Immunosenescence: a review

Avian immunosenescence

“…A reduction in ability of T-cells to proliferate, reduced B-cell responses and altered activity of immune associated cells and cytokines (Malaguarnera et al 2001) are also documented. Coinciding with the decline in immunity, older humans experience an increase in rates of cancer and autoimmunity over those of younger individuals.…”

“…Furthermore, the elderly have poor responses to influenza vaccination (Potter et al 1999, reviewed in Plackett et al 2004. Specific changes in immune function documented in the elderly include an increase in the ratio of memory to naïve lymphocytes in the blood (CD45RO + : CD45RA + ) possibly due to the atrophy of the thymus, an alteration in T-helper lymphocyte activity, especially in a decline of interleukin production, and a decrease in the ratio of T-helper to T-suppressortype cells (Malaguarnera et al 2001). In the innate branch of the immune system, natural killer cell activity (but not number) and tumoricidal ability decrease with age, as does the microbiocidal function of macrophages and polymorphonuclear cells.…”

“…In the innate branch of the immune system, natural killer cell activity (but not number) and tumoricidal ability decrease with age, as does the microbiocidal function of macrophages and polymorphonuclear cells. This decline in turn leads to longer-lasting infections in the elderly (Plackett et al 2004;Malaguarnera et al 2001). Dendritic cells, important in antigen presentation early in an immune response, are less stimulatory of lymphocytes, leading to changes in humoral immunity (Plackett et al 2004).…”

“…Dendritic cells, important in antigen presentation early in an immune response, are less stimulatory of lymphocytes, leading to changes in humoral immunity (Plackett et al 2004). Immunoglobulin production decreases, although B-cell number does not change; the Ig production changes are likely related to failing T-cell function (Malaguarnera et al 2001).…”

Transcriptome analysis of age-, gender- and diet-associated changes in murine thymus

“…In addition, an increased prevalence of specific cancers and certain autoimmune diseases have been observed with advancing age [6][7][8][9]. The increased prevalence of these conditions and the higher morbidity and mortality from infections strongly suggest functional defects in a deteriorating immune system with advancing age [10][11][12][13][14][15][16]. Many studies have centered on possible loss or alterations in the number of circulating T lymphocytes and T-cell subsets [17,18].…”