Los autores agradecen al personal del Centro de Medicina e Investigación Comparativa (CCMR) de Dartmouth por su atención experta a los ratones utilizados para estos estudios. El Fondo de Investigación Bornstein financió esta investigación.

Los autores no tienen nada que revelar.

Los métodos para evaluar la composición celular en el compartimento del SNC durante la homeostasis y la enfermedad son esenciales para comprender los estados fisiológicos y patológicos del SNC. Sin embargo, a pesar de servir como una barrera importante en el SNC y albergar una amplia gama de células inmunitarias, las meninges a menudo se omiten del análisis porque muchos métodos convencionales de extracción de tejidos para el cerebro y la médula espinal no permiten la recolección de estas membranas. Esta omisi?...

El sistema nervioso central (SNC) es un sitio inmunológicamente especializado. El parénquima del SNC, excluyendo el espacio LCR, las meninges y la vasculatura, es considerado clásicamente como un sitio inmunoprivilegiado 1,2,3,4,5 y está relativamente desprovisto de células inmunitarias durante las condiciones homeostáticas 2,6,7. Por el contrario, las meninges, compuestas por las capas duramadre, aracnoidea y pia, son componentes cruciales del compartimento del SNC, participando activamente en la vigilancia inmunitaria homeostática y en los procesos inflamatorios durante la patogénesis de la enfermedad 3,6,7,8. Durante las condiciones de estado estacionario, las meninges albergan numerosas células centinela inmunitarias, incluidas las células linfoides innatas (ILC), los macrófagos, las células dendríticas (DC), los mastocitos, las células T y, en menor medida, las células B 9,10,11.
Las meninges son estructuras altamente vascularizadas y contienen vasos linfáticos que proporcionan una conexión linfática entre el SNC y su periferia 8,12,13,14. En las afecciones inflamatorias inducidas por lesiones del SNC, infecciones, autoinmunidad o incluso neurodegeneración, las células inmunitarias de origen periférico se infiltran en el parénquima y alteran el paisaje inmunitario dentro de las meninges. Después de la infiltración celular, las meninges pueden representar un nicho funcional para las células inmunitarias derivadas periféricamente, promoviendo la agregación de células inmunitarias, la activación local de las células inmunitarias y la supervivencia a largo plazo en el compartimento del SNC. La inflamación meníngea prominente se observa en múltiples enfermedades que afectan al SNC, incluyendo la esclerosis múltiple (EM)15,16,17,18,19, el accidente cerebrovascular 20,21, la lesión estéril 22,23 (es decir, la lesión de la médula espinal y la lesión cerebral traumática), las migrañas 24 y la infección microbiana 25,26,27,28,29. Por lo tanto, la caracterización de las células residentes y las células inmunitarias derivadas periféricamente en el compartimento meníngeo es esencial para comprender el papel de estas células durante las condiciones de estado estacionario y la patogénesis de la enfermedad.
La extracción del cerebro, la médula espinal y las meninges del cráneo y los cuerpos vertebrales es técnicamente difícil y requiere mucho tiempo. Actualmente no existen técnicas disponibles para la extracción rápida del cerebro con las tres capas meníngeas intactas. Si bien la laminectomía produce una excelente morfología del tejido de la médula espinal y preserva las capas meníngeas, requiere mucho tiempo y es extremadamente complicada30,31. Por el contrario, los métodos de extracción más convencionales, como la extirpación del cerebro del cráneo y la extrusión hidráulica de la médula espinal, facilitan la extracción rápida del tejido del SNC, pero con estas técnicas se pierden tanto las meninges aracnoideas como las durales30,31. La omisión de las capas duramadre y aracnoidea durante el aislamiento convencional de los tejidos del cerebro y la médula espinal da lugar a un análisis incompleto de las células dentro del compartimento del SNC. Por lo tanto, la identificación de nuevas técnicas enfocadas a la extracción rápida de tejidos del SNC con meninges intactas es crucial para el análisis óptimo del compartimento del SNC.
Este manuscrito presenta dos métodos para la extracción rápida del cerebro, la médula espinal y las meninges de ratones, lo que facilita el análisis posterior de las células residentes y las células inmunitarias derivadas periféricamente en el parénquima y las meninges del SNC. Estos protocolos optimizados se centran en 1) aislar suspensiones unicelulares para el análisis posterior y 2) preparar el tejido para el procesamiento histológico. La obtención de suspensiones unicelulares del cerebro, del tejido de la médula espinal y de las meninges durales y aracnoideas32 permite el análisis simultáneo de las células que residen en los compartimentos parenquimatoso y meníngeo. Las suspensiones unicelulares se pueden utilizar en diferentes aplicaciones, incluidos los ensayos de cultivo celular para realizar estimulación in vitro 33, inmunopunto ligado a enzimas (ELISpot)28,34,35, citometría de flujo36,33 y transcriptómica de una sola célula 37 o a granel. Además, el protocolo optimizado para la descalcificación de cerebros enteros y médula espinal con cráneos o columnas vertebrales intactos, respectivamente, permite la descalcificación suave del hueso circundante, dejando las meninges intactas y preservando la morfología del tejido. Este método permite la identificación selectiva de proteínas o ARN mediante técnicas de inmunohistoquímica (IHQ) o hibridación in situ (ISH) tanto en el espacio parenquimatoso como en el meníngeo. La caracterización del fenotipo, el estado de activación y la localización de las células residentes y las células inmunitarias derivadas periféricamente dentro del SNC puede proporcionar información esencial para comprender cómo los tipos de células individuales en el compartimento del SNC contribuyen a la homeostasis y la patogénesis de la enfermedad.

