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

Lactic acid (LA) accumulation in tumor microenvironments (TME) has been implicated in immune suppression and tumor progress. Diverse roles of LA have been elucidated, including microenvironmental pH regulation, signal transduction, post-translational modification, and metabolic remodeling. This review summarizes LA functions within TME, focusing on the effects on tumor cells, immune cells, and stromal cells. Reducing LA levels is a potential strategy to attack cancer, which inevitably affects the physiological functions of normal tissues. Alternatively, transporting LA into the mitochondria as an energy source for immune cells is intriguing. We underscore the significance of LA in both tumor biology and immunology, proposing the burning of LA as a potential therapeutic approach to enhance antitumor immune responses.
Humans ; Tumor Microenvironment/immunology* ; Neoplasms/therapy* ; Lactic Acid/immunology* ; Mitochondria/metabolism* ; Animals ; Signal Transduction

Objective To clarify the mechanism that HIV infection mediates mitochondrial damage of CD4⁺ T lymphocytes (CD4⁺ T cells) through mitogen-activated protein kinase (MAPK) pathway. Methods From October 1st, 2022 to March 31st, 2023, 47 HIV-infected people who received antiretroviral therapy (ART) for 4 years were recruited, including 22 immune non-responders (INR) and 25 responders (IR); and 26 sex and age-matched control participants (HC) who were negative for HCV, HBV, and HIV infections. The immune parameters were analyzed by flow cytometry. Finally, peripheral blood mononuclear cells (PBMCs) from HC or HIV patients were treated with MAPK pathway inhibitor SB203580, and the changes of mitochondrial function of CD4⁺ T cells were observed. Results Compared with HC group, the proportion of CD4⁺ T cells in PBMCs in INR group and IR group was significantly lower, and the proportion of CD4⁺ T cells in PBMCs in INR group was significantly lower than that in IR group. In addition, the proportion of naive (CD45RA⁺CD27⁺)T cells in PBMCs in INR group was significantly lower than that in HC group and IR group. Compared with HC group and IR group, the proportions of CD4⁺PD-1⁺, CD4⁺Av⁺ and CD4⁺MO⁺ in PBMCs in INR group and the proportions of CD45RA⁺CD27⁺PD-1⁺, CD45RA⁺CD27⁺Av⁺, CD45RA⁺CD27⁺MO⁺ in CD4⁺ T cell subsets increased significant. Compared with HC-con group, the basal respiration, maximal respiration and adenosine triphosphate(ATP) production of CD4⁺ T cells in HIV-con group decreased significantly, and JC-1 (green/red) in CD4⁺ T cells increased significantly. Compared with HIV-con group, the basal respiration, maximal respiration, ATP production and respiratory potential of CD4⁺ T cells in HIV-SB203580 group increased significantly, and the JC-1 (green/red) in CD4⁺ T cells decreased significantly. Conclusion Abnormal activation of the MAPK signaling pathway is observed in HIV patients receiving ART treatment, especially in CD4⁺ T cells of INR patients, which may lead to impaired mitochondrial function and abnormal CD4⁺ T cell homeostasis.
Humans ; HIV Infections/immunology* ; Male ; Mitochondria/drug effects* ; Female ; CD4-Positive T-Lymphocytes/metabolism* ; Adult ; Middle Aged ; MAP Kinase Signaling System/drug effects* ; Pyridines/pharmacology* ; Imidazoles/pharmacology* ; Leukocytes, Mononuclear/immunology*

Mitochondrion is known as the energy factory of the cell, which is also a unique mammalian organelle and considered to be evolved from aerobic prokaryotes more than a billion years ago. Mitochondrial DNA, similar to that of its bacterial ancestor’s, consists of a circular loop and contains significant number of unmethylated DNA as CpG islands. The innate immune system plays an important role in the mammalian immune response. Recent research has demonstrated that mitochondrial DNA (mtDNA) activates several innate immune pathways involving TLR9, NLRP3 and STING signaling, which contributes to the signaling platforms and results in effector responses. In addition to facilitating antibacterial immunity and regulating antiviral signaling, mounting evidence suggests that mtDNA contributes to inflammatory diseases following cellular damage and stress. Therefore, in addition to its well-appreciated roles in cellular metabolism and energy production,mtDNA appears to function as a key member in the innate immune system. Here, we highlight the emerging roles of mtDNA in innate immunity.
Animals ; DNA, Mitochondrial ; genetics ; Humans ; Immunity, Innate ; immunology ; Mitochondria ; genetics ; immunology ; Signal Transduction

