Hum. Reprod. Advance Access originally published online on September 12, 2007
Human Reproduction 2007 22(11):2928-2935; doi:10.1093/humrep/dem281
Concentrations and significance of cytokines and other immunologic factors in semen of healthy fertile men
1 Fearing Research Laboratory, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA 2 Department of Obstetrics and Gynecology, Division of Reproductive Biology, Boston University School of Medicine, Boston, MA, USA
3 Correspondence address. Department of Obstetrics and Gynecology, Division of Reproductive Biology, School of Medicine, Boston University, 670 Albany Street, Suite 515, Boston, MA 02118, USA. Tel: +1-617-414-8486; Fax: +1-617-414-8481; E-mail: joseph.politch{at}bmc.org
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionFundingReferences |
|---|
BACKGROUND: The purpose of this study was to establish normal reference values for several immunologic factors in semen to provide a foundation for understanding their physiologic significance in health and disease.
METHODS: Semen from 83 healthy, fertile men was assessed by Bio-Plex or enzyme-linked immunosorbent assay to determine quantities of immunoglobulin (Ig) isotypes, chemokines, cytokines and growth factors. We also enumerated polymorphonuclear granulocytes (PMN) by peroxidase staining to examine the association of inflammation with levels of these factors.
RESULTS: High concentrations of IgG and IgA were detected in all samples. IgG concentrations were significantly higher than IgA concentrations (P < 0.0001). Likewise, two multifunctional growth factors, transforming growth factor-β1 and interleukin (IL)-7, and three chemokines, stromal cell-derived factor-1
, monocyte chemotactic/chemoattractant protein-1 and IL-8, were present in high concentrations in all samples (medians >1000 pg/ml). Other soluble factors were detectable in low concentration (medians <150 pg/ml), either in a majority of samples [IL-1 and β, IL-5, IL-6, IL-13, IL-17, regulated on activation normal T cell expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-1β, interferon (IFN)- and granulocyte colony-stimulating factor (CSF)], or in a minority of samples (MIP-1, IL-2, IL-10, IL-12, TNF-, IFN-
and granulocyte-macrophage-CSF). PMN counts significantly correlated with IL-1β, IL-6, TNF-, MIP-1, MIP-1β, IL-13 and IgA concentrations.
CONCLUSIONS: The semen of healthy, fertile men contains a broad array of immunologic factors. These normative values can serve as a foundation for future studies on the role of these factors in infertility, genital tract infections and other pathologic conditions.
Key words: semen/cytokines/chemokines/immunoglobulins/polymorphonuclear granulocytes
|
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionFundingReferences |
|---|
Various immunologic factors, including immunoglobulins (Igs), cytokines, chemokines and growth factors, have been documented in human semen. Increased levels of several of these factors in semen from men with genital infections suggest their involvement in immune defense of the male genital tract (Depuydt et al., 1996
; Anderson et al., 1998; Ochsendorf et al., 1999; Leutscher et al., 2005; Sheth et al., 2005; Berlier et al., 2006; Matalliotakis et al., 2006). In addition, some of these factors may affect physiologic events underlying male reproductive function. For example, elevated seminal plasma concentrations of several cytokines, including interleukin-1 (IL-1), IL-2, IL-6 and tumor necrosis factor-alpha (TNF-), have been associated with poor semen quality (Naz and Kaplan, 1994; Gruschwitz et al., 1996; Paradisi et al., 1997; Eggert-Kruse et al., 2001; Sanocka et al., 2003; Bezold et al., 2007) and male infertility (Dousset et al., 1997; Paradisi et al., 1997; Camejo et al., 2001; Matalliotakis et al., 2002). Furthermore, there is increasing evidence that many of these cytokines can adversely affect spermatogenesis and steroidogenesis (Hedger and Meinhardt, 2003). The interferons (IFN) are thought to protect the testis against viral infections, but may also have direct effects on testicular physiology (Hedger and Meinhardt, 2003). The transforming growth factor (TGF) family of cytokines (TGF- and -β) may be involved in the development of the mammalian testis (Itman et al., 2006), including the Leydig cells and seminiferous tubules (Hedger and Meinhardt, 2003), although TGF-1 in the human testis has been associated with fibrosis of seminiferous tubules, and as a consequence, with disruption of spermatogenesis (Dobashi et al., 2002). TGF-β is also an important immunoregulatory molecule and may play a role in immunologic tolerance of germ cells and sperm in the reproductive tract (Robertson et al., 2002). There is also evidence that cytokines and other immune factors are intrinsically involved in normal reproductive physiology, and that local or systemic perturbation of these factors due to inflammation or infection can negatively affect testicular function, and as a result affect fertility (Hedger and Meinhardt, 2003).
Cytokines and other factors in semen may also affect vaginal immunology and female fertility following insemination. For example, seminal chemokines may be partially responsible for the striking recruitment of neutrophils to the superficial epithelium of the cervix (Pandya and Cohen, 1985) and macrophages, dendritic cells and lymphocytes into deeper epithelial layers (Robertson, 2005) following intercourse. These recruited cells may have scavenger and immune defense roles in the vagina and cervix following insemination. Furthermore, studies in mice have shown that seminal TGF-β stimulates uterine granulocyte–macrophage colony-stimulating factor (GM-CSF) production, which improves uterine receptivity for the embryo (Robertson, 2005). Evidence that seminal factors also benefit human pregnancy was provided by a recent study of couples undergoing IVF: women experienced a higher ongoing pregnancy rate if unprotected intercourse occurred immediately prior to embryo transfer (Tremellen et al., 2000).
