The purpose of this study was to develop a method for the measurement of the cell kinetics of spleen lymphocytes using the ROSA 26 transgenic mouse ubiquitously expressing β-galactosidase (β-gal). Spleen lymphocytes were isolated from ROSA 26 mice and intravenously inoculated into C57BL/6 mice under normal conditions and inflammatory conditions following lipopolysaccharide (LPS) treatment. Spleen lymphocyte accumulation in tissues was determined as a measurement of β-gal activity. Spleen lymphocytes isolated from ROSA 26 mice have β-gal activities of 1.45 × 10-4 pg per cell. A good correlation between β-gal activities and cell numbers was obtained (r2=0.999) over the range 1 × 103 to 1 × 107 cells, corresponding to 70 fg to 350 pg β-gal activity. Spleen lymphocytes (4 × 107 cells) were intravenously inoculated into normal mice and subsequently each tissue was isolated and the corresponding β-gal activity measured. Spleen lymphocyte accumulation was relatively high in the spleen and lymph nodes. The accumulated spleen lymphocyte cell number was 1.39 × 107 cells/g spleen and 5.45 × 107 cells/g lymph node 1 h and 6 h after inoculation, respectively, and this remained constant up to 24 h. In the lung, lymphocyte accumulation was 3.98 × 107 cells/g tissue 10 min after inoculation then gradually fell to 7.09 × 105 cells/g tissue after 24 h. In addition, the femoral muscle following intramuscular injection of LPS showed a high accumulation of spleen lymphocytes, whereas the untreated and contralateral femoral muscle had the same level as the background. In conclusion, spleen lymphocytes isolated from ROSA 26 mice can be used to measure β-gal activity and the sensitivity is relatively high over the 70 fg to 350 pg range. This suggests that cells isolated from the ROSA 26 mouse can be applied to the study of cell kinetics.
ASJC Scopus subject areas
- Pharmaceutical Science