Direct observations of the kinetics of migrating T-cells suggest active retention by endothelial cells with continual bidirectional migration



monolayer within 15 minutes, as in the other models. This proportion increased to about 50%
after 1 hour, but <5% were found in the gel at this time. By 3 hours, about 10% were in the gel,
but these had not penetrated far compared to the neutrophils. Even at 24 hours only 10% were in
gel, and most of these were still in the first 100μm.

We also recorded the behaviour of the lymphocytes at the endothelial surface after 15min,
to allow comparison to the observations on solid substrate. Again, we observed cells undergoing
forward and backward migration, with some making multiple transits through the endothelial
monolayer, at frequencies comparable to those seen on the clear plastic (Table 1D). The phase-
dark cells were highly motile and had velocity averaging 5-6μm∕min (Table 1D).

Effects of lymphocyte activation or the presence of a subendothelial chemokine

We considered whether activated T-cells would migrate more efficiently into gels.

However, while PHA activation significantly increased lymphocyte migration through the
endothelial monolayer (64.6 ± 3.5% vs. 45.2 ± 6.4% of adherent cells migrated at 3h following
PHA treatment vs. freshly isolated PBL respectively; mean ± SEM, n=3; p<0.05 by paired t-test),
migration into the gel was not significantly altered (9.1 ± 3.9% vs. 5.1 ± 4.9% migrated at 24h
with or without PHA respectively; mean ± SEM, n=3). Furthermore, we still observed multiple
transits back and forth across EC by PHA-activated lymphocytes. In fact, the proportions of cells
undergoing at least one transit (~14%), or undergoing multiple transits (~5%) in a six-minute
period were similar to freshly isolated lymphocytes. Thus, activation was insufficient to induce
migration away from the subendothelial space, suggesting the need for a second signal
presumably from within the tissue.



More intriguing information

1. Measuring and Testing Advertising-Induced Rotation in the Demand Curve
2. The name is absent
3. The name is absent
4. Improvements in medical care and technology and reductions in traffic-related fatalities in Great Britain
5. A simple enquiry on heterogeneous lending rates and lending behaviour
6. The name is absent
7. Sex-gender-sexuality: how sex, gender, and sexuality constellations are constituted in secondary schools
8. Evolutionary Clustering in Indonesian Ethnic Textile Motifs
9. LOCAL CONTROL AND IMPROVEMENT OF COMMUNITY SERVICE
10. Factores de alteração da composição da Despesa Pública: o caso norte-americano
11. A Location Game On Disjoint Circles
12. Peer Reviewed, Open Access, Free
13. The name is absent
14. The name is absent
15. Benchmarking Regional Innovation: A Comparison of Bavaria, Northern Ireland and the Republic of Ireland
16. Großhandel: Steigende Umsätze und schwungvolle Investitionsdynamik
17. Mergers and the changing landscape of commercial banking (Part II)
18. Macro-regional evaluation of the Structural Funds using the HERMIN modelling framework
19. Constructing the Phylomemetic Tree Case of Study: Indonesian Tradition-Inspired Buildings
20. Detecting Multiple Breaks in Financial Market Volatility Dynamics