Thread by @LonnieRhea

New | Regulation of macrophage activity by surface receptors contained within Borrelia burgdorferi-enriched phagosomal fractions.

"The common gamma chain mediates the phagocytosis..." dx.plos.org/10.1371/journa… via @PLOSPathogens

@PLOSPathogens "Thus, the overall signature response to a specific pathogen is dictated by the addition of the signals initially emanating from surface receptors, further modulated by the interaction of intracellular signals generated as a result of the internalization of the pathogen. "

@PLOSPathogens "Our results show that the repertoire of surface proteins involved in this response is complex and composed of several classes of receptors, including C-lectins, scavenger receptors, siglecs and Fc receptors."

@PLOSPathogens "They also show that some of the identified receptors contribute to the binding of B. burgdorferi, while others, including the GPI-anchored proteins analyzed, seem to have an accessory role, possibly through their interaction with CR3 and potentially, other receptors."

@PLOSPathogens "In fact, we demonstrate that CD64, the high affinity Fc receptor, directly binds B. burgdorferi suggesting that Fc receptors mediate both antibody-dependent and independent responses in macrophages."

@PLOSPathogens "The role played by the opsonin-independent phagocytosis of B. burgdorferi mediated by Fc receptors and those dependent on the FcRγ-chain may be more relevant at the tissue level, once the spirochetes have disseminated to tissues with poor antibody penetration."

@PLOSPathogens "it is possible that some of the receptors herein identified may be dependent on MyD88-derived signals. Further work should defined whether this is the case. In contrast, we further define the Syk-mediated pathway, probably elicited by Fc receptors and certain C-type lectins..."

@PLOSPathogens "This diversity in the role played by different surface receptors on the biosignature of macrophages is further reinforced by the presence of proteins with positive and negative modulatory effects both in the uptake of the spirochete and the ensuing induction of TNF."

@PLOSPathogens Both composition & regulation of receptors involved in the response of macrophages to B.b. provide the capacity to eliminate the bacteria, but also the inflammatory output. It could be modulated over time in response to the signals that affect their expression, such as -> B.b