Vaccine Science:

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• Glossary

Glossary

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L

Langerhans cells: phagocytic dendritic cells found in the epidermis. They can migrate from the epidermis to regional lymph nodes via the lymphatics. In the lymph node they differentiate into dendritic cells.

Laparascopy: examination of the contents of the peritoneum with a laparoscope passed through the abdominal wall. A laparoscpe is a type of endoscope, a tube down which light is reflected. Fitted with grasping and cutting tools, the laparascope can perform minor surgery, take tissue samples for biopsy and remove eggs from the ovary.

Larvae: Immature wingless forms of insects such as mosquitoes.

Leukocyte: A general term for a white blood cell. Leukocytes include lymphocytes, monocytes, and polymorhonuclear leukocytes.

LFA-3: Lymphocyte function-associated antigen-3 is a molecule found on many cells that is the ligand for CD2 (also known as LFA-2). It is a member of the immunoglobulin superfamily.

Listeria monocytogenus: A species of the genus Listeria that is aerobic, microaerophilic, motile peritrichous bacterium. The bacteria are found in the feces of humans and other animals, in vegetation and in silage, and are parasitic on poikilothermic and warm-blooded animals including humans.

Listeriosis: A sporadic disease causing meningitis septicemia, endocarditis etc. Sometimes involved in infections of immunocompromised individuals and in neonatal infections.

Live vaccine: A vaccine in which live virus is weakened through chemical or physical processes in order to produce an immune response without causing the severe effects of the disease. Attenuated vaccines currently licensed in the United States include measles, mumps, rubella, polio, yellow fever and varicella. Also known as an attenuated vaccine.

Live-vector vaccine: A vaccine that uses a non-disease-causing organism (virus or bacterium) to transport foreign genes into the body, thereby stimulating an effective immune response to the foreign products. This type of vaccine is important because it is particularly capable of inducing CTL activity.

Long-term care facility: A long-term care facility is a facility that provides rehabilitative, restorative, and/or ongoing skilled nursing care to patients or residents in need of assistance with activities of daily living. Long-term care facilities include nursing homes, rehabilitation facilities, inpatient behavioral health facilities, and long-term chronic care hospitals.

Lupus: A disease characterized by inflammation of the connective tissue (which supports and connects all parts of the body). Chronic swelling of the connective tissue causes damage to the skin, joints, kidneys, nervous system and mucous membranes. The disease begins with fever, joint pain and fatigue. Additional symptoms continue to develop over the years including nausea, fatigue, weight loss, arthritis, headaches and epilepsy. Problems with heart, lung and kidney function may also result. This condition is diagnosed most frequently in young women but also occurs in children.

Lyme disease: A bacterial disease transmitted by infected ticks. Human beings may come into contact with infected ticks during outdoor activities (camping, hiking). Symptoms include fatigue, chills, fever, headache, joint and muscle pain, swollen lymph nodes and a skin rash (in a circular pattern). Long-term problems include arthritis, nervous system abnormalities, irregular heart rhythm and meningitis. Lyme disease can be treated with antibiotics or prevented with the use of a vaccine recently licensed by the Food and Drug Administration.

Lymph nodes: Organs that are oval-shaped, often the size of beans or peas, which are located throughout the body and contain clusters of cells called lymphocytes.

Lymphocytes: Small white blood cells that help the body defend itself against infection. These cells are produced in bone marrow and develop into plasma cells, which produce antibodies. Also know as B cells.

Lymphoma: a tumor of lymphocytes that grows in lymphoid and other tissues but do not enter the blood in large numbers. There are many types of lymphoma, which represent the transformation of various classes of lymphoid cell.

M

Macrophages: A large cell that helps the body defend itself against disease by surrounding and destroying foreign organisms (viruses).

Melanoma: A malignant cancer derived from pigment producing cells (melanin-producing) of the skin or any part of the body characterized by the ability to frequently metastasize widely.

