| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Immunology |
a Departamento de Ciências Fisiológicas-CCS-Universidade Estadual do Ceará,
b Instituto de Biomedicina de Valencia, Valencia, Spain
c Depto de Fisiologia e Farmacologia,
d Faculdade de Medicina and Depto de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza-CE, Brazil
e Depto de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto-SP, Brazil
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
immunology, oviduct, seminal vesicles, sperm, uterus
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
Spermadhesins are built by a single CUB domain [6]. CUB domains occur in diverse combinations in structurally and functionally unrelated mosaic proteins [7] and serve as a structural scaffold onto which different functionalities can be imprinted [6]. The PSP-I/PSP-II heterodimer expresses carbohydrate-binding activity associated with its PSP-II subunit [5], and the PSP-II subunit in addition possesses a mannose-6-phosphate binding site, cryptic in the heterodimer [8]. The biological functions of the PSP-I/PSP-II spermadhesin complex remain enigmatic, however. Recently, Yang et al. [9] showed that purified and biotinylated PSP-I bound to a subpopulation of porcine peripheral lymphocytes enhanced their in vitro immune activity. The same group [10] demonstrated that PSP-I and PSP-II triggered immunostimulatory activity. Noteworthy, oligosaccharides with the NeuNAc
2-6GalNAcß1-4GlcNAc-R motif, which are present in the PSP proteins [11], block adhesive- and activation-related events mediated by CD22, suggesting a possible immunoregulatory activity for PSP-I/PSP-II. These data suggest a role for PSP-I and/or PSP-II proteins in the modulation of the uterine immune activity to ensure reproductive success. For instance, entry of semen into the uterine cavity of the pig elicits, albeit not fully disclosed how, a massive invasion of polymorphonuclear leukocytes (PMNs) into the lumen, where immediate sperm phagocytosis is undertaken [12]. These PMNs are present in the lamina propia, probably related to the high levels of preovulatory estrogens, immediately subjacent to the lining epithelium at estrus but only infiltrate the epithelium shortly after semen deposition [13, 14]. There is morphologic evidence that the PMNs cooperate with intraepithelial macrophages during the first 3–6 h postsperm deposition, at least in the porcine species [12]. Noteworthy, the pig is one of the species with a large amount of spermadhesins in the seminal plasma [2–4, 5]. The rationale behind this prompt invasion of PMNs in a species where spermatozoa reach the oviductal reservoir within minutes postmating (an area that is documented free from leukocyte infiltration) is to provide a foreign cell-free uterine environment for the descending early embryos. Moreover, in many instances, animal mating elicits damage of female genital tract tissues along with infection of the lower reproductive tract by a variety of pathogens. Thus, in this context, a rapid recruitment of leukocytes to the site of infection would be advantageous for the animal and for the fertilization process. Neutrophil migration to the site of acute inflammatory reactions is one of the primary defense mechanisms used by the organism against foreign agents. Leukocyte activation, by their interactions with exogenous stimuli or via cell-cell and cell-extracellular matrix interactions, generates cytokines, leukotriene B4, PAF, C5a, etc. Cytokines and leukotriene B4, mainly from macrophages or mast cells origin, induce neutrophil migration both in vivo and in vitro and have been involved in aspects of the immune and inflammatory responses [15–17]. Cell-cell and cell-matrix interactions during the inflammatory reaction involve protein-protein and protein-carbohydrate recognition mechanisms mediated by adhesion molecules, i.e., integrins and lectins of the selectin family. Here we sought to investigate the possible in vivo proinflammatory effect of PSP-I/PSP-II and its isolated subunits on neutrophil migration to the peritoneal cavity of a model animal, the rat. In addition, we investigated the participation of resident peritoneal cells (macrophages and mast cells) as the source of endogenous neutrophil chemotactic factors involved in spermadhesin-induced leukocyte migration.
|
MATERIALS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
Female Wistar rats (150–250 g) were housed in a temperature-controlled room with free access to water and food. Investigations were conducted in accordance with current guiding principles for the care and use of research animals (NIH guidelines).
