Cutting Edge: Neutrophils License the Maturation of Monocytes into Effective Antifungal Effectors.

Neutrophils are critical for the direct eradication of conidia, but whether they mediate antifungal defense beyond their role as effectors is unclear. In this study, we demonstrate that neutrophil depletion impairs the activation of protective antifungal CCR2 inflammatory monocytes. In the absence of neutrophils, monocytes displayed limited differentiation into monocyte-derived dendritic cells, reduced formation of reactive oxygen species, and diminished conidiacidal activity.

Avirulence: an essential feature of the parasitic lifestyle.

The host plays an essential role in parasite transmission. The viability of the host-parasite relationship depends upon development of immune resistance and the induction of disease tolerance. Here I propose that pathogen coevolution of avirulence factors promoting host disease tolerance is an essential feature of the parasitic lifestyle.

The multifunctional nature of CD103 (αEβ7 integrin) signaling in tissue-resident lymphocytes.

Intestinal tissue-resident lymphocytes are critical for maintenance of the mucosal barrier and to prevent enteric infections. The activation of these lymphocytes must be tightly regulated to prevent aberrant inflammation and epithelial damage observed in autoimmune diseases, yet also ensure that antimicrobial host defense remains uncompromised. Tissue-resident lymphocytes express CD103, or αE integrin, which dimerizes with the β7 subunit to bind to E-cadherin expressed on epithelial cells.

Maternal IL-33 critically regulates tissue remodeling and type 2 immune responses in the uterus during early pregnancy in mice.

The pregnant uterus is an immunologically rich organ, with dynamic changes in the inflammatory milieu and immune cell function underlying key stages of pregnancy. Recent studies have implicated dysregulated expression of the interleukin-1 (IL-1) family cytokine, IL-33, and its receptor, ST2, in poor pregnancy outcomes in women, including recurrent pregnancy loss, preeclampsia, and preterm labor. How IL-33 supports pregnancy progression in vivo is not well understood.

Prognostic value of neutrophil-lymphocyte ratio and lactate dehydrogenase in melanoma patients treated with immune checkpoint inhibitors: A systematic review and meta-analysis.

Background: Immune checkpoint inhibitors (ICIs) showed promising therapeutic efficacy on melanoma. Neutrophil-to-lymphocyte ratio (NLR) and serum lactate dehydrogenase (LDH) showed predictive values on prognosis of various tumors, but not on melanoma yet. This meta-analysis was conducted to investigate the prognostic role of NLR and LDH levels in melanoma treated with ICIs.

Adenosine metabolized from extracellular ATP promotes type 2 immunity through triggering AAR signaling in intestinal epithelial cells.

Intestinal nematode parasites can cross the epithelial barrier, causing tissue damage and release of danger-associated molecular patterns (DAMPs) that may promote host protective type 2 immunity. We investigate whether adenosine binding to the A adenosine receptor (AAR) on intestinal epithelial cells (IECs) plays an important role. Specific blockade of IEC AAR inhibits the host protective memory response to the enteric helminth, Heligmosomoides polygyrus bakeri (Hpb), including disruption of granuloma development at the host-parasite interface.

Intravital Microscopy to Visualize Murine Small Intestinal Intraepithelial Lymphocyte Migration.

Intraepithelial lymphocytes (IELs) are critical sentinels involved in host defense and maintenance of the intestinal mucosal barrier. IELs expressing the γδ T-cell receptor provide continuous surveillance of the villous epithelium by migrating along the basement membrane and into the lateral intercellular space between adjacent enterocytes. Intravital imaging has furthered our understanding of the molecular mechanisms by which IELs navigate the epithelial compartment and interact with neighboring enterocytes at steady state and in response to infectious or inflammatory stimuli.

A Role for Basigin in Toxoplasma gondii Infection.

The role of specific host cell surface receptors during Toxoplasma gondii invasion of host cells is poorly defined. Here, we interrogated the role of the well-known malarial invasion receptor, basigin, in T. gondii infection of astrocytes.

A adenosine receptor activation prevents neutrophil aging and promotes polarization from N1 towards N2 phenotype.

Extracellular adenosine is a biologically active signaling molecule that accumulates at sites of metabolic stress in sepsis. Extracellular adenosine has potent immunosuppressive effects by binding to and activating G protein-coupled A adenosine receptors (AARs) on the surface of neutrophils. AAR signaling reproduces many of the phenotypic changes in neutrophils that are characteristic of sepsis, including decreased degranulation, impaired chemotaxis, and diminished ability to ingest and kill bacteria.

Epithelial HNF4A shapes the intraepithelial lymphocyte compartment via direct regulation of immune signaling molecules.

Hepatocyte nuclear factor 4 α (HNF4A) is a highly conserved nuclear receptor that has been associated with ulcerative colitis. In mice, HNF4A is indispensable for the maintenance of intestinal homeostasis, yet the underlying mechanisms are poorly characterized. Here, we demonstrate that the expression of HNF4A in intestinal epithelial cells (IECs) is required for the proper development and composition of the intraepithelial lymphocyte (IEL) compartment.

