title: Effector CD8+ T cells recovered from an influenza pneumonia differentiate to a state of focused gene expression.
abstract: The restriction of influenza A virus replication to mouse respiratory epithelium means that this host response is anatomically compartmentalized, on the one hand, to sites of T cell stimulation and proliferation in the secondary lymphoid tissue and, on the other hand, to the site of effector T cell function and pathology in the pneumonic lung. Thus, it is hardly surprising that virus-specific CD8(+) T cells recovered by bronchoalveolar lavage (BAL) from the infected respiratory tract seem more "activated" in terms of both cytolytic activity and cytokine production than those cells isolated from the spleen. The present analysis uses Affymetrix microarray technology to compare profiles of gene expression in these two lineage-related, yet anatomically separate, lymphocyte populations. Ninety differentially expressed genes were identified for influenza-specific CD8(+)D(b)NP(366)(+) T cells obtained directly ex vivo by BAL or spleen disruption, with nine genes being further analyzed by quantitative, real-time PCR at the population level. Integrin alphaE, for example, was shown by Affymetrix and real-time mRNA analyses and then by single-cell PCR and protein staining to be present at a much higher prevalence on the BAL CD8(+)D(b)NP(366)(+) set. The unpredicted finding, however, was that mRNA expression for 75% of the 90 genes was lower in T cells from the BAL than from the spleen. Apparently, the localization of virus-specific CD8(+) T cells to the site of virus-induced pathology is associated with a narrowing, or "focusing," of gene expression that favors enhanced effector function in the damaged, "high-antigen load" environment of the pneumonic lung.
authors.affiliation: Department of Immunology, Hartwell Center for Bioinformatics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors.forename: Dana R
authors.initials: DR
authors.lastname: Marshall
authors.forename: Elvia
authors.initials: E
authors.lastname: Olivas
authors.forename: Samita
authors.initials: S
authors.lastname: Andreansky
authors.forename: Nicole L
authors.initials: NL
authors.lastname: La Gruta
authors.forename: Geoff A
authors.initials: GA
authors.lastname: Neale
authors.forename: Astrid
authors.initials: A
authors.lastname: Gutierrez
authors.forename: David G
authors.initials: DG
authors.lastname: Wichlan
authors.forename: Suzette
authors.initials: S
authors.lastname: Wingo
authors.forename: Cheng
authors.initials: C
authors.lastname: Cheng
authors.forename: Peter C
authors.initials: PC
authors.lastname: Doherty
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Turner
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000502:physiology; D002454:Cell Differentiation; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology*; D009980:Influenza A virus / Q000235:genetics* / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D020411:Oligonucleotide Array Sequence Analysis; D009976:Orthomyxoviridae Infections / Q000235:genetics / Q000276:immunology*; D011024:Pneumonia, Viral / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology