Neutrophils are immune cells preferentially targeted by retinoic acid in elderly subjects

Abstract

BackgroundThe immune system gradually deteriorates with age and nutritional status is a major factor in immunosenescence. Of the many nutritional factors implicated in age-related immune dysfunction, vitamin A may be a good candidate, since vitamin A concentrations classically decrease during aging whereas it may possess important immunomodulatory properties via its active metabolites, the retinoic acids. This prompted us to investigate the immune response induced by retinoids in adults and elderly healthy subjects. Before and after oral supplementation with 13cis retinoic acid (0.5 mg/kg/day during 28 days), whole blood cells were phenotyped, and functions of peripheral blood mononuclear cells (PBMC) and polymorphonuclear cells (PMN) were investigated by flow cytometry and ELISA tests.ResultsIn both young adults (n = 20, 25 ± 4 years) and older subjects (n = 20, 65 ± 4 years), retinoic acid supplementation had no effect on the distribution of leukocyte subpopulations or on the functions of PBMC (Il-2 and sIl-2R production, membrane expression of CD25). Concerning PMN, retinoic acid induced an increase in both spontaneous migration and cell surface expression of CD11b in the two different age populations, whereas bactericidal activity and phagocytosis remained unchanged.ConclusionsWe demonstrated that retinoic acid induces the same intensity of immune response between adult and older subjects, and more specifically affects PMN functions, i.e. adhesion and migration, than PBMC functions.

Does aging affect the immune status? A comparative analysis in 300 healthy volunteers from France, Austria and Spain

“…A similar positive correlation between age and CD4/CD8 ratio in Irish individuals was reported by Rea et al [4]. Moreover, we observed a shift from a predominance of naïve T cells towards T cells expressing memory phenotypes from the youngest to the oldest age groups, as previously reported [12,55]. This shift may result from the age-related repetition of antigenic challenges.…”

Immune status is more affected by age than by carotenoid depletion–repletion in healthy human subjects

“…We also found alterations in immune capacity reflected by a greater proportion of NK cells, a decrease in B lymphocytes but a stable number of T cells. Moreover, a shift from a predominance of naive T cells towards T cells expressing memory phenotypes was observed from the youngest to the oldest age groups, as reported previously ( 34 , 35 ) . This shift may result from the age-related repetition of antigenic challenges.…”

Reduced levels of cytosolic DNA sensor AIM2 are associated with impaired cytokine responses in healthy elderly

“…In this study, we observed relatively stable numbers of T cells and B cells, while cells of the innate immune system including monocytes and NK cells (but not neutrophils) were found increased. In previous studies, NK cell numbers were also found to be increased in individuals older than 75 years of age, while numbers of monocytes and neutrophils were mostly unchanged (Minet-Quinard et al, 2010;Shodell and Siegal, 2002;Ratts and Weng, 2012;Chatta et al, 1994). It has been reported that aging shifts hematopoietic stem cells towards a myeloid differentiation potential, at the expense of lymphopoiesis (Pang et al, 2011).…”