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Biomedical subjects

K Nomoto

Publications and source records attributed to K Nomoto.

At least 37 records · Page 2Linked to original sources

Identification of nonsynonymous polymorphisms in the superantigen-coding region of IDDMK1,2 22 and a pilot study on the association between IDDMK1,2 22 and type 1 diabetes.

To investigate the possible involvement of IDDMK1,2 22/HERV-K18 in childhood type I diabetes mellitus, we identified two nonsynonymous A/G polymorphisms in the superantigen-coding region of IDDMK1,2 22 at the 290- and 461-nucleotide (nt) positions from the initial methionine codon and compared their frequencies in 74 Japanese patients with type 1 diabetes and in 54 nondiabetic controls. Although the G substitution was observed more frequently at either site in the patients than it was in the controls (7% vs. 4% at 290 nt, and 29% vs. 20% at 461 nt), the differences were not statistically significant. A weak significance of difference in the frequency of 461G was obtained only in an early-onset group of patients manifesting the disease at 5 years of age or less (n = 24) when compared with controls (38% vs. 20%; P = 0.03). However, in addition to the common absence of a particular allele among the expected four alleles, remarkable differences in allele frequencies were present between Japanese and European populations. This first trial investigating the association of IDDMK1,12 22 with type 1 diabetes presents intriguing suggestions for the role of this region in the etiology of autoimmune and infectious diseases.

Age of Onset↗

A technique of cervical aortic graft transplantation in mice.

A new method of mouse aortic graft transplantation into carotid artery was developed with cuff technique. By harvesting the descending aorta of the donor using a small Teflon cuff (external diameter 0.6 mm, internal diameter 0.4 mm) and super fine-tip forceps, and modifying the method of mouse heterotopic heart transplantation with cuff technique, donor descending aortic allografts could be interposed in the common carotid artery of recipient mice. Histological analysis demonstrated neither evidence of tissue damage nor intimal thickening in isograft implanted over 100 days. We strongly recommend that this new model of aortic transplantation in mice is a simple and useful technique for vascular transplantation research.

Animals↗

Suppression of allergic reactions by royal jelly in association with the restoration of macrophage function and the improvement of Th1/Th2 cell responses.

We studied the immunomodulatory effects of royal jelly (RJ), the principal food source of the queen honeybee. In this study, suppression of allergic reactions by RJ was investigated in DNP-KLH immunized mice (DNP-KLH mice). Oral administration of RJ (1 g/kg) to DNP-KLH mice significantly decreased the serum levels of antigen-specific Ig E and significantly inhibited DNP-KLH mediated-histamine release from mast cells, resulting in the suppression of immediate hypersensitivity reactions of ear skin. In DNP-KLH mice, IFN-gamma (Th1 cytokine) production from CD4+ T cells was suppressed and IL-4 (Th2 cytokine) production from CD4+ T cells was increased as compared to normal mice. On the other hand, RJ improved the balance of Th1/Th2 cell responses from Th2-dominant to Th1-dominant. RJ significantly increased GSH levels in macrophages from DNP-KLH mice. In addition, the administration of RJ to DNP-KLH mice increased IL-12 p40 mRNA expression and NO production, and decreased PG E2 production from macrophages as compared to untreated DNP-KLH mice. These results suggested that RJ suppressed antigen-specific Ig E production and histamine release from mast cells in association with the restoration of macrophage function and improvement of Th1/Th2 cell responses in DNP-KLH mice.

Adjuvants, Immunologic↗

Development of the susceptibility to oral tolerance induction in infant mice administered a herbal drug, Hochu-ekki-to (Bu-Zhong-Yi-Qi-Tang).

The susceptibility to oral tolerance in post-neonatal infant mice and the effect of a herbal drug, Hochu-ekki-to (HOT), on the susceptibility were investigated. To induce oral tolerance induction, infant and adult mice at 4 and 8 weeks of age, respectively, were orally administered a single high dose of OVA before an intraperitoneal immunization with OVA adsorbed on aluminum hydroxide. HOT (1000 mg/kg) was administered orally for 7 days before the induction. HOT significantly decreased the serum levels of OVA-specific IgE and IgG1 and the antigen-specific proliferation of spleen cells in infant mice, both of which were greatly enhanced compared to in adult mice. HOT increased the number of both CD4+ T cells and antigen-presenting cells expressing MHC class II as well as costimulatory molecules (CD40, CD80 and/or CD86) in the Peyer's patch (PP) of infant mice, which had fewer cells than adult mice. In the PP, moreover, HOT augmented the IL-12p40 mRNA expression and spontaneous or CD40-stimulated IL-12 production, and increased the number of CD4+ cells expressing CD40 ligand, which is up regulated by IL-12. These results suggest that HOT increases the number and improves the function of PP cells that are fully susceptible to the induction of oral tolerance.

