Development of a bispecific immune engager using a recombinant malaria protein

As an immune evasion and survival strategy, the Plasmodium falciparum malaria parasite has evolved a protein named VAR2CSA. This protein mediates sequestration of infected red blood cells in the placenta through the interaction with a unique carbohydrate abundantly and exclusively present in the placenta. Cancer cells were found to share the same expression of this distinct carbohydrate, termed oncofetal chondroitin sulfate on their surface. In this study we have used a protein conjugation system to produce a bispecific immune engager, V-aCD3, based on recombinant VAR2CSA as the cancer targeting moiety and an anti-CD3 single-chain variable fragment linked to a single-chain Fc as the immune engager. Conjugation of these two proteins resulted in a single functional moiety that induced immune mediated killing of a broad range of cancer cells in vitro and facilitated tumor arrest in an orthotopic bladder cancer xenograft model.Subject terms: Drug development, Preclinical research     

Galactic clouds of organic molecules

The discovery of immense organic clouds of gas embedded in the dusty regions of our Galaxy is of tremendous importance to the origin of life. It is within these clouds that the formation of stars and planetary systems is believed to take place. The collapse of these clouds to form stars takes place in a very small fraction of the astronomical lifetime of a star. It is precisely at this moment that the clouds of organic molecules appear.     

Active Recombinant Rat Dipeptidyl Aminopeptidase I (Cathepsin C) Produced Using the Baculovirus Expression System

An active form of rat dipeptidyl aminopeptidase I (DPPI, cathepsin C) was obtained by heterologous expression in insect cells. Baculoviruses carrying a cDNA sequence encoding the entire rat DPPI precursor was used to infect High Five cells in a serum-free medium. Recombinant DPPI (rDPPI) was secreted into the medium from which it was purified by a combination of ammonium sulfate fractionation, hydrophobic interaction chromatography (HIC), and ion-exchange chromatography. A polyhistidine-tagged form of the enzyme (HT-rDPPI) was purified from the medium by immobilized metal affinity chromatography (IMAC).In vivoactivation of native rat DPPI involves at least three chain cleavages per subunit and the ability of the expression system to imitate this processing was investigated. Both rDPPI and HT-rDPPI were secreted into the medium as unprocessed and inactive proenzymes and gradually converted into their active forms in the medium. This process was not completed at the time of harvest but mature enzyme processed similarly to native rat and human DPPI could be obtained by incubating the eluates from the HIC and IMAC columns at pH 4.5 and 5°C for 18–40 h. The yield of purified and matured enzyme was approximately 50 mg/liter, and it was shown that rDPPI and HT-rDPPI were active against both a dipeptide–p-nitroanilide substrate and human growth hormone N-terminally extended with an Ala-Glu dipeptide.     

Glycolysis regulates Hedgehog signalling via the plasma membrane potential

The authors regret omitting the citation of a bioRxiv preprint study by preprint: Emmons‐Bell et al (2020), who independently discovered the role of ion channel‐dependent membrane depolarization for Smo membrane accumulation in the fly wing disc. This study used a different methodological approach and did not describe the mechanism of how membrane potential affects hedgehog signaling. The reference is herewith added.