CD3⁺CD294⁺T cells of the type 2 immune response: their role in allergic inflammation

Abstract

T lymphocytes type 2 immune response protect against helminths and toxins, and also contribute to the development of allergic inflammation. One of the most specific T cell surface markers T lymphocytes 2 is the CRTH2 molecule (CD294), which is an activating receptor for prostaglandin D2. The CD3+CD294+population is negligible in the peripheral blood of healthy individuals; an increase occurs in patients with allergic diseases and an autoimmune nature of the response. The aim of the study was to study the quantitative and functional characteristics Т lymphocytes type 2 immune response in patients with rhinoconjunctival symptoms (n = 248) and drug hypersensitivity (n = 184). In 68 patients with an elevated and extremely high number of CD3+CD294+cells, a detailed phenotype of this population was characterized by flow cytometry and the functional activity of the studied cell population in relation to the production of interleukin 4 and interferon γ was studied using enzyme immunoassay. The control group consisted of 34 volunteers. The relative number of CD3+CD294+cells was significantly higher in the group of patients with drug hypersensitivity – 1.6% and rhinoconjunctival symptoms 1.2% compared to the control group – 1.0%. Elevated (1.6-3.6%) and extremely high (>3.6%) CD3+CD294+cell number were significantly more frequently detected in patients with drug hypersensitivity. In both groups, an increase in the number of CD3+CD294+cells were observed with severe damage to the skin. The phenotype of the population T lymphocytes type 2 CD45RA-CD3+CD294+CD2+CD5+CD7+CD27+CD28+CD57-CCR7-was determined, which corresponds to effector memory T lymphocytes. With a moderately increased relative amount of this population, T lymphocytes 2 were usually represented by T helpers 2. A pronounced increase in the population was observed due to T cytotoxic lymphocytes 2. Regardless of the predominance of the Т helper or Т cytotoxic 2 cells in patients revealed an increase in spontaneous production of interleukin 4 at a normal level of interferon. An increase in the peripheral blood T lymphocytes with CD294 expression contributes to the development, maintenance and exacerbation of allergic inflammation with the participation of IgEdependent and IgE-independent mechanisms. The CD3+CD294+cell population should be determined as an additional parameter in assessing the presence of sensitization in the basophil activation test in patients with hypersensitivity reactions. The use of this laboratory biomarker to assess the dominant type of immune inflammation will make it possible to personalize the therapy of the examined patients. Identification of pronounced deviations of indicators from the average values of a population will influence the tactics of patient management.