Inhibitory effect on arterial injuryinduced

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Inhibitory effect on arterial injury-induced neoin
timal formation by adoptive B cell transfer in
Rag-1 KO mice P. Dimayuga, B. Cercek, S. Oguchi,
G. N. Fredrikson, J. Yano, P. K. Shah, S.
Jovinge, J. Nilsson Department of Medicine,
Lund University, University Hospital MAS, Malmö,
Sweden Atherosclerosis Research Center,
Cedars-Sinai Medical Center, Los Angeles,
California Department of Biomedical Laboratory
Science, Health and Society, Malmö University,
Malmö, Sweden
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General Findings

• Immune-deficiency results in increased
  neointimal formation after arterial injury in
  mice.
• Humoral aspects of the immune system may be
  involved in inhibiting neointimal formation
• B cells produce natural antibodies ?

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Background

• T cell deficiency results in increased neointima
  in injured rats (antibodies against T cell CD
  markers and nu/nu rats)
• Hansson, et al PNAS/Circ 1991
• Remskar et al Circ Res. 2001
• CD40-CD40 ligand interaction mediates response to
  arterial injury
• Remskar et al Circ Res. 2001
• B cells implicated in bone-healing response as a
  limiting factor
• Marusic, et al LI 2000
• Homologous oxLDL immunization reduces neointimal
  formation in injured hypercholesterolemic rabbits
• Nilsson et al JACC 1997

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Arterial Injury
Activation of signaling cascades
Increased expression of inflammatory
proteins/ medial SMC activation
Vascular repair and Intimal formation
Immune functions physiologic IFN-g
Immunoglobulins
Immune-deficiency
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• Hypothesis B cells are involved in the response
  to
• arterial injury.
• Methods
• Injure Rag-1 KO mice and compare to WT mice.
• Rescue Rag-1 KO mice with B cell reconstitution
• from spleens of WT
• Repeat rescue with donor and recipients on
  western
• diet

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Arterial Cuff Injury
Tygon tube
Right carotid artery
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Cell enrichment procedure
add paramagnetic beads coated with T cell antibody
harvest spleen from WT mice
squeeze through mesh to isolate cells
expose solution to magnetic field and aspirate
supe negative selection of B cells
classify cell population and/or spin and
concentrate
Inject cells into Rag-1 KO mice via tail vein
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B cell reconstitution inhibits intimal
formation in Rag-1 KO mice fed normal chow
plt0.05 vs. WT NC plt0.05 vs. Rag NC
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B cell reconstitution inhibits intimal
formation in Rag-1 KO mice fed western diet
plt0.05 vs. WT HC plt0.05 vs. Rag HC
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Effect of B cell reconstitution on intimal
formation in injured Rag-1 KO mice
WT HC Rag-KO Rag-1 KO Brec
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Neointimal stain for SM a-actin (western diet-fed
mice)
WT Rag-1 KO Rag-1 KO Brec
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Mf stain in arteries 21 days after
injury (western diet-fed mice)
WT Rag-1 KO Rag-1 KO Brec
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IgM in injured arteries of western diet-fed mice
WT
Left contra-lateral (uninjured) Injured right
carotid artery
Rag-1 KO
No reconstitution B cell reconstituted
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IgG in injured arteries of western diet-fed mice
WT
Left contra-lateral (uninjured) Injured right
carotid artery
Rag-1 KO
No reconstitution B cell
reconstituted
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Relative immunoglobulin levels in B cell
reconstituted mice
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Summary of Study

• Neointimal formation after injury is inhibited in
  Rag-1
• KO mice reconstituted with B cells regardless of
  diet.
• Immunoglobulin presence is increased in injured
• arteries of WT mice and in B cell reconstituted
  Rag-1
• KO mice.