Increased adherence to vaginal epithelial cells and phagocytic killing of gonococci and urogenital meningococci associated with heat modifiable proteins

Urogenital Neisseria meningitidis were characterized with regard to serogroup, colony morphology, the presence of heat modifiable proteins (HMP), attachment to human vaginal and buccal epithelial cells, and phagocytic killing by polymorphonuclear leukocytes. The findings were compared with those on gonococci, and with those on meningococci isolated from blood or cerebrospinal fluid, with regard to colony morphology, HMP and piliation. The opacity colony morphology characteristic could be used to predict the presence of HMP in gonococci but not in meningococci, and sodium dodecyl sulphate polyacrylamide gel electrophoresis had to be used to demonstrate this surface protein. The urogenital meningococci, serogroup Y, attached significantly more efficinetly to vaginal epithelial cells in the presence of HMP and behaved in this respect like those of gonococci. Gonococci and meningococci containing HMP were more sensitive to phagocytic killing than those without HMP. Meningococci from opaque and transparent colonies and isolated from patients with meningococcal disease had no demonstrable HMP. They showed low adherence to vaginal and buccal epithelial cells, with no difference between organisms from opaque or transparent colonies.     

女大学生月经周期应激敏感性的生理心理评估

目的:评估女大学生在月经周期不同阶段应激敏感性的变化。方法:在经前、经后和排卵期对29名月经周期规律的女大学生进行静息、心算任务的心理生理测试。结果:心率变化最显著,排卵期的心率显著大于经前和经后;在排卵期和经后心算心率显著大于静息心率,而在经前两者之间无显著差异;在心率变异性上,仅发现低频成分在静息状态显著大于心算状态;皮肤电反应在心算状态显著大于静息状态。结论:女大学生在经前应激敏感性最高。     

A prospective, randomized, double-blind study of vaginal microflora and epithelium in women using a tampon with an apertured film cover compared with those in women using a commercial tampon with a cover of nonwoven fleece

Healthy women with normal menstrual cycles were randomly assigned to use either a test tampon during cycle 1 and a reference tampon during cycle 2 or a reference tampon during cycle 1 and a test tampon during cycle 2. Tampons were identical except for their cover materials: apertured film for the test tampon and nonwoven fleece for the reference tampon. Product use was doubly blinded. Qualitative and quantitative analyses of vaginal cultures were done pre-, mid-, and postmenstrually for a broad panel of microorganisms, colposcopy was performed, and diary reports were collected; 101 of 105 enrolled subjects completed the study. Midmenstrual findings for a variety of organisms differed from pre- and postmenstrual observations whether subjects were using test or reference tampons. No statistically significant differences were noted in prevalence or colony counts at premenstrual versus mid- and postmenstrual visits for most microorganisms. Prevalences of Gardnerella and anaerobic gram-negative rods were significantly different between tampons at the premenstrual visit, when unusually low values were observed for the test and reference tampons, respectively. None of the changes or differences in microflora were considered to be clinically significant. It is noteworthy, however, that declines in the prevalence and abundance of Lactobacillus during the menstrual periods were less pronounced during the use of both test and reference tampons than those reported from previous studies. Colposcopy showed no abnormal findings with either tampon and no changes in vaginal or cervical epithelial integrity. Thus, all evidence from both microbiological and colposcopic evaluations indicates that the apertured film cover of the test tampon is as safe as the nonwoven cover of the reference tampon.     

Changes in premenstrual symptoms in women with schizophrenia: a prospective study

