Search PubMedSearch

PubMed · 86161

Specificity and effector-target interaction.

Abstract

When effector cells were tested on a number of target cells, the most obvious effect observed was a nonselective cytotoxicity that is now known as natural cell-mediated cytotoxicity. The apparent nonselectivity was a result of specific cytotoxic activity against many different antigens on target cells. This specificity was demonstrated in the cross-competition assay in which target cells sharing common antigens selectively inhibited natural cytotoxicity.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M Takasugi. 1978. Specificity and effector-target interaction.. https://pubmed.ncbi.nlm.nih.gov/86161/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Determination of transforming growth factor beta 2 in human blood samples by ELISA.

Transforming growth factors beta (TGF beta s) show pleotrophic functions in vitro and in vivo. Biological effects depend on the cell type, the TGF beta isoform, and the availability of active TGF beta. Bioassays for TGF beta have not proven to be reliable tools in the measurement of TGF beta in human blood samples. Previously described sandwich ELISAs for measuring TGF beta are limited to single TGF beta isoforms and have not been evaluated for use in human sera or plasma. We describe a simple procedure to quantitate not only TGF beta 1 but also TGF beta 2 in human blood samples using commercially available antibodies. The sensitivity of the TGF beta 2 ELISA was 11 pg/ml. There was no crossreactivity between the TGF beta 1 and TGF beta 3 isoforms. High concentrations of TGF beta 1 and TGF beta 3 in spiked samples did not interfere with TGF beta 2 determination. TGF beta 2 recovery was highest in EDTA plasma (> 88%), and the intra- and interassay variance was 6% and 8.5% respectively. Applying the ELISA to human plasma specimens a significant percentage of TGF beta 2 (3.7 +/- 0.8 ng/ml) was found (about 50% of the TGF beta 1 content).

Cross Reactions

Discovery of an epidermal stearoyl-acyl carrier protein thioesterase. Its potential role in wax biosynthesis.

Plant epicuticular, or surface, waxes are synthesized primarily, if not exclusively, by epidermal cells. The epicuticular wax constitutes almost 20% of the chloroform-extractable lipids in developing leek leaf and is derived predominantly from saturated fatty acids. The significant requirement for saturated fatty acids in epidermal tissues led us to investigate whether or not epidermal extracts have thioesterase activities that prefer saturated acyl-acyl carrier protein (ACP) substrates, rather than the 18:1-ACP more commonly hydrolyzed by total leaf extracts. Epidermal extracts from Brassica, pea, and leek exhibited higher activities toward saturated acyl-ACPs relative to 18:1-ACP when compared to total leaf or leaf parenchymal extracts. We identified and purified a stearoyl-ACP (18:0-ACP)-specific thioesterase from leek epidermal extracts which could be separated from 18:1-ACP thioesterase using hydroxyapatite chromatography. The stearoyl-ACP thioesterase exhibited a high preference for 18:0-ACP, having less than 10% of the 18:0-ACP hydrolyzing activity when presented with 18:1-ACP, 16:0-ACP, or 18:0-CoA substrates. The stearoyl-ACP thioesterase was predominantly, if not exclusively, expressed in epidermis and may play a role in generating the saturated fatty acid pool required for wax production.

Cross Reactions

Receptor for interleukin 13. Interaction with interleukin 4 by a mechanism that does not involve the common gamma chain shared by receptors for interleukins 2, 4, 7, 9, and 15.

Interleukin 13 (IL-13) shares many biological properties with IL-4, and although the receptor for IL-4 (IL-4R) has been characterized, the expression and structure of IL-13 receptor are unknown. We report here that human renal cell carcinoma (RCC) cells express large numbers of functional IL-13R. Human B lymphocytes and monocytes expressed a very small number of IL-13R, while resting or activated human T cells expressed little or no IL-13R. IL-4 did not compete for IL-13 binding, while IL-13 competed for IL-4 binding, even though IL-4R and IL-13R are structurally distinct on human RCC cells. IL-13 cross-linked with one major protein that is similar in size to the gamma c subunit of IL-2, -4, -7, -9, and -15 receptors but was not recognized by anti-gamma c or anti-IL-4R antibodies. IL-4, on the other hand, cross-linked with two major proteins, the smaller of which appears to be similar in size to IL-13R and gamma c, but (like the IL-13R) it did not react with anti-gamma c antibody. Although as shown in this study and in previous studies, gamma c is a functional component of IL-4R in lymphoid cells, it does not appear to be associated with IL-4R on RCC cells. Even in the absence of common gamma chain IL-4 and IL-13 were able to up-regulate intracellular adhesion molecule-1 antigen on RCC cells. These data suggest that the interaction of IL-13 with IL-4R does not involve gamma c and IL-13R itself may be a novel subunit of the IL-4R.

Cross Reactions