Summary
The family of class I phosphoinositide-3-kinase (PI3K) is composed of four lipid kinases
involved at multiple levels in innate and adaptive immune responses. Class I PI3Ks
are divided into two subclasses, IA and IB, sharing a similar catalytic core. Whereas
class IA PI3Ks are primarily activated by receptor tyrosine kinases, the unique element
of class IB PI3K (PI3Kγ) is activated by G protein coupled receptors (GPCRs), like
chemokine receptors. PI3Kγ is mainly expressed in leukocytes where it plays a significant
role in chemotaxis. Here, we report recent advances in the analysis of the role of
PI3Kγ in leukocytes and in endothelial cells. Results, derived from studies based
on both pharmacological and genetic approaches, confirm PI3Kγ as an attractive target
for drug discovery. PI3Kγ specific inhibition has gained increasing attention for
the treatment of allergic, autoimmune and inflammatory diseases. Development of inhibitors
has already provided series of hits, whose efficacy is currently under scrutiny worldwide.
Keywords
Inflammation - leukocyte trafficking / recruitment - signal transduction - endothelial
cells