Semliki Forest virus infection is enhanced in Th1-prone SJL mice but not in Th2-prone BALB/c mice during Linomide-induced immunomodulation

We investigated the occurrence of T cells in the brain parenchyma of Alzheimer's disease (AD), non-AD degenerative dementias and controls by semi-quantitative analysis of immunohistochemically stained tissue sections. In all cases, we found at least some T cells. The number of T cells was increased in the majority of AD cases compared with other cases. The phenotype of T cells in the AD brain indicates that they are activated but are not fully differentiated. Antigen-triggered clonal expansion is not likely to take place. Local inflammatory conditions might cause accumulation and activation of T cells in the AD brain.