Atherosclerosis Vaccine Using Bacteria Salmonella typhimurium on Rat Models

Aims: To prove the effect of S. typhimurium vaccine on inhibiting foam cell formation and arterial wall thickness, and also to decrease body weight and abdominal visceral fat.
Study Design: This experimental research was conducted using rat models.
Place and Duration of Study: Faculty of Medicine, Brawijaya University, Indonesia, between February – May 2011.
Methodology: The vaccine was 108 CFU of heat-killed S. typhimurium/100µl vaccine per rat. The adjuvant was CFA-IFA 100µl per rat. Twenty Wistar rats were divided into five groups: a negative control group (have normal diet), and four treatment groups which were given with atherogenic diet. The four treatment groups were positive control group (atherogenic diet only), vaccine + adjuvant group (added with the vaccine + adjuvants), vaccine group (added with vaccine only), and adjuvant group (added with adjuvant only). The vaccines were injected intraperitoneally, five times in two-week intervals.
Results: There was no significantly difference in the average diet intake every day among the groups (P=0.17). The administration of ‘vaccine + adjuvants’, ‘vaccine only’ and ‘adjuvants only’ could decrease foam cell formation and arterial wall thickness compared to the positive control group (P= .00). The ‘vaccine alone’ treatment returned the foam cell numbers to be a normal value just like negative control (P=.15), but ‘vaccine + adjuvants ‘and ‘adjuvant alone’ did not (P=.01). There was a strong and significantly correlation between the foam cell formation with arterial wall thickness (R=0.842, P=.00). In addition, administration of ‘vaccine only’ decreased the rats’ body weight and abdominal visceral fat accumulation significantly compared to the positive control (P=.04 and P=.00 respectively).
Conclusion: The heat-killed Salmonella typhimurium vaccine without CFA-IFA adjuvant decreases foam cells expression and aortic wall thickness, body weight, and abdominal visceral fat accumulation in rat-induced atherogenic diet. In suggestion, heat-killed S. typhimurium is a potential antigen to be developed as an atherosclerosis vaccine in the future.