Itzhak Ofek | Tel Aviv University (original) (raw)

Papers by Itzhak Ofek

Research paper thumbnail of Cross-Protection among Serotypes of Group A Streptococci

Journal of Infectious Diseases, 1972

Page 1. THE JOURNAL OF INFECTIOUS DISEASES • VOL. 125 NO.4· APRIL 1972 © 1972 by the University o... more Page 1. THE JOURNAL OF INFECTIOUS DISEASES • VOL. 125 NO.4· APRIL 1972 © 1972 by the University of Chicago. All rights reserved. ' Cross-Protection among Serotypes of Group A Streptococci Sonia Bergner-Rabinowitz, Itzhak Ofek, and Max D. Moody ...

Research paper thumbnail of Epidemic Glomerulonephritis in Israel

Journal of Infectious Diseases, 1971

Page 1. THE JOURNAL OF INFECTIOUS DISEASES • VOL. 124, NO.2· AUGUST 1971 © 1971 by the University... more Page 1. THE JOURNAL OF INFECTIOUS DISEASES • VOL. 124, NO.2· AUGUST 1971 © 1971 by the University of Chicago. All rights reserved. Epidemic Glomerulonephritis in Israel Eli E. Lasch, Victoria Frankel, Peter A. Vardy ...

Research paper thumbnail of Type-Specific Streptococcal Antibodies in Pyodermal Nephritis

Journal of Infectious Diseases, 1971

... types. Table 5. Bactericidal and opsonophagocytosis tests against type 55 in 54 sera. Opsono-... more ... types. Table 5. Bactericidal and opsonophagocytosis tests against type 55 in 54 sera. Opsono-Bacteri-phago-No. of Months from eidal eytic sera onset test* testt Total *Bactericidal indices of 20 or more are considered positive. ...

Research paper thumbnail of Studies on Opacity Factor Production by Pharyngeal Isolates of Group A Streptococci

Journal of Infectious Diseases, 1976

Production of opacity factor (OF) by 841 pharyngeal isolates of group A streptococci from schoolc... more Production of opacity factor (OF) by 841 pharyngeal isolates of group A streptococci from schoolchildren in Casper, Wyoming was studied along with T- and M-typing of the streptococcal strains. The majority (89%) of M-typable strains were OF-negative in contrast to M-nontypable isolates, 45% of which were OF-positive. There was no apparent relation between the production of OF by the M-nontypable isolates and the type of infection (symptomatic vs. asymptomatic), degree of positivity of initial culture, antistreptolysin O response, and failure to eradicate the organisms by treatment with antibiotics. However, seasonal shifts in the prevalence of M-nontypable OF-positive strains provided evidence of change in streptococcal ecology, such a shift would not have been detected by T-typing alone. Thus, OF production is an additional epidemiologic marker that is helpful in differentiating M-nontypable group A strains that bear common T-antigens.

Research paper thumbnail of Bacterial Adhesion to Cells and Tissues

Principles of adhesion. Methods, models, data analyses. Bacterial cell surfaces: characteristics ... more Principles of adhesion. Methods, models, data analyses. Bacterial cell surfaces: characteristics of bacterial adhesion. The animal cell membranes and surfaces: substratum for bacterial adhesion. Lectins as adhesions. Lectinophagocytosis. The adhesion of pyogenic cocci. Oral adhesion. Molecular biology. Bacterial adhesion in the natural environment. Common themes in adhesion.

Research paper thumbnail of Anti-oral-microbial adhesion fraction derived from vaccinium

Research paper thumbnail of Interactions of Microbial Glycoconjugates with Collectins

Glycomicrobiology

The surfactant-associated proteins, SP-A and SP-D, are members of a family of collagenous host de... more The surfactant-associated proteins, SP-A and SP-D, are members of a family of collagenous host defense lectins. There is increasing evidence that these pulmonary epithelial-derived proteins are important components of the innate immune response to microbial challenge. The lung collectins bind to glycoconjugates expressed by a wide variety of microorganisms in vitro. Such binding may cause microbial aggregation with resulting enhancement

Research paper thumbnail of Adhesion and Colonization

Molecular Medical Microbiology, 2015

The binding of bacterial adhesins to host receptors is a dynamic process occurring in several ste... more The binding of bacterial adhesins to host receptors is a dynamic process occurring in several steps, which involve complex bacteria–host cell interaction. Initial weak physical interactions lead to more specific adhesion mechanisms that may be shared by several organisms, but eventually to species-specific adhesins that may elicit both bacterial and host factors leading to host cell damage, induction of inflammation and disease. Species-specific fimbrial adhesins may be viewed as direct mediators of bidirectional signalling between bacteria and host cells. Understanding of this process has been highly informative for the design of novel strategies to modulate these signalling pathways and to curb bacterial infections and their harmful sequelae. Development of mixtures of inhibitors or a polyvalent inhibitor is under investigation, since many infectious agents express multiple specificities. Multiple molecular mechanisms of adhesion are required to initiate infection, and effective anti-adhesion strategies will need to address both bacterial and host site particularities.