<table>
	<tbody>
		<tr>
			<td>Aluminum foil</td>
			<td>any</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin</td>
			<td>ThermoFisher Scientific</td>
			<td>37002D</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Beckman Coulter</td>
			<td>Allegra X-12R centrifuge</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagenase I</td>
			<td>Worthington</td>
			<td>LS004196</td>
			<td></td>
		</tr>
		<tr>
			<td>Conical tube, 15 mL</td>
			<td>VWR</td>
			<td>525-1069</td>
			<td></td>
		</tr>
		<tr>
			<td>Conical tube, 50 mL</td>
			<td>VWR</td>
			<td>89039-658</td>
			<td></td>
		</tr>
		<tr>
			<td>Cover glass</td>
			<td>Hauser Scientific</td>
			<td>5000</td>
			<td></td>
		</tr>
		<tr>
			<td>Cryomold</td>
			<td>VWR</td>
			<td>18000-128</td>
			<td></td>
		</tr>
		<tr>
			<td>Curved forceps</td>
			<td>Fine Science Tools</td>
			<td>11003-14</td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable polystyrene tube, 14 mL</td>
			<td>Fisher Scientific</td>
			<td>14-959-1B</td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable Scalpel</td>
			<td>Fisher Scientific</td>
			<td>NC0595256</td>
			<td></td>
		</tr>
		<tr>
			<td>DNAse I</td>
			<td>Worthington</td>
			<td>LS002139</td>
			<td></td>
		</tr>
		<tr>
			<td>Dry ice</td>
			<td>Airgas</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Durmont #7Forceps</td>
			<td>Fine Science Tools</td>
			<td>11271-30</td>
			<td></td>
		</tr>
		<tr>
			<td>EDTA disodium salt dihydrate</td>
			<td>Amresco</td>
			<td>0105-500g</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol, 100%</td>
			<td>any</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS)</td>
			<td>Hyclone</td>
			<td>SH30910.03</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter top tube, 5 mL</td>
			<td>VWR</td>
			<td>352235</td>
			<td></td>
		</tr>
		<tr>
			<td>Fixable viability stain 780</td>
			<td>Becton Dickinson</td>
			<td>565388</td>
			<td></td>
		</tr>
		<tr>
			<td>Flow cytometer</td>
			<td>Beckman Coulter</td>
			<td>Gallios</td>
			<td></td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Fisher Chemical</td>
			<td>D16-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-mouse IgG (488 conjugate)</td>
			<td>Jackson immunoresearch</td>
			<td>115-546-146</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-mouse IgG (594 conjugate)</td>
			<td>Jackson immunoresearch</td>
			<td>115-586-146</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-rabbit 488</td>
			<td>Jackson immunoresearch</td>
			<td>111-545-144</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-rat 594</td>
			<td>Jackson immunoresearch</td>
			<td>112-585-167</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-rat 650</td>
			<td>Jackson immunoresearch</td>
			<td>112-605-167</td>
			<td></td>
		</tr>
		<tr>
			<td>Hank&#39;s Balnced Salt Solution (HBSS)</td>
			<td>Corning</td>
			<td>21-020-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Hemacytometer</td>
			<td>Andwin Scientific</td>
			<td>02-671-51B</td>
			<td></td>
		</tr>
		<tr>
			<td>Hemostat</td>
			<td>Fine Science Tools</td>
			<td>13004-14</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES (N-2-hydroxyethylpiperazine-N-2-ethane sulfonic acid)</td>
			<td>ThermoFisher Scientific</td>
			<td>15630080</td>
			<td></td>
		</tr>
		<tr>
			<td>KCl</td>
			<td>Fisher chemical</td>
			<td>BP366-500</td>
			<td></td>
		</tr>
		<tr>
			<td>KH2PO4 (anhydrous)</td>
			<td>Sigma Aldrich</td>
			<td>P5655-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Liquid Nitrogen</td>
			<td>Airgas</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse FC block (CD16/32)</td>
			<td>Becton Dickinson</td>
			<td>553141</td>
			<td></td>
		</tr>
		<tr>
			<td>Na2HP04 (anhydrous)</td>
			<td>Fisher Chemical</td>
			<td>S374-500</td>
			<td></td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Fisher chemical</td>
			<td>S671-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Needle, 25 gauge</td>
			<td>Becton Dickinson</td>
			<td>305122</td>
			<td></td>
		</tr>
		<tr>
			<td>Normal mouse serum</td>
			<td>ThermoFisher Scientific</td>
			<td>31881</td>
			<td></td>
		</tr>
