Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P30536 (PBS)
 9,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The CNS innate immune response is a "double-edged sword" representing a fine balance between protective antipathogen responses and detrimental neurocytotoxic effects. Hence, it is important to identify the key regulatory mechanisms involved in the control of CNS innate immunity and which could be harnessed to explore novel therapeutic avenues. In analogy to the newly described neuroimmune regulatory proteins also known as "don't eat me" signals (CD200, CD47, CD22, fractalkine, semaphorins), we herein identify the key role of complement regulator factor H (fH) in controlling neuroinflammation initiated in an acute mouse model of Ab-dependent experimental autoimmune encephalomyelitis. Mouse fH was found to be abundantly expressed by primary cultured neurons and neuronal cell lines (N1E115 and Neuro2a) at a level comparable to BV2 microglia and CLTT astrocytes. Mouse neurons expressed other complement regulators crry and low levels of CD55. In the brain, the expression of fH was localized to neuronal bodies and axons, endothelial cells, microglia but not oligodendrocytes and myelin sheaths and was dramatically reduced in inflammatory experimental autoimmune encephalomyelitis settings. When exogenous human fH was administered to disease Ab-dependent experimental autoimmune encephalomyelitis animals, there was a significant decrease in clinical score, inflammation, and demyelination, as compared with PBS-injected animals. We found that the accumulation of human fH in the brain parenchyma protected neurons from complement opsonization, axonal injury, and leukocyte infiltration. Our data argue for a key regulatory activity of fH in neuroprotection and provide novel therapeutic avenues for CNS chronic inflammatory diseases.
 ...
PMID:Complement factor H, a marker of self protects against experimental autoimmune encephalomyelitis. 1929 37

Signal regulatory protein alpha (SIRPalpha) and its cognate ligand CD47 have been documented to have a broad range of cellular functions in development and immunity. Here, we investigated the role of SIRPalpha-CD47 signalling in invariant NKT (iNKT) cell responses. We found that CD47 was required for the optimal production of IFN-gamma from splenic iNKT cells following exposure to the alphaGalCer analogue PBS-57 and in vivo infection of mice with Leishmania donovani. Surprisingly, although SIRPalpha was undetectable in the liver of uninfected mice, the hepatic iNKT-cell response to infection was also impaired in CD47-/- mice. However, we found that SIRPalpha was rapidly induced on Kupffer cells following L. donovani infection, via a mechanism involving G-protein-coupled receptors. Thus, we describe a novel amplification pathway affecting cytokine production by hepatic iNKT cells, which may facilitate the breakdown of hepatic tolerance after infection.
 ...
PMID:Leishmania donovani-induced expression of signal regulatory protein alpha on Kupffer cells enhances hepatic invariant NKT-cell activation. 1987 19

Macrophage-targeted drug delivery has great therapeutic potential for the treatment of cancers and inflammatory diseases. There is also an unmet need for efficient and nontoxic means of in vivo macrophage depletion to determine the role of macrophages under normal and disease settings. Herein, we explored the potential of red blood cell (RBC)-derived nanovesicles (RDNVs) as drug nanocarriers to specifically deplete macrophages. We show that RDNVs are effective hydrophilic drug carriers and can effectively deliver drugs into macrophages both in vitro and in vivo. Nanovesicles derived from both wild-type mouse RBCs (WT-RDNVs) and CD47 KO mouse RBCs (KO-RDNVs) can encapsulate clodronate with good stability in PBS for long-term storage. However, KO-RDNVs were more efficiently engulfed by macrophages in vitro and more rapidly cleared in vivo than WT-RDNVs, indicating that CD47 also serves as a "don't eat me" molecule for RDNVs as it does for RBCs. Accordingly, clodronate-encapsulated KO-RDNVs (KO-RDNV/CLD) were significantly more toxic to mouse macrophages in vitro than drug-loaded WT-RDNVs (WT-RDNV/CLD). Furthermore, WT-RDNV/CLD showed prolonged accumulation in tissues (e.g., liver and lung) and macrophage depletion versus KO-RDNV/CLD. Importantly, RBC-derived nanovesicles are more biocompatible and less toxic in vivo than clodronate-encapsulated liposomes-the current gold-standard macrophage-depleting reagent. This study offers a useful strategy for macrophage-targeted drug delivery.
 ...
PMID:Red blood cell-derived nanovesicles for safe and efficient macrophage-targeted drug delivery in vivo. 3042 47