NAD(P)H : quinone oxidoreductase-1 C609T polymorphism analysis in human superficial bladder cancers : relationship of genotype status to NQO1 phenotype and clinical response to Mitomycin C.

NAD(P)H:Quinone oxidoreductase-1 (NQO1) has been implicated in the bioreductive activation of the clinically active anticancer drug Mitomycin C (MMC) and a polymorphic variant of NQO1 which lacks functional enzyme activity (NQO1*2) has been linked with poor survival in patients treated with MMC. The relationship between NQO1 activity and cellular response to MMC is however controversial and the aim of this study was to determine whether the response of bladder cancer patients to MMC can be forecast on the basis of NQO1*2 genotype status. Genomic DNA was extracted from formalin-fixed, paraffin-embedded tissue from 148 patients with low to intermediate grade (G1/G2) superficial (Ta/T1) bladder cancers and NQO1*2 genotype status determined by PCR-RFLP. NQO1*2 genotype status was retrospectively compared with clinical response to intravesical administered MMC with the primary end-point being time to first recurrence. NQO1 phenotype was determined by immunohistochemistry. Of the 148 patients genotyped, 85 (57.4%) were NQO1*1 (wild-type), 59 (39.8%) were NQO1*1/*2 (heterozygotes) and 4 (2.7%) were NQO1*2/*2. No NQO1 protein expression was detected in NQO1*2/*2 tumours. A broad spectrum of NQO1 protein expression existed in tumours genotyped as NQO1*1 and NQO1*1/*2 although tumours with NQO1*1 typically expressed higher NQO1 protein. A poor correlation existed between NQO1*2 genotype status and clinical response to MMC. The results of this retrospective study suggest that tailoring MMC therapy to individual patients with superficial bladder cancer on the basis of NQO1 genotype status is unlikely to be of clinical benefit

Biased T Cell Receptor Usage Directed against Human Leukocyte Antigen DQ8-Restricted Gliadin Peptides Is Associated with Celiac Disease

Transplantation and autoimmunit

High-density binding to Plasmodium falciparum circumsporozoite protein repeats by inhibitory antibody elicited in mouse with human immunoglobulin repertoire

Antibodies targeting the human malaria parasite Plasmodium falciparum circumsporozoite protein (PfCSP) can prevent infection and disease. PfCSP contains multiple central repeating NANP motifs; some of the most potent anti-infective antibodies against malaria bind to these repeats. Multiple antibodies can bind the repeating epitopes concurrently by engaging into homotypic Fab-Fab interactions, which results in the ordering of the otherwise largely disordered central repeat into a spiral. Here, we characterize IGHV3-33/IGKV1-5-encoded monoclonal antibody (mAb) 850 elicited by immunization of transgenic mice with human immunoglobulin loci. mAb 850 binds repeating NANP motifs with picomolar affinity, potently inhibits Plasmodium falciparum (Pf) in vitro and, when passively administered in a mouse challenge model, reduces liver burden to a similar extent as some of the most potent anti-PfCSP mAbs yet described. Like other IGHV3-33/IGKV1-5-encoded anti-NANP antibodies, mAb 850 primarily utilizes its HCDR3 and germline-encoded aromatic residues to recognize its core NANP motif. Biophysical and cryo-electron microscopy analyses reveal that up to 19 copies of Fab 850 can bind the PfCSP repeat simultaneously, and extensive homotypic interactions are observed between densely-packed PfCSP-bound Fabs to indirectly improve affinity to the antigen. Together, our study expands on the molecular understanding of repeat-induced homotypic interactions in the B cell response against PfCSP for potently protective mAbs against Pf infection.Author summaryMalaria is a life-threatening disease caused by Pf parasites transmitted by infected mosquitoes. The surface of infectious Pf sporozoites is covered by PfCSP, which contains multiple, short amino-acid repeats in its central domain. Antibodies targeting the repeats have been shown to be capable of neutralizing the infection. Here, we describe monoclonal antibody (mAb) 850, which was isolated following immunization with a PfCSP repeat-containing antigen in a transgenic mouse model modified to express human Ig heavy and light chain variable regions. mAb 850 binds PfCSP repeats with high affinity and inhibits Pf sporozoites in in vitro and in vivo models of infection. Our molecular analyses reveal that similar to 19 copies of mAb 850 can simultaneously bind one molecule of PfCSP and induce a spiral-like conformation of the repeat. Extensive antibody-antibody contacts between mAbs result in formation of one of the highest-density mAb-CSP complexes yet described. Our findings improve our understanding of antibody-PfCSP interactions that mediate parasite inhibition