Isolation of Spermadhesin PSP-I/PSP-II and Its Subunits
The PSP-I/PSP-II heterodimer was isolated by size-exclusion chromatography on Sephadex G-50 of the non-heparin-binding fraction from the seminal plasma of German Landrace boars. The individual subunits, PSP-I and PSP-II, were separated by reversed-phase HPLC on a C18 column using a linear gradient of 0.1% trifluoroacetic acid (TFA) in water (solution A) and 0.1% TFA in acetonitrile (solution B) [1]. The purity of the proteins was assessed by N-terminal sequencing (using an Applied Biosystems 473A instrument) and tryptic peptide mapping using a Voyager DE-Pro (Applied Biosystems, Langen, Germany) MALDI-TOF mass spectrometer. For trypsin digestion, PSP-I/PSP-II (2–5 mg in ammonium bicarbonate buffer, pH 8.3) was incubated overnight at 37°C with 1:100 (w/w) enzyme:substrate ration. Thereafter, trypsin was inactivated by heating at 100°C for 2 min, and the mixture was lyophilized. Completion of proteolysis was checked by SDS polyacrylamide gel electrophoresis, reversed-phase HPLC, and mass spectrometry. Protein concentration was determined spectrophotometrically using the molar absorption coefficient (27 332/M/cm) determined by Menéndez et al. [18] or by amino acid analysis (after sample hydrolysis in 6 M HCl for 24 h at 106°C in evacuated and sealed ampules) using a Beckman Gold Amino Acid Analyzer (Barcelona, Spain).
Drugs and Reagents
Chemicals and biochemicals were of the highest purity grade available and were purchased from the following companies: trypsin, fMLP (N-formyl-L-methionyl-L-leucyl-L-phenylalanine), compound 48/80, and mannose-6-phosphate (Sigma, St. Louis, MO); thioglycolate (Lab Difco Ltda., São Paulo, Brazil); dexamethasone (Prodome Química e Farmacêutica, Campinas, Brazil); MK-886, L-663, 536 (3-[1-(4-clorobenzyl)-3-t-butyl-thio-5-isopropylindol-2-yl]-2,2-dimethylpropanoic acid) (Merck, Montreal, Canada); indomethacin (Prodome), and BN 50730 ([3-1,1-dimethyl-ethyl] hexahydro-1,4,4,7b-trihydroxy-8-methyl-9H-1,7 (epoxy-methano) 6H-cyclopentana-(c) furo [2,3b] furo [3,2,3,4] cyclopenta [1,2-d] furan-5,9,12 (4H) trione) (Institute Henri Beaufour, Paris, France). The fMLP was solubilized in ethanol; thioglycolate in distilled water; compound 48/80, dexamethasone, and mannose-6-phosphate in NaCl 0.1 M; indomethacin in Tris HCl, pH 8.0; and MK-886 in methyl-cellulose 0.1% aqueous solution; BN 50730 was solubilized up to 10% of the total volume in DMSO and diluted to the appropriate concentration in NaCl 0.1 M.
Evaluation of In Vitro Chemotactic Activity of PSP-I/PSP-II and Its Isolated Subunits
Human neutrophils (PMN) were obtained from heparinized blood of healthy volunteers by Ficoll Hypaque gradient (d = 1.114) fractionation. Isolated neutrophils (90–95% purity) were resuspended to a final count of 106 cells/ml in RPMI 1640 medium containing 0.1% bovine serum albumin. Chemotaxis was measured in a 48-well microchamber (Neuro Probe, Cabin John, MD) composed of two compartments divided by a 5-µm pore-size polyvinylpyrolidone-free polycarbonate membrane [19]. In six different experiments, 28 µl of RPMI (Roswell Park Memorial Institute) medium containing 0.1% BSA (as negative control), fMLP (10-6 M; positive control), PSP-I/PSP-II (10-7, 10-6, 10-5, and 10-4 M), PSP-I (10-4 M), and PSP-II (10-4 M) in RPMI/BSA medium were placed in the lower part of microchamber wells. Fifty microliters of the 106 PMN/ml suspension were added to the upper chamber of each well and incubated at 37°C for 60 min under a humidified 5% CO2 atmosphere. Thereafter, the membranes were removed and their upper portions were washed with PBS (20 mM sodium phosphate, 135 mM NaCl, pH 7.3) in order to remove nonmigrating neutrophils. Neutrophils that had migrated to the lower portion of the membrane were fixed with 70% methanol and stained with Diff-Quick Stain Kit (American Scientific Products, McGraw Park, IL). Viable neutrophils were counted using optical microscopy (100x objective) in five random fields of each well (6 wells/group).
