Differential association of Borrelia species with cultured neural cells.

Studies of the interactions of relapsing fever Borrelia species with cultured neural cells have not been reported. In the present work, the interaction of the relapsing fever agents Borrelia hermsii and Borrelia turicatae with cultured neural and endothelial cells was studied and compared with Borrelia burgdorferi, the agent of Lyme disease. All Borrelia species bound each cell type tested. Host cell association was time-dependent and saturable. With the exception of human neuron cells, B. hermsii and B. turicatae associated to a greater degree with neural-derived cell types than did B. burgdorferi. In contrast, B. burgdorferi associated better with endothelial cells than did the relapsing fever borreliae. B. burgdorferi were found in human neuron cells to compete for association sites with B. hermsii and B. turicatae, suggesting the existence of some identity between the ligands or receptors used. Data indicate that the study of in vitro association of Borrelia species with neural-derived cells may provide valuable information for a better understanding of pathogenic mechanisms in neuroborreliosis.