Enhancement of Ad-CRT/E7-Mediated Antitumor Effect by Preimmunization withL. lactisExpressing HPV-16 E7

Abstract

Although current polyvalent vaccines can prevent development of cervical cancer, they cannot be used to treat patients who already have the disease. Adenovirus expressing calreticulin-E7 (Ad-CRT-E7) has shown promising results in the cervical cancer murine model. We also demonstrated that immunization with Lactococcus lactis encoding HPV-16 E7 (Ll-E7) anchored to its surface induces significant HPV-16 E7-specific immune response. Here, we assessed the combination of both approaches in the treatment of a cervical cancer animal model. Intranasal preimmunization of Ll-E7, followed by a single Ad-CRT/E7 application, induced ∼80% of tumor suppression in comparison with controls. Mice treated with a combination of Ll-E7 and Ad-CRT/E7 resulted in a 70% survival rate 300 days post-treatment, whereas 100% of the mice in the control groups died by 50 days. Significant CD8+ cytotoxic T-lymphocytes infiltration was detected in the tumors of mice treated with Ll-E7+Ad-CRT/E7. Tumors with regression showed a greater number of positive cells for in situ TUNEL staining than controls. Our results suggest that preimmunization with Ll-E7 enhances the Ad-CRT/E7-mediated antitumor effect. This treatment provides an enormous advantage over repeated applications of Ad-CRT/E7 by maintaining the effectiveness of the three-dose application of Ad-CRT/E7, but avoiding the high systemic toxicities associated with such repeat treatments.

Nanoparticles Based on Poly (β-Amino Ester) and HPV16-Targeting CRISPR/shRNA as Potential Drugs for HPV16-Related Cervical Malignancy

“…12 HPV vaccines can stimulate the body to produce antibodies to HPV and prevent it from infecting cells, 12,27 but it does not offer an effective treatment for women who already present with cervical disease. 13 An individual-based mathematical model suggests cervical screening can be modified to start at later ages, occurring at decreased frequency in HPV-vaccinated women, 28 but vaccination does not completely prevent HPV infection. Therefore, a drug for the treatment of HPV as a supplement to the vaccine is needed.…”

“…12 Furthermore, prophylactic vaccines cannot offer an effective treatment for women who already present with cervical diseases. 13 An increasing number of gene-targeting technologies based on recombinant plasmids have been developed in recent years, such as targeted gene silencing by short hairpin RNA (shRNA) or RNAi 14,15 and targeted gene knockout by CRISPR/Cas. 16 The stability of these plasmids is promising for their prospective use in pharmaceutical industrial production.…”

Development ofLactococcus lactisencoding fluorescent proteins, GFP, mCherry and iRFP regulated by the nisin-controlled gene expression system

“…The L. lactis NZ9000 strain that we used earlier (Rangel-Colmenero et al 2014), was grown in M17 medium (Becton, Dickinson Co., Franklin Lakes, NJ), supplemented with 1% (w/v) glucose (GM17) at 30° C without agitation. The plasmid, pNZ8048, is a shuttle plasmid that has the ability to replicate in both L. lactis and Escherichia coli .…”

Targeting Melanoma Hypoxia with the Food-Grade Lactic Acid Bacterium Lactococcus Lactis

“…The L. lactis-GFP and L. lactis-mCherry strains used in this study were previously reported by our group [26], both were grown in M17 medium (Becton Dickinson Co., Franklin Lakes, NJ, USA) supplemented with 1% (w/v) glucose (GM17) and 10 µg/mL chloramphenicol at 30 • C without agitation and aeration. The plasmid pNZ-IRFP713 was kindly provided by Aleš Berlec (Jožef Stefan Institute, Ljubljana, Slovenia) [60].…”

“…Lactococcus lactis (L. lactis) is a gram-positive facultative anaerobic lactic acid bacterium (LAB) generally recognized as safe (GRAS) according to the United States Food and Drug Administration (FDA). Recently, the use of LAB as a delivery vehicle has emerged as an attractive strategy to deliver a diverse range of therapeutic molecules for applications in allergic, infectious, gastrointestinal diseases and cancer [24][25][26]. Using an inducible gene expression system prevents systemic drug delivery and side effects.…”