Research paper thumbnail of High Molecular Weight Constituents of Cranberry Interfere with Influenza Virus Neuraminidase Activity In Vitro

Research paper thumbnail of Adherence of Escherichia coli to human mucosal cells mediated by mannose receptors

Research paper thumbnail of Collectins and pulmonary innate immunity

Immunological Reviews, 2000

The surfactant-associated proteins SP-A and SP-D are members of a family of host defense lectins,... more The surfactant-associated proteins SP-A and SP-D are members of a family of host defense lectins, designated collectins. There is increasing evidence that these pulmonary, epithelial-derived proteins are important components of the innate immune response to microbial challenge and participate in other aspects of immune and inflammatory regulation within the lung. Both proteins bind to glycoconjugates and/or lipid moieties expressed by a wide variety of microorganisms, and to certain organic particles, such as pollens. SP-A and SP-D have the capacity to modulate leukocyte function and, in some circumstances; to opsonize and enhance the killing of microorganisms. The biologic activity of cell wall components, such as Gram-negative bacterial polysaccharides, or viral glycoproteins, such as the hemagglutinin of influenza viruses, may be altered by interactions with collectins. In addition, complementary or cooperative interactions between SP-A, SP-D and other host defense lectins could contribute to the efficiency of this defense system. Collectins could play particularly important roles in settings of inadequate or impaired specific immunity, and acquired alterations in the levels of active collectins within the airspaces and distal airways may increase susceptibility to infection.

Research paper thumbnail of Potential Oral Health Benefits of Cranberry

Critical Reviews in Food Science and Nutrition, 2008

Research paper thumbnail of Inhibitory Effect of a High-Molecular-Weight Constituent of Cranberry on Adhesion of Oral Bacteria

Critical Reviews in Food Science and Nutrition, 2002

A high-molecular-weight nondialysable material (NDM) isolated from cranberry juice at a concentra... more A high-molecular-weight nondialysable material (NDM) isolated from cranberry juice at a concentration of 0.6 to 2.5 mg/ml dissociated coaggregates formed by many intergeneric oral bacteria. A lower concentration of NDM was required to inhibit formation of such coaggregates. NDM acted preferentially on pairs of oral bacteria in which one or both members are Gram-negative anaerobes. The high-molecular-weight material from blueberry also inhibited the coaggregation, although its activity was weaker, whereas such materials obtained from other fruits were inactive. Saliva did not interfere with the ability of NDM to inhibit coaggregation. A preliminary clinical trial showed that NDM reduces S. mutans counts in saliva. The antiadhesion activity of cranberry juice has a potential for altering the oral microbial flora resulting in improved oral hygiene.

Research paper thumbnail of Identification of type specific streptococcal antibodies by in vitro phagocytosis

Israel journal of medical sciences

Research paper thumbnail of Fragment of Streptococcal M Protein*

Human immune response to immunization with a structurally defined polypeptide fragment of strepto... more Human immune response to immunization with a structurally defined polypeptide fragment of streptococcal M protein

Research paper thumbnail of Adherence pharyngeal and skin strains of group A streptococci to human skin and oral epithelial cells

Infection and Immunity, 1977

Group A streptococci isolated from skin adhere in greater numbers to human skin epithelial cells ... more Group A streptococci isolated from skin adhere in greater numbers to human skin epithelial cells than to cells obtained from buccal mucosa whereas streptococci isolated from a throat tend to adhere in greater numbers to buccal epithelial cells than to skin epithelial cells in vitro. M protein-producing strains of group A streptococci did not adhere in significantly greater numbers than M-negative strains. Lipoteichoic acid inhibited binding of streptococci to skin epithelial cells as well as was previously shown for oral epithelial cells. Our results suggest that lipoteichoic acid is more centrally involved than M protein in binding streptococci to skin and mucosal surfaces.

