Allele-specific peptide presentation of human leukocyte antigens: implications for tumor immunotherapy.

Background: Human leukocyte antigen (HLA) class I plays a central role in the immune defense against microbes and tumors by presenting endogenously processed peptides to T-cells. Few studies have addressed the question as to what extent variants of the same allelic HLA group differ in their peptide motif.

Materials And Methods: To answer this question for the HLA-A*66 family, which is a sub-group of the widespread serological HLA-A10 group, peptides eluted from recombinant A*6602 and A*6603 molecules were sequenced and have with data previously reported for A*6601.

Aberrant expression of HLA-B*3565Q is associated with a disrupted disulfide bond.

The identification of expression variants is a challenge in HLA diagnostics. We here describe the identification of the novel allele HLA-B*3565Q. The serological HLA class I type, as determined by a lymphocytotoxicity test, was A11,24; B38; Bw4; Cw-; whereas PCR-sequence-specific primers resulted in A*11,*24, B*35,*38; Cw*12, thus suggesting the presence of a nonexpressed B*35 allele.

Peptide-binding motif of HLA-A*6603.

The peptide motif of HLA-A*6603 was determined and compared with the available data on the peptide motifs of A*6601 and A*6602. A*6601 differs from A*6602 by two amino acids at positions 90 (Asp90Ala; outer loop) and 163 (Arg163Glu; pocket A). A*6603 differs from A*6601 and A*6602 by a single amino-acid exchange at position 70 (His70Gln; pockets A, B and C).

NQO1 C609T polymorphism in distinct entities of pediatric hematologic neoplasms.

Background And Objectives: NAD(P)H:quinone oxidoreductase 1 (NQO1) is an enzyme that protects cells against mutagenicity from free radicals and toxic oxygen metabolites. The gene coding for NQO1 is subject to a genetic polymorphism at nucleotide position 609 (C-->T) of the human NQO1 cDNA. Heterozygous individuals (C/T) have intermediate activity and homozygotes for the variant allele (T/T) are deficient in NQO1 activity.

Platelet P-selectin and GPIIb/IIIa expression after liver transplantation and resection.

Platelet dysfunction contributes to haemostatic defects, possibly leading to bleeding complications. We hypothesised that liver transplantation and liver resection, together with portal clamping time, might be a potential stimulus for platelet activation. Therefore, we determined the expression of platelet GPIIb/IIIa and P-selectin, representing important platelet activation markers, and the thrombopoietin (TPO) serum level after transplantation and resection.

A single amino-acid polymorphism in pocket A of HLA-A*6602 alters the auxiliary anchors compared with HLA-A*6601 ligands.

In this study we have sequenced peptides eluted from a truncated recombinant HLA-A*6602 molecule, and compared their features with data reported for peptides presented in the A*6601 molecule. A striking change in the amino-acid binding preferences was observed at peptide position P1, which interacts with pocket A of the HLA peptide-binding region. For A*6601, aspartic acid and glutamic acid, both of which possess polar acidic side-chains, have been described as auxiliary anchors.

Lack of influence of the COX inhibitors metamizol and diclofenac on platelet GPIIb/IIIa and P-selectin expression in vitro.

BACKGROUND: The effect of non-steroidal anti-inflammatory drugs (NSAIDs) for reduced platelet aggregation and thromboxane A2 synthesis has been well documented. However, the influence on platelet function is not fully explained. Aim of this study was to examine the influence of the COX-1 inhibiting NSAIDs, diclofenac and metamizol on platelet activation and leukocyte-platelet complexes, in vitro.

The nature of introns 4-7 largely reflects the lineage specificity of HLA-A alleles.

For most HLA-A alleles the phylogeny of the 3' non-coding regions has not yet been studied systematically. In this study, we have determined the sequences of introns 4-7 in 50 HLA-A variants, and have computed nucleotide substitution rates and phylogenetic relationships. The A2/A28, A9, and A10 groups were characterized by clear lineage specificity.

Impact of different modalities of continuous venovenous hemofiltration on sepsis-induced alterations in experimental pancreatitis.

Background: Continuous venovenous hemofiltration (CVVH) is assumed to attenuate systemic complications in septic diseases. The impact of different treatment intensities of CVVH on immunologic and systemic alterations in experimental pancreatitis was evaluated.

Methods: Eighty-four minipigs were allocated either to an untreated control group (group 1) or to one of six treatment groups (groups 2 to 7) that underwent CVVH in different modalities: (1): "late" CVVH, started after a decline of total peripheral resistance of 30% versus "prophylactic" CVVH started immediately after the induction of pancreatitis; (2) no change of hemofilters versus a periodic change of filters every 12 hours; (3) low-volume CVVH with a filtrate turnover of 20 mL/kg body weight (BW)/h versus high-volume CVVH (100 mL/kg/h).