Intrinsic factors in helper T-cells lineage choice

The process of clonal expansion of T lymphocytes, or T cells, belongs to the basic characteristics of adaptive immunity. A fundamental role in the immune response is played by the CD4+ T cells which are capable of evolving into the different subtypes (for example Th1 or Tfh) that help other types of cells to effectively eliminate pathogens. Each particular subtype activates different arms of the immune system for the most effective clearance of a particular pathogen. The way how the pathogen will be eliminated depends on the type of infection. This thesis aims to analyze relevant literature and known facts about factors that influence functional T-cell differentiation. This thesis will be mainly focused on the question of how much the T-cell receptor's structure or antigen affinity plays a role in this decision- making process. Another point of interest is the capability of T cells from one clone to produce different T helper cell subtypes, or they are preferentially biased towards a single differentiation pathway. Key words: adaptive immunity, CD4+ T cells, TCR, infections, differentiatio