In December 2011, we reported an autochthonous case of Echinococcus multilocularis infection in a 42-year-old woman in Korea. The diagnosis was based on histopathological findings of the surgically resected liver cyst. In the present study, we evaluated the serological and molecular characteristics of this Korean E. multilocularis case. The patient's serum strongly reacted with affinity-purified native Em18 and recombinant Em18 antigens (specific for E. multilocularis) but negative for recombinant antigen B8/1 (reactive for Echinococcus granulosus). In immunoaffinity chromatography, the serum also strongly reacted with E. multilocularis and only weakly positive for E. granulosus. We determined the whole nucleotide sequence of cox1 (1,608 bp) using the paraffin-embedded cystic tissue which was compared with E. multilocularis isolates from China, Japan, Kazakhstan, Austria, France, and Slovakia. The Korean case showed 99.8-99.9% similarity with isolates from Asia (the highest similarity with an isolate from Sichuan, China), whereas the similarity with European isolates ranged from 99.5 to 99.6%.
Adult ; Animals ; Antibodies, Helminth/*blood ; Antigens, Helminth/genetics/*immunology/metabolism ; Base Sequence ; Echinococcosis, Hepatic/*immunology/parasitology ; Echinococcosis, Pulmonary/diagnosis/genetics/immunology ; Echinococcus granulosus/genetics/immunology ; Echinococcus multilocularis/genetics/*immunology/isolation & purification ; Electron Transport Complex IV/genetics ; Female ; Humans ; Mitochondria/genetics ; Molecular Sequence Data ; Republic of Korea ; Sequence Analysis, DNA

The 5th outbreak of trichinosis occurred in a mountainous area of North Vietnam in 2012, involving 24 patients among 27 people who consumed raw pork together. Six of these patients visited several hospitals in Hanoi for treatment. Similar clinical symptoms appeared in these patients within 5-8 days after eating infected raw pork, which consisted of fever, muscle pain, difficult moving, edema, difficult swallowing, and difficult breathing. ELISA revealed all (6/6) positive reactions against Trichinella spiralis antigen and all cases showed positive biopsy results for Trichinella sp. larvae in the muscle. The larvae detected in the patients were identified as T. spiralis (Vietnamese strain) by the molecular analysis of the mitochondrial cytochrome c oxidase subunit III (cox3) gene.
Adult ; Animals ; Antigens, Helminth/analysis/immunology ; *Disease Outbreaks ; Electron Transport Complex IV/genetics ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Larva ; Male ; Meat/*parasitology ; Mitochondria/genetics ; Muscles/parasitology/pathology ; Swine ; Trichinella spiralis/genetics/immunology/*isolation & purification ; Trichinellosis/*epidemiology/parasitology/pathology ; Vietnam/epidemiology

Animals ; Apoptosis ; Cells ; cytology ; immunology ; metabolism ; Humans ; Immunity, Innate ; Mitochondria ; immunology ; Signal Transduction

OBJECTIVETo explore the clinical and pathological features of primary biliary cirrhosis (PBC) patients with negative anti-mitochondria antibody (AMA).

METHODSTwo hundreds and eight PBC patients were enrolled. The clinical and histological data of the negative AMA cases were compared with the AMA/AMA-M2 positive cases.

RESULTS30 out of the 208 cases (14.4%) were AMA negative patients in our study. The general status, biochemical tests and histological findings between the two groups had no significant difference (P > 0.05). The Gamma-globulin, IgG, IgM and IgA levels of AMA/AMA-M2 positive PBC patients were higher than that of the AMA negative cases (P < 0.05). The abnormal rate of cholesterol in AMA negative PBC patients was 65.4% as compared to 50.4% in AMA/AMA-M2 positive cases, no significant difference existed between (P > 0.05). Anti-nuclear antibody (ANA) was observed in 29 (96.7%) AMA negative PBC patients, including 14 (48.3%) with granular pattern, 8 (27.6%) with nuclear membrane pattern, 6 (20.7%) with kinetochore pattern and 1 (3.4%) with homogeneous pattern. AMA negative PBC patients had elevated serum ALP, GGT, IgM and cholesterol levels, and decreased serum AST, IgG and IgA levels as compared with that of autoimmune hepatitis patients (P < 0.05, respectively).

CONCLUSIONIn cholestatic patients with elevated IgM and cholesterol levels, ANA positive with non-homogeneous pattern, the diagnosis of PBC should be suspected, albeit AMA negative. The clinical, biochemical and histological features of the AMA negative PBC patients were similar to classic PBC patients, but quite different from autoimmune hepatitis.

