Characterization of SARS-CoV-2-specific humoral immunity and associated factors in the healthy population post-vaccination.

OBJECTIVES: To investigate factors that may influence humoral immunity post-vaccination with a COVID-19-inactivated vaccine (SC2IV). METHODS: A total of 1596 healthy individuals from the Seventh Affiliated Hospital, Sun Yat-sen University (1217) and Shenzhen Baotian Hospital (379) were enrolled in this study among which 694 and 218 participants were vaccinated with two-dose SC2IV, respectively. Physical examination indices were recorded. The levels of neutralizing antibody (NA), Spike IgG, receptor-binding domain (RBD) IgG, RBD IgG + IgM + IgA, and nucleocapsid IgG of SARS-CoV-2 were measured by a non-virus ELISA kit. Multiple statistical analyses were carried out to identify factors that influence humoral immunity post-vaccination. RESULTS: The two-dosage vaccination could induce NA in more than 90 % of recipients. The NA has the strongest correlation with anti-RBD IgG. Age is the most important independent index that affects the NA level, while basophil count, creatine kinase-MB, mean corpuscular hemoglobin, the ratio of albumin to urine creatinine, and thyroglobulin antibody have relatively minor contributions. Indices that affect the NA level were different between males and females. Antibodies targeting other epitopes of SARS-CoV-2 were detected in recipients without anti-RBD. CONCLUSIONS: The factors identified in association with the NA level post-vaccination may help to evaluate the protective effect, risk of re-infection, the severity of symptoms, and prognosis for vaccine recipients in clinical.

Platelet dropping, bleeding and new treatment requirements in ITP patients after inactivated COVID-19 vaccination.

Significant decreases in platelet counts and ITP relapses have been documented in ITP patients receiving COVID-19 mRNA vaccines; however, the effect of the inactivated COVID-19 vaccine on ITP patients remains unclear. The present study aimed to investigate the impact of inactivated COVID-19 vaccines on ITP patients, with a focus on platelet dropping events, bleeding events/scores, and the requirement of a new round of treatment. A total of 118 ITP patients, with 97 chronic ITP and 21 persistent ITP, who received inactivated COVID-19 immunization were investigated retrospectively. Following vaccination (within 1 month), ITP patients reported platelet dropping (31.36 %), new bleeding events (22.88 %), increases in bleeding scores (23.73 %), and new treatment requirements (22.03 %). Among them, persistent ITP patients with disease duration of 3-12 months had higher ratios of the above adverse events (71.43 %, 57.14 %, 61.90 % and 71.43 %, respectively) than chronic ITP patients with duration > 1 year (22.68 %, 15.46 %, 15.46 % and 11.34 %, respectively); patients' disease duration was negatively correlated with platelet dropping events and new treatment requirements. Furthermore, logistic regression analysis also supported the above findings, revealing that persistent ITP patients had 9.40-9.70, 7.24-10.08, and 27.17-28.51 times incidence of having platelet dropping events, new bleeding events, and new treatment requirements after vaccination, respectively, when compared to chronic ITP patients. In conclusion, the present study demonstrates that after receiving inactivated COVID-19 vaccines, ITP patients may experience platelet dropping, which may lead to new bleeding events and the requirement of a new round of treatment for ITP recurrence. As a result, platelet level monitoring is crucial for ITP patients during the vaccination, especially those with persistent ITP.

Mpox virus mRNA-lipid nanoparticle vaccine candidates evoke antibody responses and drive protection against the Vaccinia virus challenge in mice.

In response to the human Mpox (hMPX) epidemic that began in 2022, there is an urgent need for a monkeypox vaccine. Here, we have developed a series of mRNA-lipid nanoparticle (mRNA-LNP)-based vaccine candidates that encode a collection of four highly conserved Mpox virus (MPXV) surface proteins involved in virus attachment, entry, and transmission, namely A29L, A35R, B6R, and M1R, which are homologs to Vaccinia virus (VACV) A27, A33, B5, and L1, respectively. Despite possible differences in immunogenicity among the four antigenic mRNA-LNPs, administering these antigenic mRNA-LNPs individually (5 µg each) or an average mixture of these mRNA-LNPs at a low dose (0.5 µg each) twice elicited MPXV-specific IgG antibodies and potent VACV-specific neutralizing antibodies. Furthermore, two doses of 5 µg of A27, B5, and L1 mRNA-LNPs or a 2 µg average mixture of the four antigenic mRNA-LNPs protected mice against weight loss and death after the VACV challenge. Overall, our data suggest that these antigenic mRNA-LNP vaccine candidates are both safe and efficacious against MPXV, as well as diseases caused by other orthopoxviruses.

