Biomedical subjects

Stephen Cose

Publications and source records attributed to Stephen Cose.

3 recordsLinked to original sources

PubMed2007

T-cell migration: a naive paradigm?

Naive T cells have long been thought to recirculate exclusively between secondary lymphoid organs via the lymph and blood. Evidence is now emerging that this view may be too simplistic and that naive T cells routinely traffic through non-lymphoid organs in a manner similar to that of memory T cells, albeit in lower numbers. This represents a fundamental shift in the current paradigm of T-cell migration through different types of tissue. This review summarizes these recent findings, along with the similarities and differences in migratory properties of naive and memory T cells, and discusses how and why naive T cells might access non-lymphoid tissues.

Cell Adhesion↗

PubMed2006

CD4 T cells inhibit the CD8 T cell response during low-dose virus infection.

CD4 T cells are not thought to play a significant role in generating an effective primary CD8 T cell response to most viral infections. We have challenged this view by demonstrating that antigen-specific CD4 T cells can indeed suppress the proliferation of antigen-specific naive CD8 T cells in response to low doses of vesicular stomatitis virus. This finding is in contrast to the established observations that at high antigen loads CD4 T cells play little role in generating CD8 T cell responses, and that in non-infectious model systems CD4 T cells actually help the CD8 T cell response. Our results suggest that at low infectious doses, CD4 T cells play a much larger role in controlling infections than previously appreciated.

Animals↗

PubMed2006

Evidence that a significant number of naive T cells enter non-lymphoid organs as part of a normal migratory pathway.

Only activated and effector memory T cells are thought to access non-lymphoid tissues. In contrast, naive T cells are thought to circulate only between the blood, lymph and secondary lymphoid organs. We examined the phenotype of endogenous T cells in various non-lymphoid organs and showed that a subset of cells exhibited an apparently naive phenotype and were functionally inactive. FTY720 treatment selectively depleted this population from the non-lymphoid tissues. In addition, RAG-deficient TCR transgenic CD4 and CD8 T cells were present in non-lymphoid tissues in bone marrow chimeric mice and in situ imaging analysis revealed their location in the parenchymal tissues. Moreover, migration of TCR transgenic T cells to non-lymphoid tissues after adoptive transfer was pertussis-toxin resistant. Overall, the results suggest that naive T cells may circulate through non-lymphoid tissues as part of their normal migratory pathway.

Animals↗