Adult ; Antibodies, Antinuclear ; analysis ; Female ; Humans ; Liver Cirrhosis, Biliary ; immunology ; pathology ; Male ; Middle Aged ; Mitochondria ; immunology ; gamma-Globulins ; metabolism

MHC class II expression is controlled mainly at transcriptional level by class II transactivator (CIITA), which is a non-DNA binding coactivator and serves as a master control factor for MHC class II genes expression. Here, we describe the function of a novel splice-isoform of CIITA, DC-expressed caspase inhibitory isoform of CIITA (or DC-CASPIC), and we show that the expression of DCCASPIC in DC is upregulated upon lipopolysaccharides (LPS) induction. DC-CASPIC localizes to mitochondria, and protein-protein interaction study demonstrates that DC-CASPIC interacts with caspases and inhibits its activity in DC. Consistently, DC-CASPIC suppresses caspases-induced degradation of nitric oxide synthase-2 (NOS2) and subsequently promotes the synthesis of nitric oxide (NO). NO is an essential regulatory molecule that modulates the capability of DC in stimulating T cell proliferation/activation in vitro; hence, overexpression of DC-CASPIC in DC enhances this stimulation. Collectively, our findings reveal that DC-CASPIC is a key molecule that regulates caspases activity and NO synthesis in DC.
Alternative Splicing ; Amino Acid Sequence ; Animals ; Base Sequence ; CARD Signaling Adaptor Proteins ; genetics ; metabolism ; Cell Line ; Dendritic Cells ; drug effects ; immunology ; metabolism ; Humans ; In Vitro Techniques ; Lipopolysaccharides ; pharmacology ; Lymphocyte Activation ; Mice ; Mice, Inbred C57BL ; Mitochondria ; metabolism ; Molecular Sequence Data ; Nitric Oxide ; biosynthesis ; Nitric Oxide Synthase Type II ; metabolism ; Nuclear Proteins ; genetics ; metabolism ; Protein Isoforms ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; T-Lymphocytes ; immunology ; metabolism ; Trans-Activators ; genetics ; metabolism ; Up-Regulation ; drug effects

OBJECTIVETo evaluate the sensitivity and the specificity of Anti-M2-3E ELISA for the detection of IgG- and IgA-specific isotypes of antimitochondrial antibody (AMA), and to investigate the significance of antimitochondrial IgA and IgG in the diagnosis of primary biliary cirrhosis (PBC).

METHODSSera were collected from 107 PBC patients, 87 disease controls and 26 healthy controls, and the antimitochondrial antibodies (IgG and IgA) were detected using indirect immunofluorescence (IFL), Anti-PDC ELISA and Anti-M2-3E ELISA.

RESULTSThe AMA IgG positive rate in PBC patients was 90.6% detected by Anti-M2-3E ELISA, which is significantly higher than that (81.3%) detected by IFL(t = 4.32, P < 0.05) and that (72.9%) detected by Anti- PDC ELISA (t = 6.03, P < 0.05). The AMA IgA was positive in 59 of the 107 PBC patients, and 99 of the 107 patients were positive for AMA IgG or/and IgA. 9 of the 20 IFL-negative patients were positive for AMA IgG as indicated by Anti-M2-3E ELISA, 11 of the 20 IFL-negative patients were positive for AMA IgG or/and IgA as indicated Anti-M2-3E ELISA. Compared to patients negative for IgG AMA, patients positive for IgG AMA had more severe histopathology and higher levels of ALP, IgG, and IgM.

CONCLUSIONThe IgG and IgA Anti- M2-3E ELISAs are more sensitive for the AMA detection than IFN and the Anti-PDC ELISA. The presence of AMA IgG is the characteristics of severe PBC.

Adult ; Aged ; Autoantibodies ; blood ; Biomarkers ; blood ; Biopsy, Needle ; Enzyme-Linked Immunosorbent Assay ; methods ; Female ; Fluorescent Antibody Technique, Indirect ; Hepatitis, Autoimmune ; blood ; diagnosis ; immunology ; Humans ; Immunoglobulin A ; blood ; Immunoglobulin G ; blood ; Liver Cirrhosis, Biliary ; blood ; diagnosis ; immunology ; Liver Function Tests ; Male ; Middle Aged ; Mitochondria, Liver ; immunology ; Sensitivity and Specificity