I have been staining human samples from subjects with asthma, interested in type 2 inflammation. A proportion of the CD3+CD4+ T cells stain positively for both the Th1 and Th2 transcription factors, T-bet and GATA3.
Are these best considered Th1 or Th2 cells? Or would they be capable of producing both Type 1 (e.g. IFN-gamma) and Type 2 cytokines (e.g. IL-5)?
Article Stable T-betGATA-3 Th1/Th2 Hybrid Cells Arise In Vivo, Can D...
May be these are your cells.
A T cell is capable of producing any T cell cytokine, irrespective of its previous active transcriptional status that determines its class or subset commitment, depending on its tissue microenvironment.
You can instruct a T cell to secrete cytokines of one particular class only in in vitro conditions.
Coming to your question... they are T-bet+ GATA3+ T cells and so must be secreting certain cytokines of both Th1 and Th2 subsets before isolation.
As Arshed indicated, there is a certain amount of plasticity between helper T cells in vivo. There is an increasing number of papers describing helper T cells with dual or triple subtype phenotype. Therefore, it might be that this is also a case with your samples: that they contain a population of Th1-Th2 cells. However, you have provided us with relatively few information, such as have you measured any other markers on those cells? Are those cells antigen specific or not? Are they effector or memory T cells? From which asthmatic patients do they come and in which stage of the disease? Do you observe this population also in healthy control samples? What is relative expression of Tbet compared to GATA3? Answers to those questions will help you to check whether you are really dealing with Th1-Th2 cells.
I second here Berislav's comments. If you want better help, more information is needed. Eventually also data, so everybody can see and compare. Have you observed that same phenotype in T cells from healthy donors? What are your controls? Have you performed any other assays that can help guide and/or confirm T cell phenotype and function (cytokine profiles, proliferation, etc)? we also do not know the source of those cells (isolated from PBMCs?) or what are your goals with these experiments. All of that would help the community provide more helpful answers.