Search

Individuals over the age of 65 comprise a substantial portion of the world population and become more susceptible to vaccine-preventable infections with age as vaccination response diminishes. The underlying reason for this impaired vaccine response in older individuals is not entirely clear. We evaluated potential differences in phenotypic and functional responses of B cells from healthy younger (22–45 years) and older (64–95 years) individuals that may associate with a diminished antibody response to influenza vaccination. We report that age is associated with expansion of atypical memory B cells (CD10 − CD20 + CD21 − CD27 − ) and an age-associated B cell (ABC, CD21 − T-bet + CD11c + ) phenotype. Reduced expression of PAX5 was also seen in older individuals. Poor influenza-specific antibody production following vaccination was associated with low PAX5 expression and a distinct composition of the ABC compartment. Collectively, these findings demonstrate that the characteristics of the ABC populations of older individuals are associated with antibody production following influenza vaccination. [ABSTRACT FROM AUTHOR]

Highly active antiretroviral therapy (HAART) for the treatment of HIV infection sustains viral suppression and increases CD4 + T cells in HIV patients. However, in 10–25% of subjects, known as immunological non-responders (INRs), HAART does not increase CD4 count. We investigated a potential role for galectin-9 and TIM-3 in INRs as galectin-9 and TIM-3 have been described to modulate NK and T cell function. PBMCs were isolated from healthy controls, HIV immunological responders (IRs, > 350 CD4 + cells/mm 3 ) and HIV INRs (< 350 CD4 + cells/mm 3 ) and TIM-3 and galectin-9 expressions on NK cell subsets and CD4 + T cells were assessed. HIV INRs and HIV IRs showed increased galectin-9 expression on CD16 − CD56 bright and CD16 + CD56 + NK cells and CD4 + T cells. Only HIV INRs showed a reduced frequency of TIM-3-expressing CD16 + CD56 + , CD16 + CD56 − and CD4 + cells, which correlated with low peripheral CD4 counts. These data suggest that TIM-3 expression may be characteristic for HIV INRs. [ABSTRACT FROM AUTHOR]