Distinct expression of cytokines and mitogenic inhibitory factors in semen of fertile and infertile men

Modulation of innate and adaptive cellular immunity relevant to HIV-1 vaccine design by seminal plasma

OBJECTIVES

Mucosal exposure to HIV-1 infection generally occurs in the presence of semen. Immunomodulation by seminal plasma is well described in the reproductive biology literature. Little is known, however, about the impact of seminal plasma on innate and adaptive anti-HIV-1 cellular immunity.

DESIGN

The study investigated the effects of seminal plasma on immune responses considered important for prophylactic HIV-1 vaccine development, namely innate and adaptive cellular immunity mediated by natural killer (NK) cells and T cells, respectively.

METHODS

The ability of seminal plasma to modulate direct, antibody-dependent and cytokine-stimulated NK cell activation was assessed utilizing intracellular cytokine staining. Direct and antibody-dependent cellular cytotoxicity was assessed using lactate dehydrogenase release assays. The effects of seminal plasma on T-cell activation upon stimulation with staphylococcus enterotoxin B or HIV-1 Gag peptides were assessed by intracellular cytokine staining. The impact of seminal plasma on redirected cytolysis mediated by T cells was measured using lactate dehydrogenase release assays.

RESULTS

Both direct and antibody-dependent NK cell activation were dramatically impaired by the presence of either HIV-1-uninfected or HIV-1-infected seminal plasma in a dose-dependent manner. Additionally, seminal plasma suppressed both direct and antibody-dependent NK cell-mediated cytolysis, including anti-HIV-1 antibody-dependent cytolysis of gp120-pulsed CEM.NKr-CCR5 cells. Finally, seminal plasma attenuated both HIV-1 Gag-specific and staphylococcus enterotoxin B-induced CTL activation.

CONCLUSIONS

Semen contains potent immunosuppressors of both NK cell and CD8 T-cell-mediated anti-HIV-1 immune responses. This could impede attempts to provide vaccine-induced immunity to HIV-1.

Profiling signaling proteins in human spermatozoa: biomarker identification for sperm quality evaluation

OBJECTIVE

To determine the correlation between semen basic parameters and the expression and activity of signaling proteins.

DESIGN

In vitro studies with human spermatozoa.

SETTING

Academic research institute.

PATIENT(S)

Thirty-seven men provided semen samples for routine analysis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Basic semen parameters tracked included sperm DNA fragmentation (SDF), the expression levels of 75 protein kinases, and the phosphorylation/cleavage patterns of 18 signaling proteins in human spermatozoa.

RESULT(S)

The results indicated that the phosphorylated levels of several proteins (Bad, GSK-3β, HSP27, JNK/SAPK, mTOR, p38 MAPK, and p53), as well as cleavage of PARP (at D214) and Caspase-3 (at D175), were significantly correlated with motility parameters. Additionally, the percentage of morphologically normal spermatozoa demonstrated a significant positive correlation with the phosphorylated levels of p70 S6 kinase and, in turn, head defects and the teratozoospermia index (TZI) showed a significant negative correlation with the phosphorylated levels of Stat3. There was a significant positive correlation between SDF and the teratozoospermia index, as well as the presence of head defects. In contrast, SDF negatively correlated with the percentage of morphologically normal spermatozoa and the phosphorylation of Akt and p70 S6 kinase. Subjects with varicocele demonstrated a significant negative correlation between head morphological defects and the phosphorylated levels of Akt, GSK3β, p38 MAPK, and Stat1. Additionally, 34 protein kinases were identified as expressed in their total protein levels in normozoospermic samples.

CONCLUSION(S)

This study contributed toward establishing a biomarker "fingerprint" to assess sperm quality on the basis of molecular parameters.

