Fig. 4

Diversity of CD4 ⁺ CD28 ⁻ T cells

To examine the question of whether the repertoire of CD4⁺ CD28⁻ T cells is generally restricted or whether few T cell clones have emerged from a polyclonal repertoire, TCR sequences sharing selected BV elements were reamplified with BV- and BJ-specific primers and size-fractionated. Results are shown for BV18-BJ combinations from the same patient, all of which had a Gaussian distribution of band intensities, suggesting polyclonality. No additional dominant clonotype was identified at the more sensitive resolution level, indicating that the CD4⁺ CD28⁻ T cell compartment is primarily polyclonal with the emergence of single clonotypes.