Isolation and Characterization of Salmonid CD4+ T Cells

• Published in: The Journal of immunology (1950) Vol. 196; no. 10; pp. 4150 - 4163
• Main Authors: Maisey, Kevin, Montero, Ruth, Corripio-Miyar, Yolanda, Toro-Ascuy, Daniela, Valenzuela, Beatriz, Reyes-Cerpa, Sebastián, Sandino, Ana María, Zou, Jun, Wang, Tiehui, Secombes, Christopher J, Imarai, Mónica
• Format: Journal Article
• Language: English
• Published: United States 15.05.2016
• Subjects: Animals; CD3 Complex - immunology; CD3 Complex - metabolism; CD4-Positive T-Lymphocytes - physiology; Cell Culture Techniques; Cell Line; Cell Proliferation; Fish Proteins - genetics; Fish Proteins - metabolism; GATA3 Transcription Factor - genetics; GATA3 Transcription Factor - metabolism; Head Kidney - immunology; Interleukin-15 - metabolism; Lymphocyte Activation; Mammals - immunology; Oncorhynchus mykiss - immunology; Phylogeny; Receptors, Antigen, T-Cell - metabolism; Spleen - immunology; STAT1 Transcription Factor - genetics; STAT1 Transcription Factor - metabolism; T-Box Domain Proteins - genetics; T-Box Domain Proteins - metabolism
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.1500439

This study reports the isolation and functional characterization of rainbow trout (Oncorhynchus mykiss) CD4-1(+) T cells and the establishment of an IL-15-dependent CD4-1(+) T cell line. By using Abs specific for CD4-1 and CD3ε it was possible to isolate the double-positive T cells in spleen and head kidney. The morphology and the presence of transcripts for T cell markers in the sorted CD4-1(+)CD3ε(+) cells were studied next. Cells were found to express TCRα, TCRβ, CD152 (CTLA-4), CD154 (CD40L), T-bet, GATA-3, and STAT-1. The sorted CD4-1(+) T cells also had a distinctive functional attribute of mammalian T lymphocytes, namely they could undergo Ag-specific proliferation, using OVA as a model Ag. The OVA-stimulated cells showed increased expression of several cytokines, including IFN-γ1, IL-4/13A, IL-15, IL-17D, IL-10, and TGF-β1, perhaps indicating that T cell proliferation led to differentiation into distinct effector phenotypes. Using IL-15 as a growth factor, we have selected a lymphoid cell line derived from rainbow trout head kidney cells. The morphology, cell surface expression of CD4-1, and the presence of transcripts of T cell cytokines and transcription factors indicated that this is a CD4-1(+) T cell line. To our knowledge, this is the first demonstration of the presence of CD4-1(+)CD3ε(+) T cells in salmonids. As in mammals, CD4-1(+) T cells may be the master regulators of immune responses in fish, and therefore these findings and the new model T cell line developed will contribute to a greater understanding of T cell function and immune responses in teleost fish.