Interleukin-1β, cyclooxygenase-2, and hypoxia-inducible factor-1α in asthenozoospermia

Impaired male fertility may have a variety of causes, among which asthenozoospermia. In its etiology, several bioactive substances, such as cytokines may be involved. In this context, our aim was to evaluate the expression of interleukin-1β, cyclooxygenase-2, and hypoxia-inducible factor-1α, in spermatozoa isolated from normospermic fertile donors and asthenozoospermic infertile patients. We evaluated twenty-eight infertile patients affected by idiopathic asthenozoospermia and twenty-three normospermic fertile donors, age-matched. Sperm parameters were evaluated; immunohistochemical analysis and enzyme-linked immunosorbent assay were then performed in isolated spermatozoa. Spermatozoa from the asthenozoospermic group presented an increased expression of IL-1β, COX-2, and HIF-1α compared with the normospermic fertile subjects. Our results can lead us to speculate that the increased expression of these substances may influence sperm motility. Nevertheless, further studies are needed in order to assess whether these bioactive mediators have a potential relevance as targets in future therapeutic strategies for the treatment of male infertility.

Distinct expression of interleukin-1α, interleukin-1β, and interleukin-1 receptor antagonist in testicular tissues and cells from human biopsies with normal and abnormal histology

Cytokines are paracrine/autocrine growth factors known to affect testicular cell functions. The cellular origin and expression levels of interleukin-1 (IL-1) in human normal and pathological testicular biopsies are not yet clear. In the present study, we have investigated the levels and cellular origin of IL-1 family members [IL-1α, IL-β, and IL-1 receptor antagonist (IL-1ra)] in human testicular normal and abnormal biopsies with incomplete maturation arrest (IMA) or Sertoli only syndrome (SOS), using real-time polymerase chain reaction and immunohistochemical staining analysis. Our results show that the levels of IL-1α were higher in Leydig/interstitial cells of biopsies with IMA and SOS compared with normal. The levels of IL-1α in Sertoli cells of normal biopsies were higher than IMA and SOS. The mRNA levels of IL-1α were similar in all biopsies. IL-1β levels were higher in Leydig/interstitial cells of normal biopsies compared with Sertoli and germ cells. The levels of IL-1β were similar in testicular cells of all biopsies. However, the mRNA levels of IL-1β were significantly lower in SOS and IMA biopsies compared with normal. IL-1ra was expressed only in Leydig/interstitial cells, and their expression in normal biopsies was higher than in biopsies with IMA and SOS. The mRNA levels of IL-1ra were similar in all biopsies. Thus, it is possible to suggest the involvement of IL-1 system in the regulation of spermatogenesis and male infertility.

Reproductive Tract Infections in Horses

Diagnosis, treatment, and, ultimately, prevention of reproductive disease are vital components of equine veterinary medicine. A thorough understanding of anatomy and physiology is necessary to reconcile the pathologic findings of disease. Only then can a rational treatment plan be formulated. Many recent advances in knowledge about the reproductive system of multiple species have application to the mare and stallion.

Relation between immunosuppressive PGE(2) and IL-10 to pro-inflammatory IL-6 in seminal plasma of infertile and fertile men

In vitro studies have reported that seminal plasma of fertile men has more inhibitory mitogenic effect and higher suppressive activity on antibody-dependent cellular cytotoxicity than seminal plasma from infertile males. Is it possible that variations in the seminal plasma composition could explain these results? The present study was conducted to investigate the relation between immunosuppressive PGE(2) and IL-10 to pro-inflammatory IL-6 in seminal plasma of infertile and fertile men. Utilizing specific ELISA commercial kit, semen samples from 45 infertile undiagnosed and 25 fertile men were examined for the presence of PGE(2), IL-10, and IL-6. The IL-6 concentration in seminal plasma of infertile men was significantly higher than that of fertile men (p<.0 4). However, levels of IL-10 were lower for the semen of infertile men than that of fertile men (p<.04). No differences were observed in PGE(2) concentrations between both groups. Increase in pro-inflammatory cytokines, such as IL-6, and decrease in immunosuppressive ones, such as IL-10, could alter the tolerance to sperm cell in male and female tracts and reduce the favorable conditions to reach the fecundation and implantation. It is necessary to conduct further studies that include other pro- and anti-inflammatory substances to evaluate the importance of the immune balance of semen in human fertility.

