Differential expression of the cytokine receptors for human interleukin (IL)‐12 and IL‐18 on lymphocytes of both CD45RA+ and CD45RO+ phenotype from tonsils, cord and adult peripheral blood

• Published in: Clinical and experimental immunology 2004-12, Vol.138 (3), p.460-465
• Main Authors: BOFILL, M., ALMIRALL, E., MCQUAID, A., PEÑA, R., RUIZ‐HERNANDEZ, R., NARANJO, M., RUIZ, L., CLOTET, B., BORRÀS, F. E.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Basic Immunology; Biological and medical sciences; CD28 Antigens - immunology; CD3 Complex - immunology; CD4-Positive T-Lymphocytes; Cells, Cultured; Child; Child, Preschool; cord blood; Fetal Blood - immunology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; IL‐12 receptor; IL‐18 receptor; Immunologic Memory - immunology; Immunopathology; Immunophenotyping - methods; Interleukin-12 - immunology; Interleukin-18 - immunology; Interleukin-18 Receptor alpha Subunit; Leukocyte Common Antigens - immunology; Lymphocyte Activation - immunology; Macrophages - immunology; Medical sciences; Palatine Tonsil - immunology; Receptors, Interleukin - analysis; Receptors, Interleukin - immunology; Receptors, Interleukin-12; Receptors, Interleukin-18; T cell activation; tonsil; Up-Regulation - immunology
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2004.02651.x

SUMMARY The objective of this study was to demonstrate the variable expression of cytokine receptors on naive versus memory human CD4+ T cell subpopulations in tonsillar tissue, cord blood and adult blood. We prove that the receptors for both interleukin (IL)‐12 and IL‐18 are expressed exclusively on memory T cells. This observation was seen not only on the CD45RO+ memory T cells but also on a significant percentage of the CD45RA+, CD62L–, CD27– and CCR7– populations. Furthermore, CD45RA+ CD62L+, CD27+ or CCR7+ CD4+ T cells that expressed IL‐12Rβ1 and IL‐18Rα did not express CD31, a marker for recent thymic emigrants. We reveal that cord blood lymphocytes do not express IL‐12Rβ1 whereas IL‐18Rα expression was detected at low levels. Importantly, the IL‐12Rβ2 signalling chain, which is absent in all resting T cells, was up‐regulated in both CD45RA+ and CD45RO+ T cells as a result of stimulation with anti‐CD3 and anti‐CD28 in vitro. This observed up‐regulation was, however, restricted to 80% of the total CD4+ population. Finally, a very small proportion of the CD4+ CD45RO+ tonsillar T cells expressed the IL‐12 and IL‐18 receptors, thereby establishing the differential expression of these receptors between peripheral and tonsillar memory T cell subpopulations.