD4+ T cells. In mice that harboured CD4+ and CD8+ T cells, we saw a similar extent of clinical signs of EAE as in mice with only CD4+ T cells. Furthermore, the dynamic motility and viability of CD4+ T cells were not disturbed by CD8+ T cells in the lesions of these mice. Therefore, we conclude that in MOG35-55-induced EAE, CD8+ T cell accumulation in the CNS represents instead an epiphenomenon with no impact on clinical disease or on the effects of CD4+ T cells, the latter being the true inducers of the disease.
We have been talking about CD8 cells first they were suppressor cells , then they were cytotoxic killing machines and now there are a few studies reporting they are suppressor cells, but in this paper they are just nothing cells. This is some fancy imaging, but at the end of the day it tells us what we already knew 10-15 years ago using monoclonal antibodies, that if you deplete CD8 positive T cells not much happens, deplete CD4 T cells and EAE stops.
Study of CD8 cells is important as some MS pathologists suggest that CD8 cells are more common than CD4 T cells…Does this tell us that MS has a viral cause?