Interleukin-1 beta and tumor necrosis factor-alpha in normal/infertile men

Cytokines play an important role in intercellular communications. Human sperm contains a wide spectrum of cytokines. such as interleukin-1 beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha). Their effects on semen quality are subject to debate. The aim of this study was to determine concentrations of IL-1beta and TNF-alpha in normal fertile men and in different groups of male infertility in an attempt to clarify the physiology and suggest possible clinical uses. Sixty-six subfertile male patients with varicocele (n = 22). infection of accessory genital glands (n = 14), varicocele plus infection (n = 4), chronic epididymitis (n = 8). post-renal transplantation status (n = 5), idiopathic oligoasthenoteratospermia (n = 9), cryptorchidism (n = 1), and homozygous beta-thalassemia (n = 3) as well as 5 male controls were studied through history, physical examination, spermiograms, plasma basal hormonal levels, and IL-1beta and TNF-alpha levels in seminal fluid. There was no significant statistical difference regarding IL-1beta and TNF-alpha among fertile men and subfertile patients of any cause. 1L-1beta and TNF-alpha were in tight positive correlation (p<.001). Determination of IL-1beta and TNF-alpha does not provide useful information in male routine infertility workup. Nevertheless, a better understanding of these mediators in semen of normal men and infertile patients may contribute to a new approach to the management of male infertility.

Involvement of intratesticular IL-1 system in the regulation of Sertoli cell functions

The Interleukin-1 (IL-1) system has been suggested to be involved in the cell-cell cross talk within the testis. To investigate the testicular autocrine, paracrine and endocrine factors involved in the regulation of Sertoli cell functions, we have examined the capacity of Sertoli cell cultures, from immature mice, to produce IL-1alpha, IL-1beta and IL-1 receptor antagonist (IL-1ra) under in vitro cultures and in the presence of testicular physiological and pathological factors. Our investigation revealed that Sertoli cells produce large amounts of IL-1alpha, IL-1ra but not IL-1beta under basal culture conditions, as examined by ELISA and immunohistochemical staining. Liposaccharides (LPS), as well as IL-1alpha and IL-1beta were found to stimulate IL-1alpha and IL-1ra, but not IL-1beta production, in Sertoli cells from immature mice. Maximum concentration of IL-1alpha and of IL-1ra was observed after 2 and 8 h after the stimulation, respectively. The addition of IL-1ra to Sertoli cells did not alter their capacity to constitutively produce IL-1alpha. However, the stimulatory effects of recombinant IL-1alpha on IL-1alpha production by Sertoli cells were reversed by the concomitant addition of recombinant IL-1ra. FSH is capable to induce IL-1ra production in Sertoli cells in a dose-dependent manner but not IL-1alpha or IL-1beta. As expected, Sertoli cell cultures were also shown to constitutively secrete transferrin. Stimulation of these cultures with IL-1alpha, IL-1beta significantly increased their capacity to secrete transferrin. Addition of IL-1ra to unstimulated Sertoli cell cultures did not affect their capacity to secrete transferrin. Stimulation of Sertoli cell cultures with a combination of both IL-1alpha and FSH or IL-1beta and FSH showed additive effect between IL-1 and FSH in their capacity to induce transferrin secretion by these cells. However, stimulation of Sertoli cells with a combination of both IL-1ra and FSH did not affect their capacity to secrete transferrin as compared with FSH-stimulated cultures. Our results with Sertoli cells, in addition to previous data on Lydig cell and germ cells, may suggest the involvement of the IL-1 system in testicular paracrine/autocrine regulation, which could be involved in the regulation of spermatogenesis and spermiogenesis processes and male fertility.

Induction of transferrin secretion in murine Sertoli cells by FSH and IL-1: the possibility of different mechanism(s) of regulation

In the present study we examined the capacity of interleukin-1 (IL-1) alpha, beta, interleukin-1 receptor antagonist (IL-1ra) and follicle stimulating hormone (FSH) to induce transferrin secretion by Sertoli cells under in vitro conditions. Primary Sertoli cell (SC) cultures from immature mice secreted constitutively transferrin. Stimulation of these cultures with IL-1alpha, IL-1beta significantly increas\d their capacity to secrete transferrin. Addition of IL-1ra to unstimulated SC cultures did not affect their capacity to secrete transferrin. Stimulation of SC cultures with a combination of both IL-1alpha and FSH or IL-1beta and FSH showed additive effect between IL-1 and FSH in their capacity to induce transferrin secretion by these cells. However, stimulation of Sertoli cells with a combination of both IL-1ra and FSH did not affect their capacity to secrete transferrin compared with FSH-stimulated cultures. Our results may suggest the involvement of testicular paracrine/autocrine factors (IL-1) and endocrine (FSH) factors in the regulation of transferrin secretion by SC. This capacity seems to be differently regulated by these factors. Thus, IL-1alpha and beta may directly affect physiological functions of the testis; which may suggest their involvement in the regulation of spermatogenesis and spermiogenesis processes and male fertility.

