Human seminal plasma antibody-binding proteins

PROBLEM: The physiological role of antibody-binding proteins in human seminal plasma and the potential role of these proteins in infertility is relatively unknown. METHOD OF STUDY: Literature on antibody-binding proteins. RESULTS: Human seminal plasma has a diverse effect on immune function of the reproductive tracts. This review describes (1) the presence of receptors like proteins that can react with monoclonal antibodies against Fcgamma receptors III (Fcgamma RIII) but are distinctly different from Fcgamma RIII; (2) IgG binding factors (IgGBF), a group of low molecular weight proteins that are capable of binding human IgG; (3) other proteins that can bind antibodies, such as prolactin-inducible protein and three other novel proteins that we have discovered. These proteins potentially all have the ability to reduce the interactions between antisperm antibodies and effector components of the immune system, such as phagocytic cells. CONCLUSIONS: Human seminal plasma contains proteins that can bind antibodies. However, to date our knowledge of these proteins especially, whether they have a physiological role in either the male and female reproductive tracts is limited.     

Mutual interactions of boar seminal plasma proteins studied by immunological and chromatographic methods

PROBLEM: Boar seminal plasma contains various types of proteins. Most of them belong to spermadhesins and some of them contain fibronectin type II domain. Almost all of these proteins are present under physiological conditions in aggregated forms differing in their relative molecular mass, composition, and binding properties. The study of mutual specific interactions between proteins of boar seminal plasma that could be involved in the formation of aggregated forms and most probably of sperm coating layers is the subject of our present communication. METHODS OF STUDY: Aggregated forms of boar seminal plasma proteins separated by size exclusion chromatography were analysed by Reversed-phase High-performance Liquid Chromatography (RP HPLC), SDS-PAGE and immunochemical methods (ELISA and immunoblotting). Mutual interactions between proteins were investigated by size exclusion chromatography of a mixture of separated monomer proteins and affinity chromatography of boar seminal plasma on immobilized spermadhesins. RESULTS: Composition of proteins that are adsorbed from boar seminal plasma to immobilized spermadhesins corresponds to that of aggregated forms found in seminal plasma. Mutual interactions between monomer forms observed by size exclusion chromatography are in good agreement with results of affinity chromatography. An existence of interactions between spermadhesins of the AQN and AWN families and the DQH sperm surface protein, as well as between proteins involved in the formation of heterodimer porcine seminal plasma I (PSP I)/PSP II was proved. CONCLUSION: Mutual specific interactions between protein components of boar seminal plasma were shown. These interactions participate in the formation of aggregated forms of proteins in seminal plasma and probably also in the arrangement and remodelling of protein coating layers of sperm. Aggregation of seminal plasma proteins is probably an important phenomenon in the fertilization process.     

Formation of P10 tubular structures during AcMNPV infection depends on the integrity of host-cell microtubules

During infection of insect cells with Autographa californica nucleopolyhedrovirus (AcMNPV), the very late protein P10 forms large fibrillar structures in the cytoplasm and nuclei of infected cells. In this study we have used confocal microscopy in association with a novel P10 antiserum to localise and study P10 in virus-infected cells. P10 was shown to be a component of tubular-like structures that spiralled throughout the cytoplasm and nucleus of AcMNPV-infected cells. These structures were observed to colocalise partly with cortical microtubules. When microtubules were depolymerised with the drug nocodazole, P10 tubules failed to form and the protein appeared concentrated in cytoplasmic foci. For the first time, we provide direct evidence using both antibody pulldown and yeast two-hybrid experiments for the interaction of P10 with host-cell tubulin. It is suggested that this interaction may be a critical factor in AcMNPV-induced cell lysis.     

Studies of the Rf = 0.58 protein in common snail command neurons during learning

Levels of the acidic brain-specific Rf = 0.58 protein in neurons of the subglottal complex of ganglia were studied in the common snail during the process of acquisition of defensive food aversion. Levels were significantly increased in neurons LPa3 and RPa3 at both the early and late stages of learning. There was a tendency to increased protein levels in neurons LPl1 and RPl2, while there were no changes in levels in neuron RPa5 and pool D. The level of involvement of defensive behavior command neurons appears to be determined by the specific involvement of their receptor and effector fields.     

Comparative genomic hybridization analysis of sperm DNA apoptosis after exposure to heat shock

Purpose: A DNA disc chip assay based on comparative genomic hybridization (CGH) was developed to measure sperm DNA integrity. The objective was to correlate DNA integrity of heat-treated sperm with the sperm capacitation index (CI) determined from the sperm penetration assay. Methods: Basic semen and kinematic parameters were measured (N = 6). Sperm were washed in two-layer colloid suspensions and split portions incubated at either 37°C (control) or 40°C for 4 h. Single-stranded DNA of heated sperm were stained in SYBR Gold and hybridized to bisbenzimide (Hoechst 33342) stained control DNA in a membrane disc. Fluorescent intensities of the discs were measured and correlation analyses with sperm parameters performed. Results: Sperm CI was positively correlated (R = 0.737) with sperm DNA integrity. Two populations of sperm could be discerned: low capacitating sperm that initiated apoptosis and high capacitating sperm unaffected by heat shock treatment. The remaining parameters were not related to sperm DNA stability. Conclusions: Fragile DNA were found in a population of sperm associated with poor capacitation characteristics and apoptosis was observed after heat treatment. The results suggested that sperm dysfunction might be due to apoptotic sperm DNA resulting from an elevated temperature in the surroundings. The data suggested that the second population of high capacitating sperm induced chaperones such as heat shock proteins hsp 70 to protect against apoptosis.     

