MANIPULATIONS OF MACROPHAGE ACTIVATION THROUGH TARGETED DELIVERY OF INTERFERON REGULATORY FACTOR GENES MEDIATED BY RECOMBINANT ADENOVIRUS-CONJUGATED ZYMOSAN

According to the different phenotypes and distinct patterns of gene expression, macrophages can be subdivided into two types: M1 and M2. The M1 macrophages, which are activated through the classical pathway, have a proinflammatory characteristic, providing an in-front defense line against different kinds of pathogens as well as malignant cells. On the other hand, the M2 macrophages are immunosuppressive and instead can promote tumor growth and dissemination. The solid tumor tissues are often infiltrated with a large number of macrophages, the so-called tumor-associated macrophages (TAMs). TAMs, which are polarized into M2 phenotype under the tumor microenvironment, promote tumor progression by favoring angiogenesis, extracellular matrix (ECM) remodeling, and tuning down of adaptive immunity. Although the molecular mechanisms underlying the process of macrophage polarization is not fully understood, defective activation of NF-ĸB signaling pathway has been frequently observed in TAMs. Pharmacological skewing of TAM polarization from an M2-like phenotype to a full M1 phenotype has been shown to sustain antitumor immunity. In the present study, a novel macrophage-targeted, particulate-mediated gene delivery system was designed aiming to modulate the activation status of the targeted macrophage cells for cancer therapy. Using zymosan particles conjugated with recombinant adenoviruses encoding different interferon regulatory factor (IRF) family genes, specifically IRF1, IRF3, and IRF7, the current system, taking advantage of the characteristic of phagocytosis of macrophages as well as the capability of adenovirus to escape from the phagosomes, achieved virtually 100% transduction efficiency in RAW-Blue macrophage cell line. Through reporter assay, cytokine antibody array, and the measurement of NO production, our results showed an increased NF-ĸB activity in the cells treated by the adenovirus-zymosan conjugates. In addition, cytokine antibody array analysis also revealed increased expressions of many pro-inflammatory cytokines down-stream of the NF-ĸB or IRF signaling pathway in treated cells. This increased expression of pro-inflammatory cytokines probably reflects an added effect from three different sources: the effect elicited by the binding of zymosan to the TLR2; the effect from the cells sensing viral dsDNA through TLR9-dependent and/or -independent pathways; and the effects directly from the expression of the transfected IRF genes. Further works are needed to study the effects of the current system in primary mouse macrophages, especially to test whether the transfected macrophages have elevated activities against tumor cells

Phosphatases and prolyl-isomerase in the regulation of the C-terminal domain of eukaryotic RNA polymerase II

textIn eukaryotes, the first step of interpreting the genetic information is the transcription of DNA into RNA. For protein-coding genes, such transcription is carried out by RNA polymerase II. A special domain of RNA polymerase II, called the C-terminal domain (CTD), functions as a master controller for the transcription process by providing a platform to recruit regulatory proteins to nascent mRNA (Chapter 1-2). The modifications and conformational states of the CTD, termed the 'CTD code', represent a critical regulatory checkpoint for transcription. The CTD, found only in eukaryotes, consists of 26--52 tandem heptapeptide repeats with the consensus sequence, Tyr₁Ser₂Pro₃Thr₄Ser₅Pro₆Ser₇. Phosphorylation of the serines and prolyl isomerization of the prolines represent two major regulatory mechanisms of the CTD. Interestingly, the phosphorylation sites are typically close to prolines, thus the conformation of the adjacent proline could impact the specificity of the corresponding kinases and phosphatases. Understanding how those modifying enzymes recognize and regulate the CTD is important for expanding our knowledge on the transcription regulation and deciphering the 'CTD code'. During my PhD study, I studied the function of CTD phosphatases and prolyl isomerase in the CTD regulation using Scp1, Ssu72 and Pin1 as model regulators. Scp1 and Ssu72 are both Ser5 phosphatases. However, Ssu72 is an essential protein and regulates the global transcription while Scp1 epigenetically silences the expression of specific neuronal genes. Pin1 is a highly conserved phosphorylation-specific prolyl isomerase that recognizes the phospho-Ser/Thr-Pro motif within the CTD as one of its primary substrates in vivo. Among these enzymes, Scp1 is the focal point of this dissertation, as it was studied from different angles, such as enzymatic mechanism (Chapter 3 describes the capture of phospho-aspartyl intermediate of Scp1 as a direct evidence for the proposed two-step mechanism), specific inhibition (Chapter 4 describes the identification and characterization of the first specific inhibitor of Scp1), and its non-active-site contact with the CTD (Chapter 5 describes the structural basis of this contact). These studies are of great importance towards understanding the molecular mechanism of the dephosphorylation process of the CTD by Scp1.Biochemistr

The moderating role of innovation capability on the relationship between slack and firm performance

Treballs Finals del Màster de Recerca en Empresa, Facultat d'Economia i Empresa, Universitat de Barcelona. Curs: 2021-2022, Tutor: Josep Maria Argiles BoschThe impact of organizational slack on firm growth always attracts a great academic concern. however, the investigation about the external factor that will affect the above-mentioned relationship can be barely found. This study undertakes an empirical analysis with regards to the moderating effect of innovation capability on the relationship between organizational slack and future firm growth. We applied a sample of 280 firms in Europe and 2520 years observation from 2011-2019. The result from fixed-effect model shows that unabsorbed slack positively affects future firm growth, also innovation capability can positively moderate the relationship between unabsorbed slack and firm growth. However, we didn’t find any evidence to support our same hypothesis in terms of absorbed slack. Additionally, we find that PP&E investment will promote the firm growth while the firm size has negative effect on firm growth

Outage Probability of Dual-Hop Multiple Antenna Relay Systems with Interference at the Relay and Destination

This paper analyzes the outage performance of a dual-hop relaying system in which the relay is equipped with multiple antennas, while the source and destination have a single antenna. New exact closed-form expressions for the outage probability of both the amplify-and-forward (AF) and the decode-and-forward (DF) relaying systems are derived, assuming that the relay and destination are impaired by cochannel interferers and additive white Gaussian noise (AWGN). Numerical results are presented to verify the theoretical analysis