Personality and aging-related immune phenotype.

Area of Science:

• Immunology
• Psychology
• Gerontology

Background:

• Aging-related immune phenotype (ARIP) is characterized by reduced naïve T cells (T_N) and increased memory T cells (T_M).
• ARIP measures, like CD4+T_N/T_M and CD8+T_N/T_M ratios, are linked to health outcomes including multimorbidity and mortality.
• Understanding factors influencing ARIP is crucial for promoting healthy aging.

Purpose of the Study:

• To investigate the relationship between psychological dispositions (personality traits) and ARIP measures (CD4+T_N/T_M and CD8+T_N/T_M ratios).
• To identify potential mediating factors, including clinical, behavioral, and biological variables, in the association between personality and ARIP.

Main Methods:

• Utilized data from 4798 older adults (aged 50-104) from the Health and Retirement Study.
• Assessed T cell ratios (CD4+T_N/T_M, CD8+T_N/T_M) and psychological dispositions (personality, depressive symptoms, stress).
• Controlled for demographic, clinical (BMI, disease burden), behavioral (physical activity, smoking, alcohol), and biological (cytomegalovirus IgG) factors.

Main Results:

• Higher conscientiousness was significantly associated with higher CD4+T_N/T_M and CD8+T_N/T_M ratios.
• Higher neuroticism and lower extraversion were associated with lower CD4+T_N/T_M ratios.
• Physical activity, BMI, disease burden, and cytomegalovirus IgG levels mediated the links between personality and ARIP measures.

Conclusions:

• Personality traits are demonstrably related to the aging-related immune phenotype.
• Conscientiousness and extraversion may confer resilience against immune aging, while neuroticism may increase susceptibility.
• These findings highlight the intricate connection between psychological well-being and immune system aging.