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A novel approach based on low-rank representations (LRRs) for image representations is proposed. LRR seeks the lowest-rank representations among all the coefficient matrices that represent the images as linear combinations of the basis in the given dictionary. Unlike LRR methods of enforcing additional constraints on the representation and dictionary, an iterative process in which the low-rank decomposition is performed on the coefficient matrices has been developed. The rank of the representation matrices will be lower and lower with the iterations, termed as the deep low-rank (DLR) method. Extensive experiments were conducted to verify the state-of-the-art performance for classification tasks of the DRL method. [ABSTRACT FROM AUTHOR]

Targeting of Mycobacterium tuberculosis (MTB) PE/PPE antigens that induce type 1 helper T cell (Th1) and Th17 responses represents a crucial strategy for the development of tuberculosis (TB) vaccines. However, only a few PE/PPE antigens induce these responses. Here, we sought to determine how the cell wall–associated antigen PPE60 (Rv3478) activates dendritic cell (DC) maturation and T-cell differentiation. We observed that PPE60 induces DC maturation by augmenting the protein expression of cluster of differentiation 80 (CD80) and CD86 and major histocompatibility complex (MHC) class I and MHC class II on the cell surface. PPE60 also stimulated the production of tumor necrosis factor-α (TNFα), interleukin (IL)-1β, IL-6, IL-12p70, and IL-23p19 but not IL-10. This induction was mediated by Toll-like receptor 2 (TLR2) and followed by activation of p38, c-Jun N-terminal kinase (JNK), and NF-κB signaling. PPE60 enhanced MHC-II expression and promoted antigen processing by DCs in a TLR2-dependent manner. Moreover, PPE60-stimulated DCs directed naïve CD4+ T cells to produce IFN-γ, IL-2, and IL-17A, expanding the Th1 and Th17 responses, along with activation of T-bet and RAR-related orphan receptor C (RORγt) but not GATA-3. Moreover, PPE60 activated the NLRP3 inflammasome followed by caspase-1–dependent IL-1β and IL-18 synthesis in DCs. Of note, pharmacological inhibition of NLRP3 activation specifically attenuated IFN-γ and IL-17A secretion into the supernatant from CD4+ T cells cocultured with PPE60-activated DCs. These findings indicate that PPE60 induces Th1 and Th17 immune responses by activating DCs in a TLR2-dependent manner, suggesting PPE60's potential for use in MTB vaccine development [ABSTRACT FROM AUTHOR]

Text summarization on non-factoid question answering (NQA) aims at identifying the core information of redundant answer guidance using questions, which can dramatically improve answer readability and comprehensibility. Most existing approaches focus on extracting query-related sentences to construct a summary, where the logical connection of natural language and the hierarchical interpretable semantic association are often neglected, thus degrading performance. To address these issues, we propose a novel question-driven abstractive answer summarization model, called the Hierarchical Sliding Inference Generator (HSIG), to form inferable and interpretable summaries by explicitly introducing hierarchical information reasoning between questions and corresponding answers. Specifically, we first apply an elaborately designed hierarchical sliding fusion inference model to determine the most relevant question sentence-level representation that provides a deeper interpretable basis for sentence selection in summarization, which further increases computational performance on the premise of following the semantic inheritance structure. Additionally, to improve summary fluency, we construct a double-driven selective generator to integrate various semantic information from two mutual question-and-answer perspectives. Experimental results illustrate that compared with stateof-the-art baselines, our model achieves remarkable improvement on two benchmark datasets and specifically improves the 2.46 ROUGE-1 points on PubMedQA, which demonstrates the superiority of our model on abstractive summarization with hierarchical sequential reasoning. [ABSTRACT FROM AUTHOR]

The persistence of cells latently infected with HIV-1, named the latent reservoir, is the major barrier to HIV-1 eradication, and the formation and maintenance of the latent reservoir might be exacerbated by activation of the immunoinhibitory pathway and dysfunction of CD81 T cells during HIV-1 infection. Our previous findings demonstrated that prophylactic vaccination combined with PD-1 blockade generated distinct immune response profiles and conferred effective control of highly pathogenic SIVmac239 infection in rhesus macaques. However, to our surprise, herein we found that a therapeutic vaccination in combination with PD-1 blockade resulted in activation of the viral reservoir, faster viral rebound after treatment interruption, accelerated AIDS progression, and, ultimately, death in chronically SIVinfected macaques after antiretroviral therapy (ART) interruption. Our study further demonstrated that the SIV provirus was preferentially enriched in PD-11CD41 T cells due to their susceptibility to viral entry, potent proliferative ability, and inability to perform viral transcription. In addition, the viral latency was effectively reactivated upon PD-1 blockade. Together, these results suggest that PD-1 blockade may be a double-edged sword for HIV-1 immunotherapy and provide important insight toward the rational design of immunotherapy strategies for an HIV-1 cure. [ABSTRACT FROM AUTHOR]