		<tr>
			<td>Nylon mesh strainer</td>
			<td>VWR</td>
			<td>352350</td>
			<td></td>
		</tr>
		<tr>
			<td>OCT</td>
			<td>Sakura</td>
			<td>4583</td>
			<td></td>
		</tr>
		<tr>
			<td>Paraformaldehyde, 20%</td>
			<td>Electron Microscopy Sciences</td>
			<td>15713-S</td>
			<td>Diluted to 4% using 1 x PBS</td>
		</tr>
		<tr>
			<td>Pasteur pipette, 9 inch, unplugged</td>
			<td>Fisher Scientific</td>
			<td>13-678-20C</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS (1x)</td>
			<td>Corning</td>
			<td>21-040-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>PE Rat Anti-Mouse CD4</td>
			<td>Becton Dickinson</td>
			<td>553730</td>
			<td></td>
		</tr>
		<tr>
			<td>PE-CF594 Rat Anti-Mouse CD19</td>
			<td>Becton Dickinson</td>
			<td>562329</td>
			<td></td>
		</tr>
		<tr>
			<td>Percoll density gradient media</td>
			<td>GE healthcare</td>
			<td>17-0891-01</td>
			<td></td>
		</tr>
		<tr>
			<td>PerCP-Cy5.5 Rat Anti-Mouse CD45</td>
			<td>Becton Dickinson</td>
			<td>550994</td>
			<td></td>
		</tr>
		<tr>
			<td>Petri dish, 100 mm</td>
			<td>VWR</td>
			<td>353003</td>
			<td></td>
		</tr>
		<tr>
			<td>pH meter</td>
			<td>Fisher Scientific</td>
			<td>13-636-AB150</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipet-Aid</td>
			<td>Drummond Scientific Corporation</td>
			<td>4-000-101</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipette 200 &#181;l</td>
			<td>Gilson</td>
			<td>FA10005M</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipette tips, 1 mL</td>
			<td>USA Scientific</td>
			<td>1111-2831</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipette tips, 200 &#181;l</td>
			<td>USA Scientific</td>
			<td>1111-1816</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipette, 1 mL</td>
			<td>Gilson</td>
			<td>FA10006M</td>
			<td></td>
		</tr>
		<tr>
			<td>Prolong Diamond mountant with DAPI</td>
			<td>ThermoFisher Scientific</td>
			<td>P36962</td>
			<td></td>
		</tr>
		<tr>
			<td>Purified Rat Anti-Mouse CD16/CD32</td>
			<td>Becton Dickinson</td>
			<td>553141</td>
			<td></td>
		</tr>
		<tr>
			<td>Rabbit anti-mouse CD3 (SP7 clone)</td>
			<td>Abcam</td>
			<td>ab16669</td>
			<td></td>
		</tr>
		<tr>
			<td>Rabbit anti-mouse laminin</td>
			<td>Abcam</td>
			<td>ab11575</td>
			<td></td>
		</tr>
		<tr>
			<td>Rat anti-mouse ERT-R7</td>
			<td>Abcam</td>
			<td>ab51824</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI 1640</td>
			<td>Corning</td>
			<td>10-040-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Serological pipet, 1 mL</td>
			<td>VWR</td>
			<td>357521</td>
			<td></td>
		</tr>
		<tr>
			<td>Serological pipet, 10 mL</td>
			<td>VWR</td>
			<td>357551</td>
			<td></td>
		</tr>
		<tr>
			<td>Serological pipet, 5 mL</td>
			<td>VWR</td>
			<td>357543</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium hydroxide</td>
			<td>Fisher Scientific</td>
			<td>S318-100</td>
			<td></td>
		</tr>
		<tr>
			<td>Sucrose</td>
			<td>Fisher chemical</td>
			<td>S5-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical scissors</td>
			<td>Fine Science Tools</td>
			<td>14001-16</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical scissors, extra fine</td>
			<td>Roboz</td>
			<td>RS-5882</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe, 10 mL</td>
			<td>Becton Dickinson</td>
			<td>302995</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe, 5 mL</td>
			<td>Becton Dickinson</td>
			<td>309646</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypan blue</td>
			<td>Gibco</td>
			<td>15250-061</td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum filter system</td>
			<td>Millipore</td>
			<td>20207749</td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum flask</td>
			<td>Thomas Scientific</td>
			<td>5340-2L</td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum in-line filter</td>
			<td>Pall Corporation</td>
			<td>4402</td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum line</td>
			<td>Cole Palmer</td>
			<td>EW-06414-20</td>
			<td></td>
		</tr>
		<tr>
			<td>Water bath</td>
			<td>ThermoFisher Scientific</td>
			<td>Versa bath</td>
			<td></td>
		</tr>
	</tbody>
</table>

