Alzheimer's disease (AD) is the most common cause of dementia and is a growing public health challenge. Neuroinflammation has been proposed as a prominent pathological feature of AD and has traditionally been attributed to the innate immune system. However, emerging evidence highlights the involvement of adaptive immunity, particularly T and B lymphocytes, in the neuroinflammatory processes of AD. It remains unclear how adaptive immune responses, originally intended to protect the body, contribute to chronic inflammation and neuronal dysfunction in AD. Here, we review the roles of adaptive immunity, cellular composition, and niches and their contribution to AD development and progression. Notably, we synthesize the crosstalk between adaptive immunity and the innate immune system of the central nervous system (CNS), which is mainly mediated by glial cells and myeloid cells, and their interrelationships with amyloid-β (Aβ)/Tau pathology. We hypothesized that the alterations observed in innate immunity in AD mirror age-related immune alterations, whereas the dysregulation of adaptive immunity contributes more accurately to disease-specific immune responses. Targeting adaptive immunity in the context of neuroinflammation may provide new insights into potential therapeutic strategies designed to modulate immune responses, thereby facilitating the diagnosis, intervention, and treatment of AD.
Alzheimer Disease/metabolism* ; Humans ; Adaptive Immunity/physiology* ; Immunity, Innate/immunology* ; Animals ; Neuroinflammatory Diseases/immunology* ; Inflammation/immunology* ; Amyloid beta-Peptides/metabolism*

The innate immune response is the first line of defense for the host against viral infections. Targeted degradation of pathogenic microorganisms through autophagy, in conjunction with pattern recognition receptors synergistically inducing the production of interferon (IFN), constitutes an important pathway for the body to resist viral infections. Rubicon, a Run domain Beclin 1-interacting and cysteine-rich domain protein, has an inhibitory effect on autophagy and IFN production. On the one hand, Rubicon, as a component of the phosphoinositide 3-kinase (PI3K) complex, interacts with different domains of vacuolar protein sorting 34 (Vps34), ultraviolet radiation resistance associated gene (UVRAG), guanosine triphosphate (GTP) kinase, and RAS oncogene family member 7 (Rab7) to mediate the inhibition of autophagy maturation; on the other hand, Rubicon inhibits the ubiquitination of nuclear factor κB essential modulator (NEMO) and the dimerization of interferon regulatory factor 3 (IRF3), thereby blocking the signal transduction related to IFN production. Research has revealed that various viruses, such as Kaposi's sarcoma-associated herpesvirus (KSHV), hepatitis B virus (HBV), Sendai virus (SeV), and hepatitis C virus (HCV), achieve innate immune evasion by regulating the expression or function of Rubicon. Rubicon is expected to be a new target for antiviral therapy.
Humans ; Autophagy/immunology* ; Immunity, Innate ; Interferons/immunology* ; Immune Evasion ; Animals ; Virus Diseases/virology* ; Signal Transduction ; Viruses/immunology* ; Intracellular Signaling Peptides and Proteins/immunology* ; Autophagy-Related Proteins

Autophagy is a fundamental biological metabolic process involved in immune defense, material metabolism, and homeostasis and closely linked to immune regulation. Systemic lupus erythematosus (SLE) is a widespread connective tissue disorder primarily resulting from immune system imbalance. Due to the immune system's failure to recognize its own substances, it generates autoantibodies that can affect various tissues and organs, leading to diverse clinical manifestations. The pathogenesis and treatment of SLE are currently under extensive investigation. In normal metabolic processes, autophagy engages in both innate and adaptive immunity, regulates the immune response, and is crucial for maintaining normal immune function and the body's internal homeostasis. Research has indicated that SLE patients exhibit immune dysfunction and altered autophagy levels. Modulating autophagy expression can influence immune system functionality and alleviate SLE symptoms. Additionally, autophagy aids in the innate immune response and adaptive immunity by clearing metabolites and regulating the life cycle of immune cells. Studies suggest that drugs targeting autophagy can positively influence the progression of SLE. This article reviews advancements in research regarding the impact of autophagy on the pathogenesis of SLE through the regulation of immune system functions.
Lupus Erythematosus, Systemic/pathology* ; Autophagy/immunology* ; Humans ; Animals ; Immunity, Innate ; Adaptive Immunity ; Disease Progression ; Immune System/immunology*

