Explore the vast range of titles available.

Park Chan-kyong is the second artist selected for the \"MMCA Artist Studies\" series. Since the late 1980s, Park has been a member of a community of critics writing art and organizing exhibitions through forums such as the Research Society for Art Criticism (misul bipyeong yeonguhoe), Forum A, BOL. Park took his first steps as an artist with the solo exhibition Black Box: The Memory of Cold War Images, held at the Kumho Museum in 1997, and has since continued to produce film and video works critically examining the Cold War, Korean modernity, and colonialism. Under the title Red Asia Complex, this book examines, from various perspectives, the nearly thirty-years trajectory of Park Chan-kyong's art and writing.--Gallery Website.

Inflammatory bowel disease (IBD) is associated with risk variants in the human genome and dysbiosis of the gut microbiome, though unifying principles for these findings remain largely undescribed. The human commensal Bacteroides fragilis delivers immunomodulatory molecules to immune cells via secretion of outer membrane vesicles (OMVs). We reveal that OMVs require IBD-associated genes, ATG16L1 and NOD2, to activate a noncanonical autophagy pathway during protection from colitis. ATG16L1-deficient dendritic cells do not induce regulatory T cells (Tregs) to suppress mucosal inflammation. Immune cells from human subjects with a major risk variant in ATG16L1 are defective in Treg responses to OMVs. We propose that polymorphisms in susceptibility genes promote disease through defects in \"sensing\" protective signals from the microbiome, defining a potentially critical gene-environment etiology for IBD.

PurposeCIPN is a common, debilitating, and dose-limiting side effect of chemotherapy. Here, we describe characteristics of patients with CIPN using both patient-reported outcomes (PRO) and quantitative sensory testing (QST).MethodsBreast cancer survivors with persistent moderate to severe CIPN defined by a rating of 4 or greater on a 0–10 Numeric Rating Scale (NRS) from two ongoing clinical trials were included. PROs included the Neuropathic Pain Scale (NPS) and Functional Assessment of Cancer Therapy-Gynecologic Oncology Group/Neurotoxicity (FACT/GOG-Ntx). QST included tactile and vibration detection threshold measurements. Data were analyzed using descriptive statistics and Spearman correlation coefficients.Results49 female patients with a mean age of 61 years were assessed; 63% were Caucasian. Mean NRS scores were 4.2, 5.7, and 4.3 on 0–10 scale for pain, numbness, and tingling, respectively. Mean NPS score was 41.0 on a 0–100 scale, and the mean FACT/GOG-Ntx score was 25.8 on a 0–44 scale. QST showed mild to moderate impairments in tactile and vibration perception. The FACT/GOG-Ntx subscale for numbness was negatively correlated with tactile and vibration thresholds in both hands and feet (both p < 0.05). NPS was positively correlated with tactile thresholds in the hands and feet (p < 0.05).ConclusionPatients with moderate to severe CIPN report moderate pain, numbness, and tingling, and exhibit reduced tactile and vibration perception on QST. Weak to moderate correlations were observed between PRO and QST. These data suggest that QST outcomes are associated with CIPN symptoms and may be useful in helping monitor and manage CIPN treatment.

Elucidating the structure and function of the HIV-1 outer envelope proteins is critical for the design of an effective vaccine. Despite the availability of many high-resolution structures, key functional correlates in the envelope trimer remain undefined. The human immunodeficiency virus type 1 (HIV-1) envelope trimer maintains a closed, metastable configuration to protect vulnerable epitopes from neutralizing antibodies. Here, we identify key hydrophobic constraints at the trimer apex that function as global stabilizers of the HIV-1 envelope spike configuration. Mutation of individual residues within four hydrophobic clusters that fasten together the V1V2, V3, and C4 domains at the apex of gp120 dramatically increases HIV-1 sensitivity to weak and restricted neutralizing antibodies targeting epitopes that are largely concealed in the prefusion Env spike, consistent with the adoption of a partially open trimer configuration. Conversely, the same mutations decrease the sensitivity to broad and potent neutralizing antibodies that preferentially recognize the closed trimer. Sera from chronically HIV-infected patients neutralize open mutants with enhanced potency, compared to the wild-type virus, suggesting that a large fraction of host-generated antibodies target concealed epitopes. The identification of structural constraints that maintain the HIV-1 envelope in an antibody-protected state may inform the design of a protective vaccine. IMPORTANCE Elucidating the structure and function of the HIV-1 envelope proteins is critical for the design of an effective vaccine. Despite the availability of many high-resolution structures, key functional correlates in the envelope trimer remain undefined. We utilized a combination of structural analysis, in silico energy calculation, mutagenesis, and neutralization profiling to dissect the functional anatomy of the trimer apex, which acts as a global regulator of the HIV-1 spike conformation. We identify four hydrophobic clusters that stabilize the spike in a tightly closed configuration and, thereby, play a critical role in protecting it from the reach of neutralizing antibodies.

