SHAPE Society

1. HSP-65, An Autoantigen for Plaque Development or
Plaque Vulnerability?
Editorial Slides
VP Watch – December 11, 2002 - Volume 2, Issue 49
Yehuda Shoenfeld, MD
Sheba Medical Center, Tel Hashomer,Israel

2.  A large number of studies
have been reported on
associations of coronary
artery disease (CAD) in
human and certain
persistent bacterial and viral
infections. 1

3.  In 1978, Fabricant et al
showed that experimental
infection of germ-free
chickens with an avian
herpes virus induces arterial
disease that resembles
human atherosclerosis. 2

4. Atherosclerosis as an
Autoimmune Disease
Autoantigens:
- Oxidized LDL
- Heat Shock Protein 65
- β2 Glycoprotein I
- ???

5.  Traditional Framingham
risk factors fail to fully
account for accelerated
atherosclerosis in systemic
lupus erythematosus. 3

6. Criteria Needed to Establish
An Autoimmune Etiology.
Witebsky-Rose criteria 4
It should be possible to:
1. Demonstrate immunological reactivity to a self-antigen.
Characterize or isolate the inciting autoantigen.
2. Induce immunological reactivity against that same antigen by
immunization of experimental animals.
3. Show pathological changes (similar or identical to those
found in human disease) in the appropriate organs/tissues of
an actively-sensitized animal.
4. As in 4 but following passive transfer of auto-Abs or auto-
reactive T cells.

7.  Human heat shock proteins (HSPs)
are expressed on endothelial cells in
response to stressors such as
hypertension, smoking, lipoproteins
- etc. 5
 HSPs offer a target for autoimmunity
under such circumstances. 5

8. Anti-HSP-65 and Atherosclerosis
 Carotid atherosclerosis
 Coronary heart disease
 Myocardial infarction
 Arteriosclerosis
 Coronary angioplasty
 Myocardial infarction

9. Expression Of Heat Shock Protein-
70 By Dendritic Cells
 In early intimal lesions, HSP70 is
over-expressed exclusively by
dendritic cells, which suggests
that dendritic cells might be
involved in the early phases of
atherogenesis. 6

10. T Lymphocytes in atheroma
 20% of the infiltrating inflammatory
cells are T-lymphocytes. 6, 7
 T- lymphocytes are in an
activated state; memory cells,
CD4+ TCRab +. 6, 7

11. Enhanced fatty formation in
C57BL/6J mice by
immunization with heat shock
protein-65
Jacob George, Yehuda Shoenfeld, Arnon
Afek, Boris Gilbourd, Pnina Keren, Aviv
Shaish, Juri Kopolovic, George Wick, Dror
Harats
Arterioscler Thromb Vasc Biol,19:505-
510,1999

14. Cellular and Humoral Immune
Responses to Heat- Shock Protein
65 Are Both Involved In Promoting
Fatty-Streak Formation In LDL-
Receptor Deficient Mice
Jacob George, Aron Afek, Boris Gilburd, Yehuda
Shoenfeld, Dror Harats.
J Am Coll Cardiol 2001; 38: 900-905.
Antibodies and lymphocytes reactive to
HSP65 promote fatty-streak formation in
mice, providing direct evidence for the
proatherogenic properties of cellular and
humoral immunity to HSP65.

15. Adoptive transfer of β2 glycoprotein I (β2GPI)
reactive lymphocytes enhances early
atherosclerosis in LDL-receptor deficient mice
* Lymphocytes obtained from draining LN
(mostly T cells) and splenocytes increased
atherogenesis.
* Deletion of T cells prevented atherogenesis.
* Ultimate evidence for autoimmunity and
immune system in atherosclerosis.
* Importance of T cells in the process.
Jacob George, Dror Harats, Boris Gilburd, Arnon Afek, Aviv Shaish, Juri Kopolovic, Yehuda Shoenfeld.
Circulation 102: 1822 - 1827, 2000.