Most of the studies performed to date on cytokines and other immunologic factors in human semen have focused on only a few factors and/or have included few normal subjects. The purpose of this study was to document the prevalence and concentration of a wide array of immunologically relevant factors in semen from a large, well-defined group of healthy, fertile men, to provide further insight into mediators of immune defense and reproductive function in the normal male genital tract, and to establish reference values to support future studies on the role of these factors in pathologic conditions.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionFundingReferences |
|---|
Patients
This study was approved by the Brigham and Women’s Hospital Institutional Review Board (IRB), and written informed consent was obtained in advance from all subjects. Subjects were male partners of women who had been pregnant or delivered a child within the previous two years, recruited via prenatal classes at Brigham and Women’s Hospital or advertisements in Hospital and University newsletters. Pregnancies were verified with medical records or birth certificates. Exclusion criteria included a history of infertility (as defined by a lack of pregnancy following a period of 12 months of regular intercourse without contraception), vasovasostomy, surgery for varicocele, previous or current major illness or any disorder of the reproductive system. Eighty-three men between the ages of 20 and 40 years participated in the study. The vast majority of subjects were college educated. The racial/ethnic composition of the men was: 90.4% white (non-Hispanic), 4.8% Hispanic, 2.4% African-American and 2.4% Asian. Subjects received $20/sample, as approved by the Brigham and Women’s IRB.
Semen collection and analysis
Semen samples were collected by masturbation following a minimum of 48 h of sexual abstinence, and were processed within 90 min of collection. A manual semen analysis with strict quality control (QC) measures was performed according to the method of Overstreet and Brazil (1997). Specifically, semen analysis was performed according to protocols established by the National Cooperative Reproductive Medicine Network, a multi-center research initiative, organized and funded by the National Institutes of Health (USA). The technician for the current study received extensive training in this andrologic methodology. In the National Cooperative Reproductive Medicine Network studies, there was strict QC with video recording of all semen analyses, and biannual proficiency testing via coded sperm suspensions and video recorded semen samples. To ensure internal QC in the current study, all samples were processed and analyzed by the same technician. The method of Overstreet and Brazil (1997) used for this study followed the classical World Health Organization (WHO) protocol (WHO, 1999), except that the motility was reported as a sum of the percentages of sperm graded as ‘a’, ‘b’ and ‘c’ for progressive motility (WHO, 1999). Table 1 presents the descriptive statistics of the semen analysis variables for the current study.
|
In addition, polymorphonuclear granulocytes (PMN) were counted microscopically following peroxidase staining as described previously (Endtz, 1974
; Politch et al., 1993). Samples were then diluted with an equal volume of sterile phosphate-buffered saline, mixed thoroughly and centrifuged for 10 min at 400 x g. Diluted seminal plasma was removed, aliquotted and frozen at –70°C.
Detection of cytokines and immune factors
Detection and quantitation of the various cytokines and other immunologic factors in aliquots of thawed seminal plasma were accomplished using commercially available enzyme-linked immunosorbent assay (ELISA) kits or the Bio-Plex Suspension Array System (Bio-Rad Laboratories, Hercules, CA, USA) following the manufacturers’ protocols. The following 11 cytokines and chemokines were assayed with Quantikine kits (R & D Systems, Inc., Minneapolis, MN, USA): IL-1, IL-1, IL-2, IL-6, IL-10, IL-12, macrophage inflammatory protein-1 alpha (MIP-1), MIP-1, regulated on activation normal T-cell expressed and secreted (RANTES), stromal cell-derived factor-1 alpha (SDF-1) and TGF-1. The ELISA for TGF-β1 was performed with and without prior acid activation of the seminal plasma samples in order to determine concentrations of total, active and latent TGF-β1 in seminal plasma. IL-8 concentrations were measured by ELISA, with kits from Endogen (Woburn, MA, USA). IFN- was measured by ELISA kits from BioSource International, Inc., (Camarillo, CA, USA), and IFN- was measured by ELISA kits from Genzyme (Cambridge, MA, USA). IgG and IgA were analyzed by ELISA kits from Bethyl Laboratories, Inc. (Montgomery, TX, USA). Details of the various ELISA kits are described in Table 2.
|
The following eight cytokines and chemokines were measured using the Bio-Plex Suspension Array System (Bio-Rad): granulocyte colony-stimulating factor (G-CSF), GM-CSF factor, IL-5, IL-7, IL-13, IL-17, monocyte chemotactic/chemoattractant protein-1 (MCP-1) and TNF-
. The limit of sensitivity for the Bio-Plex Suspension Array System is 1.95 pg/ml, and the linear range of detection is 1.95–32 000 pg/ml for all the cytokines analyzed in this study. For some assays, seminal plasma was diluted as needed, so that the values would not exceed those of the standard curve. Potential interference of seminal plasma was tested by running parallel standard curves with and without seminal plasma at the dilution used in the assay, and subtraction of any background levels (amount of analyte in seminal plasma-only well).
Statistical analysis
The data did not satisfy the assumptions of normal distribution and/or homogeneity of variance. Thus, geometric means and their respective 95% confidence intervals (CIs) were determined by performing antilogs (ex) of means and CIs calculated from natural logarithmic transformations of the data. For the purposes of these calculations, one-half the limit of detection was assigned to non-detectable values. In addition, the non-parametric Spearman Rank Correlation Coefficient was used to determine the correlation between two variables. The Wilcoxon Signed-Rank test was utilized for comparing IgA and IgG concentrations, and for interassay comparison. Data were analyzed by StatView (version 5.0.1, SAS Institute, Cary, NC, USA) statistical software. In all cases, statistical significance was assumed when P < 0.05.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionFundingReferences |
|---|
All of the cytokines and other immunologic factors analyzed in this study were detected in seminal plasma of fertile men at prevalence rates that ranged from 1 to 100%. Seminal plasma at the dilutions used in this study (1:1–1:200) did not interfere with the detection of recombinant standards in the ELISA or Bio-Plex assays.
