Increased leukocyte diversity and responsiveness to B-cell and T-cell mitogens in cell suspensions prepared by enzymatically dissociating murine lymph nodes.

The isolation of viable follicular dendritic cells (FDCs) from murine lymph nodes requires that the nodes be enzymatically dissociated with collagenase and the protease dispase. The present study was undertaken to compare leukocyte populations derived from enzymatically dissociated and mechanically disrupted lymph nodes. We examined cell viability, cell number, cell types, and the proliferative response to the mitogens LPS, PHA, and Con A. Cells were prepared by taking the inguinal, brachial, axillary, and popliteal lymph nodes from one side of the animals and mechanically disrupting them. The corresponding lymph nodes from the other side of the same animals were digested with enzymes. The enzyme-treated lymph nodes yielded substantially more cells and had a higher percentage of viable cells. Over 40% more viable cells were available for cell culture using the enzyme dissociation method. The numbers of FDCs, macrophages, plasma cells, and fibroblasts were clearly increased. The cells dispersed by enzymatic means responded better than the mechanically dispersed cells to both B-cell and T-cell mitogens. This was especially striking in cultures at lower cell densities. We conclude that the method of cell dissociation has a marked effect on the types of viable cells released and available for culture, as well as on the ability of the cells to respond. We believe the cell types released by enzymatic dissociation and their response in culture more accurately reflect conditions in vivo.