OBJECTIVE: We investigated whether the psychiatric symptoms and clinical features of schizophrenia change during the premenstrual phase in female patients. METHODS: We observed 30 female schizophrenic inpatients over one menstrual cycle. All subjects met DSM-IV criteria for schizophrenia, and all had a regular menstrual cycle. All subjects completed the Daily Rating Form (DRF) every evening, and one psychiatrist rated the subjects (using the Brief Psychiatric Rating Scale [BPRS]) once during each of the three menstrual phases (premenstrual, menstrual, and postmenstrual). Serum levels of estradiol (E2) and progesterone were measured on the fifth to seventh day of both the premenstrual and postmenstrual phases. Data from the 24 subjects who completed the DRF correctly and completely were used for statistical analysis. RESULTS: The mean total BPRS score for the 24 subjects was highest in the premenstrual phase and lowest in the postmenstrual phase, and a statistically significant difference was found among the three menstrual phases. Mean subtotal BPRS scores showed statistically significant differences among the three menstrual phases in anxiety/depression and withdrawal/retardation, but not in the psychotic symptom subscales. Mean serum E2 level showed a trend of increasing from the premenstrual phase to the postmenstrual phase. However, there was no significant correlation between DeltaBPRS and DeltaE2. When the criterion of 30% change was applied, the DRF items of depressed mood, anxious/nervous/restless, hostile/aggressive, and less/impaired work showed high frequencies of change in the premenstrual phase. Somatic items of abdominal pain, breast pain, and headache showed significant change with the 30% change rule on the DRF. On both the BPRS and DRF scores, premenstrual change of affective and behavioral symptoms was prominent, whereas the change of psychotic symptoms was minimal on the BPRS. In addition, in the premenstrual phase, there was a statistically significant correlation between the total BPRS score and the mean total DRF score. There was no correlation between premenstrual change in symptoms and hormonal levels of E2, progesterone, and the estradiol/progesterone (E/P) ratio. CONCLUSIONS: The findings of this study suggest that premenstrual exacerbation of schizophrenic symptoms in female patients may not be a worsening of the schizophrenic symptoms but a concurrence of affective, behavioral, and somatic symptoms.     

Inhibition of Neisseria gonorrhoeae epithelial cell interactions by vaginal Lactobacillus species

High levels of Lactobacillus, the dominant genus of the healthy human vaginal microbiota, have been epidemiologically linked to a reduced risk of infection following exposure to the sexually transmitted pathogen Neisseria gonorrhoeae. In this work, a cell culture model of gonococcal infection was adapted to examine the effects of lactobacilli on gonococcal interactions with endometrial epithelial cells in vitro. Precolonization of epithelial cells with Lactobacillus jensenii, Lactobacillus gasseri ATCC 33323, or L. gasseri ATCC 9857 reduced gonococcal adherence by nearly 50%. Lactobacilli also inhibited gonococcal invasion of epithelial cells by more than 60%, which was independent of the effect on adherence. Furthermore, lactobacilli were able to displace adherent gonococci from epithelial cells, suggesting that these organisms have potential as a postexposure prophylactic. Thus, vaginal lactobacilli have the ability to inhibit gonococci at two key steps of an infection, which might have a significant effect in determining whether the gonococcus will be able to successfully establish an infection following exposure in vivo.     

Toward a functional neuroanatomy of premenstrual dysphoric disorder

BACKGROUND: Premenstrual dysphoric disorder (PMDD) is a prevalent disorder in the spectrum of affective illness, and is associated with significant morbidity. The neurobiology of this underdiagnosed and undertreated illness is poorly understood. A functional magnetic resonance imaging (fMRI) probe of fronto-limbic function was used to advance understanding of PMDD pathophysiology. METHODS: We applied BOLD fMRI and Statistical Parametric Mapping to study neural response to emotional words in the context of an emotional Go/NoGo inhibitory control task. We examined alterations in this response across the menstrual cycle, in the premenstrual (late luteal) phase and the postmenstrual (late follicular) phase. RESULTS: In the premenstrual (vs. postmenstrual) phase, PMDD subjects, compared with asymptomatic subjects, showed an increased amygdala response to negative vs. neutral stimuli, and a decreased ventral striatum response to positive vs. neutral stimuli. PMDD subjects failed to show the asymptomatic subjects' patterns of increased medial and decreased lateral orbitofrontal cortex (OFC) response to negative vs. neutral stimuli in the premenstrual vs. postmenstrual phase. This decreased premenstrual medial OFC response to negative stimuli in PMDD subjects was further enhanced in the context of behavioral inhibition. LIMITATIONS: Further studies with larger numbers of subjects are needed. CONCLUSIONS: The results support a neurobiological model of enhanced negative emotional processing, diminished positive emotional processing, and diminished top-down control of limbic activity in PMDD during the premenstrual phase. These findings provide a basis for a neurocircuitry model of PMDD, and have implications for studies of mood/emotional regulation across the human menstrual cycle in health and disease.     

