Objective This study conducted molecular biological identification of the viruses carried by Culex pipiens pallens specimens collected in Shunyi District, Beijing in 2023, and observed the changes in the infection rate of the viruses carried by Cx. pipiens pallens at different collection times. Methods Cx. pipiens pallens were collected using carbon dioxide mosquito traps. The mosquito samples were ground in batches and analyzed by molecular biology technologies. The virus infection rate at different collection times was analyzed statistically. Results 17 strains of Culex pipiens pallens densovirus(CppDNV)were identified from Cx. pipiens pallens samples collected in Shunyi District, Beijing, in 2023. The nucleotide sequence analysis of the virus genome coding region showed that CppDNV was a single-stranded DNA virus with a total length of 3 335 nt, encoding 2 non-structural proteins(NS1, NS2)and 1 capsid protein(VP). The nucleotide(amino acid)sequence lengths of the three proteins were 2 376 nt(791 aa),1 092 nt(363 aa)and 1 071 nt(356 aa), respectively. Phylogenetic analysis showed that CppDNV was located in genus Brevihamaparvovirus. Statistical analysis showed no significant difference in infection rates across collection times(χ2=4.429, P=0.194). Conclusions CppDNV was identified in Cx. pipiens pallens in Beijing, and it was stably maintained in this natural population.

Objective To investigate the effect of programmed death-1(PD-1)on cell infiltration in muscle tissue and immune response types in mice infected with Trichinella spiralis.Methods C57BL/6J wild-type(WT)and PD-1 deficient(PD-1-/-)mice were infected with T.spiralis(400 muscle larvae per mouse),and samples were collected on day 35 after infection.The proportions of infiltrating inflammatory cells and fibroblasts around encapsulated larvae were assessed by immunohistochemistry.The expression levels of interferon-γ(IFN-γ),interleukin(IL)-4,IL-5,IL-13,and eotaxin in muscle tissue were measured using enzyme-linked immunosorbent assay.Peripheral blood and spleen were collected at different time points after infection.The percentages of CD4+IFN-γ+Th1 and CD4+IL-4+Th2 within CD4+T cells population in peripheral blood and spleen of mice were analyzed using flow cytometry.Results The proportions of eosinophils and fibroblasts among total infiltrating cells around the encapsulated larvae in the muscle of PD-1-/-mice were significantly lower than those in WT mice after T.spiralis infection(P＜0.01).The infected PD-1-/-mice exhibited higher proportions of macrophages,T cells and B cells in total infiltrating cells than the infected WT mice(P＜0.01).The levels of IL-4,IL-5,IL-13,and eotaxin in the muscle tissue of infected PD-1-/-mice were significantly lower than those in infected WT mice(P＜0.05).However,IFN-γ levels were not significantly different between the infected WT and PD-1-/-mice.The proportions of Th2 cells in CD4+T cells from peripheral blood and spleen of infected PD-1-/-mice were significantly lower than those in infected WT mice,whereas the proportion of Th1 cells showed no difference among the infected groups.Conclusions PD-1 deletion results in decreased expression of key chemokines of eosinophils and key cytokines of fibroblast formation,and a corresponding decrease in inflammatory cells in muscle in T.spiralis-infected mice.This effect may be associated with a diminished Th2 immune response caused by PD-1 deletion.

The continuous emergence of SARS-CoV-2 variants as well as other potential future coronavirus has challenged the effectiveness of current COVID-19 vaccines. Therefore, there remains a need for alternative antivirals that target processes less susceptible to mutations, such as the formation of six-helix bundle (6-HB) during the viral fusion step of host cell entry. In this study, a novel high-throughput screening (HTS) assay employing a yeast-two-hybrid (Y2H) system was established to identify inhibitors of HR1/HR2 interaction. The compound IMB-9C, which achieved single-digit micromolar inhibition of SARS-CoV-2 and its Omicron variants with low cytotoxicity, was selected. IMB-9C effectively blocks the HR1/HR2 interaction in vitro and inhibits SARS-CoV-2-S-mediated cell-cell fusion. It binds to both HR1 and HR2 through non-covalent interaction and influences the secondary structure of HR1/HR2 complex. In addition, virtual docking and site-mutagenesis results suggest that amino acid residues A930, I931, K933, T941, and L945 are critical for IMB-9C binding to HR1. Collectively, in this study, we have developed a novel screening method for HR1/HR2 interaction inhibitors and identified IMB-9C as a potential antiviral small molecule against COVID-19 and its variants.

