Calcitonin receptor-like receptor is expressed on gastrointestinal immune cells.
OBJECTIVE
Pharmacological and morphological studies suggest that the gut mucosal immune system and local neuropeptide-containing neurones interact. We aimed to determine whether gut immune cells are targets for calcitonin gene-related peptide (CGRP), which has potent immune regulatory properties.


METHODS
Using density gradient centrifugation, rat lamina propria mononuclear cells (LP-MNCs) and intra-epithelial lymphocytes (IELs) were isolated. RT-PCR was employed for the detection of mRNA of rat calcitonin receptor-like receptor (CRLR), which is considered to represent the pharmacologically defined CGRP receptor-1 subtype, as well as mRNA of the receptor activity-modifying proteins, which are essential for CRLR function and determine ligand specificity. A radioreceptor assay was employed for the detection of specific CGRP binding sites.


RESULTS
RT-PCR and DNA sequencing showed that LP-MNCs and IELs express CRLR. Incubation of isolated LP-MNCs with radiolabelled alphaCGRP revealed the existence of specific binding sites for CGRP.


CONCLUSIONS
These novel data indicate that mucosal immune cells of the rat gut are a target for CGRP and provide significant evidence that CGRP functions as an immune regulator in the gut mucosa.
Hagner
Stefanie
S
Institute of Physiology, Philipps University, Marburg, Germany.
Knauer
Jens
J
Haberberger
Rainer
R
Göke
Burkhard
B
Voigt
Karlheinz
K
McGregor
Gerard Patrick
GP
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000276:immunology / Q000378:metabolism; D058286:Calcitonin Receptor-Like Protein; D004848:Epithelium / Q000276:immunology / Q000378:metabolism; D005434:Flow Cytometry; D016130:Immunophenotyping; D007413:Intestinal Mucosa / Q000276:immunology* / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D007963:Leukocytes, Mononuclear / Q000737:chemistry* / Q000276:immunology; D008214:Lymphocytes / Q000737:chemistry / Q000276:immunology; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D058261:Receptor Activity-Modifying Proteins; D018003:Receptors, Calcitonin / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D058286:Calcitonin Receptor-Like Protein; C545580:Calcrl protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D058261:Receptor Activity-Modifying Proteins; D018003:Receptors, Calcitonin; D015740:Calcitonin Gene-Related Peptide