Adjuvants, Immunologic↗

Immunomodulating effect of a traditional Japanese medicine, hachimi-jio-gan (ba-wei-di-huang-wan), on Th1 predominance in autoimmune MRL/MP-lpr/lpr mice.

Hachimi-jio-gan (Ba-Wei-Di-Huang-Wan, HMG), a traditional Japanese herbal medicine, has been used for disorders accompanying aging. Oral administration of HMG from 8 to 16 weeks of age to MRL/lpr mice as a lupus-like autoimmune model ameliorated significantly some nephritis parameters, proteinuria and immune complex deposition in the kidney. Further, HMG reduced significantly the degree of lymphadenopathy and the serum level of immunoglobulin (Ig) G2a anti-dsDNA specific auto-antibody, even at 12 weeks of age. Simultaneously, interferon (IFN)-gamma production from anti-CD3 stimulated B220- T cells was suppressed by HMG, whereas interleukin (IL)-4 production was promoted. Examination of cytokine mRNA expressions in CD4 positive cells showed clearly that T cell differentiation was shifted from T helper (Th)1 to Th2 predominance by HMG. Furthermore, we demonstrated that HMG suppressed IL-12 mRNA expression in spleen cells which is a marker of Th1 predominance in MRL/lpr mice. These results suggested that HMG modulated an imbalance toward Th1 predominance in MRL/lpr mice through inhibition of IL-12 production and ameliorated autoimmune disorders.

Adjuvants, Immunologic↗

Protective effect of a traditional Japanese medicine Hochu-ekki-to (Chinese name: Bu-zhong-yi-qi-tang), on the susceptibility against Listeria monocytogenes in infant mice.

In this study, the effect of traditional Japanese (Chinese) medicine, Hochu-ekki-to, HOT (Chinese name: Bu-zhong-yi-qi-tang), on the susceptibility against Listeria monocytogenes in postneonatal infant mice was examined. Numbers of bacteria in infant mice (infected at 4 weeks of age) were significantly higher than those in adult mice (infected at 8 weeks of age) on day 3 (non-specific resistance phase) and day 5 (specific resistance phase) after infection. Oral administration of 1,000 mg/kg of HOT for 7 days to infant mice reduced bacterial numbers in the liver and spleen at 5 days after the infection. The amount of IFN-gamma and the number of IFN-gamma-producing CD4+ T cells were lower in infant mice than adult mice but those in infant mice enhanced by HOT treatment. HOT also enhanced the antigen-presenting function along with the expression of MHC class II in infant macrophages induced by heat-killed L. monocytogenes. Further, HOT enhanced the IFN-gamma production from infant CD4+ T cells independent of the deficiency in the antigen-presenting function. These findings suggest that HOT induced simultaneously functional maturation of both infant antigen-presenting cells and T cells, and consequently developed an anti-listerial Th1 response.

Animals↗

Functional properties of the rat phosphatase 1alpha promoter.

The aim of this study was to investigate the functional properties of the promoter of the protein phosphatase 1alpha catalytic subunit. Luciferase plasmids with different fragments of the rat catalytic subunit of the protein phosphatase 1alpha promoter ranging from -3.7 kbp to -59 bp were transiently transfected into cells by the calcium-phosphate precipitation method. The promoter activity was determined in the absence and presence of inotropic agents which influencing the cAMP-depending pathway. The basal transcriptional activity decreased at fragment -124 bp and shorter fragments. To identify regions of regulatory importance we investigated the cAMP-dependent influence on the transcriptional activity. Stimulation of the complete promoter region with forskolin (1-100 microM) for 6 h led to a concentration-dependent decrease of transcriptional activity. Moreover, regions shorter than 3.7 kbp were inhibited by forskolin (10 microM). Short time stimulation (10 min) with forskolin (10 microM) increased the transcriptional activity of only the 3.7 kbp fragment. The effects were antagonized by Rp-cAMPS, a specific antagonist of protein kinase A, indicating cAMP-dependent effects. The results provide evidence for cAMP-dependent regulation of the protein phosphatase 1alpha promotor.

