Interaction Between Borrelia burgdorferi and Immature Human Dendritic Cells

Abstract

Antigen uptake and the following maturation of dendritic cells (DCs) are pivotal to the initiation of specific antimicrobial immune responses. DCs also play an important role in the recruitment and activation of the cells of the innate immune system. We have examined the interactions of DCs with Borrelia burgdorferi to find explanations for the difficulties the human immune system has in dealing with the bacterium. Phagocytosis of B. burgdorferi by immature DCs and the effect of the bacterium on the maturation and interleukin-8 (IL-8) secretion of DCs were studied. Borreliae were phagocytized and processed into fragments by DCs; narrow tube-like pseudopods and broad pseudopods were used for the engulfment. The immature DC population gained a heterogeneous appearance within 2 h of incubation with the borreliae. A 24 h coculture with borreliae induced maturation and IL-8 secretion in the DCs in a manner comparable with the effect of lipopolysaccharides. All strains studied, including a mutant strain lacking outer surface proteins A and B, were capable of inducing these responses. Thus, our results did not show any clear inadequacy concerning the way DCs are dealing with B. burgdorferi. However, further studies on the subject are required.

Borrelia burgdorferi Elicited-IL-10 Suppresses the Production of Inflammatory Mediators, Phagocytosis, and Expression of Co-Stimulatory Receptors by Murine Macrophages and/or Dendritic Cells

“…While these well-developed antibodies can prevent infection of naïve mice if administered co-currently with Bb, they cannot confer protection if the infection has been established for even a few days [6,87], suggesting that even briefly delayed development of the antibody response can promote establishment of Bb infection. Others have also shown that upregulation of co-stimulatory molecules by APCs in response to Bb is inadequate [81], and that the involvement of certain of these molecules (e.g. CD86) are needed for an optimal antibody response to Bb [88].…”

Adaptive and Innate Immune Responsiveness toBorrelia burgdorferi sensu latoin Exposed Asymptomatic Children and Children with Previous Clinical Lyme Borreliosis

“…The spirochete B. burgdorferi contains a high proportion of lipoproteins that are mainly recognized by TLR2 [8]. Recognition of B. burgdorferi leads to the release of inflammatory mediators like interleukin (IL)-1 β , IL-6, IL-10, and IL-12, and tumor necrosis factor (TNF) from monocytes, macrophages, neutrophils, and DCs [9–12]. These cytokines are important for recruitment of other components of the innate host immune response but also for signaling with the adaptive immune system [12].…”

Borreliosis: recent research, diagnosis, and management

“…We have shown that contact with borreliae induces maturation and IL-8 production of immature DCs in a similar manner to contact with LPS, a known maturation inducer (56). However, our gene expression studies have shown that borreliae somehow manipulate CD38 expression in DCs (57).…”