Oral tolerance with heat shock protein 65 attenuates Mycobacterium tuberculosis-induced and high-fat-diet-driven atherosclerotic lesions.
OBJECTIVE
The goal of this study was to explore the efficacy of oral tolerance with heat shock protein (HSP) 65 in two apparently non-overlapping models of murine atherosclerosis.


BACKGROUND
Atherosclerosis is considered to be a chronic inflammatory process. Autoimmune mechanisms have been shown to influence atherogenesis in experimental animal models. Heat shock protein 65 is a candidate antigen thought to drive a proatherogenic immune-mediated response. Mucosal tolerance is a therapeutic means of accomplishing immune unresponsiveness toward a given antigen by feeding it before active induction of the disorder.


METHODS
Low-density lipoprotein receptor deficient mice were fed with different doses of HSP65 every other day for 10 days. Feeding with either bovine serum albumin (BSA) or phosphate buffered saline (PBS) served as control. One day after the last feeding, mice were challenged either by immunization with heat killed Mycobacterium tuberculosis or by a high fat diet.


RESULTS
Lymphocyte reactivity from mice fed with HSP65 and immunized either against HSP65 or M. tuberculosis was significantly reduced in comparison with BSA-fed mice. Moreover, co-incubation of splenocytes-from mice with tolerance induced with HSP65 but not BSA-with HSP65-reactive lymphocytes resulted in the suppression of HSP65 reactivity by the latter cells. Interleukin-4 production by HSP65-fed and immunized mice was increased upon priming with respective protein. Early atherosclerosis was attenuated in HSP65-fed mice, compared with either BSA- or PBS-fed mice, regardless of the method employed to induce fatty streaks (M. tuberculosis immunization or high-fat diet).


CONCLUSIONS
Oral tolerance induced with HSP65 could prove to be a novel means of suppressing atherogenesis.
Harats
Dror
D
Institute of Lipid and Atherosclerosis Research, Sheba Medical Center, Tel Hashomer, Israel. dharats@post.tau.ac.il
Yacov
Niva
N
Gilburd
Boris
B
Shoenfeld
Yehuda
Y
George
Jacob
J
D000284:Administration, Oral; D000704:Analysis of Variance; D000818:Animals; D001161:Arteriosclerosis / Q000209:etiology* / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D001327:Autoimmune Diseases / Q000209:etiology* / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D001426:Bacterial Proteins; D018834:Chaperonin 60; D018833:Chaperonins / Q000276:immunology / Q000627:therapeutic use*; D017635:Clonal Anergy / Q000276:immunology; D004036:Diet, Atherogenic; D004195:Disease Models, Animal; D005260:Female; D007108:Immune Tolerance; D018928:Immunity, Mucosal; D007150:Immunohistochemistry; D051379:Mice; D008815:Mice, Inbred Strains; D009169:Mycobacterium tuberculosis / Q000276:immunology; D011973:Receptors, LDL / Q000172:deficiency*; D018418:Th2 Cells / Q000276:immunology
D001426:Bacterial Proteins; D018834:Chaperonin 60; D011973:Receptors, LDL; C074119:heat-shock protein 65, Mycobacterium; D018833:Chaperonins