Gastric cancer clinical characteristics and their altered trends in South China: An epidemiological study with 2,800 cases spanning 26 years.

Background: Gastric cancer (GC) is a serious threat to human health. The clinical GC characteristics in China may be impacted by changes in people's lifestyles and the promotion of early GC (EGC) screening. The present study aims to evaluate the recent trends of GC characteristics in South China and search for hazardous factors limiting the survival time of GC patients. Methods: Data on GC patients that were hospitalized in the Department of Digestive Center, the First Affiliated Hospital, Sun Yat-sen University, from 1994 to 2019 were collected and divided into two categories according to the time when the EGC screening began in China: the PRE group (previous 13 years, 1994-2006) and the PAS group (past 13 years, 2007-2019). Results: We found that, although the 5-year survival rate increased in the PAS group compared with the PRE group (P < 0.0001), patients with age ≥60 years or Borrmann type IV still had a worse prognosis. In the PAS group, the larger percentages of elderly patients and patients with Borrmann type IV in the lymphatic metastases (N1) group (41.0% vs. 51.1%, P = 0.0014) and stage IV subgroup (20.7% vs. 32.2%, P = 0.016), respectively, when compared with the PRE group, may have contributed to the poor outcome of GC. By comparing the odds ratio (OR) of 5-year overall survival (OS) in the two 13-year periods, female sex and T2 turned into risk factors because of a greater proportion of Borrmann type IV or elderly patients in the PAS group (OR = 0.983, 95% CI = 0.723-1.336 vs. OR = 1.277, 95% CI = 1.028-1.586 and OR = 1.545, 95% CI = 0.499-4.775 vs. OR = 2.227, 95% CI = 1.124-4.271, respectively). Conclusions: Despite the GC epidemiology changes, the overall prognosis of GC patients has improved in South China. However, old age and Borrmann type IV are still the major restrictions affecting the survival of GC patients, a situation which calls for additional attention.

Corrigendum: Antimicrobial susceptibility profiles and tentative epidemiological cutoff values of Legionella pneumophila from environmental water and soil sources in China.

[This corrects the article DOI: 10.3389/fmicb.2022.924709.].

Antimicrobial susceptibility profiles and tentative epidemiological cutoff values of Legionella pneumophila from environmental water and soil sources in China.

Legionnaires' disease (LD), caused by Legionella, including the most prevalent Legionella pneumophila, has been treated primarily with antibiotics. Environmental water and soil are the reservoirs for L. pneumophila. Studying antimicrobial susceptibility using a large number of isolates from various environmental sources and regions could provide an unbiased result. In the present study, antimicrobial susceptibility of 1464 environmental L. pneumophila isolates that were derived from various environmental water and soil sources of 12 cities in China to rifampin (RIF), erythromycin (ERY), clarithromycin (CLA), azithromycin (AZI), ciprofloxacin (CIP), moxifloxacin (MOX), levofloxacin (LEV), and doxycycline (DOX) was investigated, and minimum inhibitory concentration (MIC) data were obtained. We show that regarding macrolides, ERY was least active (MIC90 = 0.5 mg/L), while CLA was most active (MIC90 = 0.063 mg/L). A total of three fluoroquinolones have similar MICs on L. pneumophila. Among these antimicrobials, RIF was the most active agent, while DOX was the most inactive one. We observed different susceptibility profiles between serogroup 1 (sg1) and sg2-15 or between water and soil isolates from different regions. The ECOFFs were ERY and AZI (0.5 mg/L), RIF (0.002 mg/L), CIP, CLA and MOX (0.125 mg/L), LEV (0.063 mg/), and DOX (32 mg/L). Overall, two fluoroquinolone-resistant environmental isolates (0.14%) were first documented based on the wild-type MIC distribution. Not all azithromycin-resistant isolates (44/46, 95.65%) harbored the lpeAB efflux pump. The MICs of the ERY and CLA on the lpeAB + isolates were not elevated. These results suggested that the lpeAB efflux pump might be only responsible for AZI resistance, and undiscovered AZI-specific resistant mechanisms exist in L. pneumophila. Based on the big MIC data obtained in the present study, the same defense strategies, particularly against both CLA and RIF, may exist in L. pneumophila. The results determined in our study will guide further research on antimicrobial resistance mechanisms of L. pneumophila and could be used as a reference for setting clinical breakpoints and discovering antimicrobial-resistant isolates in the clinic, contributing to the antibiotic choice in the treatment of LD.

