They are developing molecules that can fight the flu virus.

It currently accounts for 80 percent of flu-related hospitalizations in countries such as Argentina, highlighting the need for additional tools to vaccination to prevent and treat these influenza virus diseases.

As a result of interdisciplinary work, the Virus Biotechnology Group of the Institute of Biochemical Research of Bahía Blanca in Argentina (INIBIBB, Conicet-UNS), led by Conicet researcher Mariana Puntel, managed to develop and characterize a series of ten molecules of vaccinated llamas. against influenza. The authors believe that the isolated genes can be grafted onto humans to combat various influenza viruses of the H1N1 subtype. The results of the study are published in the journal PLOS ONE.

“This study offers a number of promising therapeutic candidates to combat H1N1 influenza virus infections and to develop innovative technologies for the prevention and treatment of viral diseases,” Puntel emphasizes. The work was developed in close collaboration with the INCUINTA group, linked to the Institute of Virology and Technological Innovation (IVIT, CONICET-INTA), led by CONICET researcher Viviana Parreño.

Broad protection against influenza virus

In the course of the study, the scientists were able to characterize monoclonal nanoantibodies that are effective in preventing infection with H1N1 influenza viruses. In particular, they identified four therapeutic nanoantibodies obtained by genetic engineering from heavy chain immunoglobulins present in llamas and other camelid species, each of which has a different ability to bind and neutralize different regions of influenza viruses, allowing them to provide broad protection against this pathogen.

Notably, the llama-derived nanoantibodies are ten times smaller than the most widely known antibodies. They are monoclonal and highly stable and soluble, making them an attractive tool for developing immune-boosting compounds as a complement to vaccination or as diagnostics.

“The nanoantibodies we have developed are candidates for use as active substances in drugs for prophylactic and therapeutic use. In particular, we are working on intranasal administration of drops and studying its use in nebulizer forms,” ​​explains Puntel.

Suppress virus replication

The results of the research represent a step forward in the development of new technologies capable of inhibiting viral replication of a wide range of influenza A virus strains. In addition, for the first time a nanoantibody has been described that provides sterilizing immunity against this virus. already at a very low dose. One of the identified nanoantibodies has been shown to provide protection. in natural conditions at doses ten times lower than those described so far for this type of experimental treatment. This level of protection results in an undetectable viral load in the lungs of treated mice on the fourth day after exposure to the virus.

“After the tests, no traces of the virus were detected in mice that were given intranasally and then infected. That is why we say that we have identified an ideal candidate for prevention, and we are pleased that these results will be reproduced in future studies,” concludes Puntel.

Scientific reference:

Barbieri ES, Sosa-Holt S, Ibañez LI, Baztarrica J, Garaykoechea L, Gay CL et al. (2024) ‘An anti-hemagglutinin monomeric nanobody confers prophylactic immunity against influenza A H1 viruses’. PLoS ONE 19(7): e0301664. doi: https://doi.org/10.1371/journal.pone.0301664