Researchers from the Institute of Science and Technology Austria, in collaboration with the University of Minnesota and Cornell University, have shed new light on the architecture of HTLV-1, a lesser-known but potentially dangerous virus related to HIV. Using cutting-edge Cryo-Electron Tomography, the team has uncovered unique insights into the structure and transmission of this ‘overlooked cousin’ of the more infamous HIV.
Cracking HTLV-1 puzzles
The HTLV-1 virus (Human T-cell Leukemia Virus Type 1) is still not well known, even as the HIV virus has been extensively studied and understood. The virus causes fast progressing diseases, such as adult T-cell leukemia/lymphoma and has infected approximately 5–10 million individuals worldwide.
Martin Obr and Florian Schur, the researchers in charge of this new study, wanted to turn that on its head. They hoped to better understand the form and function of HTLV-1, a close cousin of HIV-1 that receives less attention. Their research, featured in Nature Structural & Molecular Biology this week, shines a light on how the hidden pathogen operates.
A distinct symmetrical viral overall form
In their investigations, one of the key things that impressed many of the researchers belonged to a lattice structure they found in an HTLV-1 virus. Although most viruses contain a top and bottom layer to their truss, with the lower level acting like a ‘glue’ that binds it together, in HTLV-1 this is reversed.
“HTLV is the opposite. The lowest layer is, in fact, barely holding anything together,” says Florian Schur. Although, as Obr comments, “We were expecting a difference from other viruses, but the extent of it completely blew us away,” the researchers were surprised that this unusual framework of lattice designed to wrap up its genetic material for protection had never been uncovered before.
This unique lattice structure, the team proposes, is a possible evolutionary adaptation to how HTLV-1 infects—through direct contact between infected and uninfected cells as opposed to cell-free transmission in HIV-1. Although this link is so far only a hypothesis, it underscores the significance of peering into the molecular architecture of COVID-19 for unearthing its functional mysteries.
Conclusion
This new study, based on the groundbreaking Cryo-ET work performed in the lab of Krogan scientist Grant Jensen, has provided unprecedented insights into the relatively forgotten HTLV-1 virus and its unique architecture that makes it distinctly different from well-known HIV-1. In addition to extending our scientific knowledge about this dangerous microbe, these findings could also help to catalyse the development of new potential anti-viral drugs that block crucial aspects of the virus maturation process. Meanwhile, the scientists work to unravel the mysteries of HTLV-1, this overlooked cousin — one that threatens global health like nothing else.