Peritonitis Model for the Evaluation of the Spermadhesin Chemotactic Activity on Leukocyte Migration to the Peritoneal Cavity
One milliliter of sterile saline solution containing 2–20 x 10-10 moles of PSP-I/PSP-II, 4–40 x 10-10 moles of PSP-I, and 4–40 x 10-10 moles of PSP-II were injected i.p. in healthy rats. In control animals, the same amount of saline solution with no protein was injected. Leukocyte counts, both total and differential (neutrophils, eosinophils, mast cells, and mononuclears), were performed 4 h after injections by microscopy. Briefly, after washing the peritoneal cavities with 10 ml of saline or PBS containing 5 IU/ml of heparin, the peritoneal fluid was collected (approximately 6 ml). For counting total cells in a Neubauer chamber, 20 µl of this fluid were diluted 1:20 (v/v) with Turk solution. For differential counting (neutrophils, eosinophils, and mononuclears), 30 µl were centrifuged at 400 x g for 10 min, applied to a glass slide, and stained with HEMA III. No discrimination between lymphocytes from monocytes was made. One hundred cells were counted with an optical microscope using an immersion objective (100x). The time courses of neutrophils and mononuclear cell migration were determined at 2, 4, 8, 24, 48, 72, and 96 h after injection of 20 x 10-10 moles of PSP-I/PSP-II. To this end, animals were killed and cells were recovered by lavage of the peritoneal cavity with 10 ml of sterile saline containing 5 IU heparin/ml. The fluid was recovered for total and differential cell counts. Results are expressed as mean ± SEM of the number of cells per microliter of peritoneal wash of at least five different animals.
Depletion of Total Peritoneal Resident Cells by Peritoneal Lavage
The method described by Souza et al. [20] was employed. Rats were anesthetized with ethyl ether and three hypodermic needles were inserted into the abdominal cavity. Thirty milliliters of sterile saline were injected through the needle placed near the sternum. The abdominal cavity was then gently massaged for 1 min and the peritoneal fluid was collected via the two needles inserted into the inguinal region. The protocol was repeated three times. More than 83% of the peritoneal resident cell population was recovered. Control (sham) rats were manipulated in the same way except that no fluid was injected or withdrawn. Thirty minutes later, the resident cells were estimated in this group of control animals by injection of 10 ml of saline-heparin, as described above. PSP-I/PSP-II (20 x 10-10 moles), PSP-I (40 x 10-10 moles), PSP-II (40 x 10-10 moles), or fMLP (10 x 10-9 moles) were injected i.p. into depleted and sham rats and neutrophil migration was estimated 4 h later.
Increasing the Peritoneal Macrophage Population by Pretreatment with Thioglycolate
The method described by Ribeiro et al. [17] was essentially followed. Ten milliliters of a 3% (w/v) thioglycolate solution were injected i.p. and macrophages were collected 4 days later, counted, and compared with the number of the same cells obtained from a group of control, nonthioglycolate-treated rats. The fMLP (10 x 10-9 moles), PSP-I/PSP-II (20 x 10-10 moles), PSP-I (40 x 10-10 moles), and PSP-II (40 x 10-10 moles) were injected i.p. into control and thioglycolate-treated rats, and neutrophil migration was evaluated after 4 h. Neutrophils in the peritoneal washes collected from control rats 4 days after thioglycolate treatment were subtracted from the number of neutrophils counted after administration of spermadhesin to thioglycolate-treated animals.
Depletion of Peritoneal Mast Cells
Peritoneal mast cell population was depleted either by chronic treatment with compound 48/80 [21] or by i.p. administration of water [22]. Animals were treated i.p. with compound 48/80 during 4 days (0.6 mg/kg twice a day for 3 days and 1.2 mg/kg twice on the fourth day). On the fifth day, depletion of the mast cell population was estimated in a group of treated animals by counting the number of mast cells present in the peritoneal cavity. The fMLP (10 x 10-9 moles), PSP-I/PSP-II (20 x 10-10 moles), PSP-I (40 x 10-10 moles), and PSP-II (40 x 10-10 moles) were injected into control and compound 48/80-treated rats, and neutrophil migration was evaluated 4 h later. For depletion of mast cells from peritoneal cavities by water administration, the animals were injected with 10 ml of warm (37°C) bidistilled H2O 48 h before the neutrophil migration assay. The number of cells obtained from the animals that had their mast cell population depleted was compared with that of nontreated control rats. The fMLP (10 x 10-9 moles), PSP-I/PSP-II (20 x 10-10 moles), PSP-I (40 x 10-10 moles), and PSP-II (40 x 10-10 moles) were then injected into control and H2O-treated rats, and the neutrophil counts were performed after 4 h.
