Abstract
We investigated peripheral leukocyte subpopulations using flow cytometry in mouse collagen-induced arthritis (CIA), one of the most-established model of rheumatoid arthritis. DBA/1J male mice were immunized 200 μg of heterologous type II collagen (CII) emulsified in CFA and boosted with the same dose of CII plus IFA 21 days later. Freshly isolated peripheral leukocytes from intact and CIA mice on day 35 and 42 after the first immunization were stained with corresponding mAbs and FITC- or PE- conjugated mAbs. Flow cytometry was performed using FACSCan (BD Biosciences). On day 35, we detected an increased number of leukocytes and an increased proportion of granulocytes. Therefore, the percentage of lymphocytes decreased, but the number of them slightly increased. The Ly-6G (Gr-1) positive neutrophils from CIA mice also expressed significant higher levels of adhesion molecule, integrin subunit CD11b (Mac-1α) . The number of CD19 positive (B) cells was increased. The percentage and number of CD3 positive (T) cells and the distribution of T cell subpopulations (CD4, CD8) were significantly increased. And the increase in CD4/CD8 was observed. From the results of day 42, we found that these responses on leukocytes gradually returned to the intact levels by day 42. These findings indicate that neutrophils considered to contribute to host defense also play an important function in modulating the development of inflammatory-immune response; CIA. The CIA induced increment of CD4 positive cells which was more predominant than that of CD8. [Jpn J Physiol 54 Suppl:S247 (2004)]
