Potentiation of natural killer activity of human lymphocytes by Staphylococcus aureus bacteria and its protein A.

Cytotoxic activity of human lymphocytes against the myeloid cell line K-562 was augmented greatly by 24-h incubation with Staphylococcus aureus Cowan I bacteria (SpA CoI) and its protein A. This effect was not observed when these stimulants were added after preincubation, suggesting that this activity was different from so-called lectin-induced cellular cytotoxicity. Potentiation required at least 12 to 18 h incubation of lymphocytes with these stimulants.

Stimulation of Immunoglobulin production from human B lymphocytes by Staphylococcus aureus: effects of monocytes and con A-induced suppressor cells.

Significant immunoglobulin (Ig) production by human peripheral blood lymphocytes was induced in vitro by stimulating the cells with pokeweed mitogen (PWM) and Staphylococcus aureus Cowan I (SpA CoI). IgG, IgM, and IgA were determined by a combination of the latex fixation test and radioimmunoassay. High levels (1,000 to 5,000 microgram/ml of IgG and IgM and a lesser amount of IgA were constantly produced during 7 to 8 days of incubation with both stimulants.

A simple and rapid latex fixation test for measuring immunoglobulins produced in cell cultures.

A rapid and simple latex fixation test (LFT), which quantifies immunoglobulin (Ig) released into culture supernatants is described. Latex particles are coated with rabbit anti-human IgG, IgA or IgM antibodies. With this LFT technique the concentration of Ig is determined within a few minutes.

Low responsiveness of human neonatal lymphocytes to a B-cell mitogen, Staphylococcus aureus Cowan I (SpA CoI).

Responses of neonatal and adult lymphocytes to various mitogens were studied. Lymphocytes from umbilical cord blood (UCB) responded well to both phytohemagglutinin and concanavalin A, and also to pokeweed mitogen and Staphylococcus aureus Protein A. The responses of UCB lymphocytes to these mitogens were not significantly lower than those of adult peripheral blood lymphocytes (PBL).

Synthesis and secretion of alpha 1-microglobulin by human lymphocytes.

alpha 1-Microglobulin (alpha 1-m) was purified by column chromatography from a supernatant fluid of cultured T and B lymphocytes stimulated with mitogens. This protein had a molecular weight of 33,000 as determined by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis, migrated in the alpha 1-region on immunoelectrophoresis and proved immunologically identical to alpha 1-m which had been purified from the urine of patients with renal tubular disorders. Using indirect immunofluorescence, alpha 1-m was detected on the surface of both T and B lymphocytes, displaying the same intensity on each cell type.

Cellular cooperation in lymphocyte activation. II. Cooperative response of human peripheral T and B lymphocytes to rabbit anti-human beta 2-microglobulin.

In the present study we attempted to clarify the effects of anti-beta 2-microglobulin (a-beta 2m) on lymphocyte activation. Neither a-beta 2m IgG fraction nor F(ab')2 had a mitogenic effect on either highly purified T or B lymphocytes alone, while their mitogenic effect was observed when T and B lymphocytes were appropriately reconstituted. When T lymphocytes were reconstituted with mitomycin C (MMC) treated B lymphocytes, a negligible decrease in the response to a-beta 2m was observed compared to the response of an untreated mixture to a-beta 2m.

Virus plaque assay: effective detection of virus plaque forming cells at the early stage of lymphocyte activation by mitogen and alloantigen.

Activated lymphocytes were detected quantitatively by virus plaque assay (VPA) during the course of lymphocyte cultures stimulated by mitogen or alloantigen. In Con A-stimulated cultures, the number of virus-plaque forming cells (V--PFC) was a more sensitive method of detecting the early stage of lymphocyte activation than [3H]-thymidine (3H-TdR) incorporation. This evidence was obtained by two methods of collecting cells of each stage.

Tissue distribution of human alpha1-microglobulin.

Human alpha(1)-microglobulin was isolated from the urine of patients with tubular proteinuria, and its molecular weight was established by sodium dodecyl sulfate-polyacrylamide gel electrophoresis at 33,000 daltons. The carbohydrate content was 21.7%.

Cellular cooperation in lymphocyte activation. III. B-cell helper effect in the enhancement of T-cell response.

T and B cells were purified from human tonsil and peripheral blood by the removal of phagocytic cells, followed by filtration through a nylon fiber column (NC) and E-rosette formation. Purified T and B cells contained less than 1% of other cell types. The responses of T cells to concanavalin A (Con A) and soluble protein A were greatly enhanced in the presence of autologous B cells.

beta2-Microglobulin production by highly purified human T and B lymphocytes in cell culture stimulated with various mitogens.

This study attempts to evaluate beta2-microglobulin production by highly purified (greater than 98%) peripheral and tonsil T and B lymphocytes cultured with various mitogens. beta2-Microglobulin was measured by the radioimmunoassay method. It was found that PHA and Con A markedly stimulated beta2-microglobulin production in cultures of T but not B lymphocytes.