Identification and Investigation of CD4+ T cell Clonotypes Comprising a Polyclonal Repertoire Against Aeroallergen in a Murine Model of Allergic Asthma

/ABSTRACT Allergic asthma presents as either T2-high (Th2/eosinophilic) or T2-low (Th17/neutrophilic) inflammation. While external factors like co-stimulation and cytokines shape Th cell fate, the role of T cell receptor (TCR) affinity in directing Th2 vs. Th17 differentiation remains unclear. Our lab developed a fungal protease (Alp1)-driven allergic lung inflammation model and essential reagents, including an IL-5/IL-17A reporter mouse. We observed that Alp1 sensitization primarily induces a Th2 response (~30% IL-5+ Th cells, eosinophilia) but also elicits a smaller Th17 response (~5% IL-17A+ Th cells, neutrophilia). This suggests TCR-intrinsic factors influence effector fate. We hypothesize that TCR affinity dictates Th2 vs. Th17 differentiation in response to fungal protease allergens. A major limitation in allergy research is the lack of tools to study allergen-specific Th cells. We aim to develop peptide-MHCII tetramers to examine TCR affinity and its impact on Th2/Th17 fate within oligoclonal populations. Additionally, we will generate a TCR transgenic mouse and engineered protease allergens to directly test TCR affinity’s role in Th cell differentiation. Our lab has identified an immunodominant Alp1 epitope (aa 194-202) and developed a functional peptide- MHCII tetramer. We also created a transgenic mouse expressing tagged-MHCII in dendritic cells, enabling in vivo epitope discovery. With these tools, we will achieve the following aims: Aim 1: Define the relationship between TCR affinity and Th2/Th17 fate in a polyclonal response. Aim 2: Directly test the causal role of TCR affinity in Th2/Th17 differentiation. This study will advance allergy and immunology research by overcoming technical barriers in epitope discovery and immunodominance. Our transgenic models, cytokine reporters, and tetramer technology will provide a framework for understanding allergen-driven Th cell responses, with implications for new diagnostic and therapeutic strategies in allergic diseases. Project Number: 1R21AI196915-01 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of Allergy and Infectious Diseases (NIAID) | Principal Investigator: Darin Wiesner | Institution: RUTGERS BIOMEDICAL AND HEALTH SCIENCES, Newark, NJ | Award Amount: $421,098 | Activity Code: R21 | Study Section: Special Emphasis Panel[ZRG1 IMHA-B (01)] View on NIH RePORTER: https://reporter.nih.gov/project-details/1R21AI19691501