Regulation of human T-cell production of interleukin 2 by Leu 11 (CD16) positive large granular lymphocytes.

Peripheral blood large granular lymphocytes (LGL) expressing Leu 11 (CD16) antigen with potent natural killer cytotoxicity inhibited soluble antigen-induced T-cell production of interleukin 2 (IL-2). Depletion of Leu 11-reactive cells from T-cells doubled IL-2 activity (P less than 0.05). Leu 11-enriched cells did not express high affinity IL-2 receptors nor did they deplete IL-2 activity from culture media. Upon addition in low ratios to Leu 11-depleted cells, Leu 11-enriched fractions increased antigen-induced IL-2 production three-fold (P less than 0.05), whereas at higher ratios IL-2 production was suppressed P less than 0.01. Additionally, adherent monocytes were increasingly accessory when added in graded numbers to Leu 11-depleted but not T-cell cultures. In the presence of small numbers (5%) of Leu 11-enriched cells, however, monocytes down-regulated IL-2 production of Leu 11-depleted cell cultures. Thus Leu 11-reactive lymphocytes have noncytotoxic functions and may play a major role in immunoregulation.

[Toxic effects of essential oil of Cannabis sativa L. and main constituents on planarian (Dugesia tigrina) (author's transl)]. / Etude de la toxicité de l'huile essentielle de Cannabis sativa L. et de ses principaux constituants sur la planaire (Dugesia tigrina G.).

Regenerating pieces of planarian worms are able to absorbe insoluble substances deposited on the base of the vessels in which they are cultivated. This biological test was used to study the toxic effects of the essential oil of Cannabis sativa L. The hydrocarbons such as pinene (alpha and beta), caryophyllene and so on were not toxic. On the contrary caryophyllene oxide was highly toxic. It was not possible to detect any protection by 5-hydroxytryptamine as it was the case against delta 1-tétrahydro-cannabinol and cannabidiol.