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Hepatitis B virus (HBV) infection is a major health problem worldwide. Recent evidence suggests that some viruses can manipulate the infection process by packing specific viral and cellular components into exosomes, small nanometer-sized (30-150 nm) vesicles secreted from various cells. However, the impact of HBV replication on the content of exosomes produced by hepatocytes has not been fully delineated. In this work, an HBV-inducible cell line HepAD38 was used to directly compare changes in the protein content of exosomes secreted from HepAD38 cells with or without HBV replication. Exosomes were isolated from supernantants of HepAD38 cells cultured with or without doxycycline (dox) and their purity was confirmed by transmission electron microscopy (TEM) and Western immunoblotting assays. Ion-intensity based label-free LC-MS/MS quantitation technologies were applied to analyze protein content of exosomes from HBV replicating cells [referred as HepAD38 (dox)-exo] and from HBV nonreplicating cells [referred as HepAD38 (dox)-exo]. A total of 1412 exosomal protein groups were identified, among which the abundance of 35 proteins was significantly changed following HBV replication. Strikingly, 5 subunit proteins from the 26S proteasome complex, including PSMC1, PSMC2, PSMD1, PSMD7 and PSMD14 were consistently enhanced in HepAD38 (dox)-exo. Bioinformatic analysis of differential exosomal proteins confirmed the significant enrichment of components involved in the proteasomal catabolic process. Proteasome activity assays further suggested that HepAD38 (dox)-exo had enhanced proteolytic activity compared with HepAD38 (dox)-exo. Furthermore, human peripheral monocytes incubated with HepAD38 (dox)-exo induced a significantly lower level of IL-6 secretion compared with IL-6 levels from HepAD38 (dox)-exo. Irreversible inhibition of proteasomal activity within exosomes restored higher production of IL-6 by monocytes, suggesting that transmission of proteasome subunit proteins by HepAD38 (dox)-exo might modulate the production of pro-inflammatory molecules in the recipient monocytes. These results revealed the composition and potential function of exosomes produced during HBV replication, thus providing a new perspective on the role of exosomes in HBV-host interaction.

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measures are primarily based on digital cryptographic signature or physical identification tag. [8][9][10] Digital cryptographic keys generated by pseudo-random mathematic functions need to be programmed into nonvolatile memory, accompanied with complicate tamper resilient devices to protect the keys from side-channel attacks. [11] Physical identification tags such as radiofrequency identification tags (RFID), [1,12] holograms, [13,14] graphical tags, [15] watermarks, [16] security inks, [17,18] barcode, [19][20][21] and chemical tag [9,22] have already been introduced to the consumer products for property protection. Nonetheless, these tags are made in deterministic processes, thus are vulnerable to clone attacks due to the low complexity and high predictability. More complex molecular tags could be adopted with an increase in cost, and can only be accessible in specialized laboratory. [23][24][25] To combat the rising tide of counterfeiting, physical unclonable function (PUF, or physical one-way function) has been introduced. [26,27] PUF is made from an indeterministic stochastic process, whose fingerprint-like response is difficult to predict upon external stimulus, thereby naturally immune to the clone attack. The sufficiently large complexity of PUF also renders it effective against brute force reverse engineering and tamper attack. [28] Conventional integrated circuit (IC) based PUFs typically utilize the inherent variations in the gate and wire time delays (e.g., arbiter PUF [29,30] and ring oscillator PUF [31] ) or local mismatches (e.g., SRAM PUF, [32] latch PUF, [33] flip-flop PUF [34] ) as the source of randomness. IC based PUF is convenient for on-chip integration owing to its CMOS compatibility, but is vulnerable to model building attack due to the relatively low complexity and large bit error rate. Emerging technologies with higher degree of complexity such as phase change memory, [35] interfacial magnetic anisotropy, [36] carbon nanotube field effect transistor, [37][38][39][40] memristor [41][42][43][44][45] are proposed with an exponential increase in cost and fabrication difficulty. Chemically synthesized PUFs can afford large encoding capacity, small footprint and low production cost by measuring readily detectable characteristics such as scattering speckle image, [26,[46][47][48] fingerprint like textures, [49][50][51] fluorescence or lasing [25,[52][53][54][55][56] surface enhanced Raman signature, [57][58][59][60] and unpredictable defects and patterns in 2D materials. [61,62] The complexity of chemical PUFs can easily be scaled Physical unclonable function (PUF) is promising for anticounterfeiting and security applications. In this paper, a PUF concept is demonstrated based on the stochastic generation of nanodot matrix via mechanical stripping of a gold film kirigami with arrayed nanoscale split-ring cuts. The random occurrence of nanofracture of metallic nanoconnection at split-ring parts results in unpredictable remaining (labeled as "1") or peeling-off (labeled as "0") of nanodots in ea...