Members of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway are present and active in human sperm

OBJECTIVE

To investigate whether components of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway are present and active in human sperm.

DESIGN

Comparative study.

SETTING

Reproductive biology department.

PATIENT(S)

Nine sperm donors.

INTERVENTION(S)

Sperm were exposed to interferon-alpha (IFN-alpha), IFN-gamma, interleukin-12 (IL-12), Ca2+ ionophore (A23187), or progesterone under capacitating conditions.

MAIN OUTCOME MEASURE(S)

Cell lysates prepared from sperm and Jurkat T-cell line were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the expression of JAKs (1-3 and TYK 2) and STATs (1-6) was examined by Western blot analysis. Effect of IFN-alpha, IFN-gamma, IL-12, A23187, or progesterone on sperm STAT 1 or STAT 4 phosphorylation was determined by phospho-STAT 1 antibody or antiphosphotyrosine (APT) Western blot analysis. Indirect immunofluorescence and confocal laser scanning microscopy was used to confirm the specific staining of anti-TYK 2, anti-STAT 1, and anti-STAT 4 antibodies.

RESULT(S)

By Western blot analysis, only antibodies to TYK 2 of the JAK family, and antibodies to STAT 1 and STAT 4 members of the STAT family specifically recognized protein bands corresponding to TYK 2, STAT 1, and STAT 4 described in other cell types. By confocal microscopy, antibodies to TYK 2 reacted with the sperm tail as well as the apical region of sperm head, whereas antibodies to STAT 1 and STAT 4 reacted with the apical region of the sperm head. Tyrosine phosphorylation of STAT 1 in capacitated sperm was enhanced by IFN-alpha and IFN-gamma, and that of STAT 4 was enhanced by IL-12. Both A23187 and progesterone markedly inhibited tyrosine phosphorylation of sperm STAT 4.

CONCLUSION(S)

Members of the JAK/STAT proteins, TYK 2, STAT 1, and STAT 4 are present and active in human sperm. The localization of STAT 1 and STAT 4 proteins to the apical region of the sperm head and their activation by IFN-alpha, IFN-gamma, or IL-12 implicate a role for sperm STAT proteins in fertilization. We hypothesize that sperm-derived phosphorylated STAT 1 and STAT 4 could contribute to the pool of transcription factors during sperm-oocyte fusion as well as transmit signal to the oocyte nucleus. Therefore, defects in sperm TYK 2 and STAT 1- or STAT 4-mediated signaling pathway may have relevance to male factor infertility.

Production of interleukin-1-like molecules by human sperm cells

OBJECTIVE

To characterize and localize interleukin (IL)-1alpha and IL-1beta in human sperm cells.

DESIGN

Prospective and comparative study.

SETTING

Andrology clinic of a university hospital.

PATIENT(S)

Two groups of normogonadotropic men: 17 fertile men (donors with proved fertility) and 8 oligoteratoasthenospermic infertile men.

INTERVENTION(S)

None. MAIN OTUCOME MEASURE(s): Evaluation of IL-1alpha and IL-1beta levels and expression in sperm cells by immunohistochemical staining, immunoassay, and Western blot analysis.

RESULT(S)

Both types of IL-1-like molecules (IL-1alpha and IL-1beta) were expressed in the tail, neck, and head of sperm cells of fertile men and patients with oligoteratoasthenospermia. Swim-up sperm cells from fertile men and patients with oligoteratoasthenospermia secreted similar levels of IL-1-like molecules. The levels of IL-1beta-like molecules were higher than those of IL-1alpha-like molecules in both groups. The expressed IL-1-like molecules were characterized by the presence a 60-kd protein for both IL-1alpha-like and IL-1beta-like molecules. In some samples of both fertile men and infertile men with oligoteratoasthenospermia, 17-kd, 33-kd, and 45-kd IL-1beta-like molecules were detected. Impairment of sperm function, such as decreased sperm count and motility and/or impaired morphology, was not related to the capacity of sperm cells to produce IL-1-like molecules.

