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



periods from 2 to 36 hours are required for migration through the construct (e.g [7-9]). In such
systems, T-cells spontaneously migrated through unstimulated endothelium/filters over time, [7,
10, 11], although the proportion migrating only reached about 10% of those added. Perhaps
surprisingly, treatment of the EC with a range of cytokines (IL-1, TNF, IFN or TNF+IFN) caused
modest [12, 13] or negligible [8, 10, 14] increases in T cell transmigration compared to
unstimulated EC, again over prolonged periods. Addition of inflammatory chemokines, such as
CCL2 (MCP-1), CCL3 (MIP-1
α) or CCL5 (RANTES), below the filter slightly increased
migration of memory T cells, although CXCL12 (a homeostatic chemokine) caused marked
increase in the migration for naɪve and memory T-cells [12]. Transendothelial migration studies
have also been carried out for EC grown directly on collagen gels, where quite a small proportion
of added T cells (~10%) migrated into the gel over 2-4h, and cytokine stimulation of the EC
again had little effect [15, 16].

Considering the T-cell phenotype, memory CD4+ T-cells migrated more efficiently than
naive cells through resting or cytokine-treated EC (e.g [14, 16]), and in the presence of a
chemotactic gradient [12]. Transmigration of T-cells tends to be increased by stimulation prior to
assay, for instance, incubation with phorbol dibutyrate (PDB) or IL-2, culture for 2 to 24 hours
(which up-regulates expression of
αLβ2-integrin), or differentiation over weeks [7-10].

Nevertheless, studies using freshly isolated lymphocytes without manipulation reported migration
through resting or IL-1
β stimulated EC at 24h [11, 14] comparable to that observed in others
studies when T cells were cultured overnight (e.g. [7]). It should be noted that in the studies
described above, where transendothelial migration occurred in minutes under flow, the T-cells
had first been subjected to prolonged incubation in presence [5] or absence of IL-2 [3, 6].



More intriguing information

1. Strategic Investment and Market Integration
2. The name is absent
3. Pursuit of Competitive Advantages for Entrepreneurship: Development of Enterprise as a Learning Organization. International and Russian Experience
4. On the Existence of the Moments of the Asymptotic Trace Statistic
5. The name is absent
6. Implementation of Rule Based Algorithm for Sandhi-Vicheda Of Compound Hindi Words
7. The name is absent
8. PEER-REVIEWED FINAL EDITED VERSION OF ARTICLE PRIOR TO PUBLICATION
9. Measuring Semantic Similarity by Latent Relational Analysis
10. The name is absent