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.
Human Papilloma Viruses (HPV) is a very common virus; nearly 80 million people—about one in four—are currently infected in the United States. HPV is a group of more than 150 related viruses. Each HPV virus in this large group is given a number which is called its HPV type. HPV is named for the warts (papillomas) some that HPV types can cause. Some other HPV types can lead to cancer, especially cervical cancer.