Tables 3–5 present the descriptive statistics [detection rate, 25th, 50th (median) and 75th percentiles, range, geometric mean and 95% CIs] for each of the immunologic factors. IgG and IgA were detected in all semen samples in high concentrations (medians = 29 741 and 9584 ng/ml, respectively). IgG concentrations were significantly higher than IgA concentrations (P < 0.0001). TGF-β1 was present in very high concentrations in all samples (medians: active form = 1096 pg/ml, latent form = 80 118 pg/ml, total = 85 120 pg/ml). Three chemokines and one cytokine were also detected in high concentrations in the majority of samples: SDF-1 (median = 5742 pg/ml), MCP-1 (median = 2981 pg/ml), IL-8 (median = 1305 pg/ml) and IL-7 (median = 2532 pg/ml). Low concentrations (<150 pg/ml) of IL-1 and β, IL-5, IL-6, IL-13, IL-17, MIP-1β, RANTES, IFN- and G-CSF were detected in a majority of samples, whereas low concentrations of MIP-1, IL-2, IL-10, IL-12, TNF-, IFN- and GM-CSF were detected in a minority of samples.
|
|
|
There were very few significant correlations between soluble immunologic variables and semen parameters. Specifically, both seminal MCP-1 (rho = +0.30, P = 0.0235) and IgG (rho = +0.31, P = 0.0174) concentrations were positively correlated with sperm concentration (Table 6).
|
PMN were detected in 89% of samples (median=2x105/ml). Nine out of 83 (11%) men had leukocytospermia (>1x106 PMN/ml semen) as defined by the WHO (1999)
. The seminal PMN concentration was positively correlated with a number of the immunologic factors: IL-1β, IL-6, MIP-1, MIP-1β, TNF- and IgA concentrations (Table 6). Seminal PMN concentration was not significantly correlated with any semen analysis variable. In a subset of 39 randomly selected semen samples, IL-1β was measured by both ELISA and Bio-Plex assays. The respective means (6.9 versus 7.7 pg/ml), SD (10.1 versus 7.5), medians (4.0 versus 4.5 pg/ml), 25th percentiles (ND versus 2.3 pg/ml), 75th percentiles (8.0 versus 9.8 pg/ml) and ranges (ND-42.0 versus ND-31.9 pg/ml) for the two methods were very similar, and as a result, their concentrations did not differ significantly (Wilcoxon Signed-Rank test, P = 0.38).
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionFundingReferences |
|---|
To our knowledge, this is the most extensive study to date providing information on concentrations of immunologic factors including cytokines, chemokines, growth factors, Igs and PMN in the semen of healthy fertile men. In addition to confirming and extending earlier studies that have documented a variety of cytokines and other immunologic factors in normal human semen, we demonstrate for the first time the presence of the chemokine SDF-1
, and the cytokines IL-5, IL-7, IL-13 and IL-17 in normal human semen.
This study confirms earlier reports that have described Ig levels in semen from healthy men (Anderson et al., 1998; Kastner and Jakse, 2003; Moldoveanu et al., 2005), and infertility patients (Luckas et al., 1998). As previously reported, both IgG and IgA isotypes are present in semen but IgG predominates, which is unusual for a mucosal secretion (medians in this study: total IgA = 9584 ng/ml versus total IgG = 29 741 ng/ml). Furthermore, Ig concentrations in normal human semen are much lower (
1–10%) than those in blood (Moldoveanu et al., 2005). IgM isotype were not measured in this study, but are reportedly low (<1 ng/ml) in normal semen (Moldoveanu et al., 2005). Both IgG and IgA are synthesized by plasma cells associated with the glands of Litre in the penile urethra (Pudney and Anderson, 1995), but much of the Ig in semen is apparently a transudate from the blood compartment (Moldoveanu et al., 2005). In our study, as in earlier reports (Haimovici et al., 1997; Reinhardt et al., 1997), IgA concentrations positively correlated with the seminal PMN count, suggesting that IgA concentrations are elevated in the male genital tract during episodes of genital tract inflammation and/or infection.
As previously described from smaller studies (Lokeshwar and Block, 1992; Nocera and Chu, 1995; Srivastava et al., 1996; Loras et al., 1999; Robertson et al., 2002), TGF-1 is present in extremely high concentrations in human seminal plasma. Seminal plasma contains more active TGF-1 (1 ng/ml) than do other body fluids including blood plasma and breast milk (Robertson, 2005). In addition, seminal plasma contains a large amount (80 ng/ml) of latent (inactive) TGF-1 that can be converted to the short-lived active form to achieve a sustained biologic effect. Indeed, TGF-1 is thought to be synthesized in latent (inactive) form primarily in the prostate; following ejaculation, seminal TGF-1 may be converted to its active form in the female tract by the acidic vaginal pH, or enzymes found in seminal plasma or vaginal secretions (Robertson et al., 2002). TGF-s are key regulators of several aspects of the immune response (Letterio and Roberts, 1998). TGF- has been identified as a major immunosuppressive factor in human semen (Nocera and Chu, 1993; Ochsenkuhn et al., 2006), and may induce immune tolerance to seminal antigens (Robertson et al., 2002). However, this immunosuppressive effect may also suppress other immune defense functions of cells in the female genital tract, and promote infections. Recent studies have shown that TGF-β1 has dichotomous effects on human immunodeficiency virus (HIV)-1 and human T-cell leukemia virus type 1 infection in vitro (Moriuchi and Moriuchi, 2002; Alfano and Poli, 2005), suggesting that the high levels of this growth factor in semen could influence genital infections with these viruses.
