Expression of Interleukin 5 by the CD4+CD45R0+ Subset of Human T Cells

Abstract

The expression of IL5 by CD4⁺CD45RA⁺, CD4⁺CD45R0⁺ and CD3⁺CD8⁺ subsets of human peripheral blood mononuclear cells was assessed. Interleukin 5 expression was detected by RNA extraction, reverse transcription and polymerase chain reaction. Populations of highly purified cells were obtained by a protocol of sequential plastic adherence, magnetic bead separation and flow cytometric cell sorting. IL5 was clearly expressed in the CD4⁺CD45R0⁺ subset from 3 to 48 hr after activation. The CD4⁺CD45RA⁺ and CD3⁺CD8⁺ subsets expressed very much less IL5. By contrast, IL2 expression was readily detected in all sorted populations. Thus, in activated CD4⁺ cells, IL5 was predominantly expressed in the CD4⁺CD45R0⁺ subset, a pattern of expression corresponding to that reported for a number of other cytokines, and differing from that ofIL2.

Key Words:

• T lymphocytes
• memory cells
• T cell activation
• polymerase chain reaction