Expression of integrins by human periodontal ligament and gingival fibroblasts and their involvement in fibroblast adhesion to enamel matrix-derived proteins

We showed recently that human periodontal ligament (PDL) and gingival fibroblasts adhere and spread on enamel matrix protein (EMP) coatings. In the present study, we investigated whether this interaction can be attributed to integrin expression. Human PDL and gingival fibroblasts were cultured for periods up to 24 h on EMP coatings, in the presence of synthetic RGD-containing peptide or an antibody against the beta1 integrin subunit. The cells were first cultured for 24 h under serum-free conditions and then cultured on EMP coatings for 48 h. Integrin expression levels were assessed by flow cytometry analysis. It was found that attachment and spreading on EMP was inhibited by the synthetic RGD-containing peptide, but not by a synthetic RGE-peptide. Both PDL and gingival fibroblasts showed expression of the integrin subunits, alpha2, alpha5, beta1, and the integrin, alphavbeta3. Incubation with an antibody against the beta1 subunit significantly inhibited the attachment and spreading of PDL and gingival fibroblasts on EMP coatings. We conclude that integrins are involved in the interaction of PDL and gingival fibroblasts with EMP.     

Dental biofilms at healthy and inflamed gingival margins

Objectives: The increased plaque formation observed in gingival inflammation is not fully understood. Receptor proteins in the dental pellicle might influence bacterial adhesion and subsequent plaque formation. The purpose of the present study was to examine proteins and microorganisms in dental biofilms, at healthy and inflamed gingival margins. Material and methods: To see whether marginal inflammation affects the composition of the pellicle and the early dental plaque, samples were taken from the gingival and incisal parts of teeth in periodontally healthy subjects, both in gingival health and during experimental gingivitis. Pellicle proteins were analysed using gel-electrophoresis, immunoblotting and image analysis. Bacteria were analysed by culturing and the PCR technique. Results: During gingivitis, the rate of plaque formation increased significantly. The semiquantitative amounts of proteins and the numbers of bacteria varied considerably between individuals and surfaces. The amount of total and individual pellicle proteins and the total numbers of bacteria were, however, increased during gingivitis and the increase in proteins was statistically significant on the incisal parts of tooth surfaces. Compared to a healthy gingiva, reduced numbers for Actinomyces spp. (incisal parts only) and streptococci and increased numbers of periodontopathogens in the 4 h dental biofilms were seen at the inflamed gingiva. Conclusion: Increased gingival crevicular fluid flow during gingivitis affects pellicle formation and increased plasma proteins in the pellicle may modify bacterial attachment and early dental plaque composition.     

Capsaicin-sensitive nerves regulate the metabolic response to abdominal sepsis

BACKGROUND: Both the systemic release of inflammatory mediators and activation of the neuroendocrine axis by sensory afferent nerves (SANs) have been implicated as initiators of the metabolic response to infection. In this study, we investigate the role of SANs as mediators of protein catabolism and the insulin-like growth factor (IGF) axis during abdominal sepsis using capsaicin (Cap) to selectively destroy nociceptive sensory axons. METHODS: Four groups of male Sprague-Dawley rats were studied: Control, Control+Cap, Sepsis, and Sepsis+Cap. Rats were injected with Cap (75 mg/kg) on day 1 and (50 mg/kg) on day 2 to destroy SANs. Time-matched control and septic rats were pair-fed and injected with vehicle on the same schedule. Controls underwent sham laparotomy, while septic rats had a fecal-agar pellet inoculated with Escherichia coli and Bacteroides fragilis implanted in the peritoneal cavity. Blood and tissues were harvested 5 days after the induction of sepsis. Plasma IGF-I, IGFBP-1, and -3 were measured by radioimmunoassay and Western blot analysis. IGF-I, acid-labile subunit (ALS), IGFBP-1 and -3 mRNA levels were determined by Northern blot analysis. RESULTS: Mortality was 40% in septic rats vs 0% in the sepsis+Cap group. Capsaicin had no effect on muscle mass, protein content, or the IGF system in control rats. However, sepsis-induced reductions in gastrocnemius mass (25%) and protein content (35%) were ameliorated by capsaicin. The sepsis-induced decrease in hepatic IGF-I mRNA and circulating IGF-I (26%), as well as the 4-fold increase in plasma IGFBP-1 and hepatic IGFBP-1 mRNA were prevented by capsaicin. CONCLUSIONS: Capsaicin-sensitive nerves mediate mortality, the catabolism of skeletal muscle, and selected elements of the IGF system during abdominal sepsis. The results suggest an important role for nociceptive SANs and the neuroendocrine system in mediating the host response to abdominal infection.     

软骨寡聚基质蛋白在慢性胰腺炎损伤中退变腺泡细胞内的表达

目的 研究正常胰腺、慢性胰腺炎与胰腺癌组织中软骨寡聚基质蛋白(cartilage oligomeric matrix protein,COMP)mRNA和蛋白表达水平的差异,揭示COMP在慢性胰腺炎样损伤中的意义。方法 采用Northern印迹法、Western印迹法、原位杂交法与免疫组化方法对14例慢性胰腺炎、14例胰腺癌及15例正常胰腺组织进行分析。结果 在慢性胰腺炎组织中和胰腺癌组织中类似慢性胰腺炎损伤的退变腺泡细胞胞浆内,存在高水平的COMP mRNA信号与免疫反应;而在胰腺癌细胞、正常胰腺组织的导管细胞与胰岛细胞的胞浆内,COMP mRNA信号与免疫反应微弱或缺如。结论 COMP在慢性胰腺炎及胰腺癌中类似慢性胰腺炎损伤的退变腺泡细胞内高表达,可能与慢性胰腺炎中腺泡细胞功能异常有关。