Identification of Peptoniphilus vaginalis-Like Bacteria, Peptoniphilus septimus sp. nov., From Blood Cultures in a Cervical Cancer Patient Receiving Chemotherapy: Case and Implications.

A 39-year-old woman with a 3-year human papillomavirus (HPV) 18 infection history was admitted to the hospital for a 16-day history of vaginal bleeding after sex. She was diagnosed with cervical cancer based on the results of the electronic colposcopy, cervical cytology, microscopy, and magnetic resonance imaging (MRI). Then, she received chemotherapy, with paclitaxel 200 mg (day 1), cisplatin 75 mg (day 2), and bevacizumab 700 mg (day 3) twice with an interval of 27 days. During the examination for the diagnosis and treatment, many invasive operations, including removal of intrauterine device, colposcopy, and ureteral dilatation, were done. After that, the patient was discharged and entered the emergency department about 2.5 months later with a loss of consciousness probably caused by septic shock. The patient finally died of multiple organ failure and bacterial infection, although she has received antimicrobial therapy. The blood cultures showed a monobacterial infection with an anaerobic Gram-positive bacterial strain, designated as SAHP1. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) indicated that the patient was infected with Peptoniphilus asaccharolyticus, while molecular analysis and genome-based taxonomy confirmed the infection with a novel Peptoniphilus species that has a close genetic relationship with Peptoniphilus vaginalis and proposed provisionally as Peptoniphilus septimus sp. nov., which may also act as a commensal of the human vagina. Genomic features of SAHP1 have been fully described, and comparative genomic analysis reveals the known prokaryote relative of Peptoniphilus septimus sp. nov. in the genus Peptoniphilus. The invasive operations on the genital tract during the diagnosis and treatment of the patient and the tumor tissue damage and bleeding may have a certain role in the bloodstream infection. This study casts a new light on the Peptoniphilus bacteria and prompts clinicians to include anaerobic blood cultures as part of their blood culture procedures, especially on patients with genital tract tumors. Furthermore, due to the incomplete database and unsatisfying resolution of the MALDI-TOF MS for Peptoniphilus species identification, molecular identification, especially whole-genome sequencing, is required for those initially identified as bacteria belonging to Peptoniphilus in the clinical laboratory.

Correlation between thrombopoietin and inflammatory factors, platelet indices, and thrombosis in patients with sepsis: A retrospective study.

