DNA vaccines encoding IL-2 linked to HPV-16 E7 antigen generate enhanced E7-specific CTL responses and antitumor activity

DNA vaccination has emerged as a promising strategy for cancer immunotherapy. However, since DNA vaccines have low immunogenicity, various strategies have been developed to enhance the potency of DNA vaccines. In the current study, we aim to determine whether the potency of the DNA vaccine encoding human papillomavirus type 16 (HPV-16) E7 antigen can be enhanced by IL-2. We have generated a DNA vaccine encoding IL-2 linked to HPV-16 E7 antigen. Our results indicate that the DNA vaccine encoding a fusion of IL-2 and E7 proteins generated the highest frequency of E7-specific CD8(+) T cells. We also found that the DNA vaccine encoding a fusion of IL-2 and E7 proteins generated the strongest protective as well as therapeutic anti-tumor effect against E7-expressing tumors. In addition, it was observed that CD8(+) T cells were mainly responsible for the antitumor effect generated by the DNA vaccine encoding a fusion of IL-2 and E7 proteins. Thus, we conclude that the linkage of IL-2 to HPV-16 E7 antigen significantly enhances the DNA vaccine potency against E7-expressing tumors. Our strategy may potentially be used in other antigenic systems to control infectious diseases and/or cancer.     

Hollow Microparticles as a Superior Delivery System over Solid Microparticles for the Encapsulation of Peptides

Purpose

Peptides are gaining significant interests as therapeutic agents due to their high targeting specificity and potency. However, their low bioavailability and short half-lives limit their massive potential as therapeutics. The use of dense, solid particles of biodegradable polymer as a universal carrier for peptides also has its challenges, such as inefficient peptide release and low bioactivity. In this paper, it was established that hollow microparticles (h-MPs) instead of solid microparticles (s-MPs), as peptide carriers, could improve the release efficiency, while better preserving their bioactivity.

Methods

Glucagon like Peptide-1 (GLP-1) was encapsulated as a model peptide. Mass loss, average molecular weight changes, intraparticle pH, polymer-peptide interaction and release studies, together with bioactivity assessment of the peptide for s-MPs and h-MPs were systematically analyzed and evaluated for efficacy.

Results

The intraparticle pH of s-MPs was as low as 2.64 whereas the pH of h-MPs was 4.99 by day 7. Consequently, 93% of the peptide extracted from h-MPs was still bioactive while only 58% of the peptide extracted from s-MPs was bioactive. Likewise, the cumulative release of GLP-1 by day 14 from h-MPs showed a cumulative amount of 88?±?8% as compared to 33?±?6% for s-MPs.

Conclusions

The cumulative release of peptide can be significantly improved, and the bioactivity can be better preserved by simply using h-MPs instead of s-MPs as carriers.

     

Transient neonatal hemolytic anemia due to the novel gamma globin gene mutation HBG2:C.290T>C,p.Leu97Pro (hemoglobin Wareham)

Unstable gamma globin variants can cause transient neonatal hemolytic anemia. We have identified a novel variant in a newborn who presented with jaundice and anemia requiring phototherapy and red blood cell transfusion. The patient was found to be heterozygous for the mutation HGB2:c.290T>C, p.Leu97Pro, which we have termed hemoglobin (Hb) Wareham. This substitution is expected to generate an unstable hemoglobin with increased oxygen affinity based on the homologous mutation previously described in the beta globin gene, which is termed as Hb Debrousse. The patient fully recovered by 9 months of age as expected with the transition from fetal to adult hemoglobin.     

Spectrum and antibiotic sensitivity of bacteria contaminating the upper gut in patients with malabsorption syndrome from the tropics

Background  

Various causes of malabsorption syndrome (MAS) are associated with intestinal stasis that may cause small intestinal bacterial overgrowth (SIBO). Frequency, nature and antibiotic sensitivity of SIBO in patients with MAS are not well understood.     

Cytotoxic isolates of <Emphasis Type="Italic">Helicobacter pylori</Emphasis> from Peptic Ulcer Diseases decrease K<Superscript>+</Superscript>-dependent ATPase Activity in HeLa cells

Background

Helicobacter pylori is a Gram negative bacterium that plays a central role in the etiology of chronic gastritis and peptic ulcer diseases. However, not all H. pylori positive cases develop advanced disease. This discriminatory behavior has been attributed to the difference in virulence of the bacteria. Among all virulence factors, cytotoxin released by H. pylori is the most important factor. In this work, we studied variation in H. pylori isolates from Indian dyspeptic patients on the basis of cytotoxin production and associated changes in K⁺-dependent ATPase (one of its targets) enzyme activity in HeLa cells.

Methods

The patients were retrospectively grouped on the basis of endoscopic and histopathological observation as having gastritis or peptic ulcer. The HeLa cells were incubated with the broth culture filtrates (BCFs) of H. pylori isolates from patients of both groups and observed for the cytopathic effects: morphological changes and viability. In addition, the K⁺-dependent ATPase activity was measured in HeLa cells extracts.

Results

The cytotoxin production was observed in 3/7 (gastritis) and 4/4 (peptic ulcer) H. pylori isolates. The BCFs of cytotoxin producing H. pylori strains reduced the ATPase activity of HeLa cells to 40% of that measured with non-cytotoxin producing H. pylori strains (1.33 μmole Pi/mg protein and 3.36 μmole Pi/mg protein, respectively, p < 0.05). The decreased activity of ATPase enzyme or the release of cytotoxin also correlated with the increased pathogenicity indices of the patients.

Conclusions

Our results suggest that the isolation of cytotoxic H. pylori is more common in severe form of acid peptic diseases (peptic ulcer) than in gastritis patients from India. Also the cytotoxin released by H. pylori impairs the ion-transporting ATPase and is a measure of cytotoxicity.

     

The onus of cannabinoids in interrupting the molecular odyssey of breast cancer: A critical perspective on UPRER and beyond

Cannabinoids, commonly used for medicinal and recreational purposes, consist of various complex hydrophobic molecules obtained from Cannabis sativa L. Acting as an inhibitory molecule; they have been investigated for their antineoplastic effect in various breast tumor models. Lately, it was found that cannabinoid treatment not only stimulates autophagy-mediated apoptotic death of tumor cells through unfolded protein response (UPR^ER) activated downstream effectors, but also imposes cell cycle arrest. The exploitation of UPR^ER tumors as such is believed to be a major molecular event and is therefore employed in understanding the development and progression of breast tumor. Simultaneously, the data on clinical trials following administration of cannabinoid is currently being explored to find its role not only in palliation but also in the treatment of breast cancer. The present study summarizes new achievements in understanding the extent of therapeutic progress and highlights recent developments in cannabinoid biology towards achieving a better cure of breast cancer through the exploitation of different cannabinoids.