Immune evaluation of ageing individuals and possible applications in vaccine

Abstract

The world's elderly population is on a increasing rithm of growth and the same can be observed for the Brazilian population. In industrialized nations, the proportion of people aged over 85 years is growing six times faster j than other age-groups. Respiratory and infectious diseases are the 3rd and 7th causes of death in individuals over 60 years respectively. The introduction of influenza vaccine in 1999 clearly shows already in 2000 that there was a significant decrease in the rate of hospitalization for respiratory diseases. However, vaccine effectiveness is reduced in the elderly due to imunosenescence. Vaccines with adjuvants added and with an increase number of doses can improve the effectiveness and extend the time of protection. Our aim in this study is a better understanding of how the immune system in the elderly (from 60 to 64 years, both genders) works by stimulation of their cells in vitro both with an already known mitogen (fitohemaglutinin, PHA) and P.acnes inactive. The same will be performed in cells from 20 to 30 years old (younger) individuals for comparison. The post culture evaluation of cell phenotype (naive, effector memory, main memory and terminal memory) percentage will leads us to identify the responsive cell population to stimuli (PHA, p. acnes). We also will evaluate the rate of cell proliferation and cytokines such as IL-4, IL-1, IL-17A, IL-10, TNF-α and IFN-γ. With the results we will identify the differences in immune response between the male and female genders and in the groups young and old. In addition, we will evaluate the adjuvant action of P. acnes in the culture of human peripheral blood cells (young and elderly) compared to the mitogen phytohemagglutinin (PHA). The results will indicate if P.acnes offers adequate stimulus to the immune system and, therefore, could be proposed as vaccine adjuvant. (AU)