BACKGROUND: Thrombopoietin (TPO) is a primary regulator of thrombopoiesis in physiological conditions. TPO, in combination with its specific cytokine receptor c-Mpl, drives platelet production by inducing the proliferation and differentiation of megakaryocytes. However, the role of TPO in sepsis is not well determined. The elevated levels of TPO are often accompanied by a decrease of platelet count (PLT) in systemic infected conditions, which is contrary to the view that TPO promotes platelet production under physiological conditions. In addition, whether TPO mediates organ damage in sepsis remains controversial. AIM: To explore the relationships between TPO and inflammatory factors, platelet indices, and thrombotic indicators in sepsis. METHODS: A total of 90 patients with sepsis diagnosed and treated at the emergency medicine department of The First People's Hospital of Foshan between January 2020 and March 2021 were enrolled in this study. In addition, 110 patients without sepsis who came to the emergency medicine department were included as controls. Clinical and laboratory parameters including age, gender, TPO, blood cell count in peripheral blood, platelet indices, inflammatory factors such as high-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-21, and IL-6, organ damage indicators, and thrombotic indicators were collected and analyzed by using various statistical approaches. RESULTS: The results showed that the TPO levels were higher in the sepsis group than in controls [86.45 (30.55, 193.1) vs 12.45 (0.64, 46.09) pg/mL, P < 0.001], but PLT was lower (P < 0.001). Multivariable analysis showed that white blood cell count (WBC) [odds ratio (OR) = 1.32; 95% confidence interval (CI): 1.01-1.722; P = 0.044], TPO (OR = 1.02; 95%CI: 1.01-1.04; P = 0.009), IL-21 (OR = 1.02; 95%CI: 1.00-1.03; P = 0.019), troponin I (OR = 55.20; 95%CI: 5.69-535.90; P = 0.001), and prothrombin time (PT) (OR = 2.24; 95%CI: 1.10-4.55; P = 0.027) were independent risk factors associated with sepsis. TPO levels were positively correlated with IL-21, IL-6, hs-CRP, creatinine, D-dimer, PT, activated prothrombin time, international normalized ratio, fibrinogen, WBC count, and neutrophil count, and negatively correlated with PLT, thrombin time, red blood cell count, and hemoglobin concentration (P < 0.05). Receiver operating characteristic analysis showed that TPO had fair predictive value in distinguishing septic patients and non-septic patients (the area under the curve: 0.788; 95%CI: 0.723-0.852; P < 0.001). With an optimized cutoff value (28.51 pg/mL), TPO had the highest sensitivity (79%) and specificity (65%). CONCLUSION: TPO levels are independently associated with sepsis. High TPO levels and low PLT suggest that TPO might be an acute-phase response protein in patients with infection.

Tanshinone IIA Has a Potential Therapeutic Effect on Kawasaki Disease and Suppresses Megakaryocytes in Rabbits With Immune Vasculitis.

Background and Objective: It is urgent to find out an alternative therapy for Kawasaki disease (KD) since around 20% patients are resistant to intravenous immunoglobulin (IVIG) or aspirin. Tanshinone IIA is the active component of the traditional Chinese medicine Danshen (Salvia miltiorrhiza), which has anti-inflammatory and anti-platelet properties; however, whether or not tanshinone IIA has a therapeutic effect on KD remains unclear. Therefore, the present study aimed to examine the effect of tanshinone IIA on KD patients and rabbits with immune vasculitis, and to identify the potential mechanisms with special emphasis on megakaryopoiesis and megakaryocytic apoptosis. Methods: Kawasaki disease patients were recruited and prescribed with tanshinone IIA in the absence or presence of aspirin and IVIG, and the inflammatory responses and platelet functions were determined. Megakaryocytes (MKs) isolated from rabbits with immune vasculitis and human megakaryocytic CHRF-288-11 cells were treated with tanshinone IIA to examine the colony forming unit (CFU) and apoptosis, respectively. Microarray assay was conducted to identify potential targets of tanshinone IIA-induced apoptosis. Results: Tanshinone IIA reduced the serum levels of C-reactive protein (CRP), interleukin (IL)-1ß, IL-6, and P-selectin in KD patients; such inhibitory effect was more significant compared to aspirin and IVIG. It also dose-dependently lowered the levels of tumor necrosis factor (TNF)-α and IL-8 in peripheral blood mononuclear cells isolated from KD patients. In rabbits with immune vasculitis, tanshinone IIA significantly reduced the serum levels of proinflammatory cytokines and platelet functions. In addition, tanshinone IIA significantly decreased the number of bone marrow MKs and inhibited the Colony Forming Unit-Megakaryocyte (CFU-MK) formation. In human megakaryocytic CHRF-288-11 cells, tanshinone IIA induced caspase-dependent apoptosis, probably through up-regulating TNF receptor superfamily member 9 (TNFRSF9) and the receptor (TNFRSF)-interacting serine/threonine-protein kinase 1 (RIPK1), which may contribute to its anti-platelet and anti-inflammatory properties. Conclusion: Tanshinone IIA exerts better anti-inflammatory and anti-platelet effects in treating KD patients than aspirin and IVIG. It attenuates immune vasculitis likely by inhibiting IL-mediated megakaryopoiesis and inducing TNFRSF9/RIPK1/caspase-dependent megakaryocytic apoptosis. The findings therefore suggest that tanshinone IIA may be a promising alternative therapy for the treatment of KD.