Ours is the first report to document high concentrations of IL-7 in semen. This cytokine, which is classified as a hematopoietic growth factor, is produced by the thymus and promotes the proliferation of lymphoid progenitors, B cell maturation and T and natural killer cell survival (Fry and Mackall, 2005). In addition, IL-7 plays a pivotal role in the expansion and survival of CD8+ cells (Schluns et al., 2000). IL-7 is also expressed by intestinal epithelial cells and regulates the proliferation of intestinal mucosal lymphocytes (Watanabe et al., 1995). In our study, IL-7 was detected in semen from 100% of subjects with a median value of 2533 pg/ml. We speculate that this cytokine plays a role in the maintenance of intraepithelial CD8+ T cells in the male genital tract, which are thought to have an important role in cellular immune defense (Quayle et al., 1998; Musey et al., 2003; Sheth et al., 2005; Huang et al., 2006).
We also detected high concentrations of three chemokines (IL-8, SDF-1 and MCP-1) and moderate levels of two others (MIP-1 and RANTES) in a majority of samples. Another chemokine, MIP-1, was detected in a subset of samples, and was correlated with PMN concentration. All of these chemokines except for SDF-1 have been previously reported in human semen (Shimoya et al., 1995; Srivastava et al., 1996; Anderson et al., 1998; Storey et al., 1999; Naz and Leslie, 2000; Maegawa et al., 2002; Sanocka et al., 2003). Chemokines are a family of more than 30 chemoattractant cytokines involved in leukocyte migration, angiogenesis and cell activation. They play important roles in events associated with inflammation and immune defense (Rossi and Zlotnik, 2000; Garcia-Velasco and Arici, 2002), and probably have such roles in the male reproductive tract. Furthermore, SDF-1 is involved in the guidance, colonization, survival and proliferation of mammalian primordial germ cells, the progenitors of spermatozoa and oocytes (Ara et al., 2003; Raz, 2004; Stebler et al., 2004; Farini et al., 2005). Thus, it is possible that SDF-1 may have a key role in the establishment and maintenance of male fertility. We detected very high levels of SDF-1 in semen from fertile men; it will be of interest to determine whether levels of this factor are reduced in semen from azoospermic or oligospermic infertility patients. Seminal chemokines could also have a role at the insemination site where they may attract white blood cells to participate in immune defense and scavenger functions. It has been shown that PMN and other white blood cells infiltrate into tissues adjacent to semen deposition following intercourse (Pandya and Cohen, 1985; Robertson, 2005). Attraction of HIV-host cells to the insemination site (i.e. CD4+ lymphocytes by SDF-1, both lymphocytes and macrophages by RANTES and MIP-1β) could also play a role in HIV-1 sexual transmission.
This is the first study to document IL-5, IL-13 and IL-17 in human semen. Moderately high IL-5 concentrations were detected in all samples (median = 31.3 pg/ml). This cytokine promotes the development of B cells and the production of IgA (Moon et al., 2004), and may play a role in humoral immune defense of the male genital tract. Furthermore, IL-5 receptors are expressed in the germ line of human testis and in ejaculated sperm (Rauch et al., 2004), suggesting that IL-5 may also play a role in the physiology of the human testis. It would therefore be of interest to study levels of this cytokine in semen from men with infertility. IL-13 and IL-17 have been associated with allergic inflammation and autoimmunity (Aggarwal and Gurney, 2002; Ngoc et al., 2005). Low concentrations of these cytokines were detected in semen from a majority of subjects (IL-13 median = 3 pg/ml; IL-17 median = 11.6 pg/ml). It would be of interest to study levels of these factors in semen from men with antisperm antibodies to determine whether these cytokines have possible roles in this common autoimmune disorder.
Prominent cytokines associated with T cell function, including IL-2, IL-10, IL-12 and IFN-, were detected at low concentration in only a few samples. This suggests that cellular immune activity is low in the genital tract of normal men. Elevated levels of some of these factors have been detected in semen of men with genital infections (Leutscher et al., 2005), indicating that cell-mediated immunity may be up-regulated by genital tract infections.
PMN were detected in 72 of the 81 (89%) semen samples from fertile men with a median PMN concentration of 2 x 105/ml. These values are consistent with those published in an earlier report based on a smaller group of fertile donors (Wolff and Anderson, 1988; Anderson and Politch, 1996). Nine of the 81 (11%) semen samples had >1 x 106 PMN/ml, and thus are considered leukocytospermic as defined by the WHO (1999). There are few large studies on leukocytospermia in fertile men at the present time; however, studies on male infertility patients have reported the prevalence of leukocytospermia to range from 2 to 38%, depending on the detection method, the definition of leukocytospermia and geographical location of the study, among other factors (Wolff, 1995; Anderson and Politch, 1996). Leukocytospermia has been associated with poor semen parameters in a number of studies (Wolff et al., 1990; Yanushpolsky et al., 1996; Saleh et al., 2002; Lackner et al., 2006; Gambera et al., 2007; Moskovtsev et al., 2007).