16. Atherogenesis
Plaque Rupture
Thrombosis
Infection of arterial
wall
- SMC proliferation
associated with p53
inactivation
- Local inflammation
Systemic Infection
– Endothelial dysfunction
due to circulating
endotoxin
Classic risk factors
↓ HDL
Fibrinogen
Triglycerides
Autoimmunity
- HSP60 cross-reactivity
with bacterial antigens
Systemic
inflammation
CRP
Leukocyte count
Cytokines
Adapted from: J. Danesh et al. Chronic
infection and coronary heart
disease: is there a link?. Lancet
350 (1997), pp. 430–436.
Postulated Mechanisms to Link Infections And Vascular Disease

17.  As reported in VP Watch this
week, Lamb et al used a BCG
immunization model to assess the
role of HSP in the association
between infection and CAD. 7

18.  They immunized rabbits with BCG
vaccine (n=10) or saline (n=10) and
subsequently fed a cholesterol diet for 10
weeks. 7
 Plasma IgG specific for mycobacterial
antigen A60 and human HSP-60, but not
for human HSP-70, rose following BCG
immunization, reaching a peak after 8
weeks. 7

19. 0
10
20
30
40
BCG Control
BCG
Control
%aorticareacovered
P<0.05
The percentage aortic area staining positively for oil red O was calculated. Each
point is the mean±SE for seven rabbits. Statistical analysis was performed using
unpaired t-tests. *P<0.05.
*
Effect of BCG immunization on atherosclerosis in thoracic
aorta of cholesterol-fed rabbits
Lamb DJ, Ferns GA. The magnitude of the immune response to heat shock protein-65 following BCG immunization is
associated with the extent of experimental atherosclerosis. Atherosclerosis. 2002 Dec;165(2):231-40.

20.  The percentage aortic area covered by
atherosclerotic plaque was greater in
animals immunized with BCG compared
to controls.7
 The authors did not find any correlation
between anti-A60 antibody titers and
plaque area. 7

21. Conclusion:
 Immunization with an HSP-containing
BCG vaccine, using doses equivalent to
those used for tuberculosis prophylaxis,
has pro-atherogenic consequences in
the cholesterol-fed rabbits.
 This effect may be mediated in part by
immune response directed against
BCG-associated HSP.

22. Questions:
 - Is heat shock protein 65 the main
culprit autoantigen for
atherosclerosis?
 - Knowing the role of HSP-65 in
other autoimmune diseases such as
rheumatoid arthritis, how specific can
HSP-65 be for atherosclerosis?

23. Questions:
 Should we look for a single
specific antigen for
atherosclerosis in all patients?
 Or do different antigens exist in
different patients or even within
the same patient?

24. Questions:
 Do you think that the role of these
autoantigens may vary at different stages of
the disease? Do you think that some may
contribute to plaque development and
others may induce plaque complication?
 Knowing that high LDL is necessary for
atherosclerosis and HSP only enhances
atherosclerosis, is it appropriate to say that
HSP-65 may be more important in plaque
complication (vulnerability) than plaque
generation?

25. 1) J. Danesh, R. Collins and R. Peto , Chronic infection and coronary heart disease: is there a link?. Lancet 350 (1997), pp.
430–436.
2) CG Fabricant, J Fabricant, MM Litrenta and CR Minick, Virus-induced atherosclerosis. J Exp Med 148 (1978), pp. 335–
340.
3) Esdaile JM, et al Arthritis Rheum 2001, 44: 2311-7
4) Krenn V, Souto-Carneiro MM, Kim HJ, Berek C, Starostik P, Konig A, Harms H, Muller-Hermelink HK Histopathology and
molecular pathology of synovial B-lymphocytes in rheumatoid arthritis. Histol Histopathol. 2000 Jul;15(3):791-8. Review.
5) George J, Harats D, Shoenfeld Y.Clin Rev Allergy & Immunol. 18: 73-86, 2000.
6) Bobryshev YV, Lord RS. J Vascular Surgery 35: 368-75, 2002
7) A. Kinnunen et al. Scand J Immunol 2001; 54: 76-81.
8) Lamb DJ, Ferns GA.The magnitude of the immune response to heat shock protein-65 following BCG immunisation is
associated with the extent of experimental atherosclerosis. Atherosclerosis. 2002 Dec;165(2):231-40.
References