The anterior cingulate cortex (ACC) has recently been proposed as a key player in the representation of itch stimuli. However, to date, little is known about the contribution of specific ACC interneuron populations to itch processing. Using c-Fos immunolabeling and in vivo Ca²⁺ imaging, we reported that both histamine and chloroquine stimuli-induced acute itch caused a marked enhancement of vasoactive intestinal peptide (VIP)-expressing interneuron activity in the ACC. Behavioral data indicated that optogenetic and chemogenetic activation of these neurons reduced scratching responses related to histaminergic and non-histaminergic acute itch. Similar neural activity and modulatory role of these neurons were seen in mice with chronic itch induced by contact dermatitis. Together, this study highlights the importance of ACC VIP⁺ neurons in modulating itch-related affect and behavior, which may help us to develop novel mechanism-based strategies to treat refractory chronic itch in the clinic.
Animals ; Pruritus/physiopathology* ; Vasoactive Intestinal Peptide/metabolism* ; Interneurons/metabolism* ; Gyrus Cinguli/metabolism* ; Mice ; Male ; Mice, Inbred C57BL ; Histamine ; Chloroquine ; Optogenetics ; Mice, Transgenic

Lumbar disc (LD) herniation and aging are prevalent conditions that can result in substantial morbidity. This study aimed to clarify the mechanisms connecting the LD aging and herniation, particularly focusing on cellular senescence and molecular alterations in the nucleus pulposus (NP). We performed a detailed analysis of NP samples from a diverse cohort, including individuals of varying ages and those with diagnosed LD herniation. Our methodology combined histological assessments with single-nucleus RNA sequencing to identify phenotypic and molecular changes related to NP aging and herniation. We discovered that cellular senescence and a decrease in nucleus pulposus progenitor cells (NPPCs) are central to both processes. Additionally, we found an age-related increase in NFAT1 expression that promotes NPPC senescence and contributes to both aging and herniation of LD. This research offers fresh insights into LD aging and its associated pathologies, potentially guiding the development of new therapeutic strategies to target the root causes of LD herniation and aging.
Intervertebral Disc Displacement/metabolism* ; Humans ; Aging/pathology* ; Nucleus Pulposus/pathology* ; Male ; Female ; Transcriptome ; Middle Aged ; Lumbar Vertebrae/pathology* ; Adult ; Cellular Senescence ; Stem Cells/pathology* ; Aged ; Intervertebral Disc Degeneration/metabolism*

OBJECTIVE: Poxviruses are zoonotic pathogens that infect humans, mammals, vertebrates, and arthropods. However, the specific role of ticks in transmission and evolution of these viruses remains unclear. METHODS: Transcriptomic and metatranscriptomic raw data from 329 sampling pools of seven tick species across five continents were mined to assess the diversity and abundance of poxviruses. Chordopoxviral sequences were assembled and subjected to phylogenetic analysis to trace the origins of the unblasted fragments within these sequences. RESULTS: Fifty-eight poxvirus species, representing two subfamilies and 20 genera, were identified, with 212 poxviral sequences assembled. A substantial proportion of AT-rich fragments were detected in the assembled poxviral genomes. These genomic sequences contained fragments originating from rodents, archaea, and arthropods. CONCLUSION Our findings indicate that ticks play a significant role in the transmission and evolution of poxviruses. These viruses demonstrate the capacity to modulate virulence and adaptability through horizontal gene transfer, gene recombination, and gene mutations, thereby promoting co-existence and co-evolution with their hosts. This study advances understanding of the ecological dynamics of poxvirus transmission and evolution and highlights the potential role of ticks as vectors and vessels in these processes.
Animals ; Poxviridae/physiology* ; Ticks/virology* ; Phylogeny ; Transcriptome ; Evolution, Molecular ; Poxviridae Infections/virology* ; Genome, Viral

Entamoeba histolytica and Giardia lamblia are two types of parasites that can cause intestinal infections in humans. Patients can be transmitted through the ingestion of food and drinking water contaminated with cysts, and present symptoms such as abdominal pain and diarrhea after infection. If Entamoeba histolytica infection is not actively and effectively treated, patients may also present with clinical manifestations such as purulent and bloody stools and colonic ulcers. This study reports a diarrhea case with concurrent infection of Entamoeba histolytica and Giardia lamblia. During the diagnostic process, the parasites were rapidly detected using the direct saline smear method. Subsequently, iodine staining and iron hematoxylin staining techniques were employed to meticulously observe the internal structures and morphological features of the parasites under a microscope, enabling successful identification of the parasite species. The diagnostic process in this case suggests that laboratory personnel should further enhance their ability to recognize the morphological characteristics of cysts and trophozoites of Entamoeba histolytica and Giardia lamblia, providing an effective basis for the clinical differential diagnosis between Entamoeba histolytica infection and ulcerative colitis.