(Vienna, 18 June 2026) The oral mucosa is a key entry point for viruses. A research team at the Medical University of Vienna has now shown that specialised memory cells of the immune system are retained there and supported by neighbouring cells. These local cell networks could play a key role in long-term protection against reinfection. The findings have recently been published in the journal ‘Mucosal Immunology’.
Many viruses enter the body via the mouth, nose or throat. This is why the immune defence at these mucous membranes is particularly important. Crucial to this are not only antibodies in the blood, but also immune cells directly at the site, so-called tissue-resident memory T cells. They remain in the tissue after an infection and can react rapidly upon renewed contact with the same pathogen.
The team from the Department of Dermatology at MedUni Vienna examined blood and oral mucosa samples from healthy individuals who had recently recovered from a SARS-CoV-2 infection. Using modern single-cell analyses and spatial investigations, they identified which immune cells are present in the oral mucosa and which neighbouring cells they are in contact with.
The study shows that, particularly in the case of T cells associated with SARS-CoV-2 and the Epstein-Barr virus, many memory cells were found directly in the oral mucosa. These cells were not randomly distributed within the tissue, but were in close spatial proximity to fibroblasts and dendritic cells. Fibroblasts are supporting cells of the tissue, whilst dendritic cells are part of the immune defence system and help to recognise pathogens and regulate immune responses.
“Our findings show that the oral mucosa is not merely a mechanical barrier. It is also an active immune niche where memory cells can be maintained over the long term,” says study author Florian Winkler from the Department of Dermatology at MedUni Vienna.
The researchers found evidence that neighbouring cells provide important signals to memory T cells. These signals could help the cells remain in the tissue and stay functional there. This is particularly relevant because such cells could react rapidly in the event of a new infection.
“For future vaccination strategies, it is important to understand how stable immunity develops directly at the mucous membranes. Our study provides new insights into this using the oral mucosa as an example,” says study lead Johanna Strobl from the Department of Dermatology at MedUni Vienna.
The authors point out that the study was conducted with a small number of participants. Further research is therefore needed to confirm the mechanisms described. Nevertheless, the results provide important insights into how long-term immune defence can be established and maintained at sites where viruses enter the body.
Publication: Mucosal Immunology
Virus-specific resident memory T cell networks sustain immunity in human oral mucosa
Florian Winkler, Carmen Fischer, Laura Marie Gail, Florian Deckert, Lisa Kleissl, Thomas Krausgruber, Kveta Brazdilova, Ana Aguilar González, Georg Stary, Johanna Strobl
DOI: 10.1016/j.mucimm.2026.100362