Antiretroviral therapy (ART) has changed the prognosis of HIV-1 infection to a chronic illness that, in most cases, can be managed or controlled. Integrase strand transfer inhibitors (INSTIs) and reverse transcription inhibitors are essential components of ART drug cocktails. In compliant individuals, ART has been found to block viral replication completely. Additionally, blocking viral replication can prevent the emergence of drug resistance.
Tumor cell lines are important tools for the study of cancer. However, most tumor cell lines available today do not mimic physiological tumor development, progression, and host immune responses. Autochthonous tumors include spontaneously occurring tumors and chemical, viral, or physical carcinogen-induced tumors. They are considered to model human tumors more closely than transplanted tumors. Autochthonous tumors can be generated de novo in a model organism of interest and are thought to resemble physiological human tumor conditions.
Gammaretroviral vectors were the first viral gene-therapy vectors to enter clinical trials and remain in use. One potential hazard associated with the use of such vectors is the presence of replication-competent retroviruses (RCR) in the vector preparations – either as a result of: 1) recombination events between the plasmids used for vector production, 2) interactions between the plasmids and endogenous retroviral sequences in the packaging cell lines, or 3) as a result of contamination in the laboratory.
Ovarian cancer is one of the most common and lethal types of gynecological malignancies worldwide, accounting for approximately 295,000 new cases and 185,000 deaths annually. The high lethality rate is due to multiple reasons, including recurrence and the resistance of recurrent tumors to chemotherapy. Cell line models are crucial for preclinical cancer studies, to identify mechanisms of disease, to study drug resistance, and to screen for candidate therapeutics.
Bladder cancer is the fifth most common cancer in the United States and one of the costliest cancers to treat. Compared to other cancer types, bladder cancer has been understudied, and there is a need for informative mouse bladder cancer models that resemble the clinical situation and allow for evaluation of chemotherapeutic or immunotherapeutic agents. The orthotopic murine bladder cancer model MB49 resembles non-muscle invasive, nonmetastatic urothelial carcinomas and provides an opportunity to study the anti-tumor effects of immune cell checkpoint inhibitors.
The baculovirus-based protein expression system has gained increased prominence as a method for expressing recombinant proteins that are used in a wide range of biomedical applications. An important step in the use of this system is the ability to determine the virus infectious titer, i.e., the number of active baculovirus particles produced during an infection of the insect host cell.
Baculoviruses have been used for decades to produce proteins in insect cell hosts. Current systems for generating recombinant baculovirus have several shortcomings which prevent their easy use in high-throughput applications.
Researchers at the National Cancer Institute (NCI) have developed an improved insect cell line, Tni-FNL, derived from the cabbage looper, Trichoplusia ni. The Tni-FNL cell line is capable of high level expression of heterologous proteins using baculovirus-based expression systems. When compared to commercially available cell lines used for the same purpose, the Tni-FNL cell line often outperforms those for protein expression. These cells have a high growth rate and are capable of growth at a lower temperature.
Studies have shown that Tissue Inhibitor of Metalloproteinases 2 (TIMP-2) suppresses tumor growth and tumor-associated angiogenesis. Currently, the main obstacle in using TIMP-2 as a biologic therapeutic has been the inability to produce sufficient quantities of the protein for testing and development.
Heptamethine cyanines are among the most widely used near-IR fluorophores. The near-IR range (between about 650 nm and 900 nm) is very useful for imaging applications due to the absence of background autofluorescence. Despite extensive use, many of these fluorophores suffer from chemical instability. Specifically, most of the current and commonly used fluorophores undergo a phenoxy to thiol exchange reaction in the presence of primary thiols. This exchange reaction is problematic during conjugation reactions of cysteine containing macromolecules.