isolating central nervous system tissues and associated meninges for the downstream analysis of immune cells

El sistema nervioso central (SNC) está compuesto por el cerebro y la médula espinal y está envuelto por las meninges, capas membranosas que sirven como barrera entre la periferia y el SNC. El SNC es un sitio inmunológicamente especializado y, en condiciones de estado estacionario, el privilegio inmunitario es más evidente en el parénquima del SNC. Por el contrario, las meninges albergan una amplia gama de células residentes, incluidas las células inmunitarias innatas y adaptativas. Durante las afecciones inflamatorias desencadenadas por una lesión del SNC, la autoinmunidad, la infección o incluso la neurodegeneración, las células inmunitarias de origen periférico pueden entrar en el parénquima y residir dentro de las meninges. Se cree que estas células realizan acciones beneficiosas y perjudiciales durante la patogénesis de la enfermedad del SNC. A pesar de este conocimiento, las meninges a menudo se pasan por alto cuando se analiza el compartimento del SNC, porque los métodos convencionales de extracción de tejido del SNC omiten las capas meníngeas. Este protocolo presenta dos métodos distintos para el aislamiento rápido de tejidos murinos del SNC (es decir, cerebro, médula espinal y meninges) que son adecuados para el análisis posterior mediante técnicas unicelulares, inmunohistoquímica y métodos de hibridación in situ. Los métodos descritos proporcionan un análisis exhaustivo de los tejidos del SNC, ideal para evaluar el fenotipo, la función y la localización de las células que ocupan el compartimento del SNC en condiciones homeostáticas y durante la patogénesis de la enfermedad.

Este experimento representativo tuvo como objetivo cuantificar las células B y T y describir la localización de las células B y T en los compartimentos meníngeo y parenquimatoso del SNC en condiciones homeostáticas, así como en un modelo de EM progresiva murina (es decir, TMEV-IDD). La TMEV-IDD fue inducida en ratones hembra SJL de 5 semanas de edad mediante infección intracraneal con 5 x 106 unidades formadoras de placa (UFP) de TMEV BeAn como se describió anteriormente29.
...

Watch this Scientific Journal Video about Isolating Central Nervous System Tissues and Associated Meninges for the Downstream Analysis of Immune cells at JoVE.com

Isolating Central Nervous System Tissues and Associated Meninges for the Downstream Analysis of Immune cells

Este artículo presenta dos protocolos optimizados para examinar las células inmunitarias residentes y derivadas periféricas dentro del sistema nervioso central, incluyendo el cerebro, la médula espinal y las meninges. Cada uno de estos protocolos ayuda a determinar la función y composición de las células que ocupan estos compartimentos en estado estacionario y en condiciones inflamatorias.

Aislamiento de tejidos del sistema nervioso central y meninges asociadas para el análisis posterior de las células inmunitarias

The central nervous system (CNS) is comprised of the brain and spinal cord and is enveloped by the meninges, membranous layers serving as a barrier ...

isolating-central-nervous-system-tissues-associated-meninges-for

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JoVE Journal

Immunology and Infection

8.8K vistas.  Dartmouth-Hitchcock Medical Center. Este artículo presenta dos protocolos optimizados para examinar las células inmunitarias residentes y derivadas periféricas dentro del sistema nervioso central, incluyendo el cerebro, la médula espinal y las meninges. Cada uno de estos protocolos ayuda a determinar la función y composición de las células que ocupan estos compartimentos en estado estacionario y en condiciones inflamatorias.

