Activated T cells from draining lymph nodes and an effector site differ in their responses to TCR stimulation.
We previously showed that T cells from the mediastinal lymph nodes (MLN) and lung parenchyma of influenza virus-infected mice were functionally remarkably different. Here we demonstrate that the differences in cytokine production are due to differences in the frequencies of T cells within the activated pool able to produce cytokines after TCR stimulation. FACS analysis of T cells from MLN and lung tissue demonstrated that T cells expressing any of the activation markers tested (LFA-1, CD25, CD44, CD45RB, CD49d, CD62L) always expressed high levels of CD44 and LFA-1. These double-high T cells produced >99% of all anti-CD3 mAb-induced IL-4 and IFN-gamma. Separation of T cells employing mAb against the other activation markers in combination with anti-CD44 mAb did not enable further fractionation into cytokine producers and nonproducers. Despite their similar phenotype, purified double-high lung parenchyma T cells produced markedly higher levels of IL-2, IL-4, and IFN-gamma, and contained a higher frequency of cytokine producers than their MLN counterparts. Activation of the extracellular signal-regulated kinase (ERK)-2 in response to TCR cross-linking was detected in double-high T cells from lung tissue but not MLN. The requirement for ERK signaling for maximal IFN-gamma synthesis could nevertheless be demonstrated in both populations by blockade with the inhibitor PD98509. Collectively, the data suggest that inductive and effector sites differ in the frequency of activated T cells able to induce ERK-2-regulated cytokine production after TCR ligation.
Baumgarth
N
N
Cooperative Research Center for Vaccine Technology, Queensland Institute of Medical Research, Brisbane, Australia. Baumgarth@Darwin.Stanford.edu
Egerton
M
M
Kelso
A
A
D000818:Animals; D000954:Antigens, Surface / Q000096:biosynthesis; D015415:Biomarkers / Q000032:analysis; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D016130:Immunophenotyping; D007700:Kinetics; D008168:Lung / Q000166:cytology / Q000276:immunology*; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology*; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D008643:Mesentery; D051379:Mice; D008807:Mice, Inbred BALB C; D009928:Organ Specificity / Q000276:immunology; D009976:Orthomyxoviridae Infections / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D012141:Respiratory Tract Infections / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000954:Antigens, Surface; D015415:Biomarkers; D016207:Cytokines; D011948:Receptors, Antigen, T-Cell; D017871:Calcium-Calmodulin-Dependent Protein Kinases