1. What do you consider to be the most important advances in the field of CD4+ T cells and MHCII biology, over the past 10 years?
One important advance is the use of peptide:MHCII tetramer enrichment to identify rare polyclonal antigen-specific CD4+ T cells. This technology allows us to reasonably study physiological CD4+ T cell responses. Another advance is the implementation of two-photon microscopy to visualize the movement of CD4+ T cells and their interactions with antigen-presenting cells during an immune response. While flow cytometry is central to a lot of work done in immunology, a limitation is that cells are pooled together and analyzed during a snapshot in time. Two-photon microscopy provides information on how different immune cell types expand, localize and interact with each other during an immune response.
2. What advances do you hope the field will achieve in the next 5 years?
The field is accumulating knowledge relating to the factors promoting different types of CD4+ T cells. I hope that in the next 5 years, the field can implement this knowledge into potential treatments that modulate CD4+ T cell activity to treat immunological problems such as autoimmunity and cancer.
3. What are the main technical challenges currently facing the CD4+ T cell immunology field?
One technical challenge is conducting an in-depth analysis on polyclonal antigen-specific CD4+ T cells. For example, we can identify and phenotype these cells using tetramer enrichment and flow cytometry, but it is not feasible to use two photon microscopy to observe their interactions during an immune response due to the rare nature of these cells. Furthermore, adoptive transfer of these cells into recipient hosts to understand how they may affect the recipient immune response is challenging. Given that there is approximately a 10% park rate among total transferred cells, it is incredibly difficult to assess any changes in mice that received so few polyclonal CD4+ T cells.