Animals↗

Persistent infection with Listeria monocytogenes in the kidney induces anti-inflammatory invariant fetal-type gammadelta T cells.

After intraperitoneal inoculation with Listeria monocytogenes, gammadelta T cells appear in the peritoneal cavity preceding the appearance of alphabeta T cells. Such gammadelta T cells predominantly express T-cell receptor (TCR)Vgamma1/Vdelta6, develop through an extrathymic pathway, and contribute to host defence against the bacteria. We have observed a gradual increase in gammadelta T cells in kidneys of mice after intrarenal inoculation with L. monocytogenes, which resulted in an unusually long-lasting local infection. In this study, we examined the characteristics and the roles of the gammadelta T cells induced in this model. It was found that these gammadelta T cells predominantly expressed TCRVgamma6/Vdelta1 with canonical junctional sequences identical to those expressed on fetal thymocytes. Although depletion of such gammadelta T cells in vivo did not affect the number of bacteria, it resulted in histologically exacerbated inflammation in the kidneys. These results indicate that a persistent infection with L. monocytogenes in kidneys induces a different kind of gammadelta T cell from that induced after intraperitoneal infection. The former expresses invariant fetal-type Vgamma6/Vdelta1+TCR and plays a regulatory role in resolution of inflammation.

Animals↗

Evidence of the extrathymic development of tyrosinase-related protein-2-recognizing CD8+ T cells with low avidity.

The majority of the human tumour-associated antigens characterized to date are derived from non-mutated self-proteins. However, nothing is known about the development of autoreactive and tumour-associated antigen-recognizing T cells. Tyrosinase-related protein (TRP)-2 is a non-mutated melanocyte differentiation antigen and TRP-2-recognizing CD8+ T cells are known to show responses to melanoma both in humans and mice. In addition, TRP-2-reactive T cells with low avidity have been suggested to be readily induced from the spleen cells of naïve mice. On the other hand, recent reports suggest that self antigen-reactive CD8+ T cells can be positively selected in the periphery. In this study, we tested the possibility that TRP-2-reactive CD8+ T cells in naïve mice could develop via the extrathymic pathway. As a consequence, TRP-2-reactive CD8+ T cell precursors in naïve C57BL/6 mice were suggested to express both interleukin-2 (IL-2) receptor beta chain (IL-2Rbeta) and CD44 molecules, in a manner similar to that of extrathymically developed T cells. Furthermore, IL-2Rbeta+ CD44+ CD8+ T cells were detected in the adult thymectomized and bone marrow-reconstituted mice, and functional TRP-2-reactive T cells were generated from their spleen cells. Overall, these results suggest that low avidity CD8+ T cells recognizing TRP-2 can be developed extrathymically.

Animals↗

Increased resistance of mice to Salmonella enterica serovar Typhimurium infection by synbiotic administration of Bifidobacteria and transgalactosylated oligosaccharides.

AIMS: The anti-infectious activity of Bifidobacteria in combination with transgalactosylated oligosaccharides (TOS) against Salmonella enterica serovar Typhimurium LT-2 in an opportunistic antibiotic-induced murine infection model in mice was examined. METHODS AND RESULTS: B. breve (strain Yakult) with natural resistance to streptomycin sulphate (SM, MIC: > 4 mg ml(-1)), when given daily at a dose of 108 cfu/mouse orally under SM treatment was constantly excreted at 10(10) cfu g(-1) faeces so long as SM was administered, even at 2 weeks after discontinuing administration of B. breve. Explosive intestinal growth and subsequent extra-intestinal translocation of orally infected LT-2 under SM treatment were inhibited by B. breve colonization, and this anti-infectious activity was strengthened by synbiotic administration of TOS with B. breve. Comparison of anti-Salmonella activity among several Bifidobacterium strains with natural resistance to SM revealed that strains such as B. bifidum ATCC 15696 and B. catenulatum ATCC 27539T conferred no activity, even when they reached high population levels similar those of effective strains such as strain Yakult and B. pseudocatenulatum DSM 20439. Both the increase in the concentration of organic acids and the lowered pH in the intestine due to bifidobacterial colonization correlated with the anti-infectious activity. Moreover, the crude cecal extract of B. breve-colonized mice exerted growth-inhibitory activity against LT-2 in vitro, whereas that of the ineffective B. bifidum-colonized cecum showed much lower activity. CONCLUSIONS: Intestinal colonization by bifidobacteria given exogenously together with TOS during antibiotic treatment prevents the antibiotic-induced disruption of colonization resistance to oral infection with S. enterica serovar Typhimurium, and the metabolic activity needed to produce organic acids and lower the intestinal pH is important in the anti-infectious activity of synbiotics against enteric infection with Salmonella. SIGNIFICANCE AND IMPACT OF THE STUDY: These results indicate that certain bifidobacteria together with prebiotics may be used for the prophylaxis against opportunistic intestinal infections with antibiotic-resistant pathogens.

