Optimized intracellular flow cytometry panel enables CD4 and CD8 T cell cytokine profiling in Syrian hamsters.

The Syrian golden hamster has emerged as a valuable animal model in challenge experiments and vaccine efficacy studies, particularly for infectious diseases that are poorly represented in mice. In recent years, research has demonstrated that hamsters can better recapitulate certain human infectious diseases compared to mice. Syrian hamsters are used in studies with Yellow fever virus, Helicobacter spp., Hantavirus pulmonary syndrome, Japanese encephalitis, Nipah virus, Adenovirus, Influenza A/B, and SARS-CoV-2, among others. However, the model has been limited by a lack of immunological tools, forcing researchers to rely on clinical outcomes and histopathology rather than detailed immunoprofiling. While some studies have identified cross-reactive antibodies, a comprehensive and complete intracellular flow cytometry panel for measuring cytokine responses in CD4 and CD8 T cell subsets has not yet been established. This paper introduces such an optimized panel, enabling deeper insights into cell-mediated immunity and supporting the broader use of hamsters in vaccine development, therapeutic evaluation, and immune correlate discovery.