A dendritic cell (DC) is an antigen-presenting cell of the mammalian immune system. A DC's main function is to process antigen material and present it on the cell surface to the T cells of the immune system. They act as messengers between the innate and adaptive immune systems.
An immune complex, sometimes called an antigen-antibody complex or antigen-bound antibody, is a molecule formed from the binding of multiple antigens to antibodies. The bound antigen and antibody act as a unitary object, effectively an antigen of its own with a specific epitope. After an antigen-antibody reaction, the immune complexes can be subject to any of a number of responses, including complement deposition, opsonization, phagocytosis, or processing by proteases. Red blood cells carrying CR1-receptors on their surface may bind C3b-coated immune complexes and transport them to phagocytes, mostly in liver and spleen, and return to the general circulation.
Immune tolerance, also known as immunological tolerance or immunotolerance, refers to the immune system's state of unresponsiveness to substances or tissues that would otherwise trigger an immune response. It arises from prior exposure to a specific antigen and contrasts the immune system's conventional role in eliminating foreign antigens. Depending on the site of induction, tolerance is categorized as either central tolerance, occurring in the thymus and bone marrow, or peripheral tolerance, taking place in other tissues and lymph nodes. Although the mechanisms establishing central and peripheral tolerance differ, their outcomes are analogous, ensuring immune system modulation.
Plasmacytoid dendritic cells (pDCs) are a rare type of immune cell that are known to secrete large quantities of type 1 interferon (IFNs) in response to a viral infection. They circulate in the blood and are found in peripheral lymphoid organs. They develop from bone marrow hematopoietic stem cells and constitute < 0.4% of peripheral blood mononuclear cells (PBMC). Other than conducting antiviral mechanisms, pDCs are considered to be key in linking the innate and adaptive immune systems. However, pDCs are also responsible for participating in and exacerbating certain autoimmune diseases like lupus. pDCs that undergo malignant transformation cause a rare hematologic disorder, blastic plasmacytoid dendritic cell neoplasm.
OX40L is the ligand for OX40 and is stably expressed on many antigen-presenting cells such as DC2s, macrophages, and activated B lymphocytes.
B-cell activating factor (BAFF) also known as tumor necrosis factor ligand superfamily member 13B and CD257 among other names, is a protein that in humans is encoded by the TNFSF13B gene. BAFF is also known as B Lymphocyte Stimulator (BLyS) and TNF- and APOL-related leukocyte expressed ligand (TALL-1) and the Dendritic cell-derived TNF-like molecule.
Toll-like receptor 7, also known as TLR7, is a protein that in humans is encoded by the TLR7 gene. Orthologs are found in mammals and birds. It is a member of the toll-like receptor (TLR) family and detects single stranded RNA.
Fms-related tyrosine kinase 3 ligand (FLT3LG) is a protein which in humans is encoded by the FLT3LG gene.
Interferon alpha-1 is a protein that in humans is encoded by the IFNA1 gene.
CD226, PTA1 or DNAM-1 is a ~65 kDa immunoglobulin-like transmembrane glycoprotein expressed on the surface of natural killer cells, NK T cell, B cells, dendritic cells, hematopoietic precursor cells, platelets, monocytes and T cells.
Dedicator of cytokinesis protein 2 (Dock2) is a protein encoded in the human by the DOCK2 gene. Dock2 is a large protein involved in intracellular signalling networks. It is a member of the DOCK-A subfamily of the DOCK family of guanine nucleotide exchange factors (GEFs) which function as activators of small G-proteins. Dock2 specifically activates isoforms of the small G protein Rac.
Lymphocyte-activation gene 3, also known as LAG-3, is a protein which in humans is encoded by the LAG3 gene. LAG3, which was discovered in 1990 and was designated CD223 after the Seventh Human Leucocyte Differentiation Antigen Workshop in 2000, is a cell surface molecule with diverse biological effects on T cell function but overall has an immune inhibitory effect. It is an immune checkpoint receptor and as such is the target of various drug development programs by pharmaceutical companies seeking to develop new treatments for cancer and autoimmune disorders. In soluble form it is also being developed as a cancer drug in its own right.
Fc fragment of IgG receptor IIb is a low affinity inhibitory receptor for the Fc region of immunoglobulin gamma (IgG). FCGR2B participates in the phagocytosis of immune complexes and in the regulation of antibody production by B lymphocytes.
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy. It was initially regarded as a form of lymphocyte-derived cutaneous lymphoma and alternatively named CD4+CD56+ hematodermic tumor, blastic NK cell lymphoma, and agranular CD4+ NK cell leukemia. Later, however, the disease was determined to be a malignancy of plasmacytoid dendritic cells rather than lymphocytes and therefore termed blastic plasmacytoid dendritic cell neoplasm. In 2016, the World Health Organization designated BPDCN to be in its own separate category within the myeloid class of neoplasms. It is estimated that BPDCN constitutes 0.44% of all hematological malignancies.
CpG oligodeoxynucleotides are short single-stranded synthetic DNA molecules that contain a cytosine triphosphate deoxynucleotide ("C") followed by a guanine triphosphate deoxynucleotide ("G"). The "p" refers to the phosphodiester link between consecutive nucleotides, although some ODN have a modified phosphorothioate (PS) backbone instead. When these CpG motifs are unmethylated, they act as immunostimulants. CpG motifs are considered pathogen-associated molecular patterns (PAMPs) due to their abundance in microbial genomes but their rarity in vertebrate genomes. The CpG PAMP is recognized by the pattern recognition receptor (PRR) Toll-Like Receptor 9 (TLR9), which is constitutively expressed only in B cells and plasmacytoid dendritic cells (pDCs) in humans and other higher primates.
Gunther Hartmann is a German immunologist and clinical pharmacologist. Since 2007 he has been the Director of the Institute of Clinical Chemistry and Clinical Pharmacology at the University Hospital of the University of Bonn.
Jacques Banchereau is an internationally prominent French American immunologist and molecular biologist. As of 2022, he is Chief Scientific Officer at Immunai. He was formerly professor and director of immunological sciences at the Jackson Laboratory for Genomic Medicine and also the former chief science officer, senior vice president, and DTA head of inflammation & virology at Hoffman-La Roche. He is best known for his extensive research on dendritic cells with Nobel Laureate Ralph M. Steinman. He is the fifth most cited immunologist ranked by Times Higher Education's report.
George C. Tsokos is an American immunologist who is a professor of medicine at Harvard Medical School and is the chief at Division of Rheumatology and Clinical Immunology at Beth Israel Deaconess Medical Center; Boston, MA
Carla V. Rothlin is an Argentinian immunologist.She is professor of immunobiology at Dorys McConnell Duberg and professor of pharmacology at Yale University. Rothlin is also the co-leader of the Cancer Immunology Program at Yale Cancer Center as well as an Howard Hughes Medical Investigator faculty scholar.
Elina Zúñiga is an Argentinian Immunologist and Professor of Molecular Biology in the Division of Biological Sciences at the University of California, San Diego. Zúñiga has made critical discoveries regarding host-virus interactions in both acute and chronic infections. Using lymphocytic choriomeningitis models (LCMV) and murine cytomegalovirus models, her laboratory at UCSD studies host immune adaptations in chronic viral disease and methods of viral suppression of the immune system in order to develop novel methods and identify novel targets of anti-viral defence. In 2018, Zúñiga was chosen by the American Association of Immunologists to give the international Vanguard Lecture. Zúñiga is also co-founder of the Global Immunotalks series which she and Carla Rothlin started in 2020 as a means to make cutting-edge immunology research freely available and easily accessible to a global audience.