The extraordinary ability of human immunodeficiency virus type 1 (HIV-1) to evade host immunity represents a major obstacle to the development of a protective vaccine. Thus, elucidating the mechanisms whereby HIV-1 protects its external envelope (Env), which is the sole target of virus-neutralizing antibodies, is an essential step toward vaccine design. We identified a key structural element that maintains the HIV-1 Env trimer in a closed, antibody-resistant conformation. A major role is played by two conserved tyrosines at the apex of the Env spike, whose mutation causes a global opening of the trimer structure, exposing multiple concealed targets for neutralizing antibodies. We also found that HIV-infected individuals produce very large amounts of antibodies that neutralize the open Env form; however, the bulk of these antibodies are unable to penetrate the tight defensive shield of the native virus. This work may help to devise new strategies to overcome the viral defensive mechanisms and facilitate the development of an effective HIV-1 vaccine. The human immunodeficiency virus type 1 (HIV-1) envelope (Env) trimer evades antibody recognition by adopting a closed prefusion conformation. Here, we show that two conserved tyrosines (Y173, Y177) within the second variable (V2) loop of the gp120 Env glycoprotein are key regulators of the closed, antibody-protected state of the trimer by establishing intramolecular interaction with the base of the third variable (V3) loop. Mutation of Y177 and/or Y173 to phenylalanine or alanine dramatically altered the susceptibility of diverse HIV-1 strains to neutralization, increasing sensitivity to weakly and nonneutralizing antibodies directed against diverse Env regions, consistent with the adoption of an open trimer configuration. Conversely, potent broadly neutralizing antibodies (bNAbs) against different supersites of HIV-1 vulnerability exhibited reduced potency against V2 loop tyrosine mutants, consistent with their preferential targeting of the closed trimer. Mutation of V3 loop residues predicted to interact with the V2 loop tyrosines yielded a similar neutralization phenotype. Sera from chronically HIV-1-infected patients contained very high titers of antibodies capable of neutralizing V2 loop tyrosine mutants but not wild-type viruses, indicating that the bulk of antibodies produced in infected hosts are unable to penetrate the protective shield of the closed trimer. These results identify the tyrosine-mediated V2-V3 loop complex at the trimer apex as a key structural constraint that facilitates HIV-1 evasion from the bulk of host antibodies. IMPORTANCE The extraordinary ability of human immunodeficiency virus type 1 (HIV-1) to evade host immunity represents a major obstacle to the development of a protective vaccine. Thus, elucidating the mechanisms whereby HIV-1 protects its external envelope (Env), which is the sole target of virus-neutralizing antibodies, is an essential step toward vaccine design. We identified a key structural element that maintains the HIV-1 Env trimer in a closed, antibody-resistant conformation. A major role is played by two conserved tyrosines at the apex of the Env spike, whose mutation causes a global opening of the trimer structure, exposing multiple concealed targets for neutralizing antibodies. We also found that HIV-infected individuals produce very large amounts of antibodies that neutralize the open Env form; however, the bulk of these antibodies are unable to penetrate the tight defensive shield of the native virus. This work may help to devise new strategies to overcome the viral defensive mechanisms and facilitate the development of an effective HIV-1 vaccine.