Objective To investigate the differences of type 2 innate lymphocytes (ILC2) and interlukin 9 (IL-9) between chronic lymphocytic leukemia (CLL) patients and healthy controls, and to understand the effects of ILC2 on the function of regulatory T cells (Tregs), CD8⁺ T cells and CLL cells through IL-9. Methods Flow cytometry was used to detect the levels of ILC2 and Tregs in the peripheral blood of 45 newly diagnosed CLL patients and 24 healthy controls, and the expressions of granzyme B and perforin in CD8⁺ T cells in the peripheral blood of 28 patients and 15 healthy controls; ELISA was used to detect the level of IL-9 in the serum. ILC2 of patients and healthy controls was sorted by immunomagnetic beads and cultured separately, and the level of IL-9 in the culture supernatant was measured by ELISA. ILC2 sorted from CLL patients and healthy control-derived peripheral blood mononuclear cells(PBMCs) were co-cultured with the B cell leukemia MEC-1 cells, one group was supplemented with IL-9 antibody and the other group was not. After 72 hours of culture, the ratio of Tregs, programmed death 1 (PD-1), T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), cytotoxic T lymphocyte antigen 4 (CTLA-4) on Tregs, granzyme B and perforin in CD8⁺ T cells were measured by flow cytometry, IL-9 level of the culture supernatant was measured by ELISA, the apoptosis of MEC-1 cells was measured by Annexin V-PI. Results Compared with the healthy control group, the levels of ILC2, Tregs and IL-9 in the CLL group increased significantly. The levels of granzyme B and perforin in CD8⁺ T cells were positively correlated in the peripheral blood of CLL patients. Compared with the healthy control group, IL-9 levels in the supernatant of sorted ILC2 from CLL patients increased. In the anti-IL9 antibody group, the level of PD-1 and TIGIT on Tregs decreased, and the level of granzyme B in CD8⁺ T cells increased significantly. The level of IL-9 in the anti-IL9 antibody group decreased statistically. And MEC-1 cells showed increased early apoptotic rate in the anti-IL9 antibody group statistically. Conclusion In CLL, ILC2 affects CD8⁺ T cells and Tregs through IL-9, which weakens the anti-tumor effect of CD8⁺ T cells, enhances the immunosuppressive effect of Tregs, and plays a role in the occurrence and development of CLL disease.
Humans ; Leukemia, Lymphocytic, Chronic, B-Cell/immunology* ; CD8-Positive T-Lymphocytes/immunology* ; T-Lymphocytes, Regulatory/immunology* ; Middle Aged ; Male ; Female ; Interleukin-9/blood* ; Aged ; Granzymes/metabolism* ; Perforin/metabolism* ; Immunity, Innate ; Adult ; Lymphocytes/immunology*

Invasive fungal infections (IFIs) are a group of diseases caused by fungal pathogens, primarily Candida, Aspergillus, and Cryptococcus, which invade the body, proliferate in deep tissues, organs, or the bloodstream, and lead to localized or systemic severe infections. These infections impose significantclinical and economic burdens due to their high mortality rates, the high cost and limited availability of antifungal drugs, and the frequent adverse effects. Invasive fungal pathogens invade the host through hyphae, spores, and secreted adhesive proteins, primarily triggering disease via signal cascades resulting from the binding of fungal membrane ligands to host receptors, as well as through secreted substances and intrinsic toxins. Macrophages, as the first line of defense against invasive fungal pathogens, play a crucial role in combating IFIs. They combat fungal pathogens through mechanisms such as antigen recognition, phagocytosis, oxidative killing, polarization, and the regulation of various bioactive substances. This article reviews recent research progress on the mechanisms by which macrophages contribute to innate immunity against invasive fungal infections. Additionally, it discusses the immune evasion strategies employed by invasive fungal pathogens to counteract macrophages, aiming to provide new insights for the prevention and treatment of invasive fungal infections.
Humans ; Immunity, Innate ; Macrophages/immunology* ; Invasive Fungal Infections/microbiology* ; Animals ; Phagocytosis/immunology*

Mitochondria are one of the oldest and most important endomembrane systems in eukaryotic cells and serve as the hubs of multiple cellular processes. Mitophagy (mitochondrial autophagy), a major way to maintain mitochondrial homeostasis, is closely linked to antiviral immune regulation. Depending on whether ubiquitination is required for the involved receptors or adaptors, mitophagy can be classified into ubiquitin-dependent and ubiquitin-independent types. Viruses can directly or indirectly regulate mitophagy and mitochondrial dynamics through various pathways. Through these processes, they can affect innate and adaptive immunity, so as to achieve immune escape, aggravate cell damage or promote the formation of adaptive immunity. This review summarizes the latest research progress on the role of viral infection-regulated mitophagy in the regulation of immune response.
Mitophagy/immunology* ; Humans ; Animals ; Virus Diseases/immunology* ; Mitochondria/metabolism* ; Immunity, Innate ; Adaptive Immunity