In the present study, the seminal PMN concentration was positively associated with a number of immunologic factors including proinflammatory cytokines (IL-1, IL-6 and TNF-), chemokines (MIP-1 and MIP-1) and IgA. These relationships indicate a coordination of the inflammatory response in the male genital tract.
The relation between seminal PMN and proinflammatory cytokines, including IL-1β, IL-6 and TNF-, has been reported previously in infertile men (Comhaire et al., 1994; Depuydt et al., 1996; Omu et al., 1999; Sikorski et al., 2001; Maegawa et al., 2002; Sanocka et al., 2003, 2004; Bezold et al., 2007).
Likewise, we and others have reported an association between PMN counts and IgA concentrations in semen (Haimovici et al., 1997; Reinhardt et al., 1997). Since seminal IgG concentrations are not associated with PMN count, these data suggest that local IgA production and/or transport are selectively up-regulated during genital tract inflammation. This is the first study to document an association between seminal PMN count and chemokine concentrations in semen. This is potentially clinically significant since leukocytospermia has been associated with increased levels of HIV-1 in semen (Anderson et al., 1992; Speck et al., 1999), and chemokines such as MIP-1 and β may attract HIV-infectable cells to the insemination site and promote HIV-1 transmission.
Since the subjects in this study were primarily Caucasian and belonged to middle to high-income groups, the generalizability of these data to other populations is limited. Variables that could affect levels of cytokines and other immunologic factors in semen from different ethnic and demographic groups include genetic polymorphisms, differences in diet, hygiene, sexual practices and drug use. In addition, genital flora and sexually transmitted infections (STIs) can influence seminal cytokine and antibody levels (Anderson, 2007). The men enrolled in the current study were at low risk for STIs and subfertility, but more detailed testing would be required to conclusively rule out the influence of these variables in this study. Likewise, since the patients did not undergo an extensive physical examination, it is impossible to conclusively exclude other reproductive conditions that could affect semen quality such as testicular maldescent or atrophy, and current varicocele.
Nonetheless, this paper represents the most extensive report to date of immunologic factors including cytokines, chemokines, growth factors, Igs and PMN in the semen of fertile men. High levels of Igs and certain chemokines and growth factors were detected. On the other hand, proinflammatory cytokines and cytokine mediators of humoral and cellular immune defense were detectable at low levels. These data can serve as reference values for future studies on the role of these factors in male genital tract infection and infertility.
|
Funding |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionFundingReferences |
|---|
National Institutes of Health (P01AI46518).
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionFundingReferences |
|---|
Aggarwal S, Gurney AL. IL-17: prototype member of an emerging cytokine family. J Leukoc Biol (2002) 71:1–8.
Alfano M, Poli G. Role of cytokines and chemokines in the regulation of innate immunity and HIV infection. Mol Immunol (2005) 42:161–182.[CrossRef][Web of Science][Medline]
Anderson DJ. Genitourinary immune defense. In: Sexually Transmitted Diseases.—Holmes KK, ed. (2007) New York: McGraw-Hill.
Anderson DJ, O’Brien TR, Politch JA, Martinez A, Seage GR III, Padian N, Horsburgh CR Jr, Mayer KH. Effects of disease stage and zidovudine therapy on the detection of human immunodeficiency virus type 1 in semen. Jama (1992) 267:2769–2774.
Anderson DJ, Politch JA. White blood cells in semen and their impact on fertility. In: Evaluation and Treatment of the Infertile Male.—Centola GM, Ginsburg KA, eds. (1996) Cambridge: Cambridge University Press. 263–276.
Anderson DJ, Politch JA, Tucker LD, Fichorova R, Haimovici F, Tuomala RE, Mayer KH. Quantitation of mediators of inflammation and immunity in genital tract secretions and their relevance to HIV type 1 transmission. AIDS Res Hum Retroviruses (1998) 14(Suppl. 1):S43–S49.[Web of Science][Medline]
Ara T, Nakamura Y, Egawa T, Sugiyama T, Abe K, Kishimoto T, Matsui Y, Nagasawa T. Impaired colonization of the gonads by primordial germ cells in mice lacking a chemokine, stromal cell-derived factor-1 (SDF-1). Proc Natl Acad Sci USA (2003) 100:5319–5323.
Berlier W, Bourlet T, Levy R, Lucht F, Pozzetto B, Delezay O. Amount of seminal IL-1beta positively correlates to HIV-1 load in the semen of infected patients. J Clin Virol (2006) 36:204–207.[CrossRef][Web of Science][Medline]
Bezold G, Politch JA, Kiviat NB, Kuypers JM, Wolff H, Anderson DJ. Prevalence of sexually transmissable pathogens in semen from asymptomatic male infertility patients with and without leukocytospermia. Fertil Steril (2007) 87:1087–1097.[CrossRef][Web of Science][Medline]
Camejo MI, Segnini A, Proverbio F. Interleukin-6 (IL-6) in seminal plasma of infertile men, and lipid peroxidation of their sperm. Arch Androl (2001) 47:97–101.[CrossRef][Web of Science][Medline]
Comhaire F, Bosmans E, Ombelet W, Punjabi U, Schoonjans F. Cytokines in semen of normal men and of patients with andrological diseases. Am J Reprod Immunol (1994) 31:99–103.[Medline]
Depuydt CE, Bosmans E, Zalata A, Schoonjans F, Comhaire FH. The relation between reactive oxygen species and cytokines in andrological patients with or without male accessory gland infection. J Androl (1996) 17:699–707.
