Muscarinic cholinergic receptors of rat lymphocytes: effect of antigen stimulation and local brain lesion.
Expression of muscarinic cholinergic receptors (m-AchR) on thymocytes and lymphocytes supports a hypothesis of direct interaction between autonomic innervation and the immune system. Using a muscarinic antagonist, [3H]quinuclidinyl benzilate ([3H]QNB), we revealed different characteristics of m-AchR expression in lymphocytes isolated from the spleen, peripheral blood or thymus of Wistar rats. To further explore the mechanisms controlling m-AchR expression in lymphocytes we have addressed two questions: (i) whether local brain lesions will affect [3H]QNB binding activity of lymphocytes and (ii) whether different antigens will alter m-AchR expression in lymphocytes. We report here that electrolytic lesions of the area hypothalamica anterior resulted in a significant increase in [3H]QNB-specific binding in thymocytes 7 days after neurosurgery. In contrast, local lesions of other hypothalamic structures (area preoptica medialis, area hypothalamica posterior) or sensomotor cortex did not affect m-AchR expression in thymocytes. No apparent changes of [3H]QNB-binding activity were found in lymphocytes isolated from rat spleen or peripheral blood after operation. Both T-cell-dependent (sheep red blood cells) and T-cell-independent (Vi antigen of Salmonella typhi) antigens induced a significant increase in [3H]QNB-specific binding in spleen lymphocytes while [3H]QNB-binding activity of peripheral blood lymphocytes did not change. A different pattern of lymphocyte m-AchR expression found in various lymphoid tissues after immunization or brain lesions suggests a local involvement of cholinergic mechanisms in neuroimmune interaction.
D000818:Animals; D000941:Antigens / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology; D000955:Antigens, T-Independent / Q000276:immunology; D001773:Blood Cells; D004912:Erythrocytes / Q000276:immunology; D007032:Hypothalamus, Anterior / Q000293:injuries / Q000502:physiology*; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D015213:Neuroimmunomodulation / Q000502:physiology*; D009928:Organ Specificity; D011135:Polysaccharides, Bacterial; D011813:Quinuclidinyl Benzilate / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011976:Receptors, Muscarinic / Q000096:biosynthesis* / Q000187:drug effects / Q000235:genetics; D012485:Salmonella typhi / Q000276:immunology; D012756:Sheep / Q000276:immunology; D013154:Spleen / Q000166:cytology; D013950:Thymus Gland / Q000166:cytology; D015854:Up-Regulation
D000941:Antigens; D000942:Antigens, Bacterial; D000955:Antigens, T-Independent; D018727:Muscarinic Antagonists; D011135:Polysaccharides, Bacterial; D011976:Receptors, Muscarinic; D011813:Quinuclidinyl Benzilate