In Vivo, Multimodal Imaging of B Cell Distribution and Response to Antibody Immunotherapy in Mice

BACKGROUND: B cell depletion immunotherapy has been successfully employed to treat non-Hodgkin's lymphoma. In recent years, increasing attention has been directed towards also using B-cell depletion therapy as a treatment option in autoimmune disorders. However, it appears that the further development of these approaches will depend on a methodology to determine the relation of B-cell depletion to clinical response and how individual patients should be dosed. Thus far, patients have generally been followed by quantification of peripheral blood B cells, but it is not apparent that this measurement accurately reflects systemic B cell dynamics. METHODOLOGY/PRINCIPAL FINDINGS: Cellular imaging of the targeted population in vivo may provide significant insight towards effective therapy and a greater understanding of underlying disease mechanics. Superparamagnetic iron oxide (SPIO) nanoparticles in concert with near infrared (NIR) fluorescent dyes were used to label and track primary C57BL/6 B cells. Following antibody mediated B cell depletion (anti-CD79), NIR-only labeled cells were expeditiously cleared from the circulation and spleen. Interestingly, B cells labeled with both SPIO and NIR were not depleted in the spleen. CONCLUSIONS/SIGNIFICANCE: Whole body fluorescent tracking of B cells enabled noninvasive, longitudinal imaging of both the distribution and subsequent depletion of B lymphocytes in the spleen. Quantification of depletion revealed a greater than 40% decrease in splenic fluorescent signal-to-background ratio in antibody treated versus control mice. These data suggest that in vivo imaging can be used to follow B cell dynamics, but that the labeling method will need to be carefully chosen. SPIO labeling for tracking purposes, generally thought to be benign, appears to interfere with B cell functions and requires further examination

Inverse Relationship between PSA and IL-8 in Prostate Cancer: An Insight into a NF-κB-Mediated Mechanism

Background: Prostate specific antigen (PSA) is traditionally used as an indicator for the presence of prostate cancer (PCa) and radiotherapy is generally used to treat inoperable and locally advanced PCa. However, how cellular PSA level is associated with sensitivity of PCa to radiotherapy is unknown. The previous finding that the RelB-based NF-kB alternative pathway differentially regulates PSA and interleukin-8 (IL-8) in aggressive PCa has directed our attention to the role of RelB in the response of PCa to radiotherapy. Methodology/Principal Findings: RelB and its targets PSA and IL-8 in PCa cells were manipulated by ectopic expression in PCa cells with a low endogenous level of RelB (LNCaP) and by RNAi-based knock-down in PCa cells with a high constitutive level of RelB (PC3). The effects of RelB, PSA and IL-8 on the response of PCa to radiation treatment were examined in vitro and in xenograft tumors. RelB regulates PSA and IL-8 in an inverse manner. When the cellular levels of PSA and IL-8 were directly modulated by genetic manipulations or by the addition of recombinant proteins, the results demonstrate that upregulation of IL-8 enhanced radioresistance of PCa cells and concurrently down-regulated PSA. In contrast, up-regulation of PSA resulted in reduced radioresistance with concurrent down-regulation of IL-8. Conclusion/Significance: RelB plays a critical role in the response of PCa to radiotherapy and the inverse expression of IL-8 and PSA. The results identify a previously unrecognized relationship between IL-8 and PSA in the response of PCa cells t

Validation of proposed prostate cancer biomarkers with gene expression data: a long road to travel

# The Author(s) 2014. This article is published with open access at Springerlink.com Abstract Biomarkers are important for early detection of can-cer, prognosis, response prediction, and detection of residual or relapsing disease. Special attention has been given to diagnostic markers for prostate cancer since it is thought that early detection and surgery might reduce prostate cancer-specific mortality. The use of prostate-specific antigen, PSA (KLK3), has been debated on the base of cohort studies that show that its use in preventive screenings only marginally influences mortality from prostate cancer. Many groups have identified alternative or additional markers, among which PCA3, in order to detect early prostate cancer through screening, to distinguish potentially lethal from indolent prostate cancers, and to guide the treatment decision. The large number of markers proposed has led us to the present study in which we analyze these indicators for their diagnosti

Nitrate reductase transcript is expressed in the primary response of maize to environmental nitrate

The nitrate induction of NADH:nitrate reductase mRNA in maize roots, scutella and leaves was investigated in the presence and absence of inhibitors of protein synthesis. In the absence of inhibitors, nitrate treatment caused a fairly rapid (2 to 3 h) increase in the level of the nitrate reductase transcript in all tissues. When cytoplasmic protein synthesis was inhibited by cycloheximide, nitrate reductase mRNA was induced by nitrate in all tissues to levels equal to or greater than those found with nitrate treatment alone. Treatment of maize tissues with cycloheximide in the absence of nitrate had only a small effect on the accumulation of the nitrate reductase mRNA. Inhibition of organellar protein synthesis with chloramphenicol also had little or no effect on nitrate-induced nitrate reductase mRNA accumuiation in roots and scutella, but did appear to partially inhibit appearance of transcript in leaves. Excision of scutella in the absence of nitrate was sufficient to cause some accumulation of the nitrate reductase transcript. Since cytoplasmic protein synthesis was not required for expression of nitrate reductase transcripts, induction of these transcripts by nitrate is a primary response of maize to this environmental signal. Thus, it appears that the signal transduction system mediating this response is constitutively expressed in roots, scutella and leaves of maize. © 1992 Kluwer Academic Publishers