6. CONCLUSION
T cells ability to mediate the immune response makes them a valuable
tool in treating conditions where the immune system plays a crucial
role. With advances in medical research and technology, techniques have
been developed to modulate T cell activity, offering new therapeutic
strategies for many medical conditions. The traditional belief that the
CNS is immune-isolated has been challenged by recent evidence of the
presence of immune cells within the CNS in both normal and pathological
conditions. T cells are demonstrated to enter the CNS through the
lymphatic vasculature and the fenestrated capillaries within the CP and
populate the dura mater and the CSF. Further understanding of T cells in
the CNS and the molecular processes behind these changes in normal
conditions can open up new avenues of research in autoimmune diseases
like MS, caused by T cells targeting myelin. The presence of T cells
also may play a role in AD and PD, with APOE as a key factor in AD and T
cell modulation as a potential treatment strategy in PD. The BBB
regulates the traffic of immune cells into the CNS, but pathological
conditions like MS and stroke can disrupt it. There are various
therapies that target T cells to reduce symptoms of MS such as
Natalizumab, Fingolimod, and others, while regulation of T cell-mediated
response is being explored in AD and Tregs in PD. T cells may also serve
as early biomarkers in PD.
However, T cells are not just crucial in pathological conditions, they
also play a fundamental role in aging. The aging process leads to a
decline in cellular and molecular function, resulting in chronic
diseases and increased risk of ARDs. Chronic inflammation, also known as
”inflammaging”, is a hallmark of aging linked to cognitive decline and
pathology. T cells are affected by aging and the accumulation of
senescent T cells leads to pro-inflammatory cytokine release. This
age-related systemic inflammation is connected to impaired cognitive
function. Despite this field is an active field of research, more
information is needed to fully understand the impact of T cell aging on
cognitive decline.