Presence of Viable, Clinically Relevant Legionella Bacteria in Environmental Water and Soil Sources of China.

The distribution of pathogenic Legionella in the environmental soil and water of China has not been documented yet. In this study, Legionella was detected in 129 of 575 water (22.43%) and 41 of 442 soil samples (9.28%) by culture. Twelve Legionella species were identified, of which 11 were disease-associated. Of the Legionella-positive samples, 109 of 129 (84.50%) water and 29 of 41 (70.73%) soil were positive for L. pneumophila, which accounted for about 75% of Legionella isolates in both water and soil, suggesting L. pneumophila was the most frequent species. Soil showed a higher diversity of Legionella spp. as compared with water (0.6279 versus 0.4493). In contrast, serogroup (sg) 1 was more prevalent among L. pneumophila isolates from water than from soil (26.66% versus 12.21%). Moreover, many disease-associated sequence types (STs) of L. pneumophila were found in China. Intragenic recombination was acting on L. pneumophila from both water and soil. Phylogeny, population structure, and molecular evolution analyses revealed a probable existence of L. pneumophila isolates with a special genetic background that is more adaptable to soil or water sources and a small proportion of genetic difference between water and soil isolates. The detection of viable, clinically relevant Legionella demonstrates soil as another source for harboring and dissemination of pathogenic Legionella bacteria in China. Future research should assess the implication in public health with the presence of Legionella in the soil and illustrate the genetic and pathogenicity difference of Legionella between water and soil, particularly the most prevalent L. pneumophila. IMPORTANCE Pathogenic Legionella spp. is the causative agent of Legionnaires' disease (LD), and L. pneumophila is the most common one. Most studies have focused on L. pneumophila from water and clinical samples. However, the soil is another important reservoir for this bacterium, and the distribution of Legionella spp. in water and soil sources has not been compared and documented in China yet. Discovering the distribution of Legionella spp. and L. pneumophila in the two environments may help a deep understanding of the pathogenesis and molecular evolution of the bacterium. Our research systematically uncovered the distributions of Legionella spp. in different regions and sources (e.g., water and soil) of China. Moreover, phylogeny, population structure, and molecular evolution study revealed the possible existence of L. pneumophila with a special genetic background that is more adaptable to soil or water sources, and genetic difference may exist.

Toll-like receptor 10 expression in B cells is negatively correlated with the progression of primary Sjögren's disease.

Primary Sjögren's Disease (pSjD) is considered a B cell-mediated disease. Toll-like receptor 10 (TLR10) is highly expressed in human B cells, indicating that TLR10 probably plays a vital role in pSjD. We examined TLR10 expression in peripheral B subsets of pSjD patients and analyzed their association with disease activity. We observed that TLR10 expression in total, naïve, memory, and switched memory B cells was significantly increased in low-activity pSjD patients as compared with healthy controls and high-activity patients. TLR10 expression in the above mentioned B subsets (except naïve B) was negatively correlated with serum levels of anti-SSA antibody and BAFF, respectively. Moreover, a higher proportion of high-activity pSjD patients was observed in TLR10 low- than high-expressed patients. Our study concluded that TLR10 expression in CD19+ B and memory B was negatively correlated with pSjD disease activity, suggesting that TLR10 might take part in the progression of pSjD.

Polysaccharide-Based Hydrogels for Wound Dressing: Design Considerations and Clinical Applications.

