Studies On Immunological Effects And Its Mechanisms Of Human Soluble BAFF On Specific Immunocytes In Mice

The present study systemically studied the effects of human soluble BAFF (hsBAFF) on immune function and intracellular Ca²⁺ signal alteration of splenic B lymphocytes as well as CD4⁺ and CD8⁺ T lymphocytes and NK cell activity in mice by means of cell culture, flow cytometry, laser scanning confocal microscope analysis, etc. The regulation and mechanisms of hsBAFF on specific immunocytes and whole immune system in the body were discussed. The results were summarized as follows:1 Changes of body weight and eighteen blood routine indice in hsBAFF-injected miceForty-eight healthy ICR mice, half-male and half-female, were chosen and randomly divided into a control group and five hsBAFF groups of different dosages which were diluted with PBS and injected in the abdominal cavity with 0.01,0.1,0.5, 1,2mg of hsBAFF per kg body weight respectively, and control group was given PBS of the same dosage over eight days. The body weight and eighteen blood routine indice were analyzed on the 4th and 8th days after hsBAFF injection. The results showed that during the whole experiment period, body weight was no significant difference among every groups but had an increase tendency with day of age. The blood indice within all groups had no obvious changes. Although there were some fluctuations from individual indice such as Lym, Mid, GRN, RBC, HGB, et al, no index exceeded the normal physiological limit. It is suggested that hsBAFF may have no significant effect on mice, indicating that hsBAFF can not ruin the normal body. All of these give the toxicological evidence for hsBAFF entering the clinical stage.2 Studies on changes of splenic B lymphocyte activity and blood IgM, IgA and IgG concentrations of administered human soluble BAFF in miceForty healthy ICR mice, half-male and half-female, were chosen and randomly divided into a control group and three hsBAFF groups of different dosages which were diluted with PBS. We gave mice abdominal cavity injection of hsBAFF (0.1, 0.5, 1 mg/kg body weight) synthesized in Escherichia coli. The immune activities of splenic B lymphocytes and serum IgM, IgA, IgG concentrations were investigated on the 4th and 8th days. The results showed that B lymphocyte proliferation significantly increased concentration-dependently, and a greatly elevated immune response of B lymphocyte to LPS stimulation existed in hsBAFF-treated mice on day 8 post experiment. Administration of hsBAFF resulted in almost twofold increase in serum IgM and greatly elevated levels also in serum IgA on days 4 and 8, respectively. Serum IgG did not markedly increase on day 4, but significantly rose on day 8 after treatment with hsBAFF (0.5-1.0 mg/kg). These findings suggest that the hsBAFF...