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Each year, thousands of patients are at risk of cerebral ischemic injury, due to iatrogenic responses to surgical procedures. Prophylactic treatment of these patients as standard care could minimize potential neurological complications. We have shown that protection of brain tissue, in a non-human primate model of cerebral ischemic injury, is possible through pharmacological preconditioning using the immune activator D192935. We postulate that preconditioning with D192935 results in neuroprotective reprogramming that is evident in the brain following experimentally induced cerebral ischemia. We performed quantitative proteomic analysis of cerebral spinal fluid (CSF) collected post-stroke from our previously published efficacy study to determine whether CSF protein profiles correlated with induced protection. Four groups of animals were examined: naïve animals (no treatment or stroke); animals treated with vehicle prior to stroke; D192935 treated and stroked animals, further delineated into two groups, ones that were protected (small infarcts) and those that were not protected (large infarcts). We found that distinct protein clusters defined the protected and non-protected animal groups, with a 16-member cluster of proteins induced exclusively in D192935 protected animals. Seventy percent of the proteins induced in the protected animals have functions that would enhance neuroprotection and tissue repair, including several members associated with M2 macrophages, a macrophage phenotype shown to contribute to neuroprotection and repair during ischemic injury. These studies highlight the translational importance of CSF biomarkers in defining mechanism and monitoring responses to treatment in development of stroke therapeutics.

Ischemia-reperfusion brain injury can be iatrogenically induced secondary to life-saving procedures. Prophylactic treatment of these patients offers a promising prevention for lifelong complications. We postulate that a cytosine-guanine (CpG) oligodeoxynucleotide (ODN) can provide robust antecedent protection against cerebral ischemic injury with minimal release of pro-inflammatory cytokines, making it an ideal candidate for further clinical development. Mouse and nonhuman primate (NHP) models of cerebral ischemic injury were used to test whether an A-type CpG ODN, which induces minimal systemic inflammatory cytokine responses, can provide prophylactic protection. Extent of injury in the mouse was measured by histological staining of live tissue. In the NHP, injury was assessed 2 and 7 days post-occlusion from T2-weighted magnetic resonance images and neurological and motor deficits were cataloged daily. Plasma cytokine levels were measured using species-specific Luminex assays. Prophylactic administration of an A-type CpG ODN provided robust protection against cerebral ischemic injury in the mouse with minimal systemic inflammation. Rhesus macaques treated with D192935, a mixture of human optimized A-type CpG ODNs, had smaller infarcts and demonstrated significantly less neurological and motor deficits following ischemic injury. Our findings demonstrate the translational potential of D192935 as a prophylactic treatment for patients at risk of cerebral ischemic injury.