Center of Research Translation on the Osteoimmunology of Bone Infection (CoRTOBI)

摘要

Abstract Bone infection caused by Staphylococcus aureus remains the bane of orthopaedic surgery, as diagnostics, prophylactics and treatments have significant shortcomings that result in catastrophic outcomes for patients, and crippling healthcare costs. Although the incidence of infection following primary total joint replacement (TJR) is low (~1%), reinfection rates are very high (15-40%), which has led to the orthopaedic paradigm that S. aureus infection of bone is incurable. Additionally, prosthetic joint infection (PJI) is known to be a non-random event that is largely determined by patient-specific factors. To address this, we proposed the original Center of Research Translation on the Osteoimmunology of Bone Infection (CoRTOBI) to test the hypotheses that: 1) there must be a reservoir of S. aureus that is not affected by standard of care treatments, and 2) the patient’s immune proteome against S. aureus antigens impacts the incidence and outcome of bone infection. Our work on this has resulted in innovative technologies that are being translated to the clinic by industry partners, and several seminal discoveries that we will continue to work on in this renewal, including: 1) S. aureus colonization of the osteocyte lacuno-canalicular network (OLCN) of live bone, 2) novel small molecule inhibitors that specifically target these mechanisms that can be 3D-printed into custom spacers as adjuvants to antibiotics, 3) development of a custom multiplex immunoassays to elucidate the immune proteome of S. aureus, 4) development of in vivo imaging to quantify “the race for the surface” of implants in real time, and 5) identification of anti-IsdB responses as susceptible immunity vs. anti-Gmd responses as protective immunity in mice and patients with culture confirmed S. aureus bone infection. Based on this success, we propose continuation of CoRTOBI with its Administrative Core that provides operational and fiscal management of the CoRTOBI, as well as a Biostatistics Sub-Core, an Enrichment Program, and a Pilot and Feasibility Project Program. We will also continue the Research Projects. Project 1 is focused on elucidating the mechanisms of S. aureus invasion of the OLCN, and developing novel antibiotic and adjuvant impregnated 3D-printed spacers. Project 2 is focused on elucidating the mechanism responsible for the susceptible immune proteome in patients, translating our discovery of five protective antigens with a novel multivalent mRNA vaccine, and bioinformatic assessment of patient-specific factors with the strain of S. aureus with which they are infected. The Projects will be supported by an Osteoimmunology Research Core, which will provide state of the art imaging, microfabrication and immunoassay analyses. The Core will also further innovate these technologies into novel outcome measures and enhance their clinical utility towards commercial products. At the conclusion of this CoRTOBI we will have in-depth knowledge of S. aureus OLCN invasion and immune evasion, as well as novel candidate clinical assays, antimicrobials and vaccines, to diagnose, prevent and treat the most serious bone infections, whose outcomes have not improved over the last half century.