Video: Isolating Central Nervous System Tissues and Associated Meninges for the Downstream Analysis of Immune cells

Flow Cytometry Analysis of Immune Cells Within Murine Aortas

Atherosclerosis is a chronic inflammatory process of medium and large size vessels that is characterized by the formation of plaques consisting of foam cells, immune cells, vascular endothelial and smooth muscle cells, platelets, extracellular matrix, and a lipid-rich core with extensive necrosis and fibrosis of surrounding tissues.1 The innate and adaptive arms of the immune response are involved in the initiation, development and persistence of atherosclerosis.2, 3 There is a significant body of evidence that different subsets of the immune cells, such as macrophages, dendritic cells, T and B lymphocytes, are present within the aortas of healthy and atherosclerosis-prone mice4. Additionally, immune cells are found in the surrounding aortic adventitia which suggests an important role of this tissue in atherogenesis.2
For some time, the quantitative detection of different types of immune cells, their activation status, and the cellular composition within the aortic wall was limited by RT-PCR and immunohistochemical methods for the study of atherosclerosis. Few attempts were made to perform flow cytometry using human aortas, and a number of problems, such as a high autofluorescence, have been reported5,6. Human atherosclerotic plaques were digested with collagenase 1, and free cells were collected and stained for CD14+/CD11c+ to highlight macrophage-derived foam cells. In this study, a "mock" channel was used to avoid false-positive staining.6 Necrotic materials accumulating during the digestion process give rise in a large amount of debris that generates a high autofluorescence in aortic samples. To resolve this problem, a panel of negative and positive controls has been proposed, but only double staining could be applied in these samples. We have developed a new flow cytometry-based method7 to analyze the immune cell composition and characterize the activation, proliferation, differentiation of immune cells in healthy and atherosclerosis-prone aorta. This method allows the investigation of the immune cell composition of the aortic wall and opens possibilities to use a broad spectrum of immunological methods for investigations of immune aspects of this disease.

This paper presents a flow cytometry-based method to investigate the immune composition of aortas. The paper also illustrates an additional technique that allows examining surrounding adventitia and vessel wall separately. This method opens possibilities to perform phenotypical analyses of aortic leukocytes and apply several immunological assays for atherosclerosis studies.

Análisis por citometría de flujo de células inmunes dentro de aortas murino

Atherosclerosis is a chronic inflammatory process of medium and large size vessels that is characterized by the formation of plaques consisting of foam ...

Investigación

Inmunología e Infección

Culturing Microglia from the Neonatal and Adult Central Nervous System

Microglia are the resident macrophage-like cells of the central nervous system (CNS) and, as such, have critically important roles in physiological and pathological processes such as CNS maturation in development, multiple sclerosis, and spinal cord injury. Microglia can be activated and recruited to action by neuronal injury or stimulation, such as axonal damage seen in MS or ischemic brain trauma resulting from stroke. These immunocompetent members of the CNS are also thought to have roles in synaptic plasticity under non-pathological conditions. We employ protocols for culturing microglia from the neonatal and adult tissues that are aimed to maximize the viable cell numbers while minimizing confounding variables, such as the presence of other CNS cell types and cell culture debris. We utilize large and easily discernable CNS components (e.g. cortex, spinal cord segments), which makes the entire process feasible and reproducible. The use of adult cells is a suitable alternative to the use of neonatal brain microglia, as many pathologies studied mainly affect the postnatal spinal cord. These culture systems are also useful for directly testing the effect of compounds that may either inhibit or promote microglial activation. Since microglial activation can shape the outcomes of disease in the adult CNS, there is a need for in vitro systems in which neonatal and adult microglia can be cultured and studied.

We outline methods for the efficient and quick isolation/culture of viable microglia from the neonatal cerebral cortex and adult spinal cord. The dissection and plating of cortical microglia can be accomplished within 90 minutes, with the subsequent microglial harvest taking place ~ 10 days following the initial dissection.

Microglia cultivo del Sistema Nervioso Central Neonatal y Adultos

Microglia are the resident macrophage-like cells of the central nervous system (CNS) and, as such, have critically important roles in physiological and ...