Wound management remains a worldwide challenge. It is undeniable that patients with problems such as difficulties in wound healing, metabolic disorder of the wound microenvironment and even severely infected wounds etc. always suffer great pain that affected their quality of lives. The selection of appropriate wound dressings is vital for the healing process. With the advances of technology, hydrogels dressings have been showing great potentials for the treatment of both acute wounds (e.g., burn injuries, hemorrhage, rupturing of internal organs/aorta) and chronic wounds such as diabetic foot and pressure ulcer. Particularly, in the past decade, polysaccharide-based hydrogels which are made up with abundant and reproducible natural materials that are biocompatible and biodegradable present unique features and huge flexibilities for modifications as wound dressings and are widely applicable in clinical practices. They share not only common characteristics of hydrogels such as excellent tissue adhesion, swelling, water absorption, etc., but also other properties (e.g., anti-inflammatory, bactericidal and immune regulation), to accelerate wound re-epithelialization, mimic skin structure and induce skin regeneration. Herein, in this review, we highlighted the importance of tailoring the physicochemical performance and biological functions of polysaccharide-based hydrogel wound dressings. We also summarized and discussed their clinical states of, aiming to provide valuable hints and references for the future development of more intelligent and multifunctional wound dressings of polysaccharide hydrogels.

Concept about the Virulence Factor of Legionella.

Pathogenic species of Legionella can infect human alveolar macrophages through Legionella-containing aerosols to cause a disease called Legionellosis, which has two forms: a flu-like Pontiac fever and severe pneumonia named Legionnaires' disease (LD). Legionella is an opportunistic pathogen that frequently presents in aquatic environments as a biofilm or protozoa parasite. Long-term interaction and extensive co-evolution with various genera of amoebae render Legionellae pathogenic to infect humans and also generate virulence differentiation and heterogeneity. Conventionally, the proteins involved in initiating replication processes and human macrophage infections have been regarded as virulence factors and linked to pathogenicity. However, because some of the virulence factors are associated with the infection of protozoa and macrophages, it would be more accurate to classify them as survival factors rather than virulence factors. Given that the molecular basis of virulence variations among non-pathogenic, pathogenic, and highly pathogenic Legionella has not yet been elaborated from the perspective of virulence factors, a comprehensive explanation of how Legionella infects its natural hosts, protozoans, and accidental hosts, humans is essential to show a novel concept regarding the virulence factor of Legionella. In this review, we overviewed the pathogenic development of Legionella from protozoa, the function of conventional virulence factors in the infections of protozoa and macrophages, the host's innate immune system, and factors involved in regulating the host immune response, before discussing a probably new definition for the virulence factors of Legionella.

Evolutionary dissection of monkeypox virus: Positive Darwinian selection drives the adaptation of virus-host interaction proteins.

The emerging and ongoing outbreak of human monkeypox (hMPX) in 2022 is a serious global threat. An understanding of the evolution of the monkeypox virus (MPXV) at the single-gene level may provide clues for exploring the unique aspects of the current outbreak: rapidly expanding and sustained human-to-human transmission. For the current investigation, alleles of 156 MPXV coding genes (which account for >95% of the genomic sequence) have been gathered from roughly 1,500 isolates, including those responsible for the previous outbreaks. Using a range of molecular evolution approaches, we demonstrated that intra-species homologous recombination has a negligible effect on MPXV evolution. Despite the fact that the majority of the MPXV genes (64.10%) were subjected to negative selection at the whole gene level, 10 MPXV coding genes (MPXVgp004, 010, 012, 014, 044, 098, 138, 178, 188, and 191) were found to have a total of 15 codons or amino acid sites that are known to evolve under positive Darwinian selection. Except for MPXVgp138, almost all of these genes encode proteins that interact with the host. Of these, five ankyrin proteins (MPXVgp004, 010, 012, 178, and 188) and one Bcl-2-like protein (MPXVgp014) are involved in poxviruses' host range determination. We discovered that the majority (80%) of positive amino acid substitutions emerged several decades ago, indicating that these sites have been under constant selection pressure and that more adaptable alleles have been circulating in the natural reservoir. This finding was also supported by the minimum spanning networks of the gene alleles. The three positive amino acid substitutions (T/A426V in MPXVgp010, A423D in MPXVgp012, and S105L in MPXVgp191) appeared in 2019 or 2022, indicating that they would be crucial for the virus' eventual adaptation to humans. Protein modeling suggests that positive amino acid substitutions may affect protein functions in a variety of ways. Further study should focus on revealing the biological effects of positive amino acid substitutions in the genes for viral adaptation to humans, virulence, transmission, and so on. Our study advances knowledge of MPXV's adaptive mechanism and provides insights for exploring factors that are responsible for the unique aspects of the current outbreak.

