Antigen-dependent cytokine mRNA expression by individual rhesus macaque T helper cells by flow cytometry

Area of Science:

• Immunology
• Cellular Biology
• Molecular Biology

Background:

• CD4(+) T helper (Th) cells orchestrate immune responses through specific cytokine secretion patterns.
• Understanding Th cell subsets is crucial for characterizing adaptive immunity.

Purpose of the Study:

• To assess antigen-specific cytokine expression in rhesus macaque Th cells.
• To characterize the cytokine profiles of Th cells during a recall immune response using a novel assay.

Main Methods:

• Development and application of a multiparameter, flow cytometric fluorescent in situ hybridization (FISH) assay.
• Detection of cytoplasmic mRNA for cytokines within intact single Th cells.
• Analysis of simultaneous cytokine expression in antigen-specific Th cells from immunized rhesus macaques.

Main Results:

• FISH assay successfully detected antigen-induced cytokine gene expression in single Th cells.
• Recall immune responses included Th cells with classic Th1 (IL-2(+)/IFN-gamma(+)) and Th2 (IL-4(+)/IL-6(+)) patterns.
• Nonclassic Th cells expressing single Th1 or Th2 cytokines were prevalent upon antigen restimulation.

Conclusions:

• In primates, recall immune responses involve a heterogeneous population of Th cells.
• The response includes both polarized Th1 and Th2 cells, as well as nonclassic Th cells.
• The FISH assay provides a powerful tool for dissecting cellular cytokine expression in immune responses.