Enumeration of human peripheral blood dendritic cells throughout the life

Abstract

Human aging is associated with immunosenescence, a process characterized by alterations in numerical and functional features of immune system components. Dendritic cells (DCs) are the main antigen-presenting cells, playing a pivotal role in adaptive and innate immunity. Therefore, we investigated the distribution of human circulating DCs throughout the life, in order to contribute to the knowledge of the physiological background underlying the aging of immune system. Cytofluorimetric analysis of peripheral blood samples by all-aged healthy population showed a significant decrease of circulating DCs and of their two main subsets among age. This reduction was limited to the plasmacytoid cell subtype when young and old subjects were analyzed separately. The analysis of circulating Treg cell number in a cohort of the subjects showed a significant reduction with increasing age and a positive significant correlation to myeloid or plasmacytoid absolute numbers. In conclusion, this work provides a large set of data of normal reference values of peripheral blood dendritic cells in healthy population suitable for comparative clinical studies concerning pathological immune dysfunctions.

slanDCs selectively accumulate in carcinoma-draining lymph nodes and marginate metastatic cells

“…By contrast, pDCs from the same patient cohort were significantly reduced in number, not only in an age-dependent but also in a cancer-related manner (Fig. 9c), in line with published observations 31,34,[37][38][39] . Concomitantly, we also found that either the ability to ingest tumour cell-derived apoptotic bodies (Fig.…”

Dendritic cell reconstitution is associated with relapse-free survival and acute GVHD severity in children after allogeneic stem cell transplantation

“…49,51,[54][55][56] However, most studies find no difference between PBSC and BM grafts for HLA-identical siblings or matched unrelated donor in relation to aGVHD or cGVHD incidence, 48,52,53 non-relapse mortality, 50,51 disease-free survival 50,51,[54][55][56] and OS. 48,[50][51][52][53] This study has some limitations: (i) small number of patients, (ii) small number of DCs circulating in PB, which may influence accuracy for DC measurements 57 and (iii) heterogeneity with regard to the underlying disease and the stem cell source. Accuracy may be improved by choosing markers with a better signal-to-noise ratio, for example, CD303 instead of CD123.…”

Age-dependent dysregulation of innate immunity

“…Monocyte numbers are grossly unchanged in older adults 30, 31 , although age-associated increases in CD14 + CD16 + inflammatory monocytes have been reported 31-33 . Finally, decreased percentages and numbers of plasmacytoid dendritic cells (pDCs) have been reported in older adults 34, 35 (although not in all studies 36 ). Likewise, myeloid DCs (mDCs) also appear to be decreased or unchanged with age 35, 37 .…”

“…Finally, decreased percentages and numbers of plasmacytoid dendritic cells (pDCs) have been reported in older adults 34, 35 (although not in all studies 36 ). Likewise, myeloid DCs (mDCs) also appear to be decreased or unchanged with age 35, 37 . The existing evidence indicates that basal inflammation in older individuals is not associated with increased numbers of myeloid cells, despite the skewing of aged HSCs to the myeloid cell lineage.…”