We have demonstrated the catalytic CO₂ conversion, and antibacterial and antiviral activity, including against HIV-1, of zinc oxide-infused ionic porous organic frameworks.

The functional consequences of circular RNA (circRNA) expression on HIV-1 replication are largely unknown. Using a customized protocol involving direct RNA nanopore sequencing, here, we captured circRNAs from HIV-1–infected T cells and identified ciTRAN, a circRNA that modulates HIV-1 transcription. We found that HIV-1 infection induces ciTRAN expression in a Vpr-dependent manner and that ciTRAN interacts with SRSF1, a protein known to repress HIV-1 transcription. Our results suggest that HIV-1 hijacks ciTRAN to exclude serine/arginine-rich splicing factor 1 (SRSF1) from the viral transcriptional complex, thereby promoting efficient viral transcription. In addition, we demonstrate that an SRSF1-inspired mimic can inhibit viral transcription regardless of ciTRAN induction. The hijacking of a host circRNA thus represents a previously unknown facet of primate lentiviruses in overcoming transmission bottlenecks.

We show continuous tumor exposure results in a loss of chimeric antigen receptor (CAR) T cell (CART) endocytic activity due to downregulation of Rab5. Loss of endocytic activity exacerbates the effects of trogocytosis, the bidirectional transfer of tumor target antigens and CARs between malignant cells and CARTs, resulting in CART dysfunction and fratricide. Constitutive expression of Rab5 within the CARTs reduced fratricide by reducing the amount of trogocytosed antigens on the cell surface, while simultaneously enhancing CAR availability through dissociation of CAR from target, recycling unbound CAR back to the plasma membrane, and limiting CAR capture by tumor cells. Rab5-expressing CARTs exhibited superior antitumor activity in both BCMA-CARTs isolated from the bone marrow of treated patients and mesothelin-specific CARTs in a solid tumor model. These studies uncover an unexpected relationship between endocytosis and CART function and suggest that pairing Rab5 with CAR expression could improve the clinical efficacy of CART therapy.

The SERINC gene family comprises of five paralogs in humans of which SERINC3 and SERINC5 inhibit HIV-1 infectivity and are counteracted by Nef. The origin of this anti-retroviral activity, its prevalence among the remaining paralogs, and its ability to target retroviruses remain largely unknown. Here we show that despite their early divergence, the anti-retroviral activity is functionally conserved among four human SERINC paralogs with SERINC 2 being an exception. The lack of activity in human SERINC 2 is associated with its post-whole genome duplication (WGD) divergence, as evidenced by the ability of pre-WGD orthologs from yeast, fly, and a post-WGD-proximate SERINC 2 from coelacanth to inhibit nef-defective HIV-1. Intriguingly, potent retroviral factors from HIV-1 and MLV are not able to relieve the SERINC 2-mediated particle infectivity inhibition, indicating that such activity was directed towards other retroviruses that are found in coelacanth (like foamy viruses). However, foamy-derived vectors are intrinsically resistant to the action of SERINC 2, and we show that a foamy virus envelope confers this resistance. Despite the presence of weak arms-race signatures, the functional reciprocal adaptation among SERINC 2 and SERINC 5 and, in response, the emergence of antagonizing ability in foamy virus appears to have resulted from a long-term conflict with the host.