GDPLichi: a DNA Damage Repair-Related Gene Classifier for Predicting Lung Adenocarcinoma Immune Checkpoint Inhibitors Response.

Lung cancer is one of the most common and mortal malignancies, usually with a poor prognosis in its advanced or recurrent stages. Recently, immune checkpoint inhibitors (ICIs) immunotherapy has revolutionized the treatment of human cancers including lung adenocarcinoma (LUAD), and significantly improved patients' prognoses. However, the prognostic and predictive outcomes differ because of tumor heterogeneity. Here, we present an effective method, GDPLichi (Genes of DNA damage repair to predict LUAD immune checkpoint inhibitors response), as the signature to predict the LUAD patient's response to the ICIs. GDPLichi utilized only 7 maker genes from 8 DDR pathways to construct the predictive model and classified LUAD patients into two subgroups: low- and high-risk groups. The high-risk group was featured by worse prognosis and decreased B cells, CD8+ T cells, CD8+ central memory T cells, hematopoietic stem cells (HSC), myeloid dendritic cells (MDC), and immune scores as compared to the low-risk group. However, our research also suggests that the high-risk group was more sensitive to ICIs, which might be explained by increased TMB, neoantigen, immune checkpoint molecules, and immune suppression genes' expression, but lower TIDE score as compared to the low-risk group. This conclusion was verified in three other LUAD cohort datasets (GSE30219, GSE31210, GSE50081).

Virulence effector SidJ evolution in Legionella pneumophila is driven by positive selection and intragenic recombination.

Effector proteins translocated by the Dot/Icm type IV secretion system determine the virulence of Legionella pneumophila (L. pneumophila). Among these effectors, members of the SidE family (SidEs) regulate several cellular processes through a unique phosphoribosyl ubiquitination mechanism mediated by another effector, SidJ. Host-cell calmodulin (CaM) activates SidJ to glutamylate the SidEs of ubiquitin (Ub) ligases and to make a balanced Ub ligase activity. Given the central role of SidJ in this regulatory process, studying the nature of evolution of sidJ is important to understand the virulence of L. pneumophila and the interaction between the bacteria and its hosts. By studying sidJ from a large number of L. pneumophila strains and using various molecular evolution algorithms, we demonstrated that intragenic recombination drove the evolution of sidJ and contributed to sidJ diversification. Additionally, we showed that four codons of sidJ which are located in the N-terminal (NTD) (codons 58 and 200) and C-terminal (CTD) (codons 868 and 869) domains, but not in the kinase domain (KD) had been subjected to strong positive selection pressure, and variable mutation profiles of these codons were identified. Protein structural modeling of SidJ provided possible explanations for these mutations. Codons 868 and 869 mutations might engage in regulating the interactions of SidJ with CaM through hydrogen bonds and affect the CaM docking to SidJ. Mutation in codon 58 of SidJ might affect the distribution of main-chain atoms that are associated with the interaction with CaM. In contrast, mutations in codon 200 might influence the α-helix stability in the NTD. These mutations might be important to balance Ub ligase activity for different L. pneumophila hosts. This study first reported that intragenic recombination and positive Darwinian selection both shaped the genetic plasticity of sidJ, contributing to a deeper understanding of the adaptive mechanisms of this intracellular bacterium to different hosts.

Development and Characterization of High Efficacy Cell-Penetrating Peptide via Modulation of the Histidine and Arginine Ratio for Gene Therapy.

