Table 1.

The aging immune system and autoimmunity-selected changes relevant to epigenetics and inflammation.

	Aging	Autoimmunity
Influence of age and sex	DNA methylation/epigenetic drift and global T cell hypomethylation	X-chromosome inactivation and reactivation; T cell hypomethylation
Inflammation	Chronic low grade inflammation	Acute and chronic inflammation
T cells	Thymic involution; decreased T cell receptor diversity; memory T cell expansion; increased regularity T cell function; accumulation of CD28-T cells	Thymic sclf-reactivc T cells avoiding self-selection: shift in Th1/2 cytokines; selected clonal expansion; impaired regulatory T cell function; accumulation of CD28-T cells
B cells	Impaired humoral responses; non-specific autoantibodies	B cell activation; disease and organ specific autoantibodies
Dendritic cells	Impaired function	Role In induction of autoimmunity
Telomere length	Shortening in cellular senescence	Premature shortening
Chronic inflammatory conditions	Increased risk, of obesity, heart disease, cancers	Increased risk of obesity, heart disease, cancers
Microbiota	Role in age-related obesity and systemic inflammation	Promotes mucosal inflammation and autoimmunity