Lactococcus lactis as a live vector: heterologous protein production and DNA delivery systems.

Atherosclerosis is a chronic, multifactorial disease that starts in youth, manifests clinically later in life, and can lead to myocardial infarction, stroke, claudication, and death. Although inflammatory processes have long been known to be involved in atherogenesis, interest in this subject has grown in the past 30-40 years. Animal experiments and human analyses of early atherosclerotic lesions have shown that the first pathogenic event in atherogenesis is the intimal infiltration of T cells at arterial branching points. These T cells recognize heat shock protein (HSP)60, which is expressed together with adhesion molecules by endothelial cells in response to classic risk factors for atherosclerosis. Although these HSP60-reactive T cells initiate atherosclerosis, antibodies to HSP60 accelerate and perpetuate the disease. All healthy humans develop cellular and humoral immunity against microbial HSP60 by infection or vaccination. Given that prokaryotic (bacterial) and eukaryotic (for instance, human) HSP60 display substantial sequence homology, atherosclerosis might be the price we pay for this protective immunity, if risk factors stress the vascular endothelial cells beyond physiological conditions.

The role of heat shock proteins in atherosclerosis

http://digital.csic.es/bitstream/10261/127912/1/COBIOT-D-15-00008R1.pdf

Engineered bacteria as therapeutic agents.

Lactic acid bacteria (LAB) represent a heterogeneous group of microorganisms naturally present in many foods and those have proved to be effective mucosal delivery vectors. Moreover, some specific strains of LAB exert beneficial properties (known as probiotic effect) on both human and animal health. Although probiotic effects are strain-specific traits, it is theoretically possible, using genetic engineering techniques, to design strains that can exert a variety of beneficial properties. During the two past decades, a large variety of therapeutic molecules has been successfully expressed in LAB, and although this field has been largely reviewed in recent years, approximately 20 new publications appear each year. Thus, the aim of this minireview is not to extensively assess the entire literature but to update progress made within the last 2 years regarding the use of the model LAB Lactococcus lactis and certain species of lactobacilli as live recombinant vectors for the development of new safe mucosal vaccines.

Mucosal targeting of therapeutic molecules using genetically modified lactic acid bacteria: an update.

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

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

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.

Hou Jing

Papers

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

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.