Timothy grass pollen-specific T lymphocyte (Phl p-specific T cell)

Timothy grass pollen-specific T lymphocytes are a specialized subset of CD4+ helper T cells that orchestrate the allergic immune response to Timothy grass (Phleum pratense) (Durham & Shamji, 2023, PMID: 36513434). These cells recognize specific peptide fragments (epitopes) derived from major grass allergens, such as Phl p 1 and Phl p 5, which are presented by MHC class II molecules on the surface of antigen-presenting cells (Würtzen et al., 2005, PMID: 15940011). In sensitized individuals, these T cells typically exhibit a Th2 phenotype, secreting cytokines like IL-4, IL-5, and IL-13 that promote IgE synthesis and eosinophilic inflammation (Moingeon, 2013, PMID: 23415554). These cells are the primary therapeutic targets for allergen-specific immunotherapy (AIT) and novel peptide-based vaccines like Grass-PAD (Larche, 2007, PMID: 17456217). By exposing the immune system to controlled amounts of these peptides, clinicians aim to induce immunological tolerance, characterized by T-cell anergy, deletion, or the induction of regulatory T cells (Tregs) that produce suppressive cytokines like IL-10 (Jutel et al., 2015, PMID: 26111111). This shift effectively reduces the allergic symptoms associated with hay fever and asthma upon subsequent natural exposure to grass pollen.

Other names

Allergen-specific T lymphocytes recognizing Phl p-derived peptidesPhl p-reactive T cellsGrass pollen-specific CD4+ T cellsTimothy grass-reactive T lymphocyte

Induction of immunological tolerance through T-cell anergy, clonal deletion, or the induction of regulatory T cells (Tregs) that secrete inhibitory cytokines like IL-10 and TGF-beta.