Development of a novel human CD147 knock-in NSG mouse model to test SARS-CoV-2 viral infection.

Background: An animal model that can mimic the SARS-CoV-2 infection in humans is critical to understanding the rapidly evolving SARS-CoV-2 virus and for development of prophylactic and therapeutic strategies to combat emerging mutants. Studies show that the spike proteins of SARS-CoV and SARS-CoV-2 bind to human angiotensin-converting enzyme 2 (hACE2, a well-recognized, functional receptor for SARS-CoV and SARS-CoV-2) to mediate viral entry. Several hACE2 transgenic (hACE2Tg) mouse models are being widely used, which are clearly invaluable.

A transmissible γδ intraepithelial lymphocyte hyperproliferative phenotype is associated with the intestinal microbiota and confers protection against acute infection.

Intraepithelial lymphocytes expressing the γδ T cell receptor (γδ IELs) serve as a first line of defense against luminal microbes. Although the presence of an intact microbiota is dispensable for γδ IEL development, several microbial factors contribute to the maintenance of this sentinel population. However, whether specific commensals influence population of the γδ IEL compartment under homeostatic conditions has yet to be determined.

Towards an Improved Understanding of the Effects of Elevated Progesterone Levels on Human Endometrial Receptivity and Oocyte/Embryo Quality during Assisted Reproductive Technologies.

Ovarian stimulation is an indispensable part of IVF and is employed to produce multiple ovarian follicles. In women who undergo ovarian stimulation with gonadotropins, supraphysiological levels of estradiol, as well as a premature rise in progesterone levels, can be seen on the day of hCG administration. These alterations in hormone levels are associated with reduced embryo implantation and pregnancy rates in IVF cycles with a fresh embryo transfer.

Zbtb20 identifies and controls a thymus-derived population of regulatory T cells that play a role in intestinal homeostasis.

The expression of BTB-ZF transcription factors such as ThPOK in CD4 T cells, Bcl6 in T follicular helper cells, and PLZF in natural killer T cells defines the fundamental nature and characteristics of these cells. Screening for lineage-defining BTB-ZF genes led to the discovery of a subset of T cells that expressed Zbtb20. About half of Zbtb20 T cells expressed FoxP3, the lineage-defining transcription factor for regulatory T cells (T).

Neutrophils flash their GLUTs to beat back detestable fungi.

Neutrophils enforce frontline immunity to fungal infection. Potent neutrophil effector functions require vast amounts of cytosolic glucose. Li et al.

Macrophage Mediated Immunomodulation During Pulmonary Infection.

Macrophages are key cellular components of innate immunity, acting as the first line of defense against pathogens to modulate homeostatic and inflammatory responses. They help clear pathogens and shape the T-cell response through the production of cytokines and chemokines. The facultative intracellular fungal pathogen has developed a unique ability to interact with and manipulate host macrophages.

Structural basis of lipopolysaccharide maturation by the O-antigen ligase.

The outer membrane of Gram-negative bacteria has an external leaflet that is largely composed of lipopolysaccharide, which provides a selective permeation barrier, particularly against antimicrobials. The final and crucial step in the biosynthesis of lipopolysaccharide is the addition of a species-dependent O-antigen to the lipid A core oligosaccharide, which is catalysed by the O-antigen ligase WaaL. Here we present structures of WaaL from Cupriavidus metallidurans, both in the apo state and in complex with its lipid carrier undecaprenyl pyrophosphate, determined by single-particle cryo-electron microscopy.

The Capsule of Acinetobacter baumannii Protects against the Innate Immune Response.

Acinetobacter baumannii is an opportunistic pathogen that has recently emerged as a global threat associated with high morbidity, mortality, and antibiotic resistance. We determined the role of type I interferon (IFN) signaling in A. baumannii infection.

In vitro machine learning-based CAR T immunological synapse quality measurements correlate with patient clinical outcomes.

The human immune system consists of a highly intelligent network of billions of independent, self-organized cells that interact with each other. Machine learning (ML) is an artificial intelligence (AI) tool that automatically processes huge amounts of image data. Immunotherapies have revolutionized the treatment of blood cancer.

Natural Killer (NK) and CAR-NK Cell Expansion Method using Membrane Bound-IL-21-Modified B Cell Line.

Chimeric antigen receptor (CAR)-modified immune cell therapy has become an emerging treatment for cancers and infectious diseases. NK-based immunotherapy, particularly CAR-NK cell, is one of the most promising 'off-the-shelf' development without severe life-threatening toxicity. However, the bottleneck for developing a successful CAR-NK therapy is achieving sufficient numbers of non-exhaustive, long-lived, 'off-the-shelf' CAR-NK cells from a third party.

Use of Clinical Isolates to Establish Criteria for a Mouse Model of Latent Infection.

The mechanisms of latency in the context of infection remain poorly understood. Two reasons for this gap in knowledge are: 1) the lack of standardized criteria for defining latent cryptococcosis in animal models and 2) limited genetic and immunological tools available for studying host parameters against in non-murine models of persistent infection. In this study, we defined criteria required for latency in infection models and used these criteria to develop a murine model of persistent infection using clinical isolates.