Limits...
Effects of Experimental Sarcocystis neurona-Induced Infection on Immunity in an Equine Model.

Lewis SR, Ellison SP, Dascanio JJ, Lindsay DS, Gogal RM, Werre SR, Surendran N, Breen ME, Heid BM, Andrews FM, Buechner-Maxwell VA, Witonsky SG - J Vet Med (2014)

Bottom Line: Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators.Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression.Neutrophils, monocytes, and lymphocytes from infected horses displayed significantly delayed apoptosis at some time points.

View Article: PubMed Central - PubMed

Affiliation: Department of Large Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA 24061, USA ; Rangiora Veterinary Centre, Rangiora 7400, New Zealand.

ABSTRACT
Sarcocystis neurona is the most common cause of Equine Protozoal Myeloencephalitis (EPM), affecting 0.5-1% horses in the United States during their lifetimes. The objective of this study was to evaluate the equine immune responses in an experimentally induced Sarcocystis neurona infection model. Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators. Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression. All experimentally infected horses displayed neurologic signs after infection. Neutrophils, monocytes, and lymphocytes from infected horses displayed significantly delayed apoptosis at some time points. Cell proliferation was significantly increased in S. neurona-infected horses when stimulated nonspecifically with PMA/I but significantly decreased when stimulated with S. neurona compared to controls. Collectively, our results suggest that horses experimentally infected with S. neurona manifest impaired antigen specific response to S. neurona, which could be a function of altered antigen presentation, lack of antigen recognition, or both.

No MeSH data available.


Related in: MedlinePlus

Experimental design for S. neurona infection study. Following a 2-week acclimation, nine horses had baseline neurologic examinations, immune function analysis, and CSF taps with samples submitted for SnSAG1 analysis. Horses were randomly assigned to either control or S. neurona experimentally infected treatment groups. Peripheral blood was collected on day −5, day −1, days 0–10, day 14, day 21, day 28, day 35, day 42, day 56, and day 70 for infection or immune function assays. CSF taps (A/O = atlanto-occipital space) were performed on day 5 and postinfection day 73.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4590861&req=5

fig1: Experimental design for S. neurona infection study. Following a 2-week acclimation, nine horses had baseline neurologic examinations, immune function analysis, and CSF taps with samples submitted for SnSAG1 analysis. Horses were randomly assigned to either control or S. neurona experimentally infected treatment groups. Peripheral blood was collected on day −5, day −1, days 0–10, day 14, day 21, day 28, day 35, day 42, day 56, and day 70 for infection or immune function assays. CSF taps (A/O = atlanto-occipital space) were performed on day 5 and postinfection day 73.

Mentions: Complete physical examinations were performed on all the horses upon arrival at Virginia-Maryland Regional College of Veterinary Medicine (VMRCVM). Baseline physical and neurologic exams were performed (Figure 1). All care and maintenance of the horses was in accordance with the guidelines established by the Animal Use and Care, IACUC committee at Virginia Tech, and the study was approved by the IACUC committee. All horses underwent a neurological/lameness examination two weeks prior to the start of the study. Investigators Lewis (RL) and Witonsky (SW) performed blinded neurologic exams separately for each horse including baseline scores. A 97-point scoring system was used to evaluate the horses' neurological/lameness status and is described in detail later in Table 4. The scoring system was based on a protocol established by Ellison et al. [18–20], which had been used for several previous United States Department of Agriculture (USDA) approved EPM studies. Briefly, the scores ranged from zero (normal) to 3 (severely affected) for 22 different parameters with a maximum total score of 97 (Table 4). The parameters measured included, but were not limited to, cranial nerve function, ataxia, weakness (paresis), and spasticity. The 22 parameters that were evaluated included dropping feed, tongue tone, apprehension of feed, drooling, lip, facial nerve and eyelid paresis, attitude, muscle atrophy, cauda equine, weakness, lameness, conscious proprioception based on crossing over of limbs, abduction of hind limbs, tripping, paresis, circling, pivoting and toe dragging of limbs, hypermetria, inconsistent placement, and tail pull. When a horse displayed a neurologic or lameness deficit, the appropriate score was assigned, and the horse was observed closely for two weeks prior to initiation of the study. If the horse's status was unchanged during this period, the animal was subjected to a more thorough neurologic evaluation (described in the following section) to minimize the possibility of a preexisting EPM infection. A few horses displayed gait and conformation abnormalities that resulted in a measurable elevated baseline neurologic/lameness score; however these abnormalities were determined to not be attributable to an EPM infection. We predicted that an S. neurona infection would alter the baseline score; thus horses with a preexisting minimal measureable baseline neurologic/lameness score remained in the study.


Effects of Experimental Sarcocystis neurona-Induced Infection on Immunity in an Equine Model.