Research paper thumbnail of Carbohydrate-binding sites of the mannose-specific fimbrial lectins of enterobacteria

Infection and Immunity, 1984

The combining sites of type 1 fimbrial lectins of various species of enterobacteria were studied ... more The combining sites of type 1 fimbrial lectins of various species of enterobacteria were studied by measuring the inhibitory activity of linear and branched oligosaccharides and several glycosides of D-mannose on the agglutination of yeast cells by the organisms. The results showed that all five strains of Escherichia coli tested possessed an elongated combining site best fitting a trisaccharide and including a hydrophobic region. Similar results were obtained with Klebsiella pneumoniae. Within the Salmonella genus, the combining sites of the six species tested were similar, but all differed significantly from those of the E. coli strains. The combining sites of Enterobacter cloacae and Enterobacter agglomerans were different from each other and from those of Salmonella sp. and E. coli. The results suggest that although classified under the general term "mannose-specific," bacterial lectins in the form of type 1 fimbriae on different genera exhibit differences in sugar spe...

Research paper thumbnail of Identification of the leukocyte adhesion molecules CD11 and CD18 as receptors for type 1-fimbriated (mannose-specific) Escherichia coli

Infection and Immunity, 1991

Attachment of bacteria to phagocytic cells may be mediated by lectin-carbohydrate interactions, r... more Attachment of bacteria to phagocytic cells may be mediated by lectin-carbohydrate interactions, resulting in lectinophagocytosis. The best-studied system is the interaction of type 1-fimbriated (mannose-specific) Escherichia coli with human phagocytic cells. Here we demonstrate that the leukocyte integrins CD11 and CD18 (CD11/CD18) constitute the major receptors for type 1-fimbriated E. coli. Bacteria were bound in a dose-dependent and saturable manner to CD11/CD18, which was immobilized to microwells, whereas nonfimbriated E. coli cells failed to bind. The binding was efficiently inhibited (82 to 85%) by methyl-alpha-mannoside but not by galactose, and it was reduced by treatment of the immobilized CD11/CD18 with sodium metaperiodate, endoglycosidase H, or a mixture of endoglycosidase F and N-glycosidase. The fimbriated bacteria also bound to CD11a,b,c and CD18 separated by polyacrylamide gel electrophoresis with sodium dodecyl sulfate and blotted onto nitrocellulose paper. This bi...

Research paper thumbnail of Membrane glycoproteins of human polymorphonuclear leukocytes that act as receptors for mannose-specific Escherichia coli

Infection and Immunity, 1987

Type 1 fimbriated (mannose-specific) Escherichia coli cells bind to mannose residues on human pol... more Type 1 fimbriated (mannose-specific) Escherichia coli cells bind to mannose residues on human polymorphonuclear leukocytes (PMN); this leads to phagocytosis of the bacteria. To identify the mannose-containing receptors on the PMN, the cells were surface labeled with 125I and lysed in 0.5% Nonidet P-40, and the lysate was fractionated by affinity chromatography on a column of Sepharose-bound fimbriae. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography of the material eluted from the column with 500 mM methyl-alpha-mannoside revealed two radioactive bands of Mr 70,000 to 80,000 (gp70-80) and 100,000 (gp100). Another weak band of Mr 150,000 (gp150) was observed after prolonged exposure of the gel. Upon blotting of the glycoproteins separated by polyacrylamide gel electrophoresis and overlaying of the blots with concanavalin A, gp150 appeared as the major band. Membrane preparations of the PMN were enriched in gp70-80, gp100, and gp150, in comparis...

Research paper thumbnail of Adherence of Acinetobacter calcoaceticus RAG-1 to human epithelial cells and to hexadecane

Infection and Immunity, 1981

The ability of Acinetobacter calcoaceticus RAG-1 to adhere to human epithelial cells was investig... more The ability of Acinetobacter calcoaceticus RAG-1 to adhere to human epithelial cells was investigated and compared with its ability to adhere to a test hydrocarbon (hexadecane). RAG-1, a microorganism originally isolated for growth on hydrocarbon, adhered to epithelial cells when grown under conditions which promote its adherence to hexadecane; similarly, RAG-1 cells adhered poorly to epithelial cells when grown under conditions which cause the cells to possess low affinity towards hexadecane. A mutant derived from RAG-1, MR-481, deficient in its ability to adhere to hydrocarbon, was similarly unable to adhere to epithelial cells. RAG-1 adherence to epithelial cells was not blocked by a number of sugars tested. Streptococcus pyogenes, whose adherence to epithelial cells has been previously attributed to hydrophobic interactions, was also able to adhere to hexadecane. Results suggest that hydrophobic interactions mediate adherence of the strains studied to both epithelial cells and h...

Research paper thumbnail of Cross-Protection among Serotypes of Group A Streptococci

Journal of Infectious Diseases, 1972

Page 1. THE JOURNAL OF INFECTIOUS DISEASES • VOL. 125 NO.4· APRIL 1972 © 1972 by the University o... more Page 1. THE JOURNAL OF INFECTIOUS DISEASES • VOL. 125 NO.4· APRIL 1972 © 1972 by the University of Chicago. All rights reserved. ' Cross-Protection among Serotypes of Group A Streptococci Sonia Bergner-Rabinowitz, Itzhak Ofek, and Max D. Moody ...

