M CSF Human, Baculovirus

Macrophage Colony Stimulating Factor (M-CSF) is a potent hematopoietic cytokine that plays a crucial role in the regulation of proliferation, differentiation, and survival of monocytes, macrophages, osteoclasts, and their hematopoietic progenitors . M-CSF is involved in various physiological processes, including inflammatory responses, bone resorption, atherosclerosis, and brain and placental development .

The recombinant production of human M-CSF using the baculovirus expression system involves the use of insect cells, specifically Spodoptera frugiperda (Sf9) cells . The baculovirus expression system was developed based on the wild-type baculovirus life cycle, which includes early and late phases of viral replication . In the early phase, extracellular viral particles are budded from the infected cell to spread the infection within an insect host. In the late phase, occluded viruses are produced and accumulate in the nucleus of the infected cell .

The gene encoding M-CSF is cloned into a transfer vector under the control of the polyhedrin promoter. This vector is then co-transfected with wild-type baculovirus DNA into the host insect cells. Through homologous recombination, the gene of interest replaces the polyhedrin gene in a fraction of the budded virus produced . Cells infected with only recombinant virus can be plaque purified, and the budded virus recovered from these cells can be propagated to produce additional recombinant virus and direct the expression of M-CSF .

Recombinant human M-CSF produced in baculovirus is a disulfide-linked homodimer, glycosylated polypeptide chain containing 2 x 149 amino acids, with a total molecular mass of 42 kDa . The recombinant M-CSF is purified using proprietary chromatographic techniques to ensure high purity and biological activity .

Recombinant human M-CSF is widely used in various research applications, including differentiation studies, cell culture, and functional assays . It is particularly useful in the differentiation of macrophages from peripheral blood monocytes and the differentiation of osteoclasts from CD14+ monocytes . M-CSF also plays a significant role in immunological defense, bone metabolism, fertility, and pregnancy .

The biological activity of recombinant M-CSF is determined by its ability to regulate the proliferation, differentiation, and survival of monocytes and macrophages . It is also involved in the regulation of inflammatory responses in conjunction with other stimuli such as IFN-γ, LPS, and IL-4 .