In situ detection of virus- and tumor-specific T-cell immunity

The elucidation of the molecular and immunological mechanisms mediating maintenance of latency in human tuberculosis aids to develop more effective vaccines and to define biologically meaningful markers for immune protection. We analyzed granuloma-associated lymphocytes (GALs) from human lung biopsies of five patients with latent Mycobacterium tuberculosis (MTB) infection. MTB CD4+ and CD8+ T cell response was highly focused in the lung, distinct from PBL, as assessed by TCR-CDR3 spectratyping coupled with a quantitative analysis of TCR VB frequencies. GALs produced IFN-γ in response to autologous macrophages infected with MTB and to defined MTB-derived HLA-A2-presented peptides Ag85a242–250, Ag85b199–207, early secreted antigenic target 6 (ESAT-6)28–36, 19-kDa Ag88–97, or the HLA-DR-presented ESAT-61–20 epitope. Immune recognition of naturally processed and presented MTB epitopes or the peptide ESAT-61–20 could be linked to specific TCR VB families, and in two patients to unique T cell clones that constituted 19 and 27%, respectively, of the CD4+ and 17% of the CD8+ GAL population. In situ examination of MTB-reactive GALs by tetramer in situ staining and confocal laser-scanning microscopy consolidates the presence of MHC class I-restricted CD8+ T cells in MTB granuloma lesions and supports the notion that clonally expanded T cells are crucial in immune surveillance against MTB.

Section: Mtb-reactive Gals In Situ Defined By Tetramer Analysismentioning

confidence: 72%

Section: Cd4mentioning

confidence: 99%

Highly Focused T Cell Responses in Latent Human Pulmonary Mycobacterium tuberculosis Infection

Tully¹,

Kortsik

Höhn³

et al. 2005

“…Two complementary approaches were used to visualize and enumerate H-2D b restricted GP 33-41 -specific CD8 T cells in target tissues infected by LCMV (17). First, using in situ MHC class I tetramer staining (17,29,30), it was determined that the frequency of GP 33-41 -specific CD8 T cells in the islets of RIP-GP mice during the effector phase of the disease (days 7 and 10) was surprisingly only 1% of the total infiltrating CD8 T cell population (D. B. McGavern, U. Christen, M. G. von Herrath, and M. B. A. Oldstone, manuscript in preparation).…”

Section: Blockade Of Ip-10 Inhibits the Expansion And Migration Of Lcmentioning

confidence: 99%

Among CXCR3 Chemokines, IFN-γ-Inducible Protein of 10 kDa (CXC Chemokine Ligand (CXCL) 10) but Not Monokine Induced by IFN-γ (CXCL9) Imprints a Pattern for the Subsequent Development of Autoimmune Disease

Christen

McGavern

Luster

et al. 2003

178

217

Infection of the pancreas with lymphocytic choriomeningitis virus results in rapid and differential expression among CXCR3 chemokines. IFN-γ-inducible protein of 10 kDa (IP-10), in contrast with monokine induced by IFN-γ and IFN-inducible T cell-α chemoattractant, is strongly expressed within 24 h postinfection. Blocking of IP-10, but not monokine induced by IFN-γ, aborts severity of Ag-specific injury of pancreatic β cells and abrogates type 1 diabetes. Mechanistically, IP-10 blockade impedes the expansion of peripheral Ag-specific T cells and hinders their migration into the pancreas. IP-10 expression was restricted to viruses infecting the pancreas and that are capable of causing diabetes. Hence, virus-induced organ-specific autoimmune diseases may be dependent on virus tropism and its ability to alter the local milieu by selectively inducing chemokines that prepare the infected tissue for the subsequent destruction by the adaptive immune response.

“…Biotinylated K b /␤ 2 -microglobulin/peptide molecules were generated with peptides as previously described (17). Tetramers/multimers were generated by adding allophycocyanin-labeled ExtraAvidin (Sigma-Aldrich).…”

Section: Confocal Laser-scanning Microscopymentioning

confidence: 99%

Shift from Systemic to Site-Specific Memory by Tumor-Targeted IL-2

Schrama

Xiang

Eggert

et al. 2004

IL-2 has been approved for treatment of patients with cancer. Moreover, it has been used as a component of vaccines against cancer. In this regard, we have recently demonstrated that dendritic cell-based peptide vaccination in mice required IL-2 to mount an effective immune response against established melanoma metastases. In this study, we confirm this observation by use of tumor-targeted IL-2. However, the development of a protective systemic memory was substantially impaired by this measure, i.e., mice, which successfully rejected s.c. tumors of B16 melanoma after vaccination with dendritic cells pulsed with tyrosinase-related protein 2-derived peptides plus a boost with targeted IL-2, failed to reject a rechallenge with experimental pulmonary metastases. Detailed analysis revealed a change in the distribution of the tumor-reactive T cell population: although targeted IL-2 expanded the local effector population, tyrosinase-related protein 2-reactive T cells were almost completely depleted from lymphatic tissues.