Virally infected cells degrade intracellular viral proteins proteolytically and present the resulting peptides in association with major histocompatibility complex (MHC) class I molecules to CD8+ cytotoxic T lymphocytes (CTLs). These cells are normally prone to CTL-mediated elimination. However, several viruses have evolved strategies to avoid detection by the immune system that interfere with ...

This study examined the effect of the pro-inflammatory cytokines interferong (IFNg ) and tumor necrosis factora (TNFa ) on the induction of MHC class I–related genes in functionally mature brain neurons derived from cultures of dissociated rat hippocampal tissue. Patch clamp electrophysiology combined with single cell RT-PCR demonstrated that z 50% of the untreated neurons contained mRNA for MH...

Squamous cell carcinoma of the head and neck (SCCHN) cells are poorly recognized in vitro by CTL despite expressing the restricting HLA class I allele and the targeted tumor Ag (TA). Several lines of evidence indicate that the lack of SCCHN cell recognition by CTL reflects defects in targeted TA peptide presentation by HLA class I Ag to CTL because of Ag-processing machinery (APM) dysfunction. ...

TAP1/TAP2 complexes translocate peptides from the cytosol to the endoplasmic reticulum lumen to enable immune surveillance by CD8(+) T cells. Peptide transport is preceded by peptide binding to a cytosol-accessible surface of TAP1/TAP2 complexes, but the location of the TAP peptide-binding pocket remains unknown. Guided by the known contributions of polymorphic TAP variants to peptide selection...

The diophantine equation x3 _ 3xy2 _y3 = ?3no 17 n l9n2 is completely solved as follows. First, a large upper bound for the variables is obtained from the theory of linear forms in p-adic and real logarithms of algebraic numbers. Then this bound is reduced to a manageable size by p-adic and real computational diophantine approximation, based on the L3-algorithm. Finally the complete list of sol...

Expression of histocompatibility leukocyte antigen (HLA) class I molecules on the cell surface depends on the heterodimer of the transporter associated with antigen processing 1 and 2 (TAP1 and TAP2), which transport peptides cleaved by proteasome to the class I molecules. Defects in the TAP2 protein have been reported in two families with HLA class I deficiency, the so-called bare lymphocyte s...

The transporter 1 ATP-binding cassette sub-family B (MDR/TAP) gene (TAP1) is located in the major histocompatibility complex class II region, and forms a heterodimer that plays a key role in endogenous antigen presentation pathways. Investigation of polymorphisms identified in these loci has revealed an association with several autoimmune disorders. Alopecia areata (AA) is a common autoimmune d...

The HLA region has long been implicated in sporadic and familial Hodgkin disease (HD), with recent case-control studies suggesting that HLA class II loci predispose to sporadic nodular sclerosis HD (NSHD). To determine whether this predisposition extends to familial HD, HLA class II loci (DRB1, DQA1, DQB1, DRB3, DRB4, and DRB5) and transporter associated with antigen processing (TAP) loci (TAP1...

CD1d molecules are structurally similar to MHC class I, but present lipid antigens as opposed to peptides. Here, we show that MHC class I molecules physically associate with (and regulate the functional expression of) mouse CD1d on the surface of cells. Low pH (3.0) acid stripping of MHC class I molecules resulted in increased surface expression of murine CD1d on antigen presenting cells as wel...

A wide variety of human carcinomas have low expression of tumor-associated antigen presentation in the context of MHC class I antigens due to defects in the antigen presentation pathway. This immune evasion mechanism renders many tumors unrecognizable by host immune surveillance mechanisms. The present study examines the expression of HLA, tapasin, transporter associated with antigen processing...