Isolation and Flow Cytometric Analysis of Immune Cells from the Ischemic Mouse Brain

Ischemic stroke initiates a robust inflammatory response that starts in the intravascular compartment and involves rapid activation of brain resident cells. A key mechanism of this inflammatory response is the migration of circulating immune cells to the ischemic brain facilitated by chemokine release and increased endothelial adhesion molecule expression. Brain-invading leukocytes are well-known contributing to early-stage secondary ischemic injury, but their significance for the termination of inflammation and later brain repair has only recently been noticed.
Here, a simple protocol for the efficient isolation of immune cells from the ischemic mouse brain is provided. After transcardial perfusion, brain hemispheres are dissected and mechanically dissociated. Enzymatic digestion with Liberase&#160;is followed by density gradient (such as Percoll) centrifugation to remove myelin and cell debris. One major advantage of this protocol is the single-layer density gradient procedure which does not require time-consuming preparation of gradients and can be reliably performed. The approach yields highly reproducible cell counts per brain hemisphere and allows for measuring several flow cytometry panels in one biological replicate. Phenotypic characterization and quantification of brain-invading leukocytes after experimental stroke may contribute to a better understanding of their multifaceted roles in ischemic injury and repair.

Inflammation plays a central role in the pathogenesis of ischemic stroke. Increasing evidence suggests that it acts as a double-edged sword which exacerbates early brain injury, but also contributes to later repair. This protocol describes the isolation of immune cells from the ischemic brain and their subsequent flow cytometric phenotyping.

Aislamiento y análisis de citometría de flujo de células inmunes del cerebro isquémico Ratón

Ischemic stroke initiates a robust inflammatory response that starts in the intravascular compartment and involves rapid activation of brain resident ...

Induction of Experimental Autoimmune Encephalomyelitis in Mice and Evaluation of the Disease-dependent Distribution of Immune Cells in Various Tissues

Multiple sclerosis is presumed to be an inflammatory autoimmune disease, which is characterized by lesion formation in the central nervous system (CNS) resulting in cognitive and motor impairment. Experimental autoimmune encephalomyelitis (EAE) is a useful animal model of MS, because it is also characterized by lesion formation in the CNS, motor impairment and is also driven by autoimmune and inflammatory reactions. One of the EAE models is induced with a peptide derived from the myelin oligodendrocyte protein (MOG)35-55 in mice. The EAE mice develop a progressive disease course. This course is divided into three phases: the preclinical phase (day 0 - 9), the disease onset (day 10 - 11) and the acute phase (day 12 - 14). MS and EAE are induced by autoreactive T cells that infiltrate the CNS. These T cells secrete chemokines and cytokines which lead to the recruitment of further immune cells. Therefore, the immune cell distribution in the spinal cord during the three disease phases was investigated. To highlight the time point of the disease at which the activation/proliferation/accumulation of T cells, B cells and monocytes starts, the immune cell distribution in lymph nodes, spleen and blood was also assessed. Furthermore, the levels of several cytokines (IL-1&#946;, IL-6, IL-23, TNF&#945;, IFN&#947;) in the three disease phases were determined, to gain insight into the inflammatory processes of the disease. In conclusion, the data provide an overview of the functional profile of immune cells during EAE pathology.

This manuscript describes the methods for induction and scoring of the experimental autoimmune encephalomyelitis (EAE) model, together with the assessment of immune cell distribution and mRNA cytokine levels in lymph nodes, spleen, blood and spinal cord using flow cytometry and quantitative PCR, respectively, at various disease phases.

La inducción de la encefalomielitis autoinmune experimental en ratones y evaluación de la distribución de la enfermedad dependiente de las células inmunes en diversos tejidos

Multiple sclerosis is presumed to be an inflammatory autoimmune disease, which is characterized by lesion formation in the central nervous system (CNS) ...

Qualitative and Quantitative Analysis of the Immune Synapse in the Human System Using Imaging Flow Cytometry

The immune synapse is the area of communication between T cells and antigen-presenting cells (APCs). T cells polarize surface receptors and proteins towards the immune synapse to assure a stable binding and signal exchange. Classical confocal, TIRF, or super-resolution microscopy have been used to study the immune synapse. Since these methods require manual image acquisition and time-consuming quantification, the imaging of rare events is challenging. Here, we describe a workflow that enables the morphological analysis of tens of thousands of cells. Immune synapses are induced between primary human T cells in pan-leukocyte preparations and Staphylococcus aureus enterotoxin B (SEB)-loaded Raji cells as APCs. Image acquisition is performed with imaging flow cytometry, also called In-Flow microscopy, which combines features of a flow cytometer and a fluorescence microscope. A complete gating strategy for identifying T cell/APC couples and analyzing the immune synapses is provided. As this workflow allows the analysis of immune synapses in unpurified pan-leukocyte preparations and hence requires only a small volume of blood (i.e., 1 mL), it can be applied to samples from patients. Importantly, several samples can be prepared, measured, and analyzed in parallel.