Animals↗

Changes in the caudate lobe that is transplanted with extended left lobe liver graft from living donors.

BACKGROUND: Caudate lobe transplantation with an extended left lobe graft is an innovative and promising method for increasing the graft volume in living donor liver transplantation. However, little is known about the fate of the caudate lobe after transplantation. METHODS: Eight extended left lobe grafts with the caudate lobe were included in this study. No attempt was made to reconstruct the short hepatic veins. On the basis of the computed tomography scans that were obtained before the operation and 1 month after the transplantation, the increase in the graft volume by the addition of the caudate lobe and the changes in the transplanted caudate lobe were evaluated. RESULTS: The addition of the caudate lobe increased the graft volume by 25 +/- 2 g, corresponding to a 2% increase in graft volume/standard liver volume ratio. One month after the transplantation, the caudate lobe volume increased in all patients but 1. The regeneration rate of the caudate lobe and other segments (segments II-IV) 1 month after transplantation was 62% +/- 24% (24 +/- 4 mL- 37 +/- 4 mL) and 152% +/- 35% (374 +/- 45 mL-930 +/- 65 mL), respectively (P <.01). CONCLUSIONS: This technique affords a modest increase in liver volume with living donor left liver procurement.

Humans↗

Enhancement of natural killer cytotoxicity delayed murine carcinogenesis by a probiotic microorganism.

Regulation of innate immunity may be an effective means of cancer control. Delaying cancer onset is regarded as an important mode of action in cancer prevention. We have been investigating the chemopreventive mechanisms of Lactobacillus casei Shirota (LcS), a probiotic strain. In this study, we evaluated the effect of LcS on tumor onset and the involvement of natural killer (NK) cells using a 3-methylcholanthrene-induced carcinogenesis model. C3H/HeN mice were divided into three groups, according to treatment: vehicle-treated, treated with vehicle only; control, 3-methylcholanthrene treated; LcS, 3-methylcholanthrene and LcS treated. 3-Methylcholanthrene was injected intradermally at 7 weeks of age. LcS was mixed into the diet (0.05%, w/w), which the mice were fed from the day of 3-methylcholanthrene injection onward. Tumor incidence was observed weekly. Profiles of splenic NK cells, in vitro cytotoxicity and the proportion, in the early stage of carcinogenesis were analyzed at 5 weeks after the injection. The tumor suppressive effect of LcS was also evaluated in a beige mouse model that is genetically deficient in NK cells. LcS delayed tumor onset and reduced tumor incidence in the results with C3H/HeN mice (P< 0.05). More specifically, tumor incidence in the control group was 33% at 6 weeks after the injection and 83% at 11 weeks as opposed to 0 and 42%, respectively, in the LcS group. NK cell cytotoxicity was significantly higher than in the control group, and the number of NK cells also increased in the LcS group of C3H/HeN mice. However, LcS failed to suppress tumorigenesis in the beige mouse. These findings suggest that enhancement of the cytotoxicity of NK cells by LcS delays tumor onset.

Animals↗

Caspase-independent cell death and mitochondrial disruptions observed in the Apaf1-deficient cells.

