Regional topographical differences of canine microglial immunophenotype and function in the healthy spinal cord

Perspectives on Meningoencephalomyelitis of Unknown Origin

“…In dogs, several differences between resident microglia and infiltrating macrophages have been noted, along with topographic differences within the CNS. [49][50][51] Although both express CD18 1 , CD11b/c 1 , and CD45, microglia have lower levels of expression of CD45. 50 Moreover, stimulated microglia in healthy dogs generate lower levels of ROS.…”

“…50 Moreover, stimulated microglia in healthy dogs generate lower levels of ROS. 49,51 Neuroinflammation in MUO Although neuroinflammation has been investigated in several spontaneous canine CNS diseases, 48,49,52-54 mechanisms still remain enigmatic for the MUOs. When the normal immune regulatory mechanisms of the CNS are rendered dysfunctional, for instance by age, pathogen exposure, or neurodegeneration, the threshold to initiate CNS inflammation and the ability of the CNS to direct immune effector functions will change.…”

Isolation and Ex Vivo Characterization of the Immunophenotype and Function of Microglia/Macrophage Populations in Normal Dog Retina

“…We developed a protocol for ex vivo analysis of canine retinal microglia based on previous reports for brain and spinal cord [7, 9]. Five young dogs were examined and retinal cells collected under slightly different conditions to achieve the highest purified microglia populations.…”

“…The cells of dogs #4 and #5 were isolated using two successive Percoll gradients as previously done for microglia isolation from rats [8] and dogs [7, 9]; an initial gradient consisting of two densities and a major gradient with five densities, including an additional density of 1.060 g/mL. Microglia from dog #5 were collected separately from Percoll densities 1.060 and 1.072 g/mL and, as the number of cells was lower, no functional analyses were performed.…”

“…However, ex vivo analysis has the great advantage to more closely reflect in vivo conditions compared to results obtained using cell culture systems. Previous studies established microglia isolation protocols in mouse [6] and rat [8] CNS, canine spinal cord [9], and canine brain that was either normal [7] or infected with canine distemper virus [10]. Retinal microglia have been isolated and characterized in humans [11] and rats [12] using Percoll density gradient centrifugation and FACS analysis, but these experimental tools have not yet been applied to dog retinas.…”