Immune System Development and Function in Prolactin Receptor-Deficient Mice (original) (raw)

Prolactin receptor expression by lymphoid tissues in normal and immunized rats

Molecular and Cellular Endocrinology, 1993

Prolactin receptor (PRLr) expression and distribution in thymus, spleen, bone marrow, lymph nodes, and peripheral blood lymphocytes from young adult Lewis rats are analyzed using singfe-color ffow cytometry and a we&characterized monoclonal antibody directed against the rat liver PRLr. The in viva effects of regional immunization on PRLr expression are also examined. PRLr is found to be widely distributed among cells of the immune system and demonstrates Iympboid tissue-specific patterns of expression. Footpad immun~ation caused the rapid, but transient, induction of PRLr expression in the draining lymph node, with only modest effects on PRLr expression in other distant Iymphoid tissues. These studies indicate that PRL may be capable of direct interaction with the immune system through differentia1 expression of the PRL cell surface receptor on seIect iymphoid target cell populations.

Prolactin receptor gene expression in rat splenocytes and thymocytes from birth to adulthood

Molecular and Cellular Endocrinology, 1996

In vivo and in vitro studies have indicated that the anterior pituitary hormone prolactin (PRL) is an immunoregulator and functions in the development of the neonatal immune system. In this study, prolactin receptor (PRL-R) expression from birth to adulthood as well as the effect of milk ingestion on the PRL-R expression were examined in splenocytes and thymocytes of neonatal rats. Three approaches were taken to measure PRL-R expression: (i) polymerase chain reaction (RT-PCR); (ii) antibody to PRL-R and Western blotting; (iii) antibody to PRL-R and flow cytometry. RT-PCR analysis revealed the short and long form of PRL-R mRNA in both spleen and thymus at every age tested. However, the long form of PRL-R mRNA was always more abundant than that of the short form. In addition, antipeptide antibody against the long form of PRL-R recognized 84 and 42 kD proteins in the spleen, but only the 84 kD protein in the thymus. A monoclonal antibody U6 recognized 38 and 40 kD proteins in both the spleen and thymus. Although the mRNA level of PRL-R was relatively low at birth and increased with age in both the spleen and thymus, the levels of protein bands detected with both antibodies correlated with development in the spleen; whereas the levels remained steady in the thymus. Therefore, we concluded that the expression of PRL-R at the protein level is developmentally regulated in the spleen but not in the thymus. Finally. milk ingestion in the first seven hours decreased the percentage of cells expressing cell surface PRL-R, suggesting that milk-borne PRL may have a direct effect on lymphocytes.

Prolactin in the Immune System

Prolactin, 2013

PRL was originally identified as a neuroendocrine hormone of pituitary origin; however, its synthesis is not limited to the hypophysis since numerous extrapituitary tissues also express this protein, including the placenta, ovary, testis, mammary gland, skin, adipose tissue, endothelial cells, and immune cells [1]. This widespread PRL expression might explain its involvement in very different processes such as reproduction, metabolism, immunology, and behavior. PRL expression and secretion are regulated by different stimuli provided by the environment and the internal milieu. Although pituitary PRL secretion is under a tonic and Prolactin 54 2.1.1. cAMP and modulators of the cAMP/CREB pathway Consistent evidence, including studies in different leukemic cell lines as well as PBMC from normal patients, has shown that PRL gene expression is significantly stimulated by cAMP, Prolactin 56

Modulation of prolactin expression in human T lymphocytes by cytokines

Journal of Neuroimmunology, 2005

Besides its pivotal role in reproduction, the polypeptide hormone prolactin (PRL) has immunomodulatory properties. Whereas the bulk of circulating PRL is produced by the pituitary, PRL is also produced by the decidua, the myometrium, the mammary gland and leukocytes. Extrapituitary PRL expression is regulated differently from that in the pituitary, due to the use of an alternative promoter. Here we show for the first time that in T lymphocytes PRL expression is subject to regulation by cytokines. We established that both IL-2 and IL-4 reduced PRL mRNA levels in T lymphocytes to 25 and 28% of control values, respectively. PRL mRNA expression was inhibited to a lesser extent by IL-1h, which decreased PRL mRNA levels to 58% of control values. D

