Biotechnology approaches to produce potent, self-adjuvanting antigen-adjuvant fusion protein subunit vaccines

Efficacy and safety of immunological adjuvants. Where is the cut-off?

Oral administration of Lactococcus lactis delivered heat shock protein 65 attenuates atherosclerosis in low-density lipoprotein receptor-deficient mice.

Background—Studies have suggested that the prevalence of antibodies against heat-shock proteins (HSPs), Chlamydia pneumoniae (Cpn), and cytomegalovirus (CMV) is associated with coronary artery disease (CAD), but the independent or joint effects of human (h) HSP60 antibodies and these pathogens in patients have not been fully elucidated. Methods and Results—A total of 405 subjects (276 patients with CAD and 129 control individuals) were tested for serum antibodies to hHSP60, Cpn, and CMV immediate-early-1 (IE1) antigens. Patients were also assessed for serum cholesterol, triglyceride levels, and smoking habit. Significantly elevated levels of antibodies to hHSP60 and Cpn but not to CMV-IE1 antigens were documented in CAD patients. Multiple logistic regression analysis and subanalyses of selected subjects showed that these associations were independent of age, sex, smoking, and serum lipid levels. Antibodies to hHSP60 and Cpn did not correlate quantitatively; however, the relative risk of disease developmen...

Independent and Joint Effects of Antibodies to Human Heat-Shock Protein 60 and Chlamydia pneumoniae Infection in the Development of Coronary Atherosclerosis

Purpose of review This review will highlight recent advances in the understanding of mammalian bombesin receptor-related pathophysiological roles in disease states and new insights into bombesin receptor pharmacology. Recent findings Studies regarding bombesin-like peptides and mammalian bombesin receptor functions have demonstrated significant biological impact on a broad array of physiological and pathophysiological conditions. Pharmacological experiments in vitro and in vivo as well as utilization of genetic rodent models of the gastrin-releasing peptide receptor (GRP-R/BB2) and neuromedin B receptor (NMB-R/BB1) further delineated roles in memory and fear behavior, inhibition of tumor cell growth, mediating signals for pruritus and male reproductive behavior. All three mammalian bombesin receptors were shown to possess some role in the regulation of energy balance. Novel synthesis of selective high affinity agonists and antagonists of the orphan bombesin receptor subtype-3 (BRS-3/BB3) has been accomplished and will facilitate further studies using animal model systems. Summary Mammalian bombesin receptors participate in the regulation of energy homeostasis and may represent an attractive target for pharmacological treatment of obesity and certain eating disorders. Novel pharmacological insights of bombesin-like peptides and the interaction with their respective receptors have been elucidated to aid future treatment and imaging of epithelial cell-derived tumors.

Biology of mammalian bombesin-like peptides and their receptors.

Accumulating evidence established a positive association of anti-heat shock protein 60 (HSP60) autoantibodies and the presence of atherosclerosis. However, whether anti-P277 (HSP60 437-460) autoantibodies may lead to the pathological increase in vascular permeability, a vascular leak syndrome (VLS), is unknown. In the present study, anti-P277 immunity was effectively induced in C57BL/6 mice, causing a marked increase in VLS in both normal mice and those bearing melanoma as well. Further analysis of the pathological role of anti-P277 immunity revealed that the B-cell epitopes located in P277 played a causal role in the development of VLS. Moreover, studies on endothelial cells (ECs) showed that the anti-P277 antibodies could cross-react with HSP60, highly expressed in both normal and stressed ECs, and mediate damage to cells in the presence of complement. These data suggested that humoral immune response induced by anti-P277 immunity mediates EC damage and induces VLS. These negative effects may cast shadows on P277, used as a peptide vaccine.

Immunization with P277 induces vascular leak syndrome in C57BL/6 mice via endothelial damage.

The fusion protein of HSP65 with tandem repeats of β-hCG acting as a potent tumor vaccine in suppressing hepatocarcinoma

Gastrin-releasing peptide (GRP), a bombesin-like peptide, is an autocrine or paracrine growth factor that can stimulate the growth of various cancer cells, making it an ideal target antigen to develop vaccines against cancer. In this study, we developed a novel DNA vaccine that encodes six tandem repeats of B-cell epitope GRP(18-27) (GRP6) flanked by HSP65 as carrier and four tandem repeats of mycobacterial HSP70(407-426) (M4) as helper T-cell epitopes for enhancement of immunogenicity. When intramuscularly immunized to mice, this anti-GRP DNA vaccine-induced GRP-specific antibody (Ab) responses that were at least 10-fold higher in magnitude compared with HSP65-GRP6 protein vaccine. Both prophylactic and therapeutic antitumor immunities induced by vaccination significantly suppressed the growth of GRP-dependent prostate carcinoma RM-1 in vivo and prolonged the survival of tumor-inoculated mice. Out results also showed that the immune sera with high titer of GRP-specific Abs effectively inhibited the growth of tumor in mice and dose dependently inhibited proliferation of cultured RM-1 cells in vitro, suggesting that the GRP neutralizing Ab is responsible for the protective and therapeutic antitumor activity of vaccination. These findings may be of great importance in the further exploration of the applications of growth factors identified in human in cancer therapy.

Hu Xiangbing

Papers

Immunization with P277 induces vascular leak syndrome in C57BL/6 mice via endothelial damage.

The fusion protein of HSP65 with tandem repeats of β-hCG acting as a potent tumor vaccine in suppressing hepatocarcinoma

Vaccination with a potent DNA vaccine targeting B-cell epitopes of hGRP induces prophylactic and therapeutic antitumor activity in vivo.