Functional and morphologic characterization of human T cells continuously grown in vitro

Area of Science:

• Immunology
• Cell Biology

Background:

• Thymus-derived lymphocytes (T cells) are crucial for adaptive immunity.
• Establishing long-term human T cell cultures in vitro has been challenging.
• Previous methods relied solely on mitogens, which were insufficient for sustained growth.

Purpose of the Study:

• To achieve and maintain long-term growth of normal human T lymphocytes in vitro.
• To characterize the functional and morphological properties of these cultured T cells.
• To identify factors supporting continuous T cell proliferation beyond mitogenic stimulation.

Main Methods:

• Utilized a factor from mitogen-stimulated peripheral blood lymphocyte-conditioned media.
• Initiated cultures from human bone marrow and peripheral blood samples.
• Assessed cell surface markers (E rosette, B cell markers), proliferative responses to mitogens (PHA, Con A), mediator release (interferon, CSA), and mixed leukocyte reactions.

Main Results:

• Achieved sustained growth of E rosette-positive lymphocytes for over 13 months.
• Confirmed T cell identity through positive lymphoproliferative responses and mediator release.
• Demonstrated T cell alloreactivity in mixed leukocyte cultures, responding but not stimulating.
• Ruled out B cell, granulocyte, and monocyte contamination.

Conclusions:

• A novel factor enables continuous in vitro growth of human T lymphocytes.
• These cultured cells exhibit functional and morphological characteristics of mature T cells.
• This represents a significant advancement for in vitro immunology and T cell research.