Characterization of mouse nasal lymphocytes isolated by enzymatic extraction with collagenase.

A reproducible method for isolation of mouse nasal lymphocytes was developed. The cells were released from tissue fragments of dissected mouse nose by enzyme extraction with collagenase and separated by a stepwise Percoll gradient centrifugation. The partially purified nasal lymphocyte fraction from normal BALB/c mice contained CD4+ T cells (18-23%), CD8+ T cells (7-10%) and B cells (20-38%), when analysed with a FACScan fluorescence analyser. The ratio of T to B cells and that of CD4+ to CD8+ T cells in the nasal cell fraction were about twice as high as those in Peyer's path lymphocytes. The nasal lymphocyte fraction from the mice infected with influenza virus was then characterized. The nasal lymphocytes contained a twice larger number of CD4+ and a three times larger number of CD8+ T cells than those of normal mice 7 days after infection. They produced IFN-gamma which increased after infection. They contained the cells secreting influenza virus-specific IgA and IgG antibodies 4 weeks after infection. Moreover, the nasal lymphocytes from infected C3H mice lysed the virus infected-target cells. These results suggest that this method can successfully be used for investigating cellular dynamics of mucosal immunity in the upper respiratory tract of experimental animals.