The killing activity of NK cells is regulated by signals derived from inhibitory and activating NK cell receptors, including the CD300 family of proteins. CD300a was reported to be expressed on all NK cells and to deliver an inhibitory signal upon binding to a yet unknown ligand/s. The CD300a protein contains four ITIMs and is highly homologous to CD300c. Little is known about the function and distribution of these two receptors and the identity of their ligand/s. In this article, we show that CD300a is indeed an inhibitory receptor expressed by human NK cells, but surprisingly, we show that not all NK clones are inhibited in a CD300a-dependent manner. We demonstrate, using a panel of 13 new anti-CD300a and CD300c Abs that we generated, that CD300a and CD300c are indistinguishable on the surface of NK cells. Using mutational-analysis survey, we show that tyrosine 267 located in the third ITIM motif of the CD300a protein is important for the inhibitory function of CD300a.
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http://dx.doi.org/10.4049/jimmunol.0903347 | DOI Listing |
Cell Rep Med
December 2024
Department of Surgery, Division of Abdominal Transplantation, Stanford University School of Medicine, Stanford, CA, USA; Stanford Immunology, Stanford University School of Medicine, Stanford, CA, USA. Electronic address:
The oncogenic Epstein-Barr virus (EBV) can drive tumorigenesis with disrupted host immunity, causing malignancies including post-transplant lymphoproliferative disorders (PTLDs). PTLD can also arise in the absence of EBV, but the biological differences underlying EBV(+) and EBV(-) B cell PTLD and the associated host-EBV-tumor interactions remain poorly understood. Here, we reveal the core differences between EBV(+) and EBV(-) PTLD, characterized by increased expression of genes related to immune processes or DNA interactions, respectively, and the augmented ability of EBV(+) PTLD B cells to modulate the tumor microenvironment through elaboration of monocyte-attracting cytokines/chemokines.
View Article and Find Full Text PDFPharmacol Ther
January 2025
William Harvey Research Institute, Queen Mary University of London, London, United Kingdom; Centre for inflammation and Therapeutic Innovation, Queen Mary University of London, London, United Kingdom.
This review summarizes findings presented at the 19th World Congress of Basic & Clinical Pharmacology 2023 (Glasgow, Scotland, July 3rd to 7th, 2023) from 8 speakers in the field of resolution of inflammation, resolution pharmacology and resolution biology. It is now accepted that the acute inflammatory response is protective to defend the host against infection or tissue injury. Acute inflammation is self-limited and programmed to be limited in space and time: this is achieved through endogenous resolution processes that ensure return to homeostasis.
View Article and Find Full Text PDFVaccine
December 2024
Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi 221005, India. Electronic address:
Antigenic inefficacy to induce robust immune responses and durable memory are major causes of constantly failing prophylactic approaches in leishmaniasis. Here, we determine the potential of a standardized whole-killed Leishmania vaccine (Leishvacc) adjuvanted with anti-CD200 and anti-CD300a antibodies, either alone or with monophosphoryl lipid A (MPL-SE) emulsified in squalene oil, in restoring the compromised antigen presenting abilities of dendritic cells (DCs), effector properties of CD4T cells and providing protection against Leishmania donovani parasites. In animals vaccinated with antibodies adjuvanted vaccines, either alone or with MPL-SE, the antigen presenting abilities of CD11c DCs against Leishmania antigens, measured in terms of CD80, CD86, MHC-I, and MHC-II surface receptors and intracellular IL-12 were found enhanced than non-adjuvanted vaccine.
View Article and Find Full Text PDFBiosensors (Basel)
July 2024
Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium.
Orthoflaviviruses cause a major threat to global public health, and no antiviral treatment is available yet. Zika virus (ZIKV) entry, together with many other viruses, is known to be enhanced by phosphatidylserine (PS) receptors such as T-cell immunoglobulin mucin domain protein 1 (TIM-1). In this study, we demonstrate for the first time, using cell-based electrical impedance (CEI) biosensing, that ZIKV entry is also enhanced by expression of CD300a, another PS receptor.
View Article and Find Full Text PDFSci Total Environ
November 2024
Division of Gastroenterology and Hepatology; Shanghai Institute of Digestive Disease; NHC Key Laboratory of Digestive Diseases; State Key Laboratory for Oncogenes and Related Genes; Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Introduction: Air pollution and transportation noise pollution has been linked to gastrointestinal (GI) diseases, but their relationship remains unclear.
Methods: We extracted the significantly modulated genes and CpG sites related to air pollution (PM2.5, PM10, and NOx) and transportation noise pollution (aircraft, railway, and traffic road noise) from previous published studies.
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