NCIt definition : A glycoprotein complex extracted from Klebsiella pneumoniae K2O1 strain with immunostimulating
property. This glycoprotein complex consists of 2 repetitive glycoprotein subunits;
P1 comes from the bacterial capsule about 95 kD in molecular mass and F1, having an
lipopolysaccharide-related structure (350 kDa), is derived from bacterial external
membrane. Although the mechanism of action is not fully elucidated, Klebsiella pneumoniae
F1 fraction appears to suppress monocyte apoptosis, hence inducing the differentiation
of monocytes into macrophages. Furthermore, this agent also enhances humoral and cell-mediated
immune responses, and increases natural killer cell cytotoxicity functions. This glycoprotein
has been shown to reduce the incidence of infection.;