Figure 6.

CD4 down-regulation in the spleen cells of CD4 anti-H-Y T cell receptor (TCR) transgenic mice during pregnancy is transient. (a) Intracellular expression of CD4 on CD4 H-Y TCR transgenic spleen cells. CD4 H-Y TCR transgenic spleen cells that were identified as CD4⁻ Vβ6⁺ or CD4⁺ Vβ6⁺ by flow cytometry were placed onto glass slides and analysed by microscopy to determine expression of CD4. Top: Representative cell on negative control slide. Middle: representative CD4⁺ Vβ6⁺ cell by flow cytometry. Bottom: representative CD4⁻ Vβ6⁺ cells by flow cytometry. (b) Re-expression of CD4 in CD4 H-Y TCR transgenic spleen cells in pregnant mice. Left: initial sorting profile. Spleen cells from pooled CD4 H-Y TCR transgenic mice were stained with antibodies to CD4 and Vβ6 and sorted into subpools based on expression of the two markers. Each subpool was incubated in culture medium and then re-examined for expression of CD4 and Vβ6. Right: post-culture analysis of sorted cells. Top right: CD4⁺ Vβ6⁺ cells by initial flow cytometry. Bottom right: CD4− Vβ6⁺ cells by initial flow cytometry.