Generation and in vivo persistence of polarized Th1 and Th2 memory cells

Area of Science:

• Immunology
• T cell biology
• Cellular immunology

Background:

• In vitro generated CD4 T cell lines and effectors typically exhibit polarized cytokine production (Th1 or Th2).
• Resting CD4 T cells from animals primarily produce IL-2 upon stimulation.
• The development of polarized memory CD4 T cells from effector cells is not fully understood.

Purpose of the Study:

• To investigate whether in vitro polarization of CD4 effector T cells leads to the development of polarized memory T cells.
• To determine if antigen-specific Th1 and Th2 effector cells generate long-lived memory populations with restricted cytokine profiles.

Main Methods:

• Generation of antigen-specific Th1 and Th2 CD4 effector T cell lines in vitro.
• Transfer of these in vitro-generated effector cells into adoptive host animals.
• Analysis of the phenotype and cytokine production of recovered CD4 T cells after antigen challenge.

Main Results:

• Transferred CD4 effector cells generated long-lived CD4 T cell populations exhibiting a resting memory cell phenotype.
• Recovered memory cells demonstrated vigorous responses to specific antigens.
• The cytokine production pattern of the recovered memory cells closely mirrored that of the initially transferred effector cells.

Conclusions:

• Initiation of T cell culture with specific antigens and directive cytokines can generate both effector and long-lived memory CD4 T cell populations.
• These memory cell populations maintain a restricted pattern of cytokine production, reflecting their initial polarization.
• This study provides evidence for the stable inheritance of functional polarization in CD4 T cell memory.