The homeostatic chemokine CXCL13 is constitutively expressed in secondary lymphoid tissue and known to initiate lymphoid neogenesis when expressed aberrantly in mice. CXCL13 has also been detected in chronic inflammation associated with human lymphoid neogenesis, suggesting a pathogenic role. Follicular dendritic cells are generally considered to be the major source of CXCL13 both in normal and aberrant lymphoid tissue. CXCL13 has been the exclusive ligand for CXCR5, which initiates chemotaxis toward an increasing gradient in vitro and to B cell zones in lymph nodes that express CXCL13. More recently, CXCR5 expression has also been shown in DN T cells in mice, a subset of CD4 follicular Th cells, and some tonsillar CD4+ and CD25+ Tregs in humans.
<1.0 EU/μg of recombinant protein as determined by the LAL method
Biological Activity Comment
Determined by its ability to chemoattract human CXCR5 transfected mouse BaF3 B cells, the ED(50) is less than 20 ng/mL
Weight
10.0 kDa
Description
A quick spin of the vial followed by reconstitution in distilled water to a concentration not less than 0.1 mg/mL. This solution can then be diluted into other buffers.
Format
Lyophilized PowderLyophilized from a 0.2 μm filtered solution in PB,100 mM NaCl, pH 7.5
Purity
>95% as determined by SDS-PAGE
Storage
The lyophilized protein is stable for at least one year from date of receipt at -70°C. Upon reconstitution, this cytokine can be stored in working aliquots at 2° - 8°C for one month, or at -20°C for six months, with a carrier protein without detectable loss of activity. Avoid repeated freeze/thaw cycles.