Table 1.
Examples of potential signaling molecules that are substrates of ABC transporters.
| Compound | Functions | Transporter(s) | References |
|---|---|---|---|
| Platelet activating factor (PAF) | Mediator of inflammation | ABCB1 (Pgp) | Ernest and Bello-Reuss (1999), Raggers et al. (2001) |
| Phospholipids [e.g., phosphatidylcholine, phosphatidylserine (PS) phosphatidylethanolamine] | Membrane integrity, cell cycle regulation; cell signaling; schistosome PS and lyso-PS polarize DCs | ABCB1, ABCB3, ABCA1, ABCA2, ABCG2 (BCRP) | Pohl et al. (2002), Aye et al. (2009), Romsicki and Sharom (2001), Daleke (2007) |
| Cyclic nucleotides | Regulate inflammatory responses, monocyte polarization, maturation | ABCC4, ABCC5, ABCC11 | Wielinga et al. (2003), Chen et al. (2001), Guo et al. (2003) |
| Sphyngosine-1-phosphate (S1P) | T-cell homing; immunosuppression | ABCB1 | Honig et al. (2003) |
| Leukotriene LTC4 | Mediator of inflammation; DC migration | ABCC1, other ABCCs (MRPs) | Leier et al. (1994), Cui et al (1999), Rius et al. (2008) |
| LTB4, LTD4, LTE4 | Mediators of inflammation; DC migration | ABCC1, ABCC4 | Leier et al. (1994), Rius et al. (2008) |
| Prostaglandins PGE1, PGE2, PGE2α | DC migration/maturation; immune suppression | ABCC4 | Reid et al. (2003) |
| Sphingomyelin, glycolipids, cholesterol | Multiple | ABCB1, ABCAs | Kim et al. (2008) |
| Peptides | Antigen presentation | ABCB2/3 (TAP1/2) | Koopmann et al. (1996) |
| dsRNA | TLR3 activation in DCs by schistosome eggs | C. elegans ABCA, ABCBs, ABCD, ABCGs | Sundaram et al. (2006) |
Examples of some of the signaling molecules shown to be substrates of ABC transporters, and their possible functions, with an emphasis on those with relevance to immunomodulation.