CONCLUSION(S)

IL-1 molecules originating in sperm cells may play a role in the physiologic functions of sperm cells (autocrine effect) and/or in cell-cell interactions within the testis (paracrine effect).

Induction of interleukin-1alpha production in murine Sertoli cells by interleukin-1

In the present study we examined the involvement of interleukin (IL)-1alpha, -1beta, FSH, and lipopolysaccharide (LPS) in the regulation of IL-1alpha and -1beta production by Sertoli cells under in vitro conditions. Sertoli cell cultures from immature mice produced constitutively basal levels of intracellular IL-1alpha. Stimulation of Sertoli cell cultures with LPS (5 microgram/ml) resulted in a maximal production of intracellular IL-1alpha 2 h after the stimulation. Thereafter, these levels decreased but remained significantly higher within 24 h after stimulation than those in control cultures. The effect of LPS on IL-1alpha production was dose dependent. FSH did not show any effect on intracellular IL-1alpha production by Sertoli cells. IL-1alpha could not be detected in supernatants of unstimulated or stimulated Sertoli cell cultures. Sertoli cell cultures stimulated with recombinant IL-1alpha induced optimal intracellular levels of IL-1alpha within 2 h of stimulation. These levels remained high 24 h after stimulation. However, stimulation of Sertoli cell cultures with IL-1beta induced a peak of IL-1alpha production 8 h after stimulation. These levels decreased 24 h after the stimulation but were still found to be significantly higher than those in control cultures. The addition of IL-1 receptor antagonist (IL-1ra) to Sertoli cell cultures did not significantly alter their capacity to produce IL-1alpha. However, the stimulatory effects of recombinant IL-1alpha on IL-1alpha production by Sertoli cell cultures were reversed by the concomitant addition of recombinant IL-1ra. No immunoreactive IL-1beta could be detected in lysates or conditioned media of immature murine Sertoli cells under any of the stimulatory conditions outlined. Our results may suggest the involvement of physiological (IL-1) and pathophysiological factors (LPS) in the regulation of spermatogenesis and spermiogenesis processes and male fertility.

Expression of IL-12, IL-10, PGE2, sIL-2R and sIL-6R in seminal plasma of fertile and infertile men

The involvement of cytokines and other immunoregulatory factors in male infertility is still unclear. In the present study we compared the levels of IL-12, IL-10, PGE2, sIL-2R and sIL-6R in the seminal plasma (SP) of fertile and infertile men. Four groups were included: fertile donors (FERT), infertile men with azoospermia (AZOO), and infertile men with either oligoterato-asthenoazoospermia (OTA), or OTA with genital infection (OTA-INF). Cytokines and cytokine-soluble receptors in semen were evaluated by specific ELISA commercial kits. The levels of IL-12, sIL-2R and sIL-6R were similar in SP of fertile and infertile men. The mean levels of IL-10 in the SP of FERT, OTA and AZOO were 5.6 +/- 0.9, 4 +/- 2.8 and 8 +/- 3.5 pg ml-1, respectively, and did not differ significantly. The mean level of IL-10 in SP from OTA-INF (0.9 +/- 0.5 pg ml-1) was significantly lower than that for FERT (5.6 +/- 1.9 pg ml-1; P = 0.02) and AZOO (8.2 +/- 3.4 pg ml-1; P = 0.05), but not significantly different from that for OTA (3.7 +/- 2.1 pg ml-1). The mean SP level of PGE2 was significantly lower in SP of OTA-INF than FERT (7.67 +/- 2.26 and 19.67 +/- 3.69 micrograms ml-1, respectively; P < 0.02). In conclusion, the seminal plasma from fertile and infertile men contained similar levels of IL-12, sIL-2R and sIL-6R. However, the levels of IL-10 were significantly lower in SP from OTA-INF compared to FERT and AZOO. Our results indicate that specific cytokines and their soluble receptors are involved in the male reproductive system.