Development and Application of a Real-time PCR Method for Pharmacokinetic and Biodistribution Studies of Recombinant Adenovirus

Biodistribution and immunity of adenovirus 5/35 and modified vaccinia Ankara vector vaccines against human immunodeficiency virus 1 clade C

Previously, we developed a chimeric adenovirus type 5 with type 35 fiber (Ad5/35), which has high tropism to dendritic cells and low hepatoxicity. For further clinical use, we constructed two recombinant vectors expressing human immunodeficiency virus 1 (HIV-1) clade C gag (Ad5/35-Cgag and MVA-Cgag). The biodistribution of the two viral vectors in a mouse model and immunity in monkeys were assessed. The mice received a single intramuscular injection with the vectors alone. The gag gene in the tissues were periodically detected using a real-time quantitative polymerase chain reaction. The distribution of Ad5/35 was also detected using an in vivo imaging system, followed by luciferase-expressing Ad5/35 administration. We found that Ad5/35-Cgag DNA and luciferase activity were detectable until 8 weeks post-administration, whereas MVA-Cgag was undetectable 72 h post-administration. Furthermore, viral administration did not increase serum aspartate aminotransferase and alanine aminotransferase levels in either mouse or monkey models. Moreover, intramuscular administration of Ad5/35-Cgag induced the gag-specific antibody level and IFNγ-secreting PBMCs, the boost with MVA-Cgag further increased the responses and lasted more than 20 weeks from the initial administration. These data demonstrate that Ad5/35 and MVA vectors are safe for in vivo use, and prime-boost with Ad5/35-MVA vaccines is suitable for clinical use against HIV-1 clade C.

A New Insight into the Role of Calpains in Post-mortem Meat Tenderization in Domestic Animals: A review

Tenderness is the most important meat quality trait, which is determined by intracellular environment and extracellular matrix. Particularly, specific protein degradation and protein modification can disrupt the architecture and integrity of muscle cells so that improves the meat tenderness. Endogenous proteolytic systems are responsible for modifying proteinases as well as the meat tenderization. Abundant evidence has testified that calpains (CAPNs) including calpain I (CAPN1) and calpastatin (CAST) have the closest relationship with tenderness in livestock. They are involved in a wide range of physiological processes including muscle growth and differentiation, pathological conditions and post-mortem meat aging. Whereas, Calpain3 (CAPN3) has been established as an important activating enzyme specifically expressed in livestock's skeletal muscle, but its role in domestic animals meat tenderization remains controversial. In this review, we summarize the role of CAPN1, calpain II (CAPN2) and CAST in post-mortem meat tenderization, and analyse the relationship between CAPN3 and tenderness in domestic animals. Besides, the possible mechanism affecting post-mortem meat aging and improving meat tenderization, and current possible causes responsible for divergence (whether CAPN3 contributes to animal meat tenderization or not) are inferred. Only the possible mechanism of CAPN3 in meat tenderization has been confirmed, while its exact role still needs to be studied further.

Can calcium chloride injection facilitate the ageing-derived improvement in the quality of meat from culled dairy cows?

This study investigated whether the positive effects of ageing on tenderness of meat from culled dairy cows can be facilitated by CaCl₂. Injections of 250 mM CaCl₂ solution (10% wt/wt) were performed on Longissimus dorsi samples from 32 7-yrs old cows. Samples were vacuum packaged and aged for 0, 1, 3, 5 and 7 days. Ageing alone produced lighter and less red meat with lower shear force, higher myofibrillar fragmentation and tenderness scores but also elevated lipid oxidation. For most traits investigated, CaCl₂-injected meat exhibited similar ageing effects, but drip loss increased with age. The CaCl₂-injected meat had a lower shear force and myofibrillar fragmentation increased more rapidly, but drip loss, off-flavour scores, colour stability and oxidative stability were inferior to untreated meat. Overall, it was found possible to accelerate tenderisation of such meat with CaCl₂, but only at the cost of adverse effects in some other quality traits.

Intravenous injection of irradiated tumor cell vaccine carrying oncolytic adenovirus suppressed the growth of multiple lung tumors in a mouse squamous cell carcinoma model

BACKGROUND

Although cancer therapy using replication-selective oncolytic adenoviruses has been available for many years, its anti-tumor efficacy is suboptimal as a result of low and nonspecific infectivity that depends on coxsackie adenovirus receptor expression of the target cancer and normal cells, and generation of an anti-adenovirus neutralizing antibody. In addition, concerns of triggering a severe innate immune response against the adenovirus limit the systemic administration. We developed the carrier cell-based oncolytic virus system (CBOVS) using irradiated tumor cells as carrier cells and concealing the adenovirus (Ad-IAI.3B) inside to improve the specific infectivity. We investigated the anti-tumor effect of CBOVS in a multiple lung tumor mouse model.

METHODS

The ability of CBOVS to infect Ad-IAI.3B to the target cancer cells was examined in vitro in the presence of anti-adenovirus antibodies. To evaluate the systemic effect of CBOVS, we intravenously injected CBOVS into mice with lung tumors (KLN205 cell lines).

RESULTS

CBOVS enhanced the infectivity of Ad-IAI.3B to tumor cells in the presence of anti-adenovirus antibodies in vitro. Intravenous injections of CBOVS produced an accumulation of the adenovirus in the lung-bearing tumors and produced a strong anti-tumor effect in vivo. Furthermore, lymphocytes collected from the CBOVS-treated mice induced an increase in cytokines related to the Th1 response (interferon-γ, interleukin-12) by pulsing with KLN205.

CONCLUSIONS

These findings suggest that CBOVS could protect adenoviruses from neutralizing antibodies and systemically deliver them to lung tumors. Furthermore, CBOVS appears to have potential as a tumor cell vaccine that activates cytotoxic immunity against cancer cells.