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Further characterization of autoantibodies to GABAergic neurons in the central nervous system produced by a subset of children with autism.

Wills S, Rossi CC, Bennett J, Martinez Cerdeño V, Ashwood P, Amaral DG, Van de Water J - Mol Autism (2011)

Bottom Line: Autoantibody-positive cells rarely expressed calretinin.Some cell populations stained in the primate (such as the Golgi neurons in the cerebellum) were not as robustly immunoreactive in the mouse brain.Further, these findings confirm the autoantibody-targeted cells to be a subpopulation of GABAergic interneurons.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, 451 Health Sciences Drive, Suite 6510 GBSF, Davis, CA 95616, USA. javandewater@ucdavis.edu.

ABSTRACT

Background: Autism is a neurodevelopmental disorder characterized by impairments in social interaction and deficits in verbal and nonverbal communication, together with the presence of repetitive behaviors or a limited repertoire of activities and interests. The causes of autism are currently unclear. In a previous study, we determined that 21% of children with autism have plasma autoantibodies that are immunoreactive with a population of neurons in the cerebellum that appear to be Golgi cells, which are GABAergic interneurons.

Methods: We have extended this analysis by examining plasma immunoreactivity in the remainder of the brain. To determine cell specificity, double-labeling studies that included one of the calcium-binding proteins that are commonly colocalized in GABAergic neurons (calbindin, parvalbumin or calretinin) were also carried out to determine which GABAergic neurons are immunoreactive. Coronal sections through the rostrocaudal extent of the macaque monkey brain were reacted with plasma from each of seven individuals with autism who had previously demonstrated positive Golgi cell staining, as well as six negative controls. In addition, brain sections from adult male mice were similarly examined.

Results: In each case, specific staining was observed for neurons that had the morphological appearance of interneurons. By double-labeling sections with plasma and with antibodies directed against γ-aminobutyric acid (GABA), we determined that all autoantibody-positive neurons were GABAergic. However, not all GABAergic neurons were autoantibody-positive. Calbindin was colabeled in several of the autoantibody-labeled cells, while parvalbumin colabeling was less frequently observed. Autoantibody-positive cells rarely expressed calretinin. Sections from the mouse brain processed similarly to the primate sections also demonstrated immunoreactivity to interneurons distributed throughout the neocortex and many subcortical regions. Some cell populations stained in the primate (such as the Golgi neurons in the cerebellum) were not as robustly immunoreactive in the mouse brain.

Conclusions: These results suggest that the earlier report of autoantibody immunoreactivity to specific cells in the cerebellum extend to other regions of the brain. Further, these findings confirm the autoantibody-targeted cells to be a subpopulation of GABAergic interneurons. The potential impact of these autoantibodies on GABAergic disruption with respect to the etiology of autism is discussed herein.

No MeSH data available.


Related in: MedlinePlus

Fluorescence confocal photomicrographs of double-labeling with plasma from a representative child with autism (age 5 years) and an antibody directed at GABA. (A) GABA immunoreactivity in area V1 (green). (B) Immunoreactivity of V1 with plasma from a child with autism (red). (C) Merged images from Figures 3A and 3B showing several double-labeled cells (yellow). The vessels have been labeled (V) to aid in orientation with Figure 3D. (D) Schematic of the same region shown in Figures 3A to 3C, with cells coexpressing GABA and plasma immunoreactivity, depicted as yellow circles, GABAergic cells without plasma immunoreactivity, depicted as green hexagons, and a single GABA-negative, plasma-positive cell, depicted as a red star. The vessels have been labeled (V) to aid in orientation with Figure 3C. Calibration bar, 100 μm.
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Figure 3: Fluorescence confocal photomicrographs of double-labeling with plasma from a representative child with autism (age 5 years) and an antibody directed at GABA. (A) GABA immunoreactivity in area V1 (green). (B) Immunoreactivity of V1 with plasma from a child with autism (red). (C) Merged images from Figures 3A and 3B showing several double-labeled cells (yellow). The vessels have been labeled (V) to aid in orientation with Figure 3D. (D) Schematic of the same region shown in Figures 3A to 3C, with cells coexpressing GABA and plasma immunoreactivity, depicted as yellow circles, GABAergic cells without plasma immunoreactivity, depicted as green hexagons, and a single GABA-negative, plasma-positive cell, depicted as a red star. The vessels have been labeled (V) to aid in orientation with Figure 3C. Calibration bar, 100 μm.

Mentions: To provide evidence for the proposition that the plasma labeled cells were GABAergic, an additional series of sections through area V1 were double-labeled with plasma and with anti-sera to GABA (Figure 3). On the basis of evaluation using the confocal laser microscope, we confirmed that essentially all autoantibody-reactive cells were double-labeled for GABA. We also confirmed that a sizable number of GABA-positive neurons were not immunoreactive with the plasma. Many of these single-labeled GABAergic neurons were located in the deep layers of the cortex. Because only a subset of GABA-positive neurons was labeled by autoantibody-containing plasma, we wanted to get a sense of which populations of GABAergic neurons were being labeled. While it was beyond the scope of the current paper to do an exhaustive, quantitative analysis with double-labeling, we did double-label sections through area V1 with plasma and antibodies directed against the calcium-binding proteins calbindin, parvalbumin and calretinin. We determined that plasma-labeled cells were not exclusively labeled by any one of these proteins expressed in GABAergic neurons. Rather, it appears that the immunoreactive cells were most commonly labeled by calbindin, but not all calbindin-labeled cells were labeled by the autoantibodies (Figures 4A to 4C). Autoantibody-labeled cells less commonly expressed parvalbumin (Figures 4D to 4F), and labeling with calretinin in plasma-labeled cells was rare (Figures 4G to 4I).