Apaf1 is a critical molecule in the mitochondria-dependent apoptotic pathway. Here we show that Apaf1-deficient embryonic fibroblasts died at a later phase of apoptotic induction, although these cells were resistant to various apoptotic stimulants at an early phase. Neither caspase 3 activation nor nuclear condensation was observed during this cell death of Apaf1-deficient cells. Electron microscopic examination revealed that death in response to apoptotic stimulation resembled necrosis in that nuclei were round and swollen with low electron density. Necrosis-like cell death was also observed in wild-type cells treated with z-VAD-fmk. Mitochondria were not only morphologically abnormal but functionally affected, since mitochondrial transmembrane potential (DeltaPsim) was lost even in cells with intact plasma membrane integrity. These mitochondrial alterations were also observed in the wild-type cells dying of apoptosis. Combined, these data suggest that cells without caspase activation, such as Apaf1-deficient cells or cells treated with caspase inhibitors, die of necrosis-like cell death with mitochondrial damage in response to "apoptotic stimulation."

Amino Acid Chloromethyl Ketones↗

Successful induction of tumor-specific cytotoxic T lymphocytes from patients with non-small cell lung cancer using CD80-transfected autologous tumor cells.

Cytotoxic T lymphocytes (CTL) against human lung cancer cells are difficult to induce by a conventional method using tumor cell stimulation probably due to an insufficiency of tumor antigens (TA) or costimulatory molecules such as CD80. We, therefore, investigated the potential of CD80-transfected tumor cells as stimulators of the in vitro induction of autologous tumor-specific CTL from regional lymph node lymphocytes in patients with lung cancer. Five non-small cell lung cancer cell lines (two adenocarcinomas, 1 squamous cell carcinoma, 1 large cell carcinoma and 1 adenosquamous cell carcinoma) were established from surgical specimens and were successfully transduced with a plasmid constructed with expression vector pBj and human CD80 cDNA, using a lipofection method. CD80-transfected tumor cells (CD80-AT) significantly augmented the proliferation of autologous lymphocytes from all cases as compared with non-transfected tumor cells (AT). AT-stimulated lymphocytes from 4 out of 5 cases did not show any cytotoxicity against AT; however, lymphocytes stimulated with CD80-AT exhibited substantial cytotoxicity against parental AT in all 5 cases tested. AT-stimulated lymphocytes derived from only one out of 5 cases showed major histocompatibility complex (MHC)-class I-restricted cytokine production in response to AT, while the MHC-class I-restricted responses were found in CD80-AT-stimulated lymphocytes from 4 out of 5 cases. These results indicate that CD80 on tumor cells could be a beneficial costimulatory molecule to elicit CTL against lung cancer, and also show that TA recognized by CTL was frequently expressed on lung cancer cells.

Adenocarcinoma↗

Antimicrobial activity of intraurethrally administered probiotic Lactobacillus casei in a murine model of Escherichia coli urinary tract infection.

The antimicrobial activity of the intraurethrally administered probiotic Lactobacillus casei strain Shirota against Escherichia coli in a murine urinary tract infection (UTI) model was examined. UTI was induced by intraurethral administration of Escherichia coli strain HU-1 (a clinical isolate from a UTI patient, positive for type 1 and P fimbriae), at a dose of 1 x 10(6) to 2 x 10(6) CFU in 20 microl of saline, into a C3H/HeN mouse bladder which had been traumatized with 0.1 N HCl followed immediately by neutralization with 0.1 N NaOH 24 h before the challenge infection. Chronic infection with the pathogen at 10(6) CFU in the urinary tract (bladder and kidneys) was maintained for more than 3 weeks after the challenge, and the number of polymorphonuclear leukocytes and myeloperoxidase activity in the urine were markedly elevated during the infection period. A single administration of L. casei Shirota at a dose of 10(8) CFU 24 h before the challenge infection dramatically inhibited E. coli growth and inflammatory responses in the urinary tract. Multiple daily treatments with L. casei Shirota during the postinfection period also showed antimicrobial activity in this UTI model. A heat-killed preparation of L. casei Shirota exerted significant antimicrobial effects not only with a single pretreatment (100 microg/mouse) but also with multiple daily treatments during the postinfection period. The other Lactobacillus strains tested, i.e., L. fermentum ATCC 14931(T), L. jensenii ATCC 25258(T), L. plantarum ATCC 14917(T), and L. reuteri JCM 1112(T), had no significant antimicrobial activity. Taken together, these results suggest that the probiotic L. casei strain Shirota is a potent therapeutic agent for UTI.

