A Feline-specific Blood Brain Barrier

Feline Immunodeficiency Virus

• Lentivirus• Natural infection in

cats worldwide• Induces disease• Animal model of HIV

infection in man

Feline immunodeficiency virus infection- a model of HIV-1 induced encephalitis

• HIV and FIV neurotropic• Early infection of CNS• Neuroinflammation and degeneration• Limited opportunities to study early infection• Requires well-evaluated animal

models» SIV

» FIV

Ryan et al, J Neurovirol 2005

Aims

– To investigate the ability of cell-free & cell-associated FIV to cross the in vitro BBB, and the effect of inflammatory cytokines on this process.

The Blood-Brain Barrier

Blood Vessel

(Made from Endothelial Cells)

Astrocyte

TJs

Assembly of the Blood Brain Barrier Model

Plate

Transwell

Bottom Chamber

Top Chamber

Fletcher et al (2005) Vet Immuno Immunopathol

Assembly of the Blood Brain Barrier Model

Top Chamber (Blood)

Bottom Chamber (Brain)

Endothelial Cells

Astrocytes

Top Chamber (Blood)

Bottom Chamber (Brain)

Endothelial Cells

Astrocytes

FIV-infected T

cells

Top Chamber (Blood)

Bottom Chamber (Brain)

Endothelial Cells

Astrocytes

Top Chamber (Blood)

Bottom Chamber (Brain)

Endothelial Cells

Astrocytes

Top Chamber (Blood)

Bottom Chamber (Brain)

Endothelial Cells

Astrocytes

The effect of cell-free FIV on the feline BBB model

A: Mya-1 apicalB: FIV Mya-1 apicalC: Mya-1 apical; TNF basolateralD: FIV Mya-1 apical; TNF basolateralE: Mya-1 apical; TNF apicalF: FIV Mya-1 apical; TNF apicalG: FIV Mya-1 apical and basolateralH: FIV Mya-1 apical and basolateral; TNF

basolateral

Top Chamber (Blood)

Bottom Chamber (Brain)

EndothelialCells

Astrocytes

FIV-infected T cells

**p<0.05

***p<0.0001

2-tailed Unpaired t testA: Mya-1 apicalB: FIV Mya-1 apicalC: Mya-1 apical; TNF basolateralD: FIV Mya-1 apical; TNF basolateralE: Mya-1 apical; TNF apicalF: FIV Mya-1 apical; TNF apicalG: FIV Mya-1 apical and basolateralH: FIV Mya-1 apical and basolateral; TNF basolateral

Transmigration of Mya-1 cellsacross the in vitro BBB

A B C D E F G H0

25

50

75

100

Tra

nsm

igra

ted

Mya

-1

cell

s (x

104 )

***

*****

******

Permeability of BBB Models toFD-4 following Mya-1

Transmigration

1 2 3 4 5 6 7 80.0×10 -00

5.0×10 -05

1.0×10 -04

1.5×10 -04

Pap

p(c

m/s

)**

**p<0.05

2-tailed unpaired t-test1. BBB2. Mya-1 apical3. Mya-1 apical; TNF basolateral4. FIV Mya-1 apical; TNF basolateral5. Mya-1 apical; TNF apical6. FIV Mya-1 apical; TNF apical7. FIV Mya-1 apical and basolateral8. FIV Mya-1 apical and basolateral; TNF basolateral

Primary Cell Lines

Brain endothelial cells

Astrocytes

Microglia

Histopathological evaluations of tissues from exposure studies