Dobashi M, Fujisawa M, Yamazaki T, Okada H, Kamidono S. Distribution of intracellular and extracellular expression of transforming growth factor-beta1 (TGF-beta1) in human testis and their association with spermatogenesis. Asian J Androl (2002) 4:105–109.[Web of Science][Medline]
Dousset B, Hussenet F, Daudin M, Bujan L, Foliguet B, Nabet P. Seminal cytokine concentrations (IL-1beta, IL-2, IL-6, sR IL-2, sR IL-6), semen parameters and blood hormonal status in male infertility. Hum Reprod (1997) 12:1476–1479.
Eggert-Kruse W, Boit R, Rohr G, Aufenanger J, Hund M, Strowitzki T. Relationship of seminal plasma interleukin (IL) -8 and IL-6 with semen quality. Hum Reprod (2001) 16:517–528.
Endtz AW. A rapid staining method for differentiating granulocytes from ‘germinal cells’ in Papanicolaou-stained semen. Acta Cytol (1974) 18:2–7.[Web of Science][Medline]
Farini D, Scaldaferri ML, Iona S, La Sala G, De Felici M. Growth factors sustain primordial germ cell survival, proliferation and entering into meiosis in the absence of somatic cells. Dev Biol (2005) 285:49–56.[CrossRef][Web of Science][Medline]
Fry TJ, Mackall CL. The many faces of IL-7: from lymphopoiesis to peripheral T cell maintenance. J Immunol (2005) 174:6571–6576.
Gambera L, Serafini F, Morgante G, Focarelli R, De Leo V, Piomboni P. Sperm quality and pregnancy rate after COX-2 inhibitor therapy of infertile males with abacterial leukocytospermia. Hum Reprod (2007).
Garcia-Velasco JA, Arici A. Chemokines in human reproduction. In: Immunology and Allergy Clinics of North America—Arici A, ed. (2002) 22. Philadelphia: W.B. Saunders Company. 567–583.[CrossRef][Web of Science]
Gruschwitz MS, Brezinschek R, Brezinschek HP. Cytokine levels in the seminal plasma of infertile males. J Androl (1996) 17:158–163.
Haimovici F, Mayer KH, Anderson DJ. Quantitation of HIV-1-specific IgG, IgA, and IgM antibodies in human genital tract secretions. J Acquir Immune Defic Syndr Hum Retrovirol (1997) 15:185–191.[Web of Science][Medline]
Hedger MP, Meinhardt A. Cytokines and the immune-testicular axis. J Reprod Immunol (2003) 58:1–26.[CrossRef][Web of Science][Medline]
Huang XL, Fan Z, Gupta P, Rinaldo CR Jr. Activation of HIV type 1 specific cytotoxic T lymphocytes from semen by HIV type 1 antigen-presenting dendritic cells and IL-12. AIDS Res Hum Retroviruses (2006) 22:93–98.[CrossRef][Web of Science][Medline]
Itman C, Mendis S, Barakat B, Loveland KL. All in the family: TGF-beta family action in testis development. Reproduction (2006) 132:233–246.
Kastner C, Jakse G. Measurement of immunoglobulins in seminal fluid with modified nephelometry–an alternative diagnostic tool for chronic prostatitis. Prostate Cancer Prostatic Dis (2003) 6:86–89.[CrossRef][Web of Science][Medline]
Lackner JE, Herwig R, Schmidbauer J, Schatzl G, Kratzik C, Marberger M. Correlation of leukocytospermia with clinical infection and the positive effect of antiinflammatory treatment on semen quality. Fertil Steril (2006) 86:601–605.[CrossRef][Web of Science][Medline]
Letterio JJ, Roberts AB. Regulation of immune responses by TGF-beta. Annu Rev Immunol (1998) 16:137–161.[CrossRef][Web of Science][Medline]
Leutscher PD, Pedersen M, Raharisolo C, Jensen JS, Hoffmann S, Lisse I, Ostrowski SR, Reimert CM, Mauclere P, Ullum H. Increased prevalence of leukocytes and elevated cytokine levels in semen from Schistosoma haematobium-infected individuals. J Infect Dis (2005) 191:1639–1647.[CrossRef][Web of Science][Medline]
Lokeshwar BL, Block NL. Isolation of a prostate carcinoma cell proliferation-inhibiting factor from human seminal plasma and its similarity to transforming growth factor beta. Cancer Res (1992) 52:5821–5825.
Loras B, Vetele F, El Malki A, Rollet J, Soufir JC, Benahmed M. Seminal transforming growth factor-beta in normal and infertile men. Hum Reprod (1999) 14:1534–1539.
Luckas MJ, Buckett WM, Aird IA, Johnson PM, Lewis-Jones DI. Seminal plasma immunoglobulin concentrations in autoimmune male subfertility. J Reprod Immunol (1998) 37:171–180.[CrossRef][Web of Science][Medline]
Maegawa M, Kamada M, Irahara M, Yamamoto S, Yoshikawa S, Kasai Y, Ohmoto Y, Gima H, Thaler CJ, Aono T. A repertoire of cytokines in human seminal plasma. J Reprod Immunol (2002) 54:33–42.[CrossRef][Web of Science][Medline]
Matalliotakis I, Arici A, Goumenou A, Koumantakis G, Selam B, Matalliotakis G, Koumantakis E. Distinct expression pattern of cytokines in semen of men with genital infection and oligo-terato-asthenozoospermia. Am J Reprod Immunol (2002) 48:170–175.[Medline]
Matalliotakis IM, Cakmak H, Fragouli Y, Kourtis A, Arici A, Huszar G. Increased IL-18 levels in seminal plasma of infertile men with genital tract infections. Am J Reprod Immunol (2006) 55:428–433.[CrossRef][Medline]
Moldoveanu Z, Huang WQ, Kulhavy R, Pate MS, Mestecky J. Human male genital tract secretions: both mucosal and systemic immune compartments contribute to the humoral immunity. J Immunol (2005) 175:4127–4136.