Here, we describe a complete workflow for the qualitative and quantitative analysis of immune synapses between primary human T cells and antigen-presenting cells. The method is based on imaging flow cytometry, which allows the acquisition and evaluation of several thousand cell images within a relatively short period of time.

Análisis cualitativo y cuantitativo de la sinapsis inmune en el sistema humano utilizando imágenes de citometría de flujo

The immune synapse is the area of communication between T cells and antigen-presenting cells (APCs). T cells polarize surface receptors and proteins ...

Analysis of Microglia and Monocyte-derived Macrophages from the Central Nervous System by Flow Cytometry

Numerous studies have demonstrated the role of immune cells, in particular macrophages, in central nervous system (CNS) pathologies. There are two main macrophage populations in the CNS: (i) the microglia, which are the resident macrophages of the CNS and are derived from yolk sac progenitors during embryogenesis, and (ii) the monocyte-derived macrophages (MDM), which can infiltrate the CNS during disease and are derived from bone marrow progenitors. The roles of each macrophage subpopulation differ depending on the pathology being studied. Furthermore, there is no consensus on the histological markers or the distinguishing criteria used for these macrophage subpopulations. However, the analysis of the expression profiles of the CD11b and CD45 markers by flow cytometry allows us to distinguish the microglia (CD11b+CD45med) from the MDM (CD11b+CD45high). In this protocol, we show that the density gradient centrifugation and the flow cytometry analysis can be used to characterize these CNS macrophage subpopulations, and to study several markers of interest expressed by these cells as we recently published. Thus, this technique can further our understanding of the role of macrophages in mouse models of neurological diseases and can also be used to evaluate drug effects on these cells.

This protocol provides an analysis of the macrophage subpopulations in the adult mouse central nervous system by flow cytometry and is helpful for the study of multiple markers expressed by these cells.

Análisis de microglia y macrófagos derivados de monocitos del sistema nervioso central por citometría de flujo

Numerous studies have demonstrated the role of immune cells, in particular macrophages, in central nervous system (CNS) pathologies. There are two main ...

Isolating Lymphocytes from the Mouse Small Intestinal Immune System

The intestinal immune system plays an essential role in maintaining the barrier function of the gastrointestinal tract by generating tolerant responses to dietary antigens and commensal bacteria while mounting effective immune responses to enteropathogenic microbes. In addition, it has become clear that local intestinal immunity has a profound impact on distant and systemic immunity. Therefore, it is important to study how an intestinal immune response is induced and what the immunologic outcome of the response is. Here, a detailed protocol is described for the isolation of lymphocytes from small intestine inductive sites like the gut-associated lymphoid tissue Peyer&#39;s patches and the draining mesenteric lymph nodes and effector sites like the lamina propria and the intestinal epithelium. This technique ensures isolation of a large numbers of lymphocytes from small intestinal tissues with optimal purity and viability and minimal cross compartmental contamination within acceptable time constraints. The technical capability to isolate lymphocytes and other immune cells from intestinal tissues enables the understanding of immune responses to gastrointestinal infections, cancers, and inflammatory diseases.

Here we describe a detailed protocol for the isolation of lymphocytes from the inductive sites including the gut-associated lymphoid tissue Peyer&#39;s patches and the draining mesenteric lymph nodes, and the effector sites including the lamina propria and the intestinal epithelium of the small intestinal immune system.

Aislar los linfocitos desde el sistema de inmune Intestinal pequeño ratón

The intestinal immune system plays an essential role in maintaining the barrier function of the gastrointestinal tract by generating tolerant responses to ...

A Positioning Device for the Placement of Mice During Intranasal siRNA Delivery to the Central Nervous System

