Table 1.
Involvement of DCs and monocytes in IPAH, AD, and CTD-PAH.
| Disease | Major finding | Tissue | References | |
|---|---|---|---|---|
| cDC | IPAH SLE | cDCs are decreased in proportion and number | Blood | (19–23) |
| SSc | cDC2s produce more IL-6, IL-10 and TNFα after TLR2 and TLR4 stimulation | Blood | (24, 25) | |
| SSc-PAH | •A TLR2 polymorphism in AD patients is associated with PAH development •cDCs carrying this TLR2 polymorphism produce more cytokines (e.g., IL-6) |
Blood | (26) | |
| IPAH | cDCs numbers are increased | Lung | (27) | |
| IPAH ADa |
cDCs are present in TLOs in target organs | Lung, Thyroid tissue | (7, 28) | |
| pDC | IPAH | The number of pDCs is unaltered | Blood | (27) |
| SLE SSc |
pDCs are decreased in proportion and number | Blood | (22, 23, 29) | |
| SSc | pDCs predominantly secrete CXCL4 | Blood, Skin | (30) | |
| IPAH | •pDC numbers are increased •pDCs are located around pulmonary vessels |
Lung | (27) | |
| SLE SSc |
pDCs are increased in diseased tissue | Skin | (29, 31) | |
| Monocytes and mo-DCs | IPAH | hyporesponsive monocytes to TLR4 stimulation | Blood | (32) |
| SSc-PAH | Monocytes show an activated profile (mRNA expression) | Blood | (33) | |
| SSc SSc-PAH |
The number of non-classical monocytes is increased | Blood | (34) | |
| SSc | CXCL10, CXCL8, and CCL4-producing non-classical monocyte subset is increased | Blood | (24) | |
| IPAH | Monocytes have either a similar or decreased activation status, depending on the study | Blood | (19, 35) | |
| IPAH | In vitro generated mo-DCs have either an increased or decreased Th-cell stimulatory capability, depending on the study | Blood | (19, 35) | |
| SSc | mo-DCs carrying the TLR2 polymorphism produce more cytokines (e.g., IL-6) | Blood | (26) | |
| IPAH | CD14+ cells are increased around pulmonary arteries | Lung | (36) |
a
Graves disease and Hashimoto's thyroiditis, cDC, conventional dendritic cell; pDC, plasmacytoid dendritic cell; mo-DC, monocyte-derived-dendritic-cell; PAH, pulmonary arterial hypertension; IPAH, idiopathic pulmonary arterial hypertension; AD, autoimmune disease; CTD-PAH, connective tissue disease-associated PAH; SLE, systemic lupus erythematosus; SSc, systemic sclerosis; TLO, tertiary lymphoid organ; PAs, pulmonary arteries; TLR, toll-like receptor.