Moon BG, Takaki S, Miyake K, Takatsu K. The role of IL-5 for mature B-1 cells in homeostatic proliferation, cell survival, and Ig production. J Immunol (2004) 172:6020–6029.
Moriuchi M, Moriuchi H. Transforming growth factor-beta enhances human T-cell leukemia virus type I infection. J Med Virol (2002) 67:427–430.[CrossRef][Web of Science][Medline]
Moskovtsev SI, Willis J, White J, Mullen JB. Leukocytospermia: relationship to sperm deoxyribonucleic acid integrity in patients evaluated for male factor infertility. Fertil Steril (2007).
Musey L, Ding Y, Cao J, Lee J, Galloway C, Yuen A, Jerome KR, McElrath MJ. Ontogeny and specificities of mucosal and blood human immunodeficiency virus type 1-specific CD8(+) cytotoxic T lymphocytes. J Virol (2003) 77:291–300.[CrossRef][Web of Science][Medline]
Naz RK, Kaplan P. Increased levels of interleukin-6 in seminal plasma of infertile men. J Androl (1994) 15:220–227.
Naz RK, Leslie MH. Immunobiologic implication of RANTES in seminal plasma of fertile, infertile and immunoinfertile men. Am J Reprod Immunol (2000) 44:197–204.[Medline]
Ngoc PL, Gold DR, Tzianabos AO, Weiss ST, Celedon JC. Cytokines, allergy, and asthma. Curr Opin Allergy Clin Immunol (2005) 5:161–166.[Web of Science][Medline]
Nocera M, Chu TM. Transforming growth factor beta as an immunosuppressive protein in human seminal plasma. Am J Reprod Immunol (1993) 30:1–8.[Medline]
Nocera M, Chu TM. Characterization of latent transforming growth factor-beta from human seminal plasma. Am J Reprod Immunol (1995) 33:282–291.[Medline]
Ochsendorf FR, Ozdemir K, Rabenau H, Fenner T, Oremek R, Milbradt R, Doerr HW. Chlamydia trachomatis and male infertility: chlamydia-IgA antibodies in seminal plasma are C. trachomatis specific and associated with an inflammatory response. J Eur Acad Dermatol Venereol (1999) 12:143–152.[CrossRef][Web of Science][Medline]
Ochsenkuhn R, O’Connor AE, Hirst JJ, Gordon Baker HW, de Kretser DM, Hedger MP. The relationship between immunosuppressive activity and immunoregulatory cytokines in seminal plasma: influence of sperm autoimmunity and seminal leukocytes. J Reprod Immunol (2006) 71:57–74.[CrossRef][Web of Science][Medline]
Omu AE, Al-Qattan F, Al-Abdul-Hadi FM, Fatinikun MT, Fernandes S. Seminal immune response in infertile men with leukocytospermia: effect on antioxidant activity. Eur J Obstet Gynecol Reprod Biol (1999) 86:195–202.[CrossRef][Web of Science][Medline]
Overstreet JW, Brazil C. Semen analysis. In: Infertility in the Male—Lipshultz LI, Howards SS, eds. (1997) St. Louis: Mosby Year Book. 487–490.
Pandya IJ, Cohen J. The leukocytic reaction of the human uterine cervix to spermatozoa. Fertil Steril (1985) 43:417–421.[Web of Science][Medline]
Paradisi R, Mancini R, Bellavia E, Beltrandi E, Pession A, Venturoli S, Flamigni C. T-helper 2 type cytokine and soluble interleukin-2 receptor levels in seminal plasma of infertile men. Am J Reprod Immunol (1997) 38:94–99.[Medline]
Politch JA, Wolff H, Hill JA, Anderson DJ. Comparison of methods to enumerate white blood cells in semen. Fertil Steril (1993) 60:372–375.[Web of Science][Medline]
Pudney J, Anderson DJ. Immunobiology of the human penile urethra. Am J Pathol (1995) 147:155–165.[Abstract]
Quayle AJ, Coston WM, Trocha AK, Kalams SA, Mayer KH, Anderson DJ. Detection of HIV-1-specific CTLs in the semen of HIV-infected individuals. J Immunol (1998) 161:4406–4410.
Rauch MC, Brito M, Zambrano A, Espinoza M, Perez M, Yanez A, Rivas CI, Slebe JC, Vera JC, Concha II. Differential signalling for enhanced hexose uptake by interleukin (IL)-3 and IL-5 in male germ cells. Biochem J (2004) 381:495–501.[CrossRef][Web of Science][Medline]
Raz E. Guidance of primordial germ cell migration. Curr Opin Cell Biol (2004) 16:169–173.[CrossRef][Web of Science][Medline]
Reinhardt A, Haidl G, Schill WB. Granulocyte elastase indicates silent male genital tract inflammation and appropriate anti-inflammatory treatment. Andrologia (1997) 29:187–192.[Web of Science][Medline]
Robertson SA. Seminal plasma and male factor signalling in the female reproductive tract. Cell Tissue Res (2005) 322:43–52.[CrossRef][Web of Science][Medline]
Robertson SA, Ingman WV, O’Leary S, Sharkey DJ, Tremellen KP. Transforming growth factor beta—a mediator of immune deviation in seminal plasma. J Reprod Immunol (2002) 57:109–128.[CrossRef][Web of Science][Medline]
Rossi D, Zlotnik A. The biology of chemokines and their receptors. Annu Rev Immunol (2000) 18:217–242.[CrossRef][Web of Science][Medline]
Saleh RA, Agarwal A, Kandirali E, Sharma RK, Thomas AJ, Nada EA, Evenson DP, Alvarez JG. Leukocytospermia is associated with increased reactive oxygen species production by human spermatozoa. Fertil Steril (2002) 78:1215–1224.[CrossRef][Web of Science][Medline]
Sanocka D, Fraczek M, Jedrzejczak P, Szumala-Kakol A, Kurpisz M. Male genital tract infection: an influence of leukocytes and bacteria on semen. J Reprod Immunol (2004) 62:111–124.[CrossRef][Web of Science][Medline]
Sanocka D, Jedrzejczak P, Szumala-Kaekol A, Fraczek M, Kurpisz M. Male genital tract inflammation: the role of selected interleukins in regulation of pro-oxidant and antioxidant enzymatic substances in seminal plasma. J Androl (2003) 24:448–455.