Intranasal (IN) drug delivery to the brain has emerged as a promising method to bypass the blood-brain barrier (BBB) for the delivery of drugs into the central nervous system (CNS). Recent studies demonstrate the use of a peptide, RVG9R, incorporating the minimal receptor-binding domain of the Rabies virus glycoprotein, in eliciting the delivery of siRNA into neurons in the brain. In this protocol, the peptide-siRNA formulation is delivered intranasally with a pipette in the dominant hand, while the anesthetized mouse is restrained by the scruff with the nondominant hand in a "head down-and-forward position" to avoid drainage into the lung and stomach upon inhalation. This precise gripping of mice can be learned but is not easy and requires practice and skill to result in effective CNS uptake. Furthermore, the process is long-drawn, requiring about 45 min for the administration of a total volume of ~20-30 &#181;L of solution in 1-2 &#181;L droplet volumes per inhalation, with 3-4 min rest periods between each inhalation. The objective of this study is to disclose a mouse positioning device that enables the appropriate placement of mice for efficient IN administration of the peptide-siRNA formulation. Multiple features are incorporated into the design of the device, such as four or eight positioning chairs with adjustable height and tilt to restrain anesthetized mice in the head down-and-forward position, enabling easy visualization of the mice's nares and a built-in heating pad to maintain the mice's body temperatures during the procedure. Importantly, the ability to treat four or eight mice simultaneously with RVG9R-siRNA complexes in this manner enables studies on a much quicker time scale, for the testing of an IN therapeutic siRNA approach. In conclusion, this device allows for appropriate and controlled mouse head positioning for IN application of RVG9R-siRNA and other therapeutic molecules, such as nanoparticles or antibodies, for CNS delivery.

Here, we present a protocol using a mouse positioning device that enables the appropriate placement of mice for the intranasal administration of a brain-targeting peptide-siRNA formulation enabling effective gene silencing in the central nervous system.

Un dispositivo de posicionamiento para la colocación de ratones durante la entrega de siRNA intranasal al sistema nervioso central

Intranasal (IN) drug delivery to the brain has emerged as a promising method to bypass the blood-brain barrier (BBB) for the delivery of drugs into the ...

Flow Cytometric Analysis of Lymphocyte Infiltration in Central Nervous System during Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) caused by the combination of environmental factors and susceptible genetic background. Experimental autoimmune encephalomyelitis (EAE) is a typical disease model of MS widely used for investigating the pathogenesis in which T lymphocytes specific for myelin antigens initiate an inflammatory reaction in CNS. It is very important to assess how lymphocytes in the CNS regulate the development of disease. However, the approach for measuring the quantity and quality of infiltrated lymphocytes in the CNS is very limited due to the difficulties in isolating and detecting infiltrated lymphocytes from the brain. This manuscript presents a protocol for that is useful for the isolation, identification, and characterization of infiltrated lymphocytes from the CNS and will be helpful for our understanding of how lymphocytes are involved in the development of the CNS autoimmune disease.

This manuscript presents a protocol to induce active experimental autoimmune encephalomyelitis (EAE) in mice. A method for the isolation and characterization of the infiltrated lymphocytes in the central nervous system (CNS) is also presented to show how lymphocytes are involved in the development of CNS autoimmune disease.

Análisis citométrico de flujo de infiltración de linfocitos en el sistema nervioso central durante la encefalomielitis autoinmune experimental

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) caused by the combination of environmental factors and susceptible ...

Isolation of Mouse Kidney-Resident CD8+ T cells for Flow Cytometry Analysis

Tissue-resident memory T cell (TRM) is a rapidly expanding field of immunology research. Isolating T cells from various non-lymphoid tissues is one of the key steps to investigate TRMs. There are slight variations in lymphocyte isolation protocols for different organs. Kidney is an essential non-lymphoid organ with numerous immune cell infiltration especially after pathogen exposure or autoimmune activation. In recent years, multiple labs including our own have started characterizing kidney resident CD8+ T cells in various physiological and pathological settings in both mouse and human. Due to the abundance of T lymphocytes, kidney represents an attractive model organ to study TRMs in non-mucosal or non-barrier tissues. Here, we will describe a protocol commonly used in TRM-focused labs to isolate CD8+ T cells from mouse kidneys following systemic viral infection. Briefly, using an acute lymphocytic choriomeningitis virus (LCMV) infection model in C57BL/6 mice, we demonstrate intravascular CD8+ T cell labeling, enzymatic digestion, and density gradient centrifugation to isolate and enrich lymphocytes from mouse kidneys to make samples ready for the subsequent flow cytometry analysis.

Isolation of Mouse Kidney-Resident CD8+ T cells for Flow Cytometry Analysis

Following viral infection, kidney harbors a relatively large number of CD8+ T cells and offers an opportunity to study non-mucosal TRM cells. Here, we describe a protocol to isolate mouse kidney lymphocytes for flow cytometry analysis.

Aislamiento de células CD8 + T residentes en el riñón delratón para el análisis de citometría de flujo

Tissue-resident memory T cell (TRM) is a rapidly expanding field of immunology research. Isolating T cells from various non-lymphoid tissues is one of the ...