A cDNA clone encoding a product of activated human T lymphocytes

Area of Science:

• Immunology
• Molecular Biology
• Gene Expression Analysis

Background:

• Human T lymphocytes play a crucial role in adaptive immunity.
• Understanding gene expression regulation during T cell activation is vital for immunology research.
• Mitogenic stimulation is a key method to study T cell responses.

Purpose of the Study:

• To identify and characterize novel genes involved in human T lymphocyte activation.
• To investigate the differential gene expression patterns in T cells upon stimulation with phytohemagglutinin A (PHA) and 12-O-tetradecanoyl phorbol 13-acetate (TPA).

Main Methods:

• Construction of a cDNA library from activated human T lymphocytes.
• Screening of the library using colony hybridization with radioactive cDNA probes.
• Northern blot analysis to determine mRNA expression patterns across various cell types.
• Hybrid selection translation and SDS-PAGE to analyze the encoded polypeptide.

Main Results:

• Isolation of several cDNA clones showing a 10- to 20-fold increase in mRNA levels upon stimulation.
• Identification of a specific clone, pNC5A, encoding a gene expressed exclusively in PHA and TPA-stimulated human T lymphocytes and a neoplastic T cell line.
• Detection of low mRNA levels (<20 copies/cell) in resting T lymphocytes, B lymphocytes, monocytes, and various other cell lines.
• Characterization of the encoded protein as a polypeptide with a molecular weight of 30,000 to 32,000 Mr.

Conclusions:

• The cDNA clone pNC5A likely represents a novel gene specifically expressed in activated human T cells.
• This gene may serve as a marker for T cell activation or play a functional role in the activation process.