Research paper thumbnail of Epidemic Glomerulonephritis in Israel

Journal of Infectious Diseases, 1971

Page 1. THE JOURNAL OF INFECTIOUS DISEASES • VOL. 124, NO.2· AUGUST 1971 © 1971 by the University... more Page 1. THE JOURNAL OF INFECTIOUS DISEASES • VOL. 124, NO.2· AUGUST 1971 © 1971 by the University of Chicago. All rights reserved. Epidemic Glomerulonephritis in Israel Eli E. Lasch, Victoria Frankel, Peter A. Vardy ...

Research paper thumbnail of Type-Specific Streptococcal Antibodies in Pyodermal Nephritis

Journal of Infectious Diseases, 1971

... types. Table 5. Bactericidal and opsonophagocytosis tests against type 55 in 54 sera. Opsono-... more ... types. Table 5. Bactericidal and opsonophagocytosis tests against type 55 in 54 sera. Opsono-Bacteri-phago-No. of Months from eidal eytic sera onset test* testt Total *Bactericidal indices of 20 or more are considered positive. ...

Research paper thumbnail of Studies on Opacity Factor Production by Pharyngeal Isolates of Group A Streptococci

Journal of Infectious Diseases, 1976

Production of opacity factor (OF) by 841 pharyngeal isolates of group A streptococci from schoolc... more Production of opacity factor (OF) by 841 pharyngeal isolates of group A streptococci from schoolchildren in Casper, Wyoming was studied along with T- and M-typing of the streptococcal strains. The majority (89%) of M-typable strains were OF-negative in contrast to M-nontypable isolates, 45% of which were OF-positive. There was no apparent relation between the production of OF by the M-nontypable isolates and the type of infection (symptomatic vs. asymptomatic), degree of positivity of initial culture, antistreptolysin O response, and failure to eradicate the organisms by treatment with antibiotics. However, seasonal shifts in the prevalence of M-nontypable OF-positive strains provided evidence of change in streptococcal ecology, such a shift would not have been detected by T-typing alone. Thus, OF production is an additional epidemiologic marker that is helpful in differentiating M-nontypable group A strains that bear common T-antigens.

Research paper thumbnail of Bacterial Adhesion to Cells and Tissues

Principles of adhesion. Methods, models, data analyses. Bacterial cell surfaces: characteristics ... more Principles of adhesion. Methods, models, data analyses. Bacterial cell surfaces: characteristics of bacterial adhesion. The animal cell membranes and surfaces: substratum for bacterial adhesion. Lectins as adhesions. Lectinophagocytosis. The adhesion of pyogenic cocci. Oral adhesion. Molecular biology. Bacterial adhesion in the natural environment. Common themes in adhesion.

Research paper thumbnail of Anti-oral-microbial adhesion fraction derived from vaccinium

Research paper thumbnail of Interactions of Microbial Glycoconjugates with Collectins

Glycomicrobiology

The surfactant-associated proteins, SP-A and SP-D, are members of a family of collagenous host de... more The surfactant-associated proteins, SP-A and SP-D, are members of a family of collagenous host defense lectins. There is increasing evidence that these pulmonary epithelial-derived proteins are important components of the innate immune response to microbial challenge. The lung collectins bind to glycoconjugates expressed by a wide variety of microorganisms in vitro. Such binding may cause microbial aggregation with resulting enhancement

Research paper thumbnail of Adhesion and Colonization

Molecular Medical Microbiology, 2015

The binding of bacterial adhesins to host receptors is a dynamic process occurring in several ste... more The binding of bacterial adhesins to host receptors is a dynamic process occurring in several steps, which involve complex bacteria–host cell interaction. Initial weak physical interactions lead to more specific adhesion mechanisms that may be shared by several organisms, but eventually to species-specific adhesins that may elicit both bacterial and host factors leading to host cell damage, induction of inflammation and disease. Species-specific fimbrial adhesins may be viewed as direct mediators of bidirectional signalling between bacteria and host cells. Understanding of this process has been highly informative for the design of novel strategies to modulate these signalling pathways and to curb bacterial infections and their harmful sequelae. Development of mixtures of inhibitors or a polyvalent inhibitor is under investigation, since many infectious agents express multiple specificities. Multiple molecular mechanisms of adhesion are required to initiate infection, and effective anti-adhesion strategies will need to address both bacterial and host site particularities.