Memory cell: Memory cells are a subset of T cells and B cells that have been exposed to specific foreign substances (antigens) and can then proliferate (recognize the antigen and divide) more readily when the immune system re-encounters the same antigens.

Meningitis: Inflammation of the brain and spinal cord that can result in permanent brain damage and death.

Merozoite: The form of the malaria parasite that invades human red blood cells; one of the organisms formed by multiple fission of a sporozoite within the body of the host during the asexual phase of reproduction of a malarial plasmodia and other sporozoa.

Metastasis: The shifting of disease or its local manifestations from one part of the body to another via lymphatics, blood vessels, or by direct extension.

MHC class I: Molecules that present peptides generated in the cytosol to CD8 T cells.

MHC class II: Molecules that present peptides degraded in intracellular vesicles to CD4 T cells.

MHC (major histocompatibility complex): The gene cluster that controls certain aspects of the immune response. Among the products of these genes are the histocompatibility antigens, such as HLA class I antigens, which are present on every cell with a nucleus and serve as markers to distinguish self from non-self.

MHV-68: A serotype of mouse herpes virus.

Microbes: Tiny organisms (including viruses and bacteria) that can only be seen with a microscope.

Microencapsulated: Surrounded by a thin layer of biodegradable substance referred to as a microsphere. A means of protecting a drug or vaccine antigen from rapid breakdown. Microencapsulation may also enhance an antigen's absorption and the immune response to that antigen.

Monoclonal antibody: Custom-made, identical antibody that recognizes only one epitope of an antigen.

Monocyte: A large white blood cell in the blood that ingests microbes or other cells and foreign particles. When a monocyte passes out of the bloodstream and enters the tissues, it develops into a macrophage.

Monovalent vaccine: A vaccine that contains only one antigen.

MUC-1: Abnormally glycosylated mucin found in breast and pancreatic tumors.

Mucin: Any of a group of glycoproteins found especially in the secretions of mucous membranes. 

Mucosal membranes: The soft, wet tissue that lines body openings specifically the mouth, nose, rectum and vagina.

Multiple sclerosis (MS): A disease of the central nervous system characterized by the destruction of the myelin sheath surrounding neurons, resulting in the formation of "plaques." MS is a progressive and usually fluctuating disease with exacerbations (patients feeling worse) and remissions (patients feeling better) over many decades. Eventually, in most patients, remissions do not reach baseline levels and permanent disability and sometimes death occurs. The cause of MS is unknown. The most widely held hypothesis is that MS occurs in patients with a genetic susceptibility and that some environmental factors "trigger" exacerbations. MS is 3 times more common in women than men, with diagnosis usually made as young adults. Also see demyelinating disorders.

Murine: Concerning rodents, e.g., rats or mice. 

N

Naked DNA: antigen encoding DNA plasmid molecules that result in de novo production of correctly folsded antigen at the site of delivery.

Neuritis: Inflammation of the nerves.

Neuroblastoma: a malignant neoplasm characterized by immature, only slightly differentiated nerve cells of embryonic type, i.e. neuroblasts.

Neuropathy: A general term for any dysfunction in the peripheral nervous system. Symptoms include pain, muscle weakness, numbness, loss of coordination and paralysis. This condition may result in permanent disability.

NK cells: natural killer cells, a type of lymphocyte that is large, usually granular, non-T, non-B lymphocytes that can kill certain microbes and cancer cells. NK cells are important in innate immunity to viruses and other intracellular pathogens, as well as in antibody-dependent cell-mediated cytotoxicity (ADCC).

Nonamer: A compound made up of nine repeated structural units. 

Nosocomial: Referring to an infection acquired by a patient while in a hospital.

Nucleus: The central controlling body within a living cell, usually a spherical unit enclosed in a membrane and containing genetic codes for maintaining life systems of the organism and for issuing commands for growth and reproduction.

NY-ESO-1: A cancer-testis antigen.

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