Psychophysiological responses in women reporting severe premenstrual symptoms

Sixteen women attending a Premenstrual Tension Clinic and eight control women were tested experimentally in the premenstrual and postmenstrual phases with assessments of heart rate, skin conductance level, and neck electromyogram during rest, relaxation, an emotionally upsetting film, and performance of mental arithmetic and video game tasks. All participants completed daily symptom assessments for two menstrual cycles prior to the study. The clinic attenders were divided into eight (Clinic+) who showed marked increases in symptoms premenstrually, and eight (Clinic-) who recorded only modest changes in symptom severity across the menstrual cycle. There were no marked differences in resting autonomic activity. During relaxation, skin conductance level decreased to a greater extent in the premenstrual than in the postmenstrual phase, while neck electromyogram showed the reverse pattern. Heart rate reactions to the mental arithmetic and video game tasks were smaller in the premenstrual than in the postmenstrual phase in Controls and Clinic- groups, but not in the Clinic+ group. Possible explanations of these results are discussed.     

Resting heart rate (HR) in women with and without premenstrual symptoms (PMS)

A sample of 64 undergraduate female students participated in the present experiment. During 3 consecutive months women answered a chart of daily report of symptoms, and finally, two groups were formed: women with premenstrual symptoms (PMS group) and women without premenstrual symptoms (NPMS group). Heart rates (HR) at rest were recorded throughout premenstrual, menstrual, postmenstrual, and ovulatory phases. In the premenstrual phase, PMS group showed significantly higher resting HR levels than NPMS group. With regard to resting HR levels across the four phases studied, significant differences within PMS group were observed. Our results are discussed from a psychophysiological point of view.     

Adherence of bacterial to vaginal epithelial cells.

Vaginal epithelial cells from healthy women were washed and incubated in tissue culture medium with freshly isolated bacteria of the indigenous vaginal flora and with bacteria of species that have been discussed in conjunction with genital infections. After incubation and washing, the number of bacteria that adhered per cell was determined. The influence on the attachment rate of such factors as variations in the washing procedure, bacterial density, and incubation time was assessed. Lactobacillus acidophilus and other bacterial species that occur in the lower genital tract of healthy women, e.g., some strictly anaerobic species, adhered by significantly lower numbers per cell than Neisseria gonorrhoeae, group B streptococci, and Corynebacterium vaginale. Significantly more freshly isolated gonococci adhered per cell than gonococci that had been passaged on artificial medium. The adherence of gonococci increased with increasing acidity of the test medium.     

Experimental infection of native human ureteral tissue with Neisseria gonorrhoeae: adhesion, invasion, intracellular fate, exocytosis, and passage through a stratified epithelium.

The exact mechanisms by which Neisseria gonorrhoeae invades the mucosal lining to cause local and disseminated infections are still not fully understood. The ability of gonococci to infect the human ureter and the mechanism of gonococcal infection in a stratified epithelium were investigated by using distal ureters excised from healthy adult kidney donors. In morphological terms, this tissue closely resembles parts of the urethral proximal epithelium, a site of natural gonococcal infection. Using piliated and nonpiliated variants of N. gonorrhoeae MS11, we demonstrated the importance of pili in the attachment of gonococci to native epithelial cells as well as their association with epithelial damage. By electron microscopy we elucidated the different mechanisms of colonization and invasion of a stratified epithelium, including adherence to surface cells, invasion and eventual release from infected cells, disintegration of intercellular connections followed by paracellular tissue infiltration, invasion of deeper cells, and initiation of cellular destruction and exfoliation resulting in thinning of the mucosa.     

Role of Pili in the Virulence of Neisseria gonorrhoeae

Gonococci of the colonial types that are associated with virulence, types 1 and 2, have pili that enable the bacteria both to attach in vitro to human epithelial cells and to resist phagocytosis by polymorphonuclear leukocytes. These piliated gonococci also agglutinate various mammalian and chicken erythrocytes. Gonococci of an avirulent colonial type, i.e., type 4, have no pili and neither attach to epithelial cells or erythrocytes nor resist phagocytosis. Like the type 4 bacteria, mechanically or enzymatically (trypsin) depiliated type 1 gonococci failed to attach to epithelial cells and erythrocytes and were susceptible to phagocytosis. Pili of types 1 and 2 gonococci were antigenically similar. Both type 1 gonococci and pili isolated from them induced in rabbits antibody that (i) precipitated gonococcal pili in immunodiffusion, (ii) reacted with piliated gonococci as tested by indirect immunofluorescent analysis, (iii) inhibited attachment of piliated gonococci to both human epithelial cells and erythrocytes, and (iv) opsonized piliated gonococci.     

Investigation of the efficacy of progesterone pessaries in the relief of symptoms of premenstrual syndrome. progesterone Study Group.

