CD4-T-Lymphocyte Interactions with Pneumolysin and Pneumococci Suggest a Crucial Protective Role in the Host Response to Pneumococcal Infection
| Autor: | Peter W. Andrew, M. Joseph Colston, William R. Coward, Aras Kadioglu, Colin R. A. Hewitt |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
CD4-Positive T-Lymphocytes
Immunology Population Genes MHC Class II Biology In Vitro Techniques medicine.disease_cause Microbiology Pneumococcal Infections Interferon-gamma Mice Bacterial Proteins Immunity Streptococcus pneumoniae medicine Animals Humans Interferon gamma IL-2 receptor education Interleukin 4 Mice Knockout education.field_of_study Host Response and Inflammation Pneumolysin T lymphocyte Mice Inbred C57BL Chemotaxis Leukocyte Infectious Diseases Mutation Streptolysins Parasitology Female Interleukin-4 medicine.drug |
| Popis: | Previously, we had shown that T cells accumulated in peribronchiolar and perivascular areas of lungs soon after intranasal infection with Streptococcus pneumoniae . We have now presented new evidence, using major histocompatibility class II-deficient mice, that CD4 cells are important for early protective immunity. In addition, we have also shown that a population of human CD4 cells migrates towards pneumococci and that in vivo-passaged pneumococci are substantially more potent at inducing migration than in vitro-grown bacteria. This migratory process is unique to a specific population of CD4 cells, is highly reproducible, and is independent of prior CD4 cell activation, and yet the migratory process results in a significant proportion of CD4 cells becoming activated. The production of pneumolysin is a key facet in the induction of migration of CD4 cells by in vivo bacteria, as pneumolysin-deficient bacteria do not induce migration, but the data also show that pneumolysin alone is not sufficient to explain the enhanced migration. Increased CD25 expression occurs during migration, and a higher percentage of cells in the migrated population express gamma interferon or interleukin 4 (IL-4) than in the population that did not migrate. There is evidence that the activation of IL-4 expression occurs during migration. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|