Further characterization of autoantibodies to GABAergic neurons in the central nervous system produced by a subset of children with autism.

Wills S, Rossi CC, Bennett J, Martinez Cerdeño V, Ashwood P, Amaral DG, Van de Water J - Mol Autism (2011)

Fluorescence confocal photomicrographs of double-labeling with plasma from a representative child with autism (age 5 years) and an antibody directed at GABA. (A) GABA immunoreactivity in area V1 (green). (B) Immunoreactivity of V1 with plasma from a child with autism (red). (C) Merged images from Figures 3A and 3B showing several double-labeled cells (yellow). The vessels have been labeled (V) to aid in orientation with Figure 3D. (D) Schematic of the same region shown in Figures 3A to 3C, with cells coexpressing GABA and plasma immunoreactivity, depicted as yellow circles, GABAergic cells without plasma immunoreactivity, depicted as green hexagons, and a single GABA-negative, plasma-positive cell, depicted as a red star. The vessels have been labeled (V) to aid in orientation with Figure 3C. Calibration bar, 100 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3108923&req=5

Figure 3: Fluorescence confocal photomicrographs of double-labeling with plasma from a representative child with autism (age 5 years) and an antibody directed at GABA. (A) GABA immunoreactivity in area V1 (green). (B) Immunoreactivity of V1 with plasma from a child with autism (red). (C) Merged images from Figures 3A and 3B showing several double-labeled cells (yellow). The vessels have been labeled (V) to aid in orientation with Figure 3D. (D) Schematic of the same region shown in Figures 3A to 3C, with cells coexpressing GABA and plasma immunoreactivity, depicted as yellow circles, GABAergic cells without plasma immunoreactivity, depicted as green hexagons, and a single GABA-negative, plasma-positive cell, depicted as a red star. The vessels have been labeled (V) to aid in orientation with Figure 3C. Calibration bar, 100 μm.
Mentions: To provide evidence for the proposition that the plasma labeled cells were GABAergic, an additional series of sections through area V1 were double-labeled with plasma and with anti-sera to GABA (Figure 3). On the basis of evaluation using the confocal laser microscope, we confirmed that essentially all autoantibody-reactive cells were double-labeled for GABA. We also confirmed that a sizable number of GABA-positive neurons were not immunoreactive with the plasma. Many of these single-labeled GABAergic neurons were located in the deep layers of the cortex. Because only a subset of GABA-positive neurons was labeled by autoantibody-containing plasma, we wanted to get a sense of which populations of GABAergic neurons were being labeled. While it was beyond the scope of the current paper to do an exhaustive, quantitative analysis with double-labeling, we did double-label sections through area V1 with plasma and antibodies directed against the calcium-binding proteins calbindin, parvalbumin and calretinin. We determined that plasma-labeled cells were not exclusively labeled by any one of these proteins expressed in GABAergic neurons. Rather, it appears that the immunoreactive cells were most commonly labeled by calbindin, but not all calbindin-labeled cells were labeled by the autoantibodies (Figures 4A to 4C). Autoantibody-labeled cells less commonly expressed parvalbumin (Figures 4D to 4F), and labeling with calretinin in plasma-labeled cells was rare (Figures 4G to 4I).

Bottom Line: Autoantibody-positive cells rarely expressed calretinin.Some cell populations stained in the primate (such as the Golgi neurons in the cerebellum) were not as robustly immunoreactive in the mouse brain.Further, these findings confirm the autoantibody-targeted cells to be a subpopulation of GABAergic interneurons.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, 451 Health Sciences Drive, Suite 6510 GBSF, Davis, CA 95616, USA. javandewater@ucdavis.edu.

ABSTRACT

Background: Autism is a neurodevelopmental disorder characterized by impairments in social interaction and deficits in verbal and nonverbal communication, together with the presence of repetitive behaviors or a limited repertoire of activities and interests. The causes of autism are currently unclear. In a previous study, we determined that 21% of children with autism have plasma autoantibodies that are immunoreactive with a population of neurons in the cerebellum that appear to be Golgi cells, which are GABAergic interneurons.

Methods: We have extended this analysis by examining plasma immunoreactivity in the remainder of the brain. To determine cell specificity, double-labeling studies that included one of the calcium-binding proteins that are commonly colocalized in GABAergic neurons (calbindin, parvalbumin or calretinin) were also carried out to determine which GABAergic neurons are immunoreactive. Coronal sections through the rostrocaudal extent of the macaque monkey brain were reacted with plasma from each of seven individuals with autism who had previously demonstrated positive Golgi cell staining, as well as six negative controls. In addition, brain sections from adult male mice were similarly examined.

Results: In each case, specific staining was observed for neurons that had the morphological appearance of interneurons. By double-labeling sections with plasma and with antibodies directed against γ-aminobutyric acid (GABA), we determined that all autoantibody-positive neurons were GABAergic. However, not all GABAergic neurons were autoantibody-positive. Calbindin was colabeled in several of the autoantibody-labeled cells, while parvalbumin colabeling was less frequently observed. Autoantibody-positive cells rarely expressed calretinin. Sections from the mouse brain processed similarly to the primate sections also demonstrated immunoreactivity to interneurons distributed throughout the neocortex and many subcortical regions. Some cell populations stained in the primate (such as the Golgi neurons in the cerebellum) were not as robustly immunoreactive in the mouse brain.

Conclusions: These results suggest that the earlier report of autoantibody immunoreactivity to specific cells in the cerebellum extend to other regions of the brain. Further, these findings confirm the autoantibody-targeted cells to be a subpopulation of GABAergic interneurons. The potential impact of these autoantibodies on GABAergic disruption with respect to the etiology of autism is discussed herein.

No MeSH data available.


Related in: MedlinePlus