Cell-penetrating peptides (CPPs), as non-viral gene delivery vectors, are considered with lower immunogenic response, and safer and higher gene capacity than viral systems. In our previous study, a CPP peptide called RALA (arginine rich) presented desirable transfection efficacy and owns a potential clinic use. It is believed that histidine could enhance the endosome escaping ability of CPPs, yet RALA peptide contains only one histidine in each chain. In order to develop novel superior CPPs, by using RALA as a model, we designed a series of peptides named HALA (increased histidine ratio). Both plasmid DNA (pDNA) and siRNA transfection results on three cell lines revealed that the transfection efficacy is better when histidine replacements were on the C-terminal instead of on the N-terminal, and two histidine replacements are superior to three. By investigating the mechanism of endocytosis of the pDNA nanocomplexes, we discovered that there were multiple pathways that led to the process and caveolae played the main role. During the screening, we discovered a novel peptide-HALA2 of high cellular transfection efficacy, which may act as an exciting gene delivery vector for gene therapy. Our findings also bring new insights on the development of novel robust CPPs.

Elderly Male With Cardiovascular-Related Comorbidities Has a Higher Rate of Fatal Outcomes: A Retrospective Study in 602 Patients With Coronavirus Disease 2019.

Elderly with comorbidities have shown a higher rate of fatal outcomes when suffering coronavirus disease 2019 (COVID-19). However, a delineation of clinical significances of hematologic indices and underlying comorbidities in the progression and outcome of COVID-19 remains undefined. Six hundred two COVID-19 patients with established clinical outcomes (discharged or deceased) from Hankou Hospital of Wuhan, China between January 14, 2020 and February 29, 2020 were retrospectively analyzed. Of the 602 patients with COVID-19, 539 were discharged and 63 died in the hospital. The deceased group showed higher leukocyte and neutrophil counts but lower lymphocyte and platelet counts. Longer activated partial thromboplastin time (APTT) and prothrombin time (PT), as well as higher D-dimer and C-reactive protein levels, were found in non-survivors. Our observations suggest that these parameters could serve as potential predictors for the fatal outcome and in the discharged group. A higher neutrophil count and D-dimer level but lower lymphocyte were associated with a longer duration of hospitalization. A multivariable Cox regression analysis showed that higher neutrophil count, prolonged PT, and low lymphocyte count were risk factors for patients with COVID-19. Also, we found an association of lower lymphocyte count and higher C-reactive protein levels with the elderly group and those with cardiovascular-related comorbidities. The significantly different hematologic profiles between survivors and non-survivors support that distinct hematologic signatures in COVID-19 patients will dictate different outcomes as a prognostic marker for recovery or fatality. Lymphopenia and aggressive inflammatory response might be major causes for fatal outcomes in the elderly male and especially those with cardiovascular-related comorbidities.

Legionella septentrionalis sp. nov., isolated from aquatic environments in the northern PR China.

Four strains (km711T, km714, km542 and km524), representing a novel Legionella species, were isolated from aquatic environments in northern PR China. Cells were Gram-stain-negative, rod-shaped, microaerobic, motile and growth depended on l-cysteine. They grew at 25‒42 °C (optimum, 35‒37 °C) and could tolerate up to 1.5 % (w/v) NaCl (optimum, 0.5 %). The major fatty acids (>5 %) of the type strain km711T were C17 : 0 anteiso, C15 : 0 anteiso, iso-C16 : 0 and C16 : 1 ω7c and/or iso-C15 : 0 2OH. The pairwise comparison values were <96.1 % for 16S rRNA gene sequences, 23.3‒28.7 % interspecies variation for mip gene sequences, <93.6 % average nucleotide identity and <72.8 % average amino acid identity between these four strains and related type strains within the genus Legionella. The phylogenetic tree based on the four concatenated genes (16S rRNA, mip, rpoB and rnpB) and protein-concatamer tree based on concatenation of 21 protein markers both revealed that these four strains formed a separate phylogenetic branch cluster within the genus Legionella. The results of phenotypic and genotypic features suggest that these four strains represent a novel species of the genus Legionella, for which the name Legionella septentrionalis sp. nov. is proposed (type strain km711T=KCTC 15655T=NBRC 113219T).