Schluns KS, Kieper WC, Jameson SC, Lefrancois L. Interleukin-7 mediates the homeostasis of naive and memory CD8 T cells in vivo. Nat Immunol (2000) 1:426–432.[CrossRef][Web of Science][Medline]
Sheth PM, Danesh A, Shahabi K, Rebbapragada A, Kovacs C, Dimayuga R, Halpenny R, Macdonald KS, Mazzulli T, Kelvin D, et al. HIV-specific CD8+ lymphocytes in semen are not associated with reduced HIV shedding. J Immunol (2005) 175:4789–4796.
Shimoya K, Matsuzaki N, Ida N, Okada T, Taniguchi T, Sawai K, Itoh S, Ohashi K, Saji F, Tanizawa O. Detection of monocyte chemotactic and activating factor (MCAF) and interleukin (IL)-6 in human seminal plasma and effect of leukospermia on these cytokine levels. Am J Reprod Immunol (1995) 34:311–316.[Medline]
Sikorski R, Kapec E, Krzeminski A, Zaleska W. Levels of proinflammatory cytokines (Il-1 alpha, Il-6, TNF-alpha) in the semen plasma of male partners of infertile couples. Ginekol Pol (2001) 72:1325–1328.[Medline]
Speck CE, Coombs RW, Koutsky LA, Zeh J, Ross SO, Hooton TM, Collier AC, Corey L, Cent A, Dragavon J, et al. Risk factors for HIV-1 shedding in semen. Am J Epidemiol (1999) 150:622–631.
Srivastava MD, Lippes J, Srivastava BI. Cytokines of the human reproductive tract. Am J Reprod Immunol (1996) 36:157–166.[Web of Science][Medline]
Stebler J, Spieler D, Slanchev K, Molyneaux KA, Richter U, Cojocaru V, Tarabykin V, Wylie C, Kessel M, Raz E. Primordial germ cell migration in the chick and mouse embryo: the role of the chemokine SDF-1/CXCL12. Dev Biol (2004) 272:351–361.[CrossRef][Web of Science][Medline]
Storey DF, Dolan MJ, Anderson SA, Meier PA, Walter EA. Seminal plasma RANTES levels positively correlate with seminal plasma HIV-1 RNA levels. Aids (1999) 13:2169–2171.[CrossRef][Web of Science][Medline]
Tremellen KP, Valbuena D, Landeras J, Ballesteros A, Martinez J, Mendoza S, Norman RJ, Robertson SA, Simon C. The effect of intercourse on pregnancy rates during assisted human reproduction. Hum Reprod (2000) 15:2653–2658.
Watanabe M, Ueno Y, Yajima T, Iwao Y, Tsuchiya M, Ishikawa H, Aiso S, Hibi T, Ishii H. Interleukin 7 is produced by human intestinal epithelial cells and regulates the proliferation of intestinal mucosal lymphocytes. J Clin Invest (1995) 95:2945–2953.[Web of Science][Medline]
WHO. WHO Laboratory Manual for the Examination of Human Semen and Sperm–Cervical Interaction. (1999) Cambridge: Cambridge University Press.
Wolff H. The biologic significance of white blood cells in semen. Fertil Steril (1995) 63:1143–1157.[Web of Science][Medline]
Wolff H, Anderson DJ. Immunohistologic characterization and quantitation of leukocyte subpopulations in human semen. Fertil Steril (1988) 49:497–504.[Web of Science][Medline]
Wolff H, Politch JA, Martinez A, Haimovici F, Hill JA, Anderson DJ. Leukocytospermia is associated with poor semen quality. Fertil Steril (1990) 53:528–536.[Web of Science][Medline]
Yanushpolsky EH, Politch JA, Hill JA, Anderson DJ. Is leukocytospermia clinically relevant? Fertil Steril (1996) 66:822–825.[Web of Science][Medline]
Submitted on June 12, 2007; resubmitted on August 1, 2007; accepted on August 16, 2007.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  J. A. Espinoza, U. Paasch, and J. V. Villegas Mitochondrial membrane potential disruption pattern in human sperm Hum. Reprod., May 29, 2009; (2009) dep120v2. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Barbonetti, M.R.C. Vassallo, C. Antonangelo, V. Nuccetelli, A. D'Angeli, F. Pelliccione, M. Giorgi, F. Francavilla, and S. Francavilla RANTES and human sperm fertilizing ability: effect on acrosome reaction and sperm/oocyte fusion Mol. Hum. Reprod., July 1, 2008; 14(7): 387 - 391. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||