Correlation between the V beta 4+ CD8+ T-cell population and the H-2d haplotype

Area of Science:

• Immunology
• T-cell biology
• Molecular immunology

Background:

• T cells play a crucial role in adaptive immunity.
• T-cell receptor (TCR) V beta gene usage is diverse and influences T-cell repertoire.
• The V beta 4 T-cell subset and its specific functions require further characterization.

Purpose of the Study:

• To quantify the V beta 4+ T-cell population in peripheral blood of mice.
• To investigate the distribution of V beta 4+ T cells within CD4+ and CD8+ T-cell subsets.
• To explore the impact of T-cell deletion mechanisms on V beta 4+ T-cell numbers.

Main Methods:

• Development and application of a novel antibody (KT4) specific for V beta 4.
• Flow cytometry analysis of peripheral T cells (CD3+) from various mouse strains and F1 hybrids.
• Analysis of T-cell populations based on CD4 and CD8 co-receptor expression.

Main Results:

• V beta 4 expression was detected in 4.8%-19.4% of CD3+ peripheral T cells across different mouse strains.
• CD4+ T cells exhibited a higher frequency of V beta 4+ T cells (5.5%-20.6%) compared to CD8+ T cells (2.5%-10.7%).
• Relative proportions of V beta 4+ T cells increased when other V beta-expressing T cells were deleted due to Mlsa antigen or Tcrb-V gene absence.

Conclusions:

• The V beta 4 T-cell population is a significant component of the peripheral T-cell repertoire in mice.
• Differential expression of V beta 4+ T cells in CD4+ versus CD8+ subsets suggests distinct functional roles.
• Positive selection of V beta 4+ CD8+ T cells by H-2d molecules is hypothesized, warranting further investigation.