No abstract

The number of circulating T and B cells and the sensitivity of lymphocytes to stimulation with phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) was studied in 233 atopic children. The number of T lymphocytes was found to be decreased in cases of rhinoconjunctivitis, asthma as well as atopic eczema. Levels of B lymphocytes were normal. Sensitivity to stimulation with PHA and to a lesser degree, Con A, was significantly decreased whereas stimulation with PWM was unaffected. The severity of the atopic eczema was inversely correlated to T cell numbers. Several lines of evidence indicated that the abnormalities observed were intrinsically associated with the atopic conditions and not evoked by corticosteroid treatment. The results are compatible with the hypothesis that atopy is associated with a defect of a subpopulation of T cells. The possibility that this subpopulation has a suppressor function on reagin formation is discussed.

Graft-versus-host (GVH) reactions induced by thymus or spleen cells in new-born mice were found to trigger the development of plasma cells in the medullary areas of lymph nodes. N o germinal centers were found. The plasma cells were found from the fourth day of the GVH reactions and increased in numbers over the next few days. On the 14th day the plasma cells were still present, although in lower numbers. Results of immunodiffusion experiments indicated that during GVH reactions induced by spleen cells, donor as well as host plasma cells develop. In contrast, induction of GVH reactions by thymus cells leads to the development of plasma cells, which probably originate exclusively from the host.Positive Coombs' reactions were detected 15-20 days after induction of GVH reactions and host immunoglobulins were found to contribute to the Coombs' positivity .

No abstract

In mice, the plaque-forming cell response to sheep red blood cells was stimulated by a mixture of methoxy-substituted glycerol ethers isolated from Greenland shark liver oil and by synthetic 1-0-(2-methoxyhexadecyl)-glycerol, given in the diet. In preliminary experiments, this synthetic compound also increased the ability of parental spleen cells to induce graft-vs.-host reactions in F1 hybrid mice. Glycerol ethers occur in the bone marrow fat of mammals and in the membrane phospholipids. It is postulated that the methoxy-substituted glycerol ethers supplied in the diet may stimulate the bone marrow and/or may be incorporated into membrane lipids, thereby changing the structure and function of the membranes.