Interleukin-7: physiological roles and mechanisms of action

Cytokine Growth Factor Rev. 1999 Mar;10(1):41-60. doi: 10.1016/s1359-6101(98)00025-2.

Abstract

Interleukin-7 (IL-7), a product of stromal cells, provides critical signals to lymphoid cells at early stages in their development. Two types of cellular responses to IL-7 have been identified in lymphoid progenitors: (1) a trophic effect and (2) an effect supporting V(D)J recombination. The IL-7 receptor is comprised of two chains, IL-7R alpha and gamma(c). Following receptor crosslinking, rapid activation of several classes of kinases occurs, including members of the Janus and Src families and PI3-kinase. A number of transcription factors are subsequently activated including STATs, c-myc, NFAT and AP-1. However, it remains to be determined which, if any, previously identified pathway leads to the trophic or V(D)J endpoints. The trophic response to IL-7 involves protecting lymphoid progenitors from a death process that resembles apoptosis. This protection is partly mediated by IL-7 induction of Bcl-2, however other IL-7-induced events are probably also involved in the trophic response. The V(D)J response to IL-7 is partly mediated through increased production of Rag proteins (which cleave the target locus) and partly by increasing the accessibility of a target locus to cleavage through chromatin remodeling.

Publication types

  • Review

MeSH terms

  • Animals
  • Gene Targeting
  • Humans
  • Interleukin-7 / biosynthesis
  • Interleukin-7 / physiology*
  • Lymphocytes / metabolism
  • Lymphocytes / physiology*
  • Protein Structure, Tertiary
  • Receptors, Interleukin-7 / biosynthesis
  • Recombination, Genetic
  • Signal Transduction / physiology
  • Structure-Activity Relationship

Substances

  • Interleukin-7
  • Receptors, Interleukin-7