[Immunity and physiology]. / Immunité et physiologie.

Immune system is described as a physiological system in its function and relations with the other organs (nervous, endocrine, nutritional and reproductive systems). Communications are mediated by common receptors and cytokines. Physiological reality of these interrelations has been discussed in function of stress and age.

Testosterone inhibits the immunostimulant effect of thymosin fraction 5 on secondary immune response in mice.

The purpose of the present investigation was to examine the in vivo influence of testosterone on the immune properties of a thymic factor (thymosin fraction 5, TF5) a partially purified thymic preparation in male Swiss IOPS/OF1 mice (5-10 weeks old). Testosterone administration (100 micrograms/ml) significantly inhibited the enhanced anti-sheep red blood cell antibody response induced by TF5 (100 micrograms/ml); this inhibition was only observed on the secondary antibody response and not on the primary. These results suggest that gonadal steroids can affect the immune response by modulating the activity of thymic factors.

Effects of metal ions on cyprinid fish immune response: in vitro effects of Zn2+ and Mn2+ on the mitogenic response of carp pronephros lymphocytes.

Lymphocytes from the pronephros of carp (Cyprinus carpio L) have been subjected to transformation by mitogens, concanavalin A (Con A), phytohemagglutinin (PHA), and lipopolysaccharides (LPS), with Zn or Mn at varying concentrations. Addition of Zn2+ (10(-7) to 10(-3) M) to mitogen-stimulated T and B cells enhanced [3H]thymidine incorporation. Addition of 10(-5) M Zn2+ inhibited the response to Con A, PHA, and LPS. At this concentration, Zn was toxic. Addition of Mn2+ (10(-7) to 10(-3) M) to mitogen-stimulated lymphocytes enhanced [3H]thymidine incorporation. This effect was observed with Con A- and PHA-stimulated lymphocytes, but not with LPS-stimulated lymphocytes. In contrast, addition of 10(-1) M Mn2+ to lymphocyte cultures exerted an inhibitor on the response to Con A or to PHA, while the response to LPS was unaffected. Addition of 10(-1) M Mn2+ to Con A- or PHA-stimulated cultures at different times after initiation of stimulation indicated that Mn2+ was inhibitory only when it was added before the first 16 hr of cultures. The inhibition induced by 10(-1) M Mn2+ could be reversed by adding 2 mM CaCl2 to the culture.

Interaction between luteotrophic hormone (LH) and thymosin on natural killer cell activity in BALB/c mice.

The present study investigates the effect of a pituitary hormone (luteotrophic hormone, LH) and a thymic factor (thymosin fraction V, TVF) on in vitro and in vivo natural killer (NK) cell activity of BALB/c mice (2, 6 and 8 months old). In vitro it was found that LH at various concentrations (0.5, 5, 50 and 500 ng/ml) significantly reduced the NK cell activity. This inhibition was not blocked by TFV. In vivo it was observed that there was a great inhibition of NK cell activity by LH (5 and 50 ng/ml) on 2- and 6-month-old mice, but a significant increase of NK cell activity on 8-month-old mice. The physiological significance of these observations points to an intimate connection between immune and endocrine system functions.

[Neuroimmunomodulation of the immune response by the endocrine system: effect of luteinizing hormone (LH) on the proliferative response of lymphocytes]. / Contribution a l'etude de la neuroimmunomodulation de la response immunitaire par le systeme endocrinien: effet de l'hormone luteinisante (LH) sur la response proliferative des lymphocytes.

Proliferative response of splenic lymphocytes from adult (2 months old) male mice to human luteotrophic hormone (hLH) was studied in vitro. hLH induced lymphoblastic transformation at a concentration of 0.1 micrograms/ml or higher. This hormone potentiated the mitogen activities of concanavalin A (ConA) and phytohemagglutinin (PHA) for T cells and of pokweed mitogen for B and T cells. The data suggest that peripherally circulating LH may regulate a certain function of lymphoid cells.

Presence of tonofilaments and thymic serum factor (FTS) in thymic epithelial cells of a fresh water fish (carp: Cyprinus carpio) and a sea water fish (bass: Dicentrarchus labrax).

Using indirect immunofluorescence we demonstrated the presence of FTS in two fishes; the size of epithelial cells of the carp is smaller than of the bass.