CD8 T Cell-Initiated Blood–Brain Barrier Disruption Is Independent of Neutrophil Support

Abstract

Blood–brain barrier (BBB) disruption is a common feature of numerous neurologic disorders. A fundamental question in these diseases is the extent inflammatory immune cells contribute to CNS vascular permeability. We have previously shown that CD8 T cells play a critical role in initiating BBB disruption in the peptide-induced fatal syndrome model developed by our laboratory. However, myelomonocytic cells such as neutrophils have also been implicated in promoting CNS vascular permeability and functional deficit in murine models of neuroinflammatory disease. For this reason, we evaluated neutrophil depletion in a murine model of CD8 T cell-initiated BBB disruption by employing traditionally used anti-granulocyte receptor-1 mAb RB6-8C5 and Ly-6G–specific mAb 1A8. We report that CNS-infiltrating antiviral CD8 T cells express high levels of granulocyte receptor-1 protein and are depleted by treatment with RB6-8C5. Mice treated with RB6-8C5, but not 1A8, display: 1) intact BBB tight junction proteins; 2) reduced CNS vascular permeability visible by gadolinium-enhanced T1-weighted magnetic resonance imaging; and 3) preservation of motor function. These studies demonstrate that traditional methods of neutrophil depletion with RB6-8C5 are broadly immune ablating. Our data also provide evidence that CD8 T cells initiate disruption of BBB tight junction proteins and CNS vascular permeability in the absence of neutrophil support.

Improved Treatment Efficacy of Antiangiogenic Therapy when Combined with Picornavirus Vaccination in the GL261 Glioma Model

“…A Bruker DRX-300 (300 MHz 1H) 7-Tesla vertical-bore small animal imaging system (Bruker Biospin, Billerica, MA, USA) was used to acquire all MR images, similarly to published protocols [45,46]. Anesthesia was maintained by inhalation of 3-4 % isofluorane in air, with respiratory rate monitored throughout imaging.…”

“…At collection, brains were flash frozen and embedded in Optimal Cutting Temperature compound (Tissue-Tek, Torrance, CA, USA). Tissue sections were prepared as previously described [45]. Briefly, 6-μm sections were fixed in 4 % paraformaldehyde, washed with PBS, and blocked with 5 % normal goat serum containing 0.5 % IGEPAL CA-630 (Sigma) for 1 h. Primary antibodies recognizing claudin-5 (341600, rabbit; Invitrogen, Carlsbad, CA, USA) or VEGF (46154, rabbit; Abcam, Cambridge, UK) were diluted 1:200 in 5 % normal goat serum plus 0.5 % IGEPAL CA-630 and incubated overnight at room temperature.…”

Perforin Expression by CD8 T Cells Is Sufficient To Cause Fatal Brain Edema during Experimental Cerebral Malaria

“…Flow cytometry for brain-infiltrating lymphocytes was performed as previously described (50). Briefly, brains were homogenized and digested in type IV collagenase.…”

“…Samples were prepared as previously described (50). Mice were injected with 10 mg FITC-albumin 1 h before the brains were harvested.…”

Blood cells and endothelial barrier function

“…T-cells have also been implicated in mediating the bloodbrain barrier (BBB) disruption that is associated with experimental autoimmune encephalomyelitis (EAE). 103 In this model of neurological disease, CD4C T cells appear to elicit changes in tight junction architecture and BBB permeability by inducing astrocytes to release vascular endothelial growth factor (VEGF). Studies of a CD8C T-cell dependent model of BBB disruption that mimics multiple sclerosis have revealed that stimulation of CNS infiltrating CD8 T cells leads to astrocyte activation, alteration of BBB tight junction proteins and increased BBB permeability in a non-apoptotic manner, but these responses were not observed in perforin deficient mice.…”