Age-Dependent Changes of the Fcγ-Receptor-Mediated Functions of Human Monocytes

Abstract

The age-dependent alterations of phagocytosis and age-dependent cell change (ADCC) activity through Fey receptors of human monocyte monolayers using anti-D human IgG-coated ⁵¹Cr-labeled human red blood cells were determined. 40 healthy aged subjects of both sexes (age: 60–85 years) and 20 healthy young people of both sexes (age: 18–25 years) were studied. The phagocytosis increased significantly with aging in both sexes, whereas a decrease in ADCC activity was found.

Influence of Age on Oxidative Bursts (Chemiluminescence) of Polymorphonuclear Neutrophil Leukocytes

“…In the elderly, phagocytosis has not been found to be statistically different from that of young people [27,28], but it was reduced in two other studies [29,30]; likewise, the intracellular killing of microorganisms by neutrophils was either not different [31,32] or reduced in elderly people [24,28].…”

“…The literature does contain a few scattered findings on this last subject but, once again, discrepancies exist. The superoxide generation of PMNs (investigated by means of nitroblue tetrazolium dye reduction) has been reported to decrease in the elderly [24,28], whereas neutrophil chemiluminescence has been found to be both increased [33] and decreased [34,35].…”

“…This finding is in agreement with that of MacGregor and Shalit [23], who used opsonized zymosan as a stimulant. However, after using corpuscular stimulants alone, van Epps et al [34], Mege et al [37] and Fülöp et al [28] observed a significant reduction in oxidative bursts in the elderly. Fülöp et al [28] associated this effect with a dysregulation of the cyclic nucleotide system characterized by a delayed turnoff at cAMP level and a loss of cGMP responsiveness that would impair the fusion of lysosome and phagosome membranes [38,39].…”

Sex, the aging immune system, and chronic disease

“…Aged NK cells exhibit decreased cytotoxicity and produce lower levels of cytokines [72]. Neutrophils from aged hosts consistently show impairments in the phagocytosis of opsonized bacteria and the ability to kill phagocytosed microorganisms which appear to be dependent upon age-related diminishment of CD16 expression [73][74][75][76][77][78][79][80][81].…”

Immunosenescence in renal transplantation

“…However, migration, cytokine and phagocytotic responses of DCs encountering new antigens had been compromised, linked to an impaired functional status [69]. Similarly, function of neutrophilic granulocytes appears to diminish with age in parallel with a compromised capacity for phagocytosis, Fcγ receptor type III (CD16) expression and subsequent superoxide production [71,72]. Of interest, an elevated basal cytokine production of DCs and macrophages has been reported in elderly individuals [73].…”