Influence of prolactin on the differentiation of mouse B-lymphoid precursors

Cell growth & differentiation : the molecular biology journal of the American Association for Cancer Research, 1999

Development and activation of immune cells are submitted to hormonal influences, as illustrated by the roles of corticosteroids in thymus, pregnancy-related estrogens in B-cell development, or prolactin (PRL) on T-cell generation and function. We have analyzed the putative role of PRL in B lymphopoiesis and differentiation. We chose as an experimental model the interleukin (IL)-3 dependent BaF-3 pro-B cell line, which was transfected with the rat long form of the PRL receptor (PRL-R) and transferred from IL-3- to PRL-enriched media. When stimulated with PRL, the PRL-R transfectants underwent some changes characteristic of B-cell differentiation: (a) IL-2R alpha chain became positively controlled by PRL; (b) antiapoptotic Bcl-2 protein was induced by PRL in a dose-dependent manner; and (c) transcription of the pre-B cell receptor encoding the lambda5 gene was strongly up-regulated. We attempted to evaluate the differentiation-promoting activity of PRL in more physiological conditions...

Prolactin receptor expression by splenocytes from rats in various hormonal states

Cell Proliferation, 1997

Prolactin (PRL) is mitogenic for lymphocytes in vitro, but the responsiveness of lymphocytes depends on the in vivo hormonal status of the rats from which the cells were obtained. Lymphocytes from ovariectomized (OVX) rats, but not from rats in oestrus or from male rats, respond to prolactin; administration of oestradiol to OVX rats diminishes the response. In order to determine if a correlation exists between lymphocyte responsiveness to prolactin and levels of cell surface prolactin receptors (PRL-R) expression, the percentage of splenocytes and each splenocyte subpopulation expressing surface PRL-R from rats of various hormonal states (OVX, oestradiol-injected OVX, oestrus and male) was analysed by single-colour and dual-colour flow cytometric analysis. We found that approximately 20% of splenocytes expressed surface PRL-R regardless of hormonal states (n= 16). The majority (85%) of PRL-R positive splenocytes were B lymphocytes whereas 11.1% and 4.8% of splenocytes expressing the PRL-R were CD4 positive T-helper (TH) and CD8 positive T-cytotoxic (Tc) lymphocytes, respectively. B lymphocytes also stained more brightly than T lymphocytes. This distribution of PRL-R expression did not show significant alterations on total splenocytes or TH and Tc lymphocytes during various hormonal stages. However, the percentage of PRL-R-positive B lymphocytes increased markedly in OVX rats (twofold), compared to rats at oestrus. In summary, no correlation was found between the responsiveness to prolactin as a mitogen and levels of PRL-R expression by lymphocytes from rats at different hormonal states. This result suggests that sex steroid hormones may control prolactin responsiveness of lymphocytes by affecting the signal transduction pathway through PRL-R rather than by altering the level of the cell surface receptor expression.

Immunohistochemical Study of Postnatal Development of Prolactin-Producing Cells in C57BL Mice

Acta Histochemica et Cytochemica, 1985

Sexual dimorphic changes in postnatal development of prolactin (PRL)producing cells in the anterior pituitary gland in C57BL mice were immunohistochemically investigated. When examined at birth, PRL cells were already present in both male and female mice. With advancement of age, PRL cells increased in number. The shape of PRL cells at birth was oval, but on day 7 irregular-shaped PRL cells appeared. The shape of immunoreactive secretory granules in PRL cells were spherical at birth and also at day 7. However, on day 14 polymorphic PRL granules began to appear in type III PRL cells in both male and female mice. The ratios among type I, II, and III PRL cells and also the total number of all types of PRL cells were not different between male and female mice until 4 weeks of age. Meanwhile, type II PRL cells were predominant in both sexes. From 5 weeks of age, type III PRL cells began to increase in number in female mice only, thus sexual dimorphism in PRL cell types became noticeable during pubertal changes. The present results suggest that postnatal morphological, particularly sexual dimorphic, changes observed in secretory granules as well as cell shapes of PRL cells are mainly due to the reflection of endocrine functions in pubertal female mice.