Expression of prolactin receptors in murine lymphoid cells in normal and autoimmune situations.
We have analyzed the expression of prolactin receptors (PRL-R) on murine lymphoid cells by using flow cytofluorometry analysis with biotinylated anti-PRL-R mAb raised against several epitopes of the extracellular domain of the PRL-R and by using polymerase chain reaction amplification. We demonstrated that PRL-R were universally expressed in normal rat and mouse hematopoietic tissues. In both primary lymphoid organs, namely, thymus and bone marrow, > 90% of cells were labeled by the anti-PRL-R mAb, but the density of PRL-R (assessed by fluorescence intensity) was lower on thymocytes than on bone marrow cells. In peripheral lymphoid organs there were smaller proportions of cells bearing PRL-R and we could clearly distinguish cell subsets of various fluorescence intensities. By using classical markers for lymphoid cell populations, we noted that all B cells and macrophages from spleen, lymph nodes, and blood strongly expressed the PRL-R. Regarding T cell populations, large proportions (> 85%) of PRL-R+ cells were detected in the four thymocyte subsets, thus contrasting with the smaller proportions (50 to 65%) of T cells labeled in the periphery. Similar percentages of PRL-R+ cells were observed in CD4+ and CD8+ peripheral lymphocyte subsets. Importantly, the stimulation of thymocytes and spleen cells with the T cell mitogen Con A promoted an enhancement of the density of PRL-R molecules on the cell membranes. Because hyperprolactinemia is associated with some autoimmune diseases, we also investigated PRL-R expression in the NZB autoimmune mouse. In contrast to the pattern observed in normal animals, the frequencies of PRL-R-bearing T cells as well as the density of PRL-R per cell increased with age in NZB mice, suggesting that some imbalances of PRL/PRL-R interaction might occur in autoimmune situations. In conclusion, our data provide a molecular basis for a better understanding on the mode of action of PRL within the immune system in physiologic and pathologic situations.
Gagnerault
M C
MC
CNRS URA 1461, Hôpital Necker, Paris, France.
Touraine
P
P
Savino
W
W
Kelly
P A
PA
Dardenne
M
M
D000818:Animals; D001327:Autoimmune Diseases / Q000378:metabolism*; D001483:Base Sequence; D005260:Female; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000737:chemistry*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008814:Mice, Inbred NZB; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011388:Prolactin / Q000502:physiology; D051381:Rats; D011917:Rats, Inbred Lew; D011981:Receptors, Prolactin / Q000032:analysis* / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000737:chemistry
D011981:Receptors, Prolactin; D011388:Prolactin