Neutrophil migration into joint

In this chapter, we described IFIC, FCM, and MPO assays as complementary methods to quantitate neutrophil migration into the joint. A combination of these techniques is helpful for the accurate quantification of neutrophils in the joint. For instance, IFIC is particularly useful to determine the location of neutrophils in the joint. In contrast, FCM is good for the quantification of neutrophils and also for additional phenotyping of the neutrophils in the joint. The MPO assay is a complementary method for quantification of neutrophils infiltration in the joint. However, while these end point studies provide useful information, they do provide information about neutrophil behavior in the joint tissue in live mice. 

Chemokines regulate the migration of cells in vivo and dysregulated expression of chemokines and their receptors are implicated in autoimmune and inflammatory diseases. Inflammatory arthritides, such as rheumatoid arthritis (RA), are characterized by the recruitment of inflammatory cells into joints. The K/BxN serum transfer mouse model of inflammatory arthritis shares many similar features with RA. In this autoantibody-induced model of arthritis, neutrophils are the critical immune cells necessary for the development of joint inflammation and damage. In this review, we describe the use of several methods to study the role of chemoattractant receptors, including chemokine receptors, on the recruitment of neutrophils into the joint in the K/BxN model of inflammatory arthritis. This includes both traditional methods, such as flow cytometry, immunohistochemistry, and enzyme assays, as well as multiphoton in vivo microscopy that we have adapted to study the role of immune cell trafficking in and around the joint in live mice. 

Gout is a condition in which excess plasma urate precipitates in joints, forming uric acid crystals. These crystals precipitate an inflammatory response, which involves the migration of neutrophils into the affected area, and release of inflammatory mediators. 

Recently, imaging technology has provided new insights into immune cell migration in five animals. Therefore, we have been developing new techniques to apply MP-FVM technology to study the arthritic joint in five mice. Our new method of joint MP-FVM allows the analysis of neutrophil... 

The injection of CxcU or Cxcl2 into the tibiofemoral joint of mice leads to rapid migration of significant numbers of neutrophils into the knee. The injection of 100 ng of CxcU in the joint is optimal to induce recruitment of neutrophils and cells can be easily recovered from the joint cavity 3 h after injection of the chemokine. Injection of human CXCL8 also induces the recruitment of neutrophils, albeit the dose necessary to cause recruitment is higher, approximately 1 j. /joint. Steps for the intra-articular injection of the chemokine and details for the evaluation of cells are given below. 

---