Prolactin promoter polymorphism (-1149 G/T) is associated with anti-DNA antibodies in Mexican patients with systemic lupus erythematosus.

Prolactin (PRL) is a 23-kDa protein hormone that is synthesized mainly by the anterior pituitary gland. However, PRL can also be synthesized and secreted by extrapituitary tissues, particularly immune cells. A biallelic polymorphism (-1149 G/T) in the prolactin promoter has been shown to be functionally important, as modulation of prolactin expression has been associated with SLE in some populations.

Identification of prolactin as a novel immunomodulator on the expression of co-stimulatory molecules and cytokine secretions on T and B human lymphocytes.

We investigate the immunomodulator role of prolactin (PRL) on CD4+ and B cell activation from healthy subjects in comparison with hyperprolactinemic patients. Peripheral blood mononuclear cells, CD4+ or B cells, purified, were cultured under different conditions, as follows: with mitogen, without stimulus, with different concentrations of human PRL, with unspecific mitogen plus PRL, or with antibodies against PRL. The results revealed that PRL is produced by lymphocytes, the expression of CD69 and CD154 molecules, and interleukin secretions depend partially on the autocrine PRL, this is supported by the findings that secretions of IL-2, IFNgamma, and co-stimulatory molecule expression were markedly reduced when autocrine PRL was blocked with anti-PRL antibodies.