Cryo-EM analyses of the initial contact of the HIV-1 Env trimer with the CD4 receptor reveal that CD4 interacts with two gp120 protomers; these quaternary contacts are important for viral infectivity. Binding of the gp120 envelope (Env) glycoprotein to the CD4 receptor is the first step in the HIV-1 infectious cycle. Although the CD4-binding site has been extensively characterized, the initial receptor interaction has been difficult to study because of major CD4-induced structural rearrangements. Here we used cryogenic electron microscopy (cryo-EM) to visualize the initial contact of CD4 with the HIV-1 Env trimer at 6.8-Å resolution. A single CD4 molecule is embraced by a quaternary HIV-1–Env surface formed by coalescence of the previously defined CD4-contact region with a second CD4-binding site (CD4-BS2) in the inner domain of a neighboring gp120 protomer. Disruption of CD4-BS2 destabilized CD4-trimer interaction and abrogated HIV-1 infectivity by preventing the acquisition of coreceptor-binding competence. A corresponding reduction in HIV-1 infectivity occurred after the mutation of CD4 residues that interact with CD4-BS2. Our results document the critical role of quaternary interactions in the initial HIV-Env-receptor contact, with implications for treatment and vaccine design.

PurposeChemotherapy-induced peripheral neuropathy (CIPN) is a common, debilitating side effect in cancer survivors. This study aimed to assess the characteristics of quantitative sensory testing (QST) and its correlation with patient-reported outcomes (PROs) in cancer patients with and without CIPN.MethodsWe conducted a cross-sectional analysis using baseline data from two clinical trials in solid tumor cancer survivors with no CIPN symptoms rated < 2 on a 0–10 Numerical Rating Scale (NRS) or moderate-to-severe CIPN rated ≥ 4 on the NRS. We collected PROs (NRS, Neuropathic Pain Scale, and Functional Assessment of Cancer Therapy-Gynecologic Oncology Group/Neurotoxicity subscale at baseline. QST [Tactile Threshold (TT), Vibration Threshold (VT), Thermal Threshold (THT)] measurements were used to assess sensory fiber function; they were compared between patients with and without CIPN using Wilcoxon rank-sum tests. We used Spearman correlation coefficients to estimate associations between PROs and QST in all patients.ResultsAmong 116 participants with CIPN (median NRS 5.00) and 10 participants without CIPN (median NRS 0.00), the median (interquartile range) TT was 3.84 (3.47, 4.12) and 3.53 (3.00, 3.84) in feet, respectively (p = 0.043). The median VT was 17.90 (9.42, 26.95) and 7.73 (5.94, 11.11) in feet, respectively (p = 0.001). Thermal cool threshold was 30.00 °C (28.90, 30.57) and 30.67 °C (30.57, 30.93), respectively (p = 0.007). Correlation coefficients between PROs and QST measures ranged between 0.02 and 0.50 in absolute magnitude.ConclusionPatients with moderate-to-severe CIPN had significantly impaired tactile, vibratory, and thermal thresholds compared to patients without CIPN. QST correlates with PROs, suggesting CIPN symptom severity may correspond to sensory fiber functionality. QST may be incorporated into future CIPN research.

Enteric glial cells (EGCs) are a major component of the enteric nervous system. Despite sharing some molecular and functional similarities to astrocytes in the central nervous system, the role of EGCs in a non-sterile, immunogenic environment is still largely unexplored. To investigate whether EGCs exhibit normal astrocytic functions or provide tissue-specific functions in the gut, translating ribosome affinity purification was used to enrich for and profile colonic EGC mRNA transcripts. This method revealed expression of Ltf (Lactoferrin), an iron-binding antimicrobial protein, known to be secreted by neutrophils during active inflammation. This feature of EGCs was anatomically restricted to the colon, and within the healthy mouse colon, EGCs were the primary source of LTF. Mice with EGC-specific ablation of Ltf exhibited colon-specific reduction in goblet cell numbers and associated changes in mucus properties. Further, EGC-specific Ltf-deficient mice had alterations in specific species of commensal gut bacteria, demonstrating a role for EGCs in regulating the gut microbiome.

The Geometrization Theorem for 3-manifolds states that every closed orientable 3-manifold can be cut along spheres and tori into pieces which have a geometric structure modeled on one of the eight, 3-dimensional geometries. In joint work with Dennis Sullivan, we combine the different geometries on the toroidal ends of 3-manifolds to describe a uniform geometric structure for all oriented closed prime 3-manifolds. Hyperbolic structures on links in the thickened torus and their geometric properties have been of great interest recently. We discuss geometric properties of augmented and fully augmented links in the thickened torus. We show how sequences of fully augmented links in the 3-sphere which diagrammatically converge to a biperiodic fully augmented link have interesting asymptotic volume growth.