Neuroimmunomodulation of the mucosal immune system is though to exist, but has not been demonstrated. Evidence to support this hypothesis is based on animal studies of systemic and non-mucosal immunocytes. Functional immunomodulation by neuropeptides via specific membrane receptors has been demonstrated in peripheral blood lymphocytes (PBL) and other tissues in animals; no studies have characterized the immune response of mucosal, lamina propria lymphocytes (LPL) to neuropeptide stimulation, in animals or humans. Phenotypic and functional differences in circulating and tissue-based lymphocytes are apparent as well as are differences in levels of neuropeptide concentration. Given these, demonstration of functional neuropeptide receptors on LPL with characteristics different from those in peripheral blood is probable, and would suggest a mechanism for selective modulation of immunity by sensory nerves in human gut mucosa. During Phase 1, PBL from normal healthy donors and LPL from resected intestinal specimens will be examined to determine which subsets express surface receptors for the neuropeptides Substance P (SP) and/or Vasoactive Intestinal Peptide (VIP). Lymphocyte subsets with significant numbers of receptors will be rapidly identified by simultaneous fluorescent activated cell (FACS) analysis using phycoerythrin-conjugated monoclonal antibodies against lymphocyte surface antigens and fluorescein-tagged neuropeptides binding to putative receptors. Focused attention will then be directed toward the identified subsets which will be purified using antibody-panning and complement lysis techniques in order to perform classical radioligand binding studies. Receptor characteristics will be determined. Modulatory effects of neuropeptide stimulation will be measured using appropriate function assays for the identified subset (cytotoxicity, proliferation and immunoglobulin production). Correlations between a subset's receptor characteristics and altered biological activity will be made. The hypothesis of differences in mucosal and systemic neuroimmunomodulation will be determined. During Phase 2, the previous investigations which examined cellular characteristics of neuropeptide-lymphocyte interaction will progress to investigations of the mechanism of sub-cellular activation. In studying a few subsets with marked alteration in function following neuropeptide stimulation, the role of secondary messengers in mediating the receptor-initiated signal will be examined.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Physician Scientist Award (K11)
Project #
5K11DK001879-05
Application #
3086477
Study Section
Diabetes, Endocrinology and Metabolic Diseases B Subcommittee (DDK)
Project Start
1989-07-15
Project End
1994-06-30
Budget Start
1993-07-01
Budget End
1994-06-30
Support Year
5
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Type
Schools of Medicine
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Vidrich, A; Anton, P A; Shanahan, F (1998) Immuno-epithelial interactions: cytokine modulation of normal rabbit colonocyte function. In Vitro Cell Dev Biol Anim 34:743-6
Bernstein, C N; Seeger, L L; Sayre, J W et al. (1995) Decreased bone density in inflammatory bowel disease is related to corticosteroid use and not disease diagnosis. J Bone Miner Res 10:250-6
Bernstein, C N; Artinian, L; Anton, P A et al. (1994) Low-dose 6-mercaptopurine in inflammatory bowel disease is associated with minimal hematologic toxicity. Dig Dis Sci 39:1638-41
Anton, P A; Shanahan, F; Sun, X P et al. (1993) VIP modulates intracellular calcium oscillations in human lymphoblasts. Immunopharmacol Immunotoxicol 15:429-46
Martin, F C; Anton, P A; Gornbein, J A et al. (1993) Production of interleukin-1 by microglia in response to substance P: role for a non-classical NK-1 receptor. J Neuroimmunol 42:53-60
Anton, P A; Reeve Jr, J R; Vidrich, A et al. (1991) Development of a biotinylated analog of substance P for use as a receptor probe. Lab Invest 64:703-8
Anton, P A; Reeve Jr, J R; Rivier, J E et al. (1991) Biotinylation of a bombesin/gastrin-releasing peptide analogue for use as a receptor probe. Peptides 12:375-81