Effect of Pharmacological Modulators on the Neutrophil Migration Induced by PSP-I/PSP-II
Control animals were injected i.p. with 1 ml of sterile saline. PSP-I/PSP-II (20 x 10-10 moles) was injected in saline-treated animals or in animals treated with 0.5 ml of either dexamethasone (1 mg/kg, s.c., for 1 h), MK-886 (1 mg/kg, p.o., for 1 h), indomethacin (5 mg/kg, s.c., for 30 min), or BN 50730 (10 mg/kg, s.c., for 30 min). Neutrophil migration was evaluated 4 h after injections and compared with the respective controls.
Effect of Trypsin Treatment on PSP-I/PSP-II-Induced Neutrophil Migration
This approach was used in order to demonstrate whether the spermadhesin-induced neutrophil migration was due to the native protein conformation. MALDI-TOF mass spectrometric peptide mapping showed that both PSP-I and PSP-II were degraded down to the expected tryptic peptides and no undegraded protein or proteolysis-resistant core remained after trypsin treatment. The heterodimer PSP-I/PSP-II (20 x 10 -10 moles), intact or after trypsin digestion (1:100 enzyme-substrate, 37°C, overnight), was injected i.p. in 1 ml of sterile saline. The neutrophil migration was evaluated 4 h later using the sterile saline-injected animals as controls.
Effect of Mannose-6-Phosphate on the Neutrophil Migration Induced by PSP-I/PSP-II Isolated Subunits
One milliliter of PSP-I (40 x 10-10 moles) or PSP-II (40 x 10-10 moles) alone or containing 20 x 10-10 moles of mannose-6-phosphate (PSP-II-specific binding sugar) was injected into rat peritoneal cavities. The effect was evaluated 4 h after injection and compared with the saline-treated group.
Statistical Analysis
All results were expressed as mean ± SEM for n = 5 experiments. Statistical evaluation was undertaken by analysis of variance (ANOVA) followed by the Duncan test. A P-value of less than 0.05 was considered statistically significant.
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
The concentration-dependent chemotactic activity of PSP-I/PSP-II dimer and isolated PSP-I and PSP-II was evaluated in vitro using a 48-well microchemotaxis chamber. Maximal activity was found at 10-4 M; the three proteins significantly induced migration of PMNs (Fig. 1A). At this concentration, PSP-I/PSP-II, PSP-I, and PSP-II enhanced neutrophil migration by 900%, 900%, and 800%, respectively, compared with RPMI medium. This activity was similar to that induced by 10-6 M fMLP, an established neutrophil chemoattractant used as positive control.
|
Dose- and Time-Dependent Proinflammatory Action of PSP-I/PSP-II
PSP-I/PSP-II stimulated in a dose-dependent manner the migration of neutrophils to the peritoneal cavity of rats 4 h after i.p. injection. This effect was 117%, 235%, and 356% compared with the control, saline-treated group upon injection of 2, 7, and 20 x 10-10 moles of the heterodimer, respectively. Administration of 20 x 10-10 moles of PSP-I/PSP-II showed the maximal response and was chosen for subsequent experiments. Time-course experiments showed that neutrophil migration was already significant 2 h after PSP-I/PSP-II injection, with maximal effect 4 h after spermadhesin administration, decreasing thereafter and reaching control levels 48 h after PSP-I/PSP-II injection (Fig. 1B). PSP-I/PSP-II also induced mononuclear migration (Fig. 1B). The time course of leukocyte recruitment induced by PSP-I/PSP-II followed the classical curve of leukocyte migration, i.e., the number of mononuclear cells increased along with a neutrophil count decrease. The peak of mononuclear migration was 96 h after PSP-I/PSP-II injection.
Neutrophil Migration Induced by PSP-I and PSP-II Subunits
Similar to PSP-I/PSP-II, the isolated subunits, PSP-I and PSP-II, induced neutrophil migration to the peritoneal cavity of rats in a dose-dependent manner 4 h after administration (Fig. 2). Injections of 4, 14, and 40 x 10-10 moles of PSP-I increased neutrophil migration by 107%, 136%, and 263%, respectively, compared with control animals (Fig. 2A). The neutrophil migration induced by PSP-II at the same dose as PSP-I was 25%, 239%, and 174%, respectively, of control rats (Fig. 2B).