BACKGROUND. A variety of definitions have been applied to premenstrual syndrome. The severity of the syndrome is also variable. AIM. A study was undertaken to compare progesterone pessaries with placebo in the relief of symptoms of premenstrual syndrome. In this study the condition was characterized by a wide range of symptoms recurring in the late luteal phase but absent in the follicular phase (that is, the specific definition published by Dalton in 1953). METHOD. A multicentre, prospective, double-blind, randomized, parallel group study was undertaken by 45 general practitioners. Patients were deemed eligible after two prospective menstrual cycles of observation (selection phase) in which a precise definition of symptoms was applied. Patients were randomized to use either progesterone pessaries (400 mg twice a day) or matching placebo, by vaginal or rectal administration, from 14 days before the expected onset of menstruation until the onset of vaginal bleeding, for four consecutive cycles. Baseline data for the outcome variables were determined in the selection phase. The main outcome variables were changes in the severity (categorized as none, mild, moderate or severe) of each patient's most severe symptom, and in the average score of all the patient's symptoms characteristic of premenstrual syndrome. Spontaneous reports of adverse events were recorded. RESULTS. A total of 281 patients were screened for premenstrual syndrome; of these, 141 patients were randomized to treatment or placebo groups. Efficacy was evaluated in 93 patients. Reductions in the scores of the highest scoring, most severe, symptoms and in the average symptom score, were consistently observed in patients receiving progesterone pessaries and in those receiving placebo. The response to progesterone was greater than to placebo during each cycle; the differences were clinically and statistically significant. Adverse events were reported by 51% of patients in the progesterone treatment group and by 43% in the placebo group. Irregularity of menstruation, vaginal pruritus and headache were reported more frequently by patients taking active therapy. CONCLUSION. In this study, progesterone, given as pessaries by vaginal or rectal administration, was more effective than placebo in the relief of symptoms of premenstrual syndrome in a population of patients selected by strict entry criteria.     

Influences of premenstrual syndrome on daily psychological states and salivary cortisol level

The purpose of this study is to investigate the influences of premenstrual syndrome (PMS) on daily psychological states and salivary cortisol level. First, 42 women recorded their PMS symptoms and basal body temperatures every day for approximately two menstrual cycles. Based on these prospective records of PMS symptoms, participants were divided into two groups: Normal group (n=22) and PMS group (n=17). There were no significant differences between the two groups in age, height, weight, age at menarche, menstrual cycle length, menstrual period, depression score, and stressor score. Next, 14 women (7 Normal group, 7 PMS group) were selected and they were measured twice, once during the premenstrual phase and once during the postmenstrual phase of their cycles. Each day, they took saliva samples and recorded their psychological states six times (from waking to going to bed) per day at their homes. Results showed that the fear score in PMS group was high in the premenstrual phase, whereas salivary cortisol level in PMS group was low in the same phase compared to the Normal group. These results suggested the possibility of dysregulation of the stress system in women with PMS.     

CD46-independent binding of neisserial type IV pili and the major pilus adhesin, PilC, to human epithelial cells

Neisseria gonorrhoeae is a gram-negative bacterial pathogen which infects the human mucosal epithelium. An early critical event in neisserial infection is the type IV pilus-mediated adherence to the host cell. The PilC protein, located on the pilus tip, has earlier been identified as the major pilus adhesin. Previous studies suggested that the cell surface protein CD46 is a pilus receptor for Neisseria. We investigated the role of CD46 in pilus-mediated gonococcal infection of epithelial cells. Differences in binding efficiencies of piliated gonococci as well as purified pilus adhesin PilC2 on human epithelial cell lines did not correlate to the level of surface-expressed CD46. Additionally, no binding of piliated gonococci or PilC2 protein was observed on CD46-transfected CHO and MDCK cells. Furthermore, specific down-regulation of CD46 expression in human epithelial cell lines by RNA interference did not alter the binding efficiency of piliated gonococci or purified PilC2 protein, although other CD46-dependent processes, such as measles virus infection and C3b cleavage, were significantly reduced. These data support the notion that pilus-mediated gonococcal infection of epithelial cells can occur in a CD46-independent manner, thus questioning the function of CD46 as an essential pilus receptor for pathogenic neisseriae.     

