The aminopeptidase ERAAP is essential for trimming peptides presented by major histocompatibility complex (MHC) class I molecules. Inhibition of ERAAP by cytomegalovirus results in evasion of the immune response by this virus, and polymorphisms in ERAAP are associated with autoimmune disorders. How normal ERAAP function is monitored is unknown. We found that inhibition of ERAAP rapidly induced presentation of the peptide FYAEATPML (FL9) by the MHC class Ib molecule Qa-1(b). Antigen-experienced T cells specific for the Qa-1(b)-FL9 complex were frequent in naive mice. Wild-type mice immunized with ERAAP-deficient cells mounted a potent CD8(+) T cell response specific for Qa-1(b)-FL9. MHC class Ib-restricted cytolytic effector cells specifically eliminated ERAAP-deficient cells in vitro and in vivo. Thus, nonclassical Qa-1(b)-peptide complexes direct cytotoxic T cells to targets with defective antigen processing in the endoplasmic reticulum.
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http://dx.doi.org/10.1038/ni.2282 | DOI Listing |
ACS Nano
December 2024
The Fifth Affiliated Hospital, Guangdong Provincial Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, the School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou 511436, China.
Tumor-specific cytotoxic T cell immunity is critically dependent on effective antigen presentation and sustained signal transduction. However, this immune response is frequently compromised by the inherently low immunogenicity of breast cancer and the deficiency in major histocompatibility complex class I (MHC-I) expression. Herein, a chimeric peptide-engineered stoichiometric polyprodrug (PDPP) is fabricated to potentiate the cytotoxic T cell response, characterized by a high drug loading capacity and precise stoichiometric drug ratio, of which the immunogenic cell death (ICD) inducer of protoporphyrin IX (PpIX) and the epigenetic drug of decitabine (DAC) are condensed into a polyprodrug called PpIX-DAC.
View Article and Find Full Text PDFSci Rep
December 2024
Sydney School of Veterinary Science, University of Sydney, Camperdown, NSW, 2006, Australia.
Chlamydiosis is a common infectious disease impacting koalas and is a major cause of population decline due to resulting mortality and infertility. Polymorphisms of major histocompatibility complex (MHC) genes influence chlamydial disease outcomes in several species but koala studies have produced variable results. We aimed to identify the MHC II DAB and DBB repertoire of koalas from Liverpool Plains, NSW, a population heavily impacted by chlamydiosis.
View Article and Find Full Text PDFCancer Lett
December 2024
Zhejiang Province Key Laboratory of Anti-Cancer Drug Research, Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China; School of Medicine, Hangzhou City University, Hangzhou, Zhejiang, 310015, China; The Innovation Institute for Artificial Intelligence in Medicine, Zhejiang University, Hangzhou 310018, China. Electronic address:
Major histocompatibility complex (MHC) class I load antigens and present them on the cell surface, which transduces the tumor-associated antigens to CD8 T cells, activating the acquired immune system. However, many tumors downregulate MHC I expression to evade immune surveillance. The low expression of MHC I not only reduce recognition by- and cytotoxicity of CD8 T cells, but also seriously weakens the anti-tumor effect of immunotherapy by restoring CD8 T cells, such as immune checkpoint inhibitors (ICIs).
View Article and Find Full Text PDFCell Mol Life Sci
December 2024
Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada.
Varicella-zoster virus (VZV) infection downregulates surface major histocompatibility complex class I (MHC-I) expression and retains MHC-I in the Golgi complex of infected cells. However, the underlying mechanism is not fully understood. The VZV IE4 protein is a multifunctional protein that is essential for VZV infection.
View Article and Find Full Text PDFJ Radiat Res
December 2024
Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
Recently, ultra-high dose rate (> 40 Gy/s, uHDR; FLASH) radiation therapy (RT) has attracted interest, because the FLASH effect that is, while a cell-killing effect on cancer cells remains, the damage to normal tissue could be spared has been reported. This study aimed to compare the immune-related protein expression on cancer cells after γ-ray, conventionally used dose rate (Conv) carbon ion (C-ion), and uHDR C-ion. B16F10 murine melanoma and Pan02 murine pancreas cancer were irradiated with γ-ray at Osaka University and with C-ion at Osaka HIMAK.
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