|
Neutrophil Migration Activity of PSP-I/PSP-II and PSP-II Is Enhanced by an Indirect Mechanism
Depletion of 83% (Fig. 3A) of total resident cells by lavage of the peritoneal cavity reduced the neutrophil chemotactic activity of 20 x 10-10 moles PSP-I/PSP-II and 40 x 10-10 moles PSP-II to 51% and 74%, respectively. However, the neutrophil chemotactic activity of PSP-I (40 x 10-10 moles) or fMLP (10 x 10-9 moles) was not altered (Fig. 3B). These data suggest that PSP-I/PSP-II and the PSP-II subunit enhanced their neutrophil chemotactic activity by a mechanism dependent on resident cells. On the other hand, neutrophil migration induced by the neutrophil chemotactic reagent fMLP and by PSP-I was independent of resident peritoneal cells, indicating that these agonists may act directly on neutrophils.
|
Increase of Macrophage Population Potentiates the PSP-I/PSP-II and PSP-II Neutrophil Infiltration of the Peritoneal Cavity
Intraperitoneal injection of thioglycolate (3% w/v) 96 h before the neutrophil migration assay increased by 130% the number of mononuclear cells in the peritoneal cavity (Fig. 4A). The neutrophil-inducing activity of 20 x 10-10 moles of PSP-I/PSP-II and 40 x 10-10 moles PSP-II was potentiated (267% and 177% of the value obtained with control animals, respectively) by prior treatment with thioglycolate (Fig. 4B). On the other hand, neither fMLP (10 x 10-9 moles) nor the PSP-I subunit (40 x 10-10 moles) had an effect on the neutrophil counts (Fig. 4B). These data suggest that the peritoneal cells involved in the neutrophil migration recruitment activity of PSP-I/PSP-II and PSP-II might be macrophages. The mechanism used by the PSP-I subunit seems to be independent of these cells.
|
Mast Cell Depletion Potentiates the Neutrophil Influx to the Peritoneal Cavity Induced by PSP-I/PSP-II and the PSP-II Subunit
Figure 5A shows that chronic treatment of animals with compound 48/80 completely depleted the mast cell population in comparison with the control (C) group. Compared with nontreated rats, the neutrophil migration induced by PSP-I/PSP-II (20 x 10-10 moles) and PSP-II (40 x 10-10 moles) was potentiated in the mast cell-depleted animals in 366% and 410%, respectively (Fig. 5B). However, injection of 40 x 10-10 moles of PSP-I into the peritoneal cavity of compound 48/80-treated rats did not alter the onset of neutrophil migration. Moreover, the neutrophil migration induced by fMLP (10 x 10-9 moles) was not affected by depletion of mast cells that followed after treatment with compound 48/80. In addition, another strategy was used to deplete the mast cell population from peritoneal cavities of rats. Intraperitoneal injection of 10 ml of water also reduced the mast cell population to 14% of control animals 48 h after the treatment (Fig. 5C). Similar to compound 48/80 treatment, injection of water also potentiated the neutrophil migration induced by PSP-I/PSP-II (20 x 10-10 moles) and PSP-II (40 x 10-10 moles) by 275% and 201%, respectively, whereas the neutrophil migration induced by PSP-I (40 x 10-10 moles) and fMLP (10 x 10-9 moles) was not altered (Fig. 5D).
|
Dexamethasone but Not Indomethacin, MK886, or BN50739 Inhibited the Neutrophil Migration to Rat Peritoneal Cavities Induced by PSP-I/PSP-II
Figure 6 shows the effect of the cyclooxygenase inhibitor indomethacin, a leukotriene inhibitor MK886, a PAF antagonist BN 50730, and the glucocorticoid dexamethasone on neutrophil migration induced by i.p. injection of 20 x 10-10 moles of PSP-I/PSP-II. Treatment of the animals with indomethacin (5 mg/kg, s.c.), BN 50730 (10 mg/kg, s.c.), or MK886 (1 mg/kg, oral) did not modify the neutrophil migration induced by the spermadhesin heterodimer. On the other hand, dexamethasone (1 mg/kg, s.c.) injected 1 h previous to the spermadhesin administration inhibited by 71% the PSP-I/PSPII-induced neutrophil migration to the peritoneal cavity of rats.
|
Effect of Proteolysis on PSP-I/PSP-II-Induced Neutrophil Migration
This approach was undertaken in order to investigate whether the spermadhesin PSP-I/PSP-II-induced neutrophil migration was due to the native protein conformation. PSP-I/PSP-II heterodimer (20 x 10-10 moles), intact or after trypsin digestion, were injected i.p. in 1 ml of sterile saline, and neutrophil migration was evaluated 4 h later using sterile saline-injected animals as controls. Trypsin treatment did not impair the neutrophil migration-inducing ability of the spermadhesin (data not shown), suggesting that a linear epitope (a polypeptide stretch or a carbohydrate structure) may retain this biological activity.
