Challenges in staining T cells using HLA class II tetramers

The development of HLA class II tetramers is driven in part by the desire to understand the CD4(+) T cell repertoire and its immune-mediated functional dynamic responses in humans. For example, HLA class II tetramers can be used to monitor CD4(+) responses in individuals after viral or bacterial infection and after prophylactic or immunotherapeutic vaccination. The CD4(+) responses against allergens in affected and unaffected subjects can also be compared. The tight linkage between autoimmunity and HLA class II alleles and the supporting evidence that common autoimmune diseases are T-cell-mediated have led to a quest in using class II tetramers to identify autoreactive CD4(+) T cells.