Lewis SR, Ellison SP, Dascanio JJ, Lindsay DS, Gogal RM, Werre SR, Surendran N, Breen ME, Heid BM, Andrews FM, Buechner-Maxwell VA, Witonsky SG - J Vet Med (2014)

Experimental design for S. neurona infection study. Following a 2-week acclimation, nine horses had baseline neurologic examinations, immune function analysis, and CSF taps with samples submitted for SnSAG1 analysis. Horses were randomly assigned to either control or S. neurona experimentally infected treatment groups. Peripheral blood was collected on day −5, day −1, days 0–10, day 14, day 21, day 28, day 35, day 42, day 56, and day 70 for infection or immune function assays. CSF taps (A/O = atlanto-occipital space) were performed on day 5 and postinfection day 73.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4590861&req=5

fig1: Experimental design for S. neurona infection study. Following a 2-week acclimation, nine horses had baseline neurologic examinations, immune function analysis, and CSF taps with samples submitted for SnSAG1 analysis. Horses were randomly assigned to either control or S. neurona experimentally infected treatment groups. Peripheral blood was collected on day −5, day −1, days 0–10, day 14, day 21, day 28, day 35, day 42, day 56, and day 70 for infection or immune function assays. CSF taps (A/O = atlanto-occipital space) were performed on day 5 and postinfection day 73.
Mentions: Complete physical examinations were performed on all the horses upon arrival at Virginia-Maryland Regional College of Veterinary Medicine (VMRCVM). Baseline physical and neurologic exams were performed (Figure 1). All care and maintenance of the horses was in accordance with the guidelines established by the Animal Use and Care, IACUC committee at Virginia Tech, and the study was approved by the IACUC committee. All horses underwent a neurological/lameness examination two weeks prior to the start of the study. Investigators Lewis (RL) and Witonsky (SW) performed blinded neurologic exams separately for each horse including baseline scores. A 97-point scoring system was used to evaluate the horses' neurological/lameness status and is described in detail later in Table 4. The scoring system was based on a protocol established by Ellison et al. [18–20], which had been used for several previous United States Department of Agriculture (USDA) approved EPM studies. Briefly, the scores ranged from zero (normal) to 3 (severely affected) for 22 different parameters with a maximum total score of 97 (Table 4). The parameters measured included, but were not limited to, cranial nerve function, ataxia, weakness (paresis), and spasticity. The 22 parameters that were evaluated included dropping feed, tongue tone, apprehension of feed, drooling, lip, facial nerve and eyelid paresis, attitude, muscle atrophy, cauda equine, weakness, lameness, conscious proprioception based on crossing over of limbs, abduction of hind limbs, tripping, paresis, circling, pivoting and toe dragging of limbs, hypermetria, inconsistent placement, and tail pull. When a horse displayed a neurologic or lameness deficit, the appropriate score was assigned, and the horse was observed closely for two weeks prior to initiation of the study. If the horse's status was unchanged during this period, the animal was subjected to a more thorough neurologic evaluation (described in the following section) to minimize the possibility of a preexisting EPM infection. A few horses displayed gait and conformation abnormalities that resulted in a measurable elevated baseline neurologic/lameness score; however these abnormalities were determined to not be attributable to an EPM infection. We predicted that an S. neurona infection would alter the baseline score; thus horses with a preexisting minimal measureable baseline neurologic/lameness score remained in the study.

Bottom Line: Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators.Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression.Neutrophils, monocytes, and lymphocytes from infected horses displayed significantly delayed apoptosis at some time points.

View Article: PubMed Central - PubMed

Affiliation: Department of Large Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA 24061, USA ; Rangiora Veterinary Centre, Rangiora 7400, New Zealand.

ABSTRACT
Sarcocystis neurona is the most common cause of Equine Protozoal Myeloencephalitis (EPM), affecting 0.5-1% horses in the United States during their lifetimes. The objective of this study was to evaluate the equine immune responses in an experimentally induced Sarcocystis neurona infection model. Neurologic parameters were recorded prior to and throughout the 70-day study by blinded investigators. Recombinant SnSAG1 ELISA for serum and CSF were used to confirm and track disease progression. All experimentally infected horses displayed neurologic signs after infection. Neutrophils, monocytes, and lymphocytes from infected horses displayed significantly delayed apoptosis at some time points. Cell proliferation was significantly increased in S. neurona-infected horses when stimulated nonspecifically with PMA/I but significantly decreased when stimulated with S. neurona compared to controls. Collectively, our results suggest that horses experimentally infected with S. neurona manifest impaired antigen specific response to S. neurona, which could be a function of altered antigen presentation, lack of antigen recognition, or both.

No MeSH data available.


Related in: MedlinePlus