T cells are one of the important types of white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface.
A cytotoxic T cell (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cell or killer T cell) is a T lymphocyte (a type of white blood cell) that kills cancer cells, cells that are infected by intracellular pathogens (such as viruses or bacteria), or cells that are damaged in other ways.
Natural killer cells, also known as NK cells, are a type of cytotoxic lymphocyte critical to the innate immune system. They are a kind of large granular lymphocytes (LGL), and belong to the rapidly expanding family of known innate lymphoid cells (ILC) and represent 5–20% of all circulating lymphocytes in humans. The role of NK cells is analogous to that of cytotoxic T cells in the vertebrate adaptive immune response. NK cells provide rapid responses to virus-infected cells, stressed cells, tumor cells, and other intracellular pathogens based on signals from several activating and inhibitory receptors. Most immune cells detect the antigen presented on major histocompatibility complex I (MHC-I) on infected cell surfaces, but NK cells can recognize and kill stressed cells in the absence of antibodies and MHC, allowing for a much faster immune reaction. They were named "natural killers" because of the notion that they do not require activation to kill cells that are missing "self" markers of MHC class I. This role is especially important because harmful cells that are missing MHC I markers cannot be detected and destroyed by other immune cells, such as T lymphocyte cells.
Memory T cells are a subset of T lymphocytes that might have some of the same functions as memory B cells. Their lineage is unclear.
Immunosenescence is the gradual deterioration of the immune system, brought on by natural age advancement. A 2020 review concluded that the adaptive immune system is affected more than the innate immune system. Immunosenescence involves both the host's capacity to respond to infections and the development of long-term immune memory. Age-associated immune deficiency is found in both long- and short-lived species as a function of their age relative to life expectancy rather than elapsed time.
Gamma delta T cells are T cells that have a γδ T-cell receptor (TCR) on their surface. Most T cells are αβ T cells with TCR composed of two glycoprotein chains called α (alpha) and β (beta) TCR chains. In contrast, γδ T cells have a TCR that is made up of one γ (gamma) chain and one δ (delta) chain. This group of T cells is usually less common than αβ T cells. Their highest abundance is in the gut mucosa, within a population of lymphocytes known as intraepithelial lymphocytes (IELs).
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.
Gabrielle T. Belz is an Australian molecular immunologist and viral immunologist. She is a faculty member of the Walter and Eliza Hall Institute of Medical Research, within the Molecular Immunology division. Belz has made important contributions to the understanding of immune system function, especially in relation to the molecular and cellular signalling pathways of immune response to viruses. Her research has focused on understanding the signals that drive the initial development of protective immunity against pathogen infections, such as influenza and herpes viruses. This includes research into how cytotoxic T cells recognise and remove virally-infected cells from the body following infection. Research into the description of the specific factors and response during infection will contribute towards the long-term development of vaccines for infectious disease, and the development of better treatments for autoimmune diseases.
Immune checkpoints are regulators of the immune system. These pathways are crucial for self-tolerance, which prevents the immune system from attacking cells indiscriminately. However, some cancers can protect themselves from attack by stimulating immune checkpoint targets.
ILC2 cells, or type 2 innate lymphoid cells are a type of innate lymphoid cell. Not to be confused with the ILC. They are derived from common lymphoid progenitor and belong to the lymphoid lineage. These cells lack antigen specific B or T cell receptor because of the lack of recombination activating gene. ILC2s produce type 2 cytokines and are involved in responses to helminths, allergens, some viruses, such as influenza virus and cancer.
Tissue-resident memory T cells or TRM cells represent a subset of a long-lived memory T cells that occupies epithelial, mucosal and other tissues without recirculating. TRM cells are transcriptionally, phenotypically and functionally distinct from central memory (TCM) and effector memory (TEM) T cells which recirculate between blood, the T cell zones of secondary lymphoid organ, lymph and nonlymphoid tissues. Moreover, TRM cells themself represent a diverse populations because of the specializations for the resident tissues. The main role of TRM cells is to provide superior protection against infection in extralymphoid tissues.
Immunological memory is the ability of the immune system to quickly and specifically recognize an antigen that the body has previously encountered and initiate a corresponding immune response. Generally, they are secondary, tertiary and other subsequent immune responses to the same antigen. The adaptive immune system and antigen-specific receptor generation are responsible for adaptive immune memory.
Sharon Ruth Lewin is an Australian infectious diseases expert who is the inaugural Director of The Peter Doherty Institute for Infection and Immunity and the Cumming Global Centre for Pandemic Therapeutics. She is also a Melbourne Laureate Professor of Medicine at The University of Melbourne, and the current President of the International AIDS Society (IAS).
Weiping Zou is the Charles B. de Nancrede Professor of Pathology, Immunology, Biology, and Surgery at the University of Michigan. He is a scientist noted for his work regarding understanding the nature of human tumor immune responses and developing mechanism-informed combination therapies for cancer. He has developed an international reputation in human tumor immunosuppressive mechanisms in the tumor microenvironment.
Franca Ronchese is an Italian-New Zealand immunologist. She currently leads the immune cell biology programme at the Malaghan Institute of Medical Research in Wellington, New Zealand and is a research professor at Victoria University of Wellington.
Miram Merad is a French-Algerian professor in Cancer immunology and the Director of the Marc and Jennifer Lipschultz Precision Immunology Institute (PrIISM) at the Icahn School of Medicine at Mount Sinai (ISMMS) in New York, NY. She is the corecipient of the 2018 William B. Coley Award for Distinguished Research in Basic Immunology and a member of the United States National Academy of Sciences and the National Academy of Medicine.
Wendy Havran was an American immunologist at the Scripps Research Institute. She specialized in T cells, showing that they are scarce in certain areas of the body.
Thomas S. Kupper is an American physician, academic, and clinician. His work with clinical and research experience spans dermatology, cutaneous oncology, and immunology. He is the Thomas B. Fitzpatrick Professor at Harvard Medical School, and chairs the Departments of Dermatology at Brigham and Women's Hospital. He also leads the Cutaneous Oncology Disease Center at the Dana Farber Cancer Institute.
Fabienne Mackay is a French Australian research immunologist and institutional leader within the Australian medical research, education and innovation sectors. She is the Director and CEO of the QIMR Berghofer Medical Research Institute since 2020, after being the inaugural Head of the School of Biomedical Sciences at the University of Melbourne during the preceding five years. She is also an Honorary Professor at the Faculties of Medicine of the University of Queensland and the University of Melbourne. Her work has attracted public attention for its contribution to the pathophysiological understanding and treatment of lupus and other autoimmune diseases. Mackay has been notably awarded, achieving international reputation for her widely cited research describing B-cell activating factor (BAFF) and other cytokines of the TNF receptor superfamily, and their roles in B cell physiology, autoimmunity and cancer. She is an elected Fellow of the Australian Academy of Health and Medical Sciences.
Roslyn A. Kemp is a New Zealand immunologist, and as of 2023 is a full professor at the University of Otago. Her research focuses on T cells, mucosal and tumour immune responses, inflammation and T cell memory.
