Development of CD8alpha/alpha and CD8alpha/beta T cells in major histocompatibility complex class I-deficient mice

Abstract

Peripheral CD8(+) T cells mainly use CD8alpha/beta, and their development is mainly dependent on the major histocompatibility complex (MHC) class I proteins K(b) and D(b) in H-2(b) mice. In this report, we have shown that the development of CD8alpha/beta TCR-alpha/beta cells in lymphoid organs as well as in intestinal intraepithelial lymphocytes (iIELs) is dependent on the MHC class I K(b) and D(b) proteins. In contrast, TCR-alpha/beta CD8alpha/alpha cells are found mainly in iIELs, and their numbers are unaffected in K(b)D(b) double knockout mice. Most of the TCR-gamma/delta cells in the iIELs also bear CD8alpha/alpha, and they are also unaffected in K(b)D(b) -/- mice. In beta2-microglobulin (beta2m)-deficient mice, all of the TCR-alpha/beta CD8alpha/alpha and CD8alpha/beta T cells disappear, but TCR-gamma/delta cells are unaffected by the absence of beta2m.

Figure 1

Organ distribution of CD8α/α and CD8α/β T cells. (a) In three-color staining, gating on CD8α-bearing T cells shows most of the CD8α⁺ cells bear TCR-α/β and CD8β as well. (b) Only a few, or no, CD8α⁺ cells are found in TCR-γ/δ⁺ in spleen, lymph node (LN), thymus, and liver, whereas a large portion of the cells are found in iIELs. (c) Gating on TCR-α/β shows that in iIELs only a small portion of the cells bear CD8α/β and the majority of the cells are CD8α⁺. In all other organs, all of the CD8α⁺ cells are positive for CD8β also.

Figure 2

Composition of iIELs and their CD8 coreceptor. (a) Two-color staining shows that the numbers of TCR-α/β and TCR-γ/δ T cells are more or less equal, and only a few CD4⁺ cells are found. (b) Gating on TCR-γ/δ shows that most of the cells bear CD8α but none are positive for CD8β.

Figure 2

Composition of iIELs and their CD8 coreceptor. (a) Two-color staining shows that the numbers of TCR-α/β and TCR-γ/δ T cells are more or less equal, and only a few CD4⁺ cells are found. (b) Gating on TCR-γ/δ shows that most of the cells bear CD8α but none are positive for CD8β.

Figure 3

Composition of CD8α/α and CD8α/β T cells in different organs in K^bD^b double knockout mice. (a) Gating on TCR-α/β shows that in spleen, lymph node (LN), and liver, only a few CD8⁺ cells were found. In thymus and iIELs, a large number of CD8 cells were seen. They are CD8α/β⁺ in thymus and CD8α⁺CD8β⁻ in iIELs. In staining of thymus cells (b), gating on TCR-α/β CD8α shows that all of the cells are CD8β⁺ as well. (c) Gating on TCR-α/β shows that only a few CD4⁻CD8α⁺ or CD4⁻CD8β⁺ cells are found. (d) In staining of iIELs gating on CD8α, there were large numbers of TCR-α/β and TCR-γ/δ cells.

Figure 3

Composition of CD8α/α and CD8α/β T cells in different organs in K^bD^b double knockout mice. (a) Gating on TCR-α/β shows that in spleen, lymph node (LN), and liver, only a few CD8⁺ cells were found. In thymus and iIELs, a large number of CD8 cells were seen. They are CD8α/β⁺ in thymus and CD8α⁺CD8β⁻ in iIELs. In staining of thymus cells (b), gating on TCR-α/β CD8α shows that all of the cells are CD8β⁺ as well. (c) Gating on TCR-α/β shows that only a few CD4⁻CD8α⁺ or CD4⁻CD8β⁺ cells are found. (d) In staining of iIELs gating on CD8α, there were large numbers of TCR-α/β and TCR-γ/δ cells.

Figure 4

Evaluation of CD8⁺ T cells in β2m^−/− mice. (a) Spleen, lymph node (LN), and liver show absence of CD8⁺ cells; however, in thymus, vast numbers of CD4⁺CD8⁺ cells were found but no SP (CD8⁺) cells were seen. In iIELs, there are large numbers of CD8⁺ cells. (b) Gating on CD8α shows that all of the cells in iIELs possess TCR-γ/δ but not TCR-α/β, and gating on TCR-γ/δ shows that most of the cells bear CD8α but not CD8β.