title: Neonatal immunoglobulin secretion and lymphocyte phenotype in rat small intestine lamina propria.
abstract: We characterized the lymphocyte phenotype and the ability to produce Ig by lamina propria (LP) cells from rat ileum throughout the suckling period. In the first week after birth, <10% of LP lymphocytes were B cells, but at weaning, this figure rose to >30% as found in the adult. These B cells did not bear surface IgA (sIgA-). However, the number of sIgA+, which may correspond to B blast cells because they were outside lymphocyte cytometer gate, increased. In LP, IgM-secreting cells (SC) appeared during the second week of life, and IgA-SC were detected later but at a lower number. Regarding LP T cells, CD8+ cells were more abundant than CD4+ cells along the first 2 postnatal weeks, and CD3+CD8alphaalpha+TCRalphabeta+CD5-CD25- was their predominating phenotype. In this 2-wk period, between 8 and 20% of LP were natural killer cells. LP CD4+ lymphocytes in neonatal rats showed increasing co-expression of TCRalphabeta, whereas the co-expression of CD90 decreased and the CD4+CD25+ cell percentage did not achieve adult values. In conclusion, in the first 2 wk of the rat life, the gut LP immune system shows abundant CD8alphaalpha+ cells, including NK cells. Thereafter, LP B cells increase dramatically and Ig-SC appear, with IgM-SC being more abundant than IgA-SC. CD4+ LP lymphocytes acquire a mature phenotype and adult proportions later after weaning.
authors.affiliation: Department of Physiology, Faculty of Pharmacy, University of Barcelona, E-08028 Barcelona, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Pérez-Cano
authors.forename: Cristina
authors.initials: C
authors.lastname: Castellote
authors.forename: Silvia
authors.initials: S
authors.lastname: Marín-Gallén
authors.forename: Angels
authors.initials: A
authors.lastname: Franch
authors.forename: Margarida
authors.initials: M
authors.lastname: Castell
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017252:CD3 Complex / Q000096:biosynthesis; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology; D018956:CD5 Antigens / Q000096:biosynthesis; D016827:CD8 Antigens / Q000096:biosynthesis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D007070:Immunoglobulin A / Q000737:chemistry; D007075:Immunoglobulin M / Q000737:chemistry; D007136:Immunoglobulins / Q000378:metabolism*; D007421:Intestine, Small / Q000276:immunology* / Q000378:metabolism*; D007694:Killer Cells, Natural / Q000166:cytology; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D008071:Lipoprotein Lipase / Q000378:metabolism; D016131:Lymphocyte Subsets / Q000737:chemistry; D008214:Lymphocytes / Q000166:cytology* / Q000378:metabolism; D008297:Male; D008856:Microscopy, Fluorescence; D010641:Phenotype; D051381:Rats; D011917:Rats, Inbred Lew; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D018800:Thy-1 Antigens / Q000096:biosynthesis; D013997:Time Factors
chemical_list: D017252:CD3 Complex; D018956:CD5 Antigens; D016827:CD8 Antigens; D007070:Immunoglobulin A; D007075:Immunoglobulin M; D007136:Immunoglobulins; D015375:Receptors, Interleukin-2; D018800:Thy-1 Antigens; D008071:Lipoprotein Lipase; D017493:Leukocyte Common Antigens