• ANXA1 plays important roles in the innate immune response as effector of glucocorticoid-mediated responses and regulator of the inflammatory process. Has anti-inflammatory activity. Plays a role in glucocorticoid-mediated down-regulation of the early phase of the inflammatory response. Contributes to the adaptive immune response by enhancing signaling cascades that are triggered by T-cell activation, regulates differentiation and proliferation of activated T-cells. Promotes the differentiation of T-cells into Th1 cells and negatively regulates differentiation into Th2 cells .
• ANXA1 has no effect on unstimulated T-cells. Negatively regulates hormone exocytosis via activation of the formyl peptide receptors and reorganization of the actin cytoskeleton.
• ANXA1 has high affinity for Ca2+ and can bind up to eight Ca2+ ions.

Gene targeting strategy for B-hANXA1 mice. The exons 2-13 of mouse Anxa1 gene that encode signal peptide, extracellular domain, transmembrane domain, cytoplasmic region and 3’UTR are replaced by human counterparts in B-hANXA1 mice. The promoter and 5’UTR region of the mouse gene are retained. The human ANXA1 expression is driven by endogenous mouse Anxa1 promoter, while mouse Anxa1 gene transcription and translation will be disrupted. 

Strain specific analysis of ANXA1 mRNA expression in wild-type C57BL/6JNifdc mice and homozygous B-hANXA1 mice by RT-PCR. Lung RNA were isolated from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-hANXA1 mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human ANXA1 primers. Mouse Anxa1 mRNA was detectable in wild-type mice. Human ANXA1 mRNA was detectable only in homozygous B-hANXA1 mice (H/H) but not in wild-type mice. 

Western blot analysis of ANXA1 protein expression in homozygous B-hANXA1 mice. Various tissue lysates were collected from wild-type C57BL/6JNifdc mice (+/+) and homozygous B-hANXA1 mice, and then analyzed by western blot with anti-ANXA1 antibody (Abcam, ab138512). 40 μg total proteins were loaded for western blotting analysis. ANXA1 was detected in bladder and lung in wild-type mice and homozygous B-hANXA1 mice, as the antibody is cross-recognized between human and mouse ANXA1.