免疫学技术

T-cell differentiation is a tightly controlled developmental program observed as the stepwise progression of immature thymocytes through several unique stages characterized by the expression of distinct combinations of cell surface markers. The advancement of thymocytes ...

CD45 is a leukocyte specific protein tyrosine phosphatase and is a major lymphocyte cell surface glycoprotein (see refs. 1–3 for reviews). CD45 has been shown to be important for the transmission of signals by the T and B cell antigen receptors during both development and antigen induced activat ...

The earliest steps along the pathway leading to mature T cells in mouse thymus have been defined (1,2). Within the thymus, several minute but discrete populations of T cell precursors develop in sequence, preceding the stage of CD4+8+ thymocytes (Fig. 1). The earliest identifiable intrathymic p ...

The recognition phase of the cell-mediated immune response is studied in vitro by monitoring responses of CD4+ T cells, cultured in the presence of specific antigen. Conventional cultures include mononuclear cells separated from peripheral blood by a complex and time-consuming proc ...

Transmembrane stimulation of lymphocytes at the G0–G1 resting phase, induced by specific antigens, mitogens, or by antibodies to certain cell surface molecules, results in a complex series of well-characterized molecular events, culminating in lymphocyte activation, transfo ...

T-cell activation by antigen-receptor ligation results in rapid activation of phospholipase-Cγ1 (PLC). Activated PLC hydrolyzes membrane inositol phospholipids (PIP2) generating two second messengers: inositol(1,4,5)tris phosphate (IP3) and diacylglycerol (DG) (1). I ...

If truth be told, when asked to write this chapter my first reaction was not positive; I thought “I am too young! (aren’t I?).” However, when I considered the Editor’s request, I realized that I had been fortunate to have had my formative scientific years coincide with extraordinary advances in our underst ...

T-cell hybridomas were first produced some 20 yr ago (1). They have been used for research in almost all aspects of T-cell biology ranging from experiments on T-cell receptors and their specificity to the cytokines produced by T cells and the factors that lead to T-cell death. For biological studies, T- ...

Intrathymic T-cell differentiation proceeds through a series of discrete stages in which developmental changes in gene expression modify cell surface phenotype and functional potential (reviewed in 1–3). Thymocyte progenitors in the CD4−8− double negative (DN) compartment gi ...

As T cells develop in the thymus, they undergo distinct changes in their morphology and expression of cell surface antigens. Phenotypic changes in mature peripheral T cells also occur subsequent to T-cell activation, resulting from engagement of the T-cell antigen receptor (TCR) or exposu ...

Expression cloning is a powerful tool in isolating a cDNA for a protein when the protein is difficult to purify but can be detected by antibody staining or some biological activity, such as growth promoting activity. In this chapter, we focus on the cloning of cDNAs for surface proteins by expression c ...

T cells are defined by the expression of CD3 molecules on the cell surface in association with the T-cell receptor (TCR) to form the TCR/CD3 complex. Within the CD3+ cell population there are two main subsets identified by the expression of CD4 (CD4+ T cells) and CD8 (CD8+ T cells) cell surface molecules. In add ...

Apoptosis is a highly regulated process by which eukaryotic cells undergo cell death (1–4). Often synonymous with “cell suicide” and “programmed cell death,” apoptosis is distinguishable from another major form of cell death, necrosis, by a number of key morphological and biochemical fea ...

The pathway of T-cell development follows a series of highly regulated steps beginning with the differentiation of bone marrow-resident pluripotent hematopoietic stem cells (HSCs) into T-cell progenitors that migrate to the thymus. Upon colonizing the thymic microenvironment, ...

Superantigens (SAgs) stimulate large fractions of T cells by circumventing normal antigen presentation through binding both class II major histocompatibility complex (MHC) molecules on antigen-presenting cells, and specific variable regions on the β-chain (Vβ) of the T-cell an ...

The small intestine selectively absorbs digested macromolecules, vitamins, minerals, and electrolytes, whereas the large intestine supports the majority of the gut microflora and reabsorbs water. These activities are the primary functions of the intestinal epithelium, a sing ...

The main characteristic of a superantigen (SAg) is that it activates specific subsets of T cells that are composed of particular T-cell receptor (TCR) variable region β chain gene products (TCRBV). SAgs are thought to form a bridge between the TCRBV region on the T cell and the MHC class II molecule on the an ...

In order to get the full picture of the cytokine response generated by stimulation of various pathogens and superantigens in particular it is of crucial importance to collect data at various timepoints after stimulation. It is clear from those experiments performed that the production of t ...

Staphylococcus enterotoxin superantigens (SAgs) have the capacity to strongly activate oligoclonal populations of T lymphocytes expressing T-cell antigen receptors (TCR) that share particular Vβ elements. These superantigens stimulate T lymphocytes by binding simult ...

Among the antigens presented by the major histocompatibility complex (MHC) class II molecules, the superantigens (SAgs) constitute a particular family of ligands that are able to signal via the MHC class II molecules (1). The SAg are characterized by their ability to bind to both the MHC class II mo ...