title: Impaired mammary gland T cell population during early lactation in hypoprolactinemic lactation-deficient rats.
abstract: Mammary stroma is composed of various cell types, including migratory leukocytes. Although mammary antibody-secreting cells have been extensively studied, reports focusing on mammary T cells are scarce. It is thought that the recruitment mechanism of leukocytes to the mammary gland (MG) is controlled by pregnancy- and lactation-specific stimuli. But whether prolactin (PRL) modulates the T-cell population in MG is still unknown. Our aim was to study the relationship between PRL levels and T and B cells during early lactation (L2, day 2 post partum) and mid-lactation (L12, day 12 of lactation). In order to investigate whether PRL is associated with homing events to MG, female Sprague Dawley (SD) and SD-derived desmoglein 4(-/-) hairless (phenotype with lactation deficit, OFA hr/hr) rats were killed during estrus, pregnancy, and post partum, and blood, MG, and corpora lutea were obtained to perform fluorescent-activated cell sorting (FACS), real-time PCR, and histological and RIA studies. Serum PRL levels were lower in OFA hr/hr rats than in SD rats during early lactation. MG of OFA hr/hr rats showed less secretory material compared with SD rats. FACS analysis showed lower percentage of MG CD3+ cells in OFA hr/hr rats compared with SD rats on L2 and L12. OFA hr/hr rats showed higher absolute numbers of circulating CD3+ cells compared with SD rats on L2 but not on L12. These results show that T-cell population in MG is affected in early lactating OFA hr/hr rats and strongly suggest that serum PRL levels may be involved in the homing events to MG, probably helping antibody-secreting cells and protecting the gland during lactation development.
authors.affiliation: Instituto de Medicina y Biología Experimental de Cuyo, CCT Mendoza, CONICET, Mendoza CP5500, Argentina. jpmackern@mendoza-conicet.gob.ar
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Mackern-Oberti
authors.forename: Susana Ruth
authors.initials: SR
authors.lastname: Valdez
authors.forename: Laura María
authors.initials: LM
authors.lastname: Vargas-Roig
authors.forename: Graciela Alma
authors.initials: GA
authors.lastname: Jahn
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology; D005260:Female; D007774:Lactation; D007962:Leukocytes / Q000378:metabolism; D018655:Lymphocyte Count; D008297:Male; D008321:Mammary Glands, Animal / Q000254:growth & development / Q000276:immunology*; D011247:Pregnancy; D011388:Prolactin / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019707:Receptors, Chemokine / Q000378:metabolism; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D019707:Receptors, Chemokine; D011388:Prolactin