title: Expression of the T-cell markers CD2 and CD28 in healthy and atopic children during the first 18 months of life.
abstract: Atopy may be associated with a reduced T-cell function early in life, particularly regarding maturation of Th1 responses. The T-cell surface molecules CD2 and CD28 are involved in important T-cell activation pathways. Stimulation via the CD2 receptor increases the responsiveness to interleukin (IL)-12, which is a potent inducer of Th1 responses, whereas CD28 stimulation is critical for Th2 differentiation. Our aim was to prospectively study the expression of the cell-surface markers CD2 and CD28 on T-cells in relation to development of atopic disease. Children (n = 172) were followed from birth to 18 months and the cumulative history of atopic disease was recorded. Blood samples were obtained at birth and at 18 months, and in a subgroup of 78 infants also at 3, 6 and 12 months. Flow cytometry was used to analyze the T-cell markers CD2 and CD28, the latter also within the subsets of T-helper (CD4+) and T-cytotoxic (CD8+) cells. At 18 months, 31 children had and 118 did not have atopic symptoms. At this age, skin prick test (SPT) positive children with atopic symptoms with or without an atopic family history (AFH) showed a lower expression of CD2 mode fluorescence intensity (FI) as well as a lower proportion of CD2+ cells, as compared with non-sensitized children with neither atopic symptoms nor AFH. This was accompanied by a higher expression of CD28 FI on CD2+CD8+CD28+ cells. No significant differences were seen at time points before 18 months, although the proportion of CD2+ tended to be low also earlier in life. In conclusion, the observed reduced expression of CD2 in atopic infants may support previous findings that atopy is associated with a reduced CD2 function. The high CD28 FI in SPT positive children with atopic symptoms may possibly be a consequence of a TH2-skewed immune system.
authors.affiliation: Department of Molecular and Clinical Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden. helena.zdolsek@lio.se
authors.forename: Helena A
authors.initials: HA
authors.lastname: Zdolsek
authors.forename: Maria C
authors.initials: MC
authors.lastname: Jenmalm
mesh_terms: D018801:CD2 Antigens / Q000378:metabolism*; D018106:CD28 Antigens / Q000378:metabolism*; D003876:Dermatitis, Atopic / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D011446:Prospective Studies; D012882:Skin Tests; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism
chemical_list: D018801:CD2 Antigens; D018106:CD28 Antigens