Administration, Intravesical↗

Protective effect of Lactobacillus casei strain Shirota on Shiga toxin-producing Escherichia coli O157:H7 infection in infant rabbits.

We examined colonization patterns of Shiga toxin-producing Escherichia coli (STEC), concentrations of Shiga toxins (Stxs) and specific immunoglobulin A (lgA) against Stxs and STEC bacterial cell surface antigen in various portions of the gastrointestinal tract in an infant rabbit infection model. After inoculation of 3-day-old infant rabbits with STEC strain 89020087 at low doses (approximately 10(3) CFU/body), numbers of colonizing STEC bacteria and concentrations of Stxs in the intestine increased dramatically and the animals developed diarrhea within a couple of days after infection. Daily administration of Lactobacillus casei from the day of birth dramatically decreased the severity of diarrhea and lowered STEC colonization levels in the gastrointestinal tract 100-fold day 7 after infection. Both Stx1 and Stx2 concentrations in the intestines and histological damage to the intestinal mucus induced by STEC infection were decreased by the administration of L. casei. Examination of the concentrations of volatile fatty acids and pH of the intestinal contents revealed that the protective effect of L. casei administration against STEC infection was not due to fermented products such as lactic acid in the gastrointestinal tract. Administration of L. casei increased levels of lgAs against Stx1, Stx2, and formalin-killed STEC cells in the colon approximately two-, four-, and threefold, respectively, compared with those of the untreated controls by day 7 after infection. These results suggest that administration of L. casei strain Shirota enhances the local immune responses to STEC cells and Stxs and leads to elimination of STEC and thus decreases Stx concentrations in the intestines.

Animals↗

Heterogeneity of DNA methylation status analyzed by bisulfite-PCR-SSCP and correlation with clinico-pathological characteristics in colorectal cancer.

Aberrant DNA methylation has been identified as an important mechanism for inactivation of tumor suppressor genes and mismatch repair genes during carcinogenesis. We used bisulfite treatment and the PCR-single strand conformation polymorphism (SSCP) (BiPS) technique to analyze methylation status of the promoter regions of the hMLH1, p16, and HIC1 genes in several cancer cell lines and colorectal cancer tissues. The methylation of the hMLH1, p16 and HIC1 genes was observed in 2, 8, and 13 of 13 cancer cell lines, respectively. The SSCP for p16 and HIC1 in each of the methylation-positive cell lines were similar, indicating relative homogeneity of methylation status and complete methylation in the cell lines. Methylation was observed in 8, 5, and 21 of 25 colorectal cancer tissues for the hMLH1, p16, and HIC1 genes, respectively. The methylated bands revealed by BiPS analysis of the hMLH1 gene were homogeneous, whereas those of the p16 and HIC1 genes were different in each case. The methylation of the promoter region of the HIC1 gene in colorectal cancer was observed most frequently and could serve as a sensitive marker for colorectal cancer. Methylation status of the hMLH1 and p16 gene promoters was correlated with microsatellite instability status, tumor location, and differentiation but not with K-ras mutation or allelic loss of p53.

Adaptor Proteins, Signal Transducing↗

Lactobacillus casei acquires the binding activity to fibronectin by the expression of the fibronectin binding domain of Streptococcus pyogenes on the cell surface.

Fibronectin binding domain was expressed on the cell surface of Lactobacillus casei strain Shirota which hardly adheres to fibronectin. DNA for the fibronectin binding domain of the sfbl gene, which encodes a fibronectin binding protein of Streptococcus pyogenes ATCC 21059, was amplified with polymerase chain reaction, cloned into a surface display vector pSAK332, and introduced into L. casei. The fibronectin binding domain was expressed as a fusion protein consisting of staphylokinase of Staphylococcus aureus and the anchor sequence of cell wall-associated 763 proteinase of Lactococcus lactis NCDO 763. The fibronectin binding ability of the resulting L. casei was confirmed with Western blot analysis, immunoelectron microscopic analysis, and adherence to fibroblast cells. These results indicate that L. casei has acquired a new phenotype to bind fibronectin upon the expression of the fibronectin binding domain on the cell surface. This L. casei also shows binding affinity to fibrinogen, indicating that fibronectin binding domain is involved in the binding to fibrinogen as well.

Adhesins, Bacterial↗