Increased CD44 gene expression in lymphocytes derived from Alzheimer disease patients

In this study, we demonstrated for the first time an increased CD44 gene expression in lymphocytes derived from Alzheimer's disease (AD) patients in comparison with healthy subjects. CD44 is a surface antigen expressed by cells of the immune and central nervous system as well as in a variety of other tissues. Functioning as adhesion molecule, CD44 is furthermore involved in driving immune response into infected tissues, including the CNS. We also found that lymphocytes of the same patients expressed significant levels of unfolded p53 isoform, confirming what we already demonstrated in fibroblasts and lymphocytes derived from other cohorts of AD patients. A correlation between p53 and CD44 expression has been well demonstrated in cancer cells, suggesting that CD44 could be a target gene of mutant p53, or either mutant p53 could lack its ability to negatively regulate CD44 expression. The contemporaneous increased expression of unfolded p53 and CD44 in AD lymphocytes may suggest that these two molecules cross-talk together participating in peripheral immune response during the development of the disease.