免疫学技术

The T-cell receptor (TCR) is a membrane-bound, multi-subunit complex that plays a key role in antigen recognition of cell-mediated immunity. The α and β chains of the TCR are extracellular domains that are the primary contact regions for two types of antigens. In conventional T-cell recognition, ...

A T-cell recognizes two major classes of antigens. Binding of the αβ T-cell receptor (TCR) to an intracellularly-processed peptide antigen in the context of a major histocompatibility complex (pMHC) provides for the specificity of a cell-mediated immune response. However, this normal a ...

There are several key differences between the nature of interactions of a T-cell receptor (TCR) with a conventional MHCpeptide complex and a bacterial superantigen (SAg). Apart from being powerful T-cell mitogens, these SAgs do not require antigen processing, they interact with the Vβ reg ...

An important characteristic of superantigens (SAgs) is their high structural stability. For instance, it is well known that staphylococcal enterotoxins are stable enough to traverse the stomach while retaining their biological activity. Despite this high stability, structur ...

Mouse mammary tumor viral superantigens (vSAgs) are produced by germline-encoded proviruses and infectious viruses (for reviews see refs. 1,2. Like other superantigens, they interact with class II major histocompatiblity complex (MHC) proteins and trigger T-cell proliferati ...

Superantigens (SAgs) are a class of bacterial or viral proteins that aberrantly alter immune system function through simultaneous interaction with lateral surfaces of major histocompatibility (MHC) class II molecules on antigen presenting cells, and to particular variable re ...

Bacterial superantigens are potent T-cell stimulatory protein molecules produced by Staphylococcus aureus and Streptococcus pyogenes 1. Their function in the microbe appears primarily to debilitate the host sufficiently through their effects on cells of the immune system to pe ...

Natural killer (NK) cells are a distinct compartment of lymphoid cells that have been shown to function as an effector cell population against virus infections, to provide a means of surveillance against tumor metastases, and, in some cases, to serve as an effector cell population for immunoth ...

Natural killer (NK) cells are a subset of lymphocytes with a distinct morphologic appearance (large granular lymphocytes ) and the ability to spontaneously kill virally infected or tumor targets but to spare most normal cells (1). These effector cells are now known to be able to eliminate tumor c ...

The study of hybrid resistance was greatly aided by the development of an in vitro assay by Chadwick and Miller (1). The assay allows one to test for the presence of negative or positive signaling in natural killer (NK) cells, and the ability of monoclonal antibodies (MAbs) or F(ab′)2 reagents to block those ...

The studies of hybrid resistance (HR) to murine bone marrow cell (BMC) grafts have been helpful in elucidating the biology and genetics of natural killer (NK) cell mediated recognition of incompatible cells (1). The discovery and claim for HR is contrary to the laws of transplantation genetics. T ...

Natural killer (NK) cellsexpress receptors specific for class I major histocompatibility complex (MHC) molecules. In the mouse, the class I specific receptors identified to date belong to the polymorphic Ly49 receptor family. Engagement of Ly49 receptors with their respective MHC l ...

Normal human lymphoblastoid cell lines (LCLs) express six classical class I HLA genes from three gene loci, HLA-A, HLA-B, and HLA-C, which are located within the major histocompatibility complex (MHC). Because of the extensive allelic polymorphism of HLA class I genes, cell lines from heteroz ...

The relationship of natural killer (NK) cells to T cells has been a longstanding enigma. It is well established that development of NK cells does not require a thymus (because they are present in athymic mice), recombination activating genes (because they are present in RAG-1 and RAG-2 knockout mic ...

Immunotoxicology can be simply defined as the study of adverse effects to the immune system. However, because of the complexity of the normal immune system, adverse effects by a xenobiotic can alter the system in a variety of ways: suppression, upregulation as in the case of xenobiotic-induced au ...

The nonspecific cytotoxic cell (NCC) is believed to be the evolutionary precursor of the mammalian natural killer (NK) cell. Evidence for a phylogenetic linkage between NCCs of teleost fish and NK cells from higher vertebrates was first obtained functionally; that is, NCCs lyse many of the same ...

Chicken natural killer (NK) cells have been characterized mainly based on functional properties in a variety of systems (reviewed in refs.1,2). A detailed analysis of their ontogeny, phenotype, function, tissue distribution and the receptors involved in killing of target cells has been d ...

Natural killer (NK) cells mediate host defense through recognition and lysis of tumors, virally infected cells and “missing self” hematopoietic blast cells (1). Various in vitro experimental systems to assay NK cell function have been established, which indeed contribute to determin ...

The elucidation of intracytoplasmic signaling pathways is a ctriical step in the precise understanding of cell biology. In this regard, the identification of intracytoplasmic domains, which are specialized in the transmission of biological messages, has been an enormous breakth ...

The interaction between killer cells and target cells can be dissected into three steps. First, the two cells form random conjugates mediated by nonspecific interactions between adhesion molecules (1). Second, specific recognition results in the activation of signal transduction ...