Premenstrual symptomatology,locus of control,anxiety and depression in women with normal menstrual cycles

Summary The present study was designed to investigate the relationships between premenstrual symptomatology, locus of control, anxiety, and depression in women with normal menstrual cycles. Sixty-nine female participants completed a survey, comprised of the Menstrual Distress Questionnaire (MDQ; Moos, 1968), Levenson's (1981) locus of control scales, the Depression Anxiety Stress Scale (DASS; Lovibond and Lovibond, 1995), and a questionnaire constructed by the researchers based on the DSM-IV criteria for Premenstrual Dysphoric Disorder (PMDD). Both overall and specific subtypes of premenstrual symptomatology were found to correlate with external locus of control, anxiety, and depression. In addition, locus of control was found to moderate the relationship between premenstrual symptomatology, anxiety and depression. Finally, women who were in the premenstrual phase when completing the questionnaire scored significantly lower on the internal scale than those in either the follicular or early luteal phases. It was concluded that an external locus of control may be associated with a susceptibility to depression or anxiety when certain premenstrual or postmenstrual changes are experienced. Received August 10, 2002; accepted January 12, 2003 Published online February 19, 2003 Abbreviations · ANOVA · Analysis of variance · DASS · Depression anxiety stress scale · LOC · Locus of control · MANOVA · Multivariate analysis of variance · MDQ · Menstrual distress questionnaire · PMDD · Premenstrual dysphoric disorder · PMS · Premenstrual syndrome Acknowledgement The authors would like to thank John Reece, Department of Psychology and Disability Studies, RMIT University, Melbourne, Australia, for assistance with data analysis. Correspondence: Dr. Andrew Francis, Department of Psychology and Disability Studies, Faculty of Applied Science, RMIT University, P.O. Box 71, Bundoora, Victoria 3083, Australia; e-mail: andrew.francis@rmit.edu.au     

Distinct proinflammatory host responses to Neisseria gonorrhoeae infection in immortalized human cervical and vaginal epithelial cells

In this study we utilized immortalized morphologically and functionally distinct epithelial cell lines from normal human endocervix, ectocervix, and vagina to characterize gonococcal epithelial interactions pertinent to the lower female genital tract. Piliated, but not nonpiliated, N. gonorrhoeae strain F62 variants actively invaded these epithelial cell lines, as demonstrated by an antibiotic protection assay and confocal microscopy. Invasion of these cells by green fluorescent protein-expressing gonococci was characterized by colocalization of gonococci with F actin, which were initially detected 30 min postinfection. In all three cell lines, upregulation of interleukin 8 (IL-8) and IL-6, intercellular adhesion molecule 1 (CD54), and the nonspecific cross-reacting antigen (CD66c) were detected 4 h after infection with piliated and nonpiliated gonococci. Furthermore, stimulation of all three cell lines with gonococcal whole-cell lysates resulted in a similar upregulation of IL-6 and IL-8, confirming that bacterial uptake is not essential for this response. Increased levels of IL-1 were first detected 8 h after infection with gonococci, suggesting that the earlier IL-8 and IL-6 responses were not mediated through the IL-1 signaling pathway. The IL-1 response was limited to cultures infected with piliated gonococci and was more vigorous in the endocervical epithelial cells. The ability of gonococci to stimulate distinct proinflammatory host responses in these morphologically and functionally different compartments of the lower female genital tract may contribute directly to the inflammatory signs and symptoms characteristic of disease caused by N. gonorrhoeae.     

Infection of human fallopian tube epithelial cells with Neisseria gonorrhoeae protects cells from tumor necrosis factor alpha-induced apoptosis

Following infection with Neisseria gonorrhoeae, bacteria may ascend into the Fallopian tubes (FT) and induce salpingitis, a major cause of infertility. In the FT, interactions between mucosal epithelial cells and gonococci are pivotal events in the pathogen's infection cycle and the inflammatory response. In the current study, primary FT epithelial cells were infected in vitro with different multiplicities of infection (MOI) of Pil+ Opa+ gonococci. Bacteria showed a dose-dependent association with cells and induced the secretion of tumor necrosis factor alpha (TNF-alpha). A significant finding was that gonococcal infection (MOI = 1) induced apoptosis in approximately 30% of cells, whereas increasing numbers of bacteria (MOI = 10 to 100) did not induce apoptosis. Apoptosis was observed in only 11% of cells with associated bacteria, whereas >84% of cells with no adherent bacteria were apoptotic. TNF-alpha was a key contributor to apoptosis, since (i) culture supernatants from cells infected with gonococci (MOI = 1) induced apoptosis in na?ve cultures, suggesting that a soluble factor was responsible; (ii) gonococcal infection-induced apoptosis was inhibited with anti-TNF-alpha antibodies; and (iii) the addition of exogenous TNF-alpha induced apoptosis, which was inhibited by the presence of increasing numbers of bacteria (MOI = 10 to 100). These data suggest that TNF-alpha-mediated apoptosis of FT epithelial cells is likely a primary host defense mechanism to prevent pathogen colonization. However, epithelial cell-associated gonococci have evolved a mechanism to protect the cells from undergoing TNF-alpha-mediated apoptosis, and this modulation of the host innate response may contribute to establishment of infection. Understanding the antiapoptotic mechanisms used by Neisseria gonorrhoeae will inform the pathogenesis of salpingitis and could suggest new intervention strategies for prevention and treatment of the disease.     

