Table 1.
Hematopoietic cells identified in the valve
| Cell Type | Immunological Role | Identifiers | Notes | Referencess |
|---|---|---|---|---|
| In the healthy valve (murine unless otherwise noted) | ||||
| Dendritic cells | Initiate innate immune response, antigen-presentation | CD45+, CD11c+, F4/80− | ||
| CD11b+ dendritic cells | CD11b+ | (32) | ||
| CD11b− dendritic cells | CD11b− | (68) | ||
| Macrophages | Phagocytose pathogens, initiate innate immune response, antigen-presentation | CD11c+, F4/80+ | (9, 68) | |
| MHC II+ macrophages | MHC II+ | (68) | ||
| CD206+ macrophages | CD206+ | Murine | (68) | |
| CD68+, CD206+ | Human | (92) | ||
| Enriched in CAVD (human unless otherwise noted) | ||||
| Myeloid cells | ||||
| Dendritic cells | Initiate innate immune response, antigen-presentation | S100A9+ | (121, 157) | |
| Macrophages | Phagocytose pathogens, initiate innate immune response, antigen-presentation | CD68+ | (36, 93, 112, 157, 162) | |
| M1-like macrophages | Initiate inflammatory and cytotoxic immune responses | CD11c+ | ↑ in CAVD | (92) |
| M2-like macrophages | Initiate tolerogenic and profibrotic immune responses | CD206+ | ↓ in CAVD | (92) |
| Lymphocytes | ||||
| T cells | CD3+, IL2R+, CD6+ | (36, 112, 132, 157) | ||
| T helper cells | Coordinate the immune response by providing “help” to other cells | CD4+ | (121, 162) | |
| CTLs | Kill infected cells or tumor cells | CD8+, IFNγ+ | (123, 162) | |
| Regulatory T cells | Resolve immune response, promote tolerogenic environment | CD25+, Foxp3+ | In circulation; ↓ after surgical intervention | (155) |
| Memory-effector T cells | Initiate immune responses to prior pathogens | CD8+, CD28null, CD57+ | In both valve and circulation | (178) |
| Natural killer T cells | Release cytokines in response to various glycolipid antigens | ↑ with worsening echo metrics | (111) | |
| B cells | CD20+, BAFF-R+ | (126, 162) | ||
| Plasma cells | Produce antibody | CD138+ | (162) | |
| Other | ||||
| Mast cells | Rapidly release histamines and inflammatory substances during allergic reactions | CD117+, tryptase+, chymase+ | ↑ in bicuspid aortic valves; increased with worsening echo | (119, 163, 183) |
| Osteogenic progenitor cells | Bone formation | OCN+, CD34+, KDR+ | ↑ with worsening echo; in both valve and circulation | (44, 55, 167) |
CAVD, calcific aortic valve disease; CTLs, cytotoxic T lymphocytes; MHC II, molecular histocompatibility complex II; OCN, osteocalcin; IFNγ, interferon-γ; Foxp3, forkhead box P3; BAFF-R, B cell-activating factor receptor; KDR, kinase insert domain receptor.