Identification of Chlamydia pneumoniae-derived mouse CD8 epitopes.

Chlamydia pneumoniae is a common intracellular human pathogen that has been associated with several severe pathological conditions, including coronary heart disease and atherosclerosis. There is no vaccine against C. pneumoniae infection, but CD8(+) T cells have been shown to be crucial for protection during experimental infection.

Induction of HA-1-specific cytotoxic T-cell clones parallels the therapeutic effect of donor lymphocyte infusion.

Donor lymphocyte infusions (DLI) can induce a graft-versus-leukaemia (GvL) reaction in patients with relapsed disease. However, the mechanisms involved in remission induction are not completely known. A patient with chemotherapy-refractory relapse 1 year after human leucocyte antigen (HLA)-identical, unrelated stem cell transplantation (SCT) for bcr/abl-positive common acute lymphoblastic leukaemia (ALL) received a DLI from the original donor, and achieved complete cytogenetic and molecular remission concomitantly with extensive graft-versus-host disease (GvHD).

Expression of the proteasome activator PA28 rescues the presentation of a cytotoxic T lymphocyte epitope on melanoma cells.

The proteasome system represents a major source of HLA class I- presented peptides exposed to CTLs. Stimulation of cells with IFN-gamma instantly induces the expression of the proteasome immunosubunits as well as the proteasome activator PA28. These proteins have been shown to optimize class I antigen presentation of several viral CTL epitopes; however, their contribution to tumor antigen processing remains poorly understood.

Sensitive detection of human cytomegalovirus peptide-specific cytotoxic T-lymphocyte responses by interferon-gamma-enzyme-linked immunospot assay and flow cytometry in healthy individuals and in patients after allogeneic stem cell transplantation.

Reconstitution of human cytomegalovirus (HCMV)-specific cytotoxic T lymphocytes (CTLs), predominantly directed against pp65, provides protective immunity for the development of HCMV disease after allogeneic stem cell transplantation (SCT). To define pp65-derived CTL epitopes that would allow sensitive detection of HCMV-specific immune reconstitution, a computer-based epitope prediction was performed. Peptide-specific CTL responses were assessed by interferon-gamma release.

Identification of known and novel immunogenic T-cell epitopes from tumor antigens recognized by peripheral blood T cells from patients responding to IL-2-based treatment.

In previous studies CD8+ T cells specific for melanocyte antigens have been frequently found in melanoma patients responding to interleukin-2 (IL-2)-based therapies. In our study we analyzed the suitability of using circulating T cells from melanoma patients with clinical response after IL-2-based therapy to identify novel T-cell epitopes from defined tumor antigens. Using unstimulated peripheral blood mononuclear cells and the interferon-gamma (IFN-gamma) ELISPOT assay, we studied CD8(+) T-cell responses against 5 peptides from the tumor antigen tyrosinase (Tyr) selected by epitope prediction using an HLA-A1-binding computer algorithm.

Proteasome-assisted identification of a SSX-2-derived epitope recognized by tumor-reactive CTL infiltrating metastatic melanoma.

The tumor Ag SSX-2 (HOM-MEL-40) was found by serological identification of Ags by recombinant expression cloning and was shown to be a cancer/testis Ag expressed in a wide variety of tumors. It may therefore represent a source of CD8(+) T cell epitopes useful for specific immunotherapy of cancer. To identify potential SSX-2-derived epitopes that can be recognized by CD8(+) T cells, we used an approach that combined: 1) the in vitro proteasomal digestion of precursor peptides overlapping the complete SSX-2 sequence; 2) the prediction of SSX-2-derived peptides with an appropriate HLA-A2 binding score; and 3) the analysis of a tumor-infiltrated lymph node cell population from an HLA-A2(+) melanoma patient with detectable anti-SSX-2 serum Abs.

Plantaricin W from Lactobacillus plantarum belongs to a new family of two-peptide lantibiotics.

Plantaricin W (Plw) is a new two-peptide bacteriocin, from Lactobacillus plantarum, which inhibits a large number of Gram-positive bacteria. The two peptides, Plwalpha (comprising 29 residues) and Plwbeta (comprising 32 residues), were isolated from the culture supernatants and characterized. The individual peptides had low antimicrobial activity but acted synergistically, and synergism was seen at all mixing ratios tested.