Premenstrual changes: patterns and correlates of daily ratings

Daily ratings of 20 measures of mood, behavior, and physical condition made by 64 women for one menstrual cycle were analysed to determine patterns of covariance between the pre- and postmenstrual periods. Five discriminantly different dimensions of premenstrual change were identified. They were found to be differentially related to a lifetime diagnosis of affective disorder. These results, and others, support the recommendation that research should be focused upon diversified premenstrual changes rather than a single premenstrual syndrome.     

Global gene expression and the role of sigma factors in Neisseria gonorrhoeae in interactions with epithelial cells

Like many bacterial pathogens, Neisseria gonorrhoeae must adapt to environmental changes in order to successfully colonize and proliferate in a new host. Modulation of gene expression in response to environmental signals is an efficient mechanism used by bacteria to achieve this goal. Using DNA microarrays and a tissue culture model for gonococcal infection, we examined global changes in gene expression in N. gonorrhoeae in response to adherence to host cells. Among those genes induced upon adherence to human epithelial cells in culture was rpoH, which encodes a homolog of the heat shock sigma factor, sigma(32) (RpoH), as well as genes of the RpoH regulon, groEL and groES. Attempts to construct an rpoH null mutant in N. gonorrhoeae were unsuccessful, suggesting that RpoH is essential for viability of N. gonorrhoeae. The extracytoplasmic sigma factor, RpoE (sigma(E)), while known to regulate rpoH in other bacteria, was found not to be necessary for the up-regulation of rpoH in gonococci upon adherence to host cells. To examine the role of RpoH in host cell interactions, an N. gonorrhoeae strain conditionally expressing rpoH was constructed. The results of our experiments showed that while induction of rpoH expression is not necessary for adherence of gonococci to epithelial cells, it is important for the subsequent invasion step, as gonococci depleted for rpoH invade cells two- to threefold less efficiently than a wild-type strain. Taken together, these results indicate that sigma(32), but not sigma(E), is important for the response of gonococci in the initial steps of an infection.     

Vitronectin mediates internalization of Neisseria gonorrhoeae by Chinese hamster ovary cells.

Gonococci producing a distinct opacity protein (OpaA in strain MS11) adhere to and are efficiently internalized by cultured epithelial cells such as the Chang conjunctiva cell line. Both adherence and uptake require interactions between OpaA and heparan sulfate proteoglycans on the mammalian cell surface. Chinese hamster ovary (CHO) cells also support adherence of gonococci through interactions of OpaA with cell surface heparan sulfate proteoglycans. However, despite this similarity in the requirements for adherence, CHO cells are not capable of internalizing gonococci. In this report, we characterized this apparent deficiency and identified a factor in fetal calf serum (FCS) which is capable of mediating uptake of gonococci by CHO cells. In the absence of FCS, OpaA+ gonococci adhered to but were not internalized by CHO cells, whereas in the presence of up to 15% FCS, the bacteria were efficiently internalized by the cells. Preincubation of bacteria, but not cells, with FCS also stimulated internalization, suggesting that a factor present in FCS was binding to the surface of gonococci and subsequently stimulating entry. Using a combination of chromatographic purification procedures, we identified the adhesive glycoprotein vitronectin as the serum factor which mediates the internalization of gonococci by CHO cells. Vitronectin-depleted serum did not support gonococcal entry, and this deficiency was restored by the addition of purified vitronectin. Further experiments using a set of gonococcal recombinants, each expressing a single member of the family of Opa outer membrane proteins, demonstrated that vitronectin bound to the surface of OpaA-producing gonococci only and that the vitronectin-mediated uptake by the CHO cells was limited to this bacterial phenotype. To our knowledge, our data are the first example that vitronectin can serve as a molecule that drives bacterial entry into epithelial cells.