CD8+ T cells in human uterine endometrial lymphoid aggregates: evidence for accumulation of cells by trafficking
Article first published online: 21 DEC 2001
Volume 102, Issue 4, pages 434–440, April 2001
How to Cite
Yeaman, G. R., Collins, J. E., Fanger, M. W. and Wira, C. R. (2001), CD8+ T cells in human uterine endometrial lymphoid aggregates: evidence for accumulation of cells by trafficking. Immunology, 102: 434–440. doi: 10.1046/j.1365-2567.2001.01199.x
- Issue published online: 21 DEC 2001
- Article first published online: 21 DEC 2001
- Received 25 July 2000; revised 4 December 2000; accepted 12 December 2000.
Lymphoid aggregates (LA) develop during the proliferative phase of the menstrual cycle in the human uterine endometrium (EM). They contain mostly CD8+ T cells and B cells. As these LA are absent immediately following menses, they may arise by division of cells resident in the EM, or by division of a limited number of precursor cells that traffic into the EM during the early proliferative phase of the menstrual cycle. Alternatively, they may arise by the continuous trafficking of cells into the EM throughout the proliferative phase of the menstrual cycle. In this study we investigated the distribution and frequency of CD8+ T cells in the aggregates using expression of Vβ2 or Vβ8 as markers of clonality and Ki-67 as a marker of dividing cells. Confocal microscopic analysis of endometrial tissues showed the random distribution of CD8+ T cells within aggregates within the same sample and in aggregates from different samples. Furthermore, comparisons of the distribution of Vβ2 and Vb8 with expected values predicted from Poisson distribution values were not significantly different, suggesting that CD8+ T cells do not arise by division from single precursors. A low level of T-cell division within LAs was confirmed by positive staining for Ki-67. Dividing T cells were randomly dispersed throughout the LA and the frequency of dividing cells did not vary greatly between aggregates within the same tissue. Nearest-neighbour analysis of dividing cells showed no statistically significant deviations from a random distribution. Taken together, these results suggest that LA develop during the menstrual cycle largely by the trafficking of cells to nucleation sites within the EM, rather than by division of a limited number of precursor cells.