Endosomes are characterized by the presence of various phosphoinositides that are essential for defining the membrane properties. However, the interplay between endosomal phosphoinositides metabolism and innate immunity is yet to be fully understood. Here, our findings highlight the evolutionary continuity of RAB-10/Rab10's involvement in regulating innate immunity. Upon infection of Caenorhabditis elegans with Pseudomonas aeruginosa, an increase in RAB-10 activity was observed in the intestine. Conversely, when RAB-10 was absent, the intestinal diacylglycerols (DAGs) decreased, and the animal's response to the pathogen was impaired. Further research revealed that UNC-16/JIP3 acts as an RAB-10 effector, facilitating the recruitment of phospholipase EGL-8 to endosomes. This leads to a decrease in endosomal phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and an elevation of DAGs, as well as the activation of the PMK-1/p38 MAPK innate immune pathway. It is noteworthy that the dimerization of UNC-16 is a prerequisite for its interaction with RAB-10(GTP) and the recruitment of EGL-8. Moreover, we ascertained that the rise in RAB-10 activity, due to infection, was attributed to the augmented expression of LET-413/Erbin, and the nuclear receptor NHR-25/NR5A1/2 was determined to be indispensable for this increase. Hence, this study illuminates the significance of endosomal PI(4,5)P2 catabolism in boosting innate immunity and outlines an NHR-25-mediated mechanism for pathogen detection in intestinal epithelia.
Animals ; Caenorhabditis elegans/genetics* ; Endosomes/immunology* ; Caenorhabditis elegans Proteins/immunology* ; Phosphatidylinositol 4,5-Diphosphate/immunology* ; Immunity, Innate ; Pseudomonas aeruginosa/immunology* ; rab GTP-Binding Proteins/genetics* ; Diglycerides/metabolism*

Bluetongue virus (BTV) usually infects sheep, cattle, deer and other domesticated and wild ruminants through the bite of the vector insects, Culicoide, causing bluetongue (BT). BT in subtropical and even temperate regions poses a serious threat to the development and international trade of the livestock industry. This article introduced the structure and cellular invasion, and summarized the mechanisms of anti-BTV immune response of host cells and antagonism of host cell innate immune response by the non-structural proteins (e.g., NS3 and NS4) and structural proteins (e.g., VP3 and VP4) of BTV. This review provided a basis for understanding the antagonism mechanisms of BTV against the interferon (IFN) immune response in the host cell and the pathogenesis of BTV as well as for developing novel vaccines against this virus.
Bluetongue virus/immunology* ; Animals ; Bluetongue/prevention & control* ; Immunity, Innate ; Interferons/immunology* ; Sheep ; Viral Nonstructural Proteins/immunology* ; Cattle

The cyclic GMP-AMP (cGAMP) synthase (cGAS) has been identified as a cytosolic double stranded DNA sensor that plays a pivotal role in the type I interferon and inflammation responses via the STING-dependent signaling pathway. In the past several years, a growing body of evidence has revealed that cGAS is also localized in the nucleus where it is associated with distinct nuclear substructures such as nucleosomes, DNA replication forks, the double-stranded breaks, and centromeres, suggesting that cGAS may have other functions in addition to its role in DNA sensing. However, while the innate immune function of cGAS is well established, the non-canonical nuclear function of cGAS remains poorly understood. Here, we review our current understanding of the complex nature of nuclear cGAS and point to open questions on the novel roles and the mechanisms of action of this protein as a key regulator of cell nuclear function, beyond its well-established role in dsDNA sensing and innate immune response.
Cell Nucleus/immunology* ; Humans ; Immunity, Innate ; Nucleotidyltransferases/immunology* ; Signal Transduction/immunology*

In this research, we studied the formation of Drosophila melanogaster FADD (Fas-associated death domain-containing protein) amyloid fiber and its influence on signal transduction in IMD (Immune deficiency) signaling pathway to better understand the regulation mechanism of Drosophila innate immune signaling pathway, which will provide reference for the immune regulation in other species. First, we purified dFADD protein expressed in Escherichia coli and performed Sulfur flavin T binding and transmission electron microscopy to identify the dFADD amyloid fibers formed in vitro. Then we investigated the formation of dFADD polymers in S2 cells using SDD-AGE and confocal microscope. We also constructed dFADD mutants to find out which domain is essential to fiber formation and its effect on IMD signal transduction. Our results revealed that dFADD could be polymerized to form amyloid fiber polymers in vitro and inside the cells. Formation of fibers relies on DED (Death-effector domain) domain of dFADD, since DED domain-deleted mutant existed as a monomer. Dual luciferase reporter assay showed that intact DED domain was required for the induction of downstream antimicrobial peptides, indicating that fiber formation was the key to IMD signal transduction. Our study revealed the role of dFADD in mediating the cascade between IMD and Dredd in the IMD signaling pathway by forming amyloid fibers, suggesting an evolutionarily conserved regulatory mechanism of innate immune signaling pathway.
Animals ; Drosophila Proteins ; biosynthesis ; immunology ; Drosophila melanogaster ; immunology ; Fas-Associated Death Domain Protein ; biosynthesis ; immunology ; Immunity, Innate ; immunology ; Signal Transduction