Transient nuclear location of the IL-2 receptor during T cell activation.

Binding of interleukin-2 (IL-2) to its membrane receptor (IL-2R) on target cells is followed by internalization of the IL-2R. The subsequent intracellular fate of IL-2R is not known. This paper describes the intracellular location of the p55 subunit of the IL-2R during IL-2 mediated T cell activation and growth of two mouse T helper clones.

Nuclear location of the p55 subunit of the IL-2 receptor following activation of the HT-2 T helper cell line.

After mitogenic or antigenic stimulation, T cells express interleukin-2 receptors (IL-2R). The mechanism and control of signal transduction following binding of IL-2 to IL-2R are poorly understood. Using two rat monoclonal antibodies (5A2 and 7D4) specific for two distinct epitopes of the p55 subunit of mouse IL-2R, we have studied the cellular localization of this molecule by immunocytochemistry during the IL-2-mediated activation of mouse T helper cell clone HT-2.

Regulation of interleukin 2 (IL2) receptor expression: IL2 as an inducing signal for the expression of its own receptor on a murine T helper cell line.

The interleukin 2 receptor (IL2R) expression of a terpolymer of L-Glu60, L-Ala30, L-Tyr10 (GAT)-specific T helper (Th) cell line, L14, was studied using two different rat monoclonal antibodies specific for the murine IL2R, 7D4 and 5A2-2. L14 T cells expressed IL2R transiently, but contrary to the general assumption that IL2R expression is maintained only by periodic antigen stimulation, we observed that IL2 itself was able to regulate the level of IL2R on L14 Th lymphocytes. In particular, it was found that L14 T cells, which had not been recently stimulated and which expressed a very low level of high affinity IL2R, could be induced to exhibit a high level of this receptor after exposure to recombinant IL2, in the absence of any specific signal.

LPS and specific T cell responses: interleukin 1 (IL 1)-independent amplification of antigen-specific T helper (TH) cell proliferation.

Lipopolysaccharide (LPS) fraction of endotoxin induces a significant potentiation of the antigen-specific proliferative response of T helper (TH) cell lines. This effect was obtained with LPS from different bacterial sources and reproduced with the lipid A moiety of endotoxin. Purified adherent spleen cells used as antigen-presenting cells (APC) support this LPS-enhanced TH cell proliferation.

In vitro induction and expression of interleukin 2 receptor in a clonal T helper cell differentiation model.

Induction and expression of interleukin 2 (IL 2) receptor have been studied using a poly( Glu60 Ala30 Tyr10 ) (GAT)-specific T cell clone of mouse origin. This clone (52-3) has been characterized and it exhibits functional properties of T helper (TH) cells: it leads to a specific anti-DNP response in the presence of DNP-GAT and DNP-primed B cells and it secretes biological activities which can induce polyclonal B cell proliferation and IgM secretion. In vitro this clone mimics the activation stages of normal T lymphocytes and can be obtained under two states of differentiation.

[Preparation of immunosorbents from lipopolysaccharides and polysaccharides extracted from various gram-negative and gram-positive bacteria].

The method of binding of lipopolysaccharides (LPS) extracted from Salmonella typhimurium to aminohexyl-sepharose 4B by activation with benzoquinone was applied to three different LPS extracted from several enterobacteria species: S. seftenberg 1,3,19, S. cholerae suis 6(2),7 and Escherichia coli O141:H32.

[Preparation of monospecific anti-Salmonella LPS antibodies from bacteria immobilized in polyacrylamide gel].

The use of an immunoabsorbent obtained by entrapping Salmonella cells into a polyacrylamide gel lattice enabled us to obtain anti-O monospecific immune sera which can be used for a quick serological identification of some species of Salmonella in the course of a diagnosis. In this paper we describe a method for immobilization of S. typhimurium as well as the preparation of monospecific anti-05 antibodies from plurispecific anti-S.

[Assay of human anti-exoproteins to group A streptococci by microhaemagglutination: correlation with anti-streptolysin O and various anti-enzymes (author's transl)].

A microhaemagglutination test in disposable U plates has been devised for rapid, quantitative evaluation in antistreptococcal antibodies in human sera. Fresh or freeze-dried glutaraldehyde-treated sheep erythrocytes sensitized with over fifteen extracellular proteins released by group A Streptococcus pyogenes including streptolysin O, deoxyribonucleases, hyaluronatelyase, streptokinase and nicotinamide dinucleotide glycohydrolase were used. Haemagglutination and anti-streptolysin O (ASLO) titers were determined in parallel on 434 serum specimens from 123 healthy subjects ("controls") and 311 patients with a history of supposed or evident streptococcal infection.