5-HT And The Immune System. In: Vanhoutte PM, Saxena PR, Paoletti R, Brunello N, Jackson AS, editors. Serotonin. Dordrecht: Springer Netherlands; 1993. pp. 329-35. [DOI: 10.1007/978-94-011-1920-7_38]

Immunohistochemical and ultrastructural study of the immune cell system and epithelial surfaces of the respiratory organs in the bimodally-breathing African sharptooth catfish (Clarias gariepinus Burchell, 1822)

Ach, represents the old neurotransmitter in central and peripheral nervous system. Its muscarinic and nicotinic receptors (mAChRs and nAChRs) constitute an independent cholinergic system that is found in immune cells and playsa key role in regulation of the immune function and cytokine production. Gas exchanging surfaces of the gills and air-breathing organs (ABOs) of the sharptooth catfish Clarias gariepinus were investigated using ultrastructural and confocal immunofluorescence techniques. This study was predominantly focused on the structure of the immune cell types, the expression of their neurotransmitters, including the antimicrobial peptide piscidin 1, and the functional significance of respiratory gas exchange epithelia. A network of immune cells (monocytes, eosinophils, and mast cells) was observed in the gill and theABO epithelia. Eosinophils containing 5HT immunoreactivity were seen in close association with mast cells expressing acetylcholine (Ach), 5HT, nNOS and piscidin 1. A rich and dense cholinergic innervation dispersing across the islet capillaries of the gas exchange barrier, and the localization of Ach in the squamous pavement cells covering the capillaries, were evidenced byVAChT antibodies.We report for the first time that piscidin 1(Pis 1) positive mast cells interact with Pis 1 positive nerves found in the epithelia of the respiratory organs.Pis 1 immunoreactivity was also observed in the covering respiratory epithelium of the ABOs and associated with a role in local mucosal immune defense . The above results anticipate future studies on the neuro-immune interactions at mucosal barrier surfaces, like the gill and the skin of fish, areas densely populated by different immune cells and sensory nerves that constantly sense and adapt to tissue-specific environmental challenges. This article is protected by copyright. All rights reserved.

Effect of d-fenfluramine on the lymphocyte response of HIV+ humans

The objective of this study was to analyse the effect of d-dexfenfluramine (d-FEN) on the human lymphocyte response, in vitro. Experiments were designed to determine whether d-FEN augments specific human immune parameters associated with protection from opportunistic microbial pathogens and particularly focuses on d-FEN as a means by which to augment the function of CD8+ and CD4+ lymphocytes. Lymphocytes were examined for three reasons: (1) for their ability to inhibit the growth of Candida albicans; (2) for their ability to proliferate in response to a mitogen; and, (3) their cytokine profile (vis., production of IL-2, IFN-gamma and TNF-alpha). Peripheral blood mononuclear cells (PBMC) were obtained from 20 HIV+ patients. The patients were diagnosed as HIV+ within the past 0.5-9 years. d-FEN was found to augment the capacity of CD8+ lymphocytes to inhibit the growth of the opportunistic microbial pathogen, C. albicans. d-FEN enhanced the capacity of CD4+ lymphocytes to proliferate in response to the mitogen, Concanavalin A, and to increase the amount of IL-2 produced by CD4+ and CD8+ lymphocytes from AIDS patients. d-FEN increased the number of CD4+ and CD8+ lymphocytes that produced IFN-gamma from either non-AIDS or AIDS patients and increased the number of AIDS patient's CD8+ lymphocytes that produce TNF-alpha. These in vitro data suggest that d-FEN may be effective in enhancing immune function in immunocompromised individuals.