Pathogenesis and Immune Defense

Abstract

Since the discovery of the etiological agents of Lyme disease, Borrelia burgdorferi sensu lato (s.l.), many efforts have been undertaken to understand the nature of the pathobiology these pathogens cause in humans. Here we describe the current knowledge of the most important borrelial determinants and factors and how they interact in different ways with soluble host proteins, tissues, and organs at different time points within the multistep infection process. We also describe the specific responses and signaling pathways that are induced by the human host to combat the intruding pathogen. While not a complete list, factors involved in host adaptation, tissue colonization, dissemination, and persistence of Borrelia are addressed, as well as factors playing a key role in immune evasion. Further aspects such as the induction of inflammatory mediators and the role of B and T cells in host responses, as well as the recognition and persistence of spirochetes are also discussed. Despite the huge collection and collation of data within the last two decades, our picture of the pathogenesis of Lyme diseases is still a big puzzle, in which the shape and certain characteristics are visible, but the whole picture is covered with a blurry veil.