We investigated existence of global weak solutions for a system of
chemotaxis-hapotaxis type with nonlinear degenerate diffusion, arising in
modelling Multiple Sclerosis disease. The model consists of three equations
describing the evolution of macrophages (m), cytokine (c) and apoptotic
oligodendrocytes (d). The main novelty in our work is the presence of a
nonlinear diffusivity D(m), which results to be more appropriate from the
modelling point of view. Under suitable assumptions and for sufficiently
regular initial data, adapting the strategy in [30,44], we show the existence
of global bounded solutions for the model analysed