Mannose-6-Phosphate Inhibited the Neutrophil Migration Induced by PSP-II but Not by PSP-I
The i.p. administration of 40 x 10-10 moles of PSP-II coincubated with 20 x 10-10 moles of its specific binding sugar mannose-6-phosphate resulted in a 52% reduction of the neutrophil migration compared with that induced by PSP-II alone. The chemotactic effect of PSP-I (40 x 10-10 moles) was not altered by coincubation with mannose-6-phosphate. Mannose-6-phosphate alone did not induce neutrophil migration (data not shown). The results suggested that the lectin domain present at the PSP-II subunit could be involved in the proinflammatory activity of the spermadhesin.
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
In conclusion, our data show a proinflammatory effect of spermadhesin PSP-I/PSP-II heterodimer and that the two subunits are involved in neutrophil activation via different mechanisms. PSP-I and PSP-II [4] represent more than 50% of the total boar seminal plasma proteins. During natural mating in the pig, the first spermatozoa reach the uterotubal junction and the adjacent first portion of the oviductal isthmus within minutes [28], where a preovulatory sperm reservoir (of the order of 105) sufficient for full fertilization is established [29, 30]. The remaining spermatozoa (10–50 x 109) is either voided by retrograde reflux (about 35%) or eliminated by phagocytosis by uterine PMNs that traverse the uterine lumen within 3–6 h postmating [31]. Several factors have been suggested as mediators for PMN recruitment, such as fluid distention [32], spermatozoa [33], and seminal plasma [34]. The results presented here support a role for PSP-I/PSP-II as a postmating inflammation mediator. Ongoing investigations in our laboratories show that the initial fraction of the boar ejaculate, which contains the sperm population that eventually colonizes the oviductal isthmus, is devoid of spermadhesins. The absence of the inflammation mediator PSP-I/PSP-II in this sperm fraction may provide a window of opportunity for spermatozoa to reach the sperm reservoir before the PMNs reach the lumen.
Leshin et al. [10] have shown that PSP-I and PSP-II are immunostimulatory proteins that modulate pig lymphocyte activity in vitro. Besides, lymphocyte binding of PSP-I was recently demonstrated by histochemical techniques [9]. These findings are in line with our results and as a whole indicate that the PSP proteins may modulate immune responses in the porcine uterine environment that may contribute to the reproductive success of the species.
|
ACKNOWLEDGMENTS |
|---|
|
FOOTNOTES |
|---|
2 Correspondence: Juan J. Calvete, Instituto de Biomedicina, CSIC, Jaime Roig 11, 46010 Valencia, Spain. FAX: 34963690800; jcalvete{at}ibv.csic.es; Ronaldo A. Ribeiro, Dept. de Fisiologia e Farmacologia, Universidade Federal do Ceará, R. Cel. Nunes de Melo, 1127-Rodolfo Teófilo, 60 430.270 Fortaleza, CE, Brazil. FAX: 55 85 2888333; ribeiror{at}ufc.br
Received: 30 April 2002.
First decision: 30 May 2002.
Accepted: 1 July 2002.
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
This article has been cited by other articles:
|
|
 |
|
  E. M. Garcia, J. M. Vazquez, J. J. Calvete, L. Sanz, I. Caballero, I. Parrilla, M. A. Gil, J. Roca, and E. A. Martinez Dissecting the Protective Effect of the Seminal Plasma Spermadhesin PSP-I/PSP-II on Boar Sperm Functionality J Androl, May 1, 2006; 27(3): 434 - 443. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Centurion, J. M. Vazquez, J. J. Calvete, J. Roca, L. Sanz, I. Parrilla, E. M. Garcia, and E. A. Martinez Influence of Porcine Spermadhesins on the Susceptibility of Boar Spermatozoa to High Dilution Biol Reprod, August 1, 2003; 69(2): 640 - 646. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. S. Assreuy, N. M.N. Alencar, B. S. Cavada, D. R. Rocha-Filho, R. F.G. Feitosa, F. Q. Cunha, J. J. Calvete, and R. A. Ribeiro Porcine Spermadhesin PSP-I/PSP-II Stimulates Macrophages to Release a Neutrophil Chemotactic Substance: Modulation by Mast Cells Biol Reprod, May 1, 2003; 68(5): 1836 - 1841. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