Research paper thumbnail of High Molecular Weight Constituents of Cranberry Interfere with Influenza Virus Neuraminidase Activity In Vitro

Research paper thumbnail of Adherence of Escherichia coli to human mucosal cells mediated by mannose receptors

Research paper thumbnail of Collectins and pulmonary innate immunity

Immunological Reviews, 2000

The surfactant-associated proteins SP-A and SP-D are members of a family of host defense lectins,... more The surfactant-associated proteins SP-A and SP-D are members of a family of host defense lectins, designated collectins. There is increasing evidence that these pulmonary, epithelial-derived proteins are important components of the innate immune response to microbial challenge and participate in other aspects of immune and inflammatory regulation within the lung. Both proteins bind to glycoconjugates and/or lipid moieties expressed by a wide variety of microorganisms, and to certain organic particles, such as pollens. SP-A and SP-D have the capacity to modulate leukocyte function and, in some circumstances; to opsonize and enhance the killing of microorganisms. The biologic activity of cell wall components, such as Gram-negative bacterial polysaccharides, or viral glycoproteins, such as the hemagglutinin of influenza viruses, may be altered by interactions with collectins. In addition, complementary or cooperative interactions between SP-A, SP-D and other host defense lectins could contribute to the efficiency of this defense system. Collectins could play particularly important roles in settings of inadequate or impaired specific immunity, and acquired alterations in the levels of active collectins within the airspaces and distal airways may increase susceptibility to infection.

Research paper thumbnail of Potential Oral Health Benefits of Cranberry

Critical Reviews in Food Science and Nutrition, 2008

Research paper thumbnail of Inhibitory Effect of a High-Molecular-Weight Constituent of Cranberry on Adhesion of Oral Bacteria

Critical Reviews in Food Science and Nutrition, 2002

A high-molecular-weight nondialysable material (NDM) isolated from cranberry juice at a concentra... more A high-molecular-weight nondialysable material (NDM) isolated from cranberry juice at a concentration of 0.6 to 2.5 mg/ml dissociated coaggregates formed by many intergeneric oral bacteria. A lower concentration of NDM was required to inhibit formation of such coaggregates. NDM acted preferentially on pairs of oral bacteria in which one or both members are Gram-negative anaerobes. The high-molecular-weight material from blueberry also inhibited the coaggregation, although its activity was weaker, whereas such materials obtained from other fruits were inactive. Saliva did not interfere with the ability of NDM to inhibit coaggregation. A preliminary clinical trial showed that NDM reduces S. mutans counts in saliva. The antiadhesion activity of cranberry juice has a potential for altering the oral microbial flora resulting in improved oral hygiene.

Research paper thumbnail of Identification of type specific streptococcal antibodies by in vitro phagocytosis

Israel journal of medical sciences

Research paper thumbnail of Fragment of Streptococcal M Protein*

Human immune response to immunization with a structurally defined polypeptide fragment of strepto... more Human immune response to immunization with a structurally defined polypeptide fragment of streptococcal M protein

Research paper thumbnail of Adherence pharyngeal and skin strains of group A streptococci to human skin and oral epithelial cells

Infection and Immunity, 1977

Group A streptococci isolated from skin adhere in greater numbers to human skin epithelial cells ... more Group A streptococci isolated from skin adhere in greater numbers to human skin epithelial cells than to cells obtained from buccal mucosa whereas streptococci isolated from a throat tend to adhere in greater numbers to buccal epithelial cells than to skin epithelial cells in vitro. M protein-producing strains of group A streptococci did not adhere in significantly greater numbers than M-negative strains. Lipoteichoic acid inhibited binding of streptococci to skin epithelial cells as well as was previously shown for oral epithelial cells. Our results suggest that lipoteichoic acid is more centrally involved than M protein in binding streptococci to skin and mucosal surfaces.

Research paper thumbnail of Carbohydrate-binding sites of the mannose-specific fimbrial lectins of enterobacteria

Infection and Immunity, 1984

The combining sites of type 1 fimbrial lectins of various species of enterobacteria were studied ... more The combining sites of type 1 fimbrial lectins of various species of enterobacteria were studied by measuring the inhibitory activity of linear and branched oligosaccharides and several glycosides of D-mannose on the agglutination of yeast cells by the organisms. The results showed that all five strains of Escherichia coli tested possessed an elongated combining site best fitting a trisaccharide and including a hydrophobic region. Similar results were obtained with Klebsiella pneumoniae. Within the Salmonella genus, the combining sites of the six species tested were similar, but all differed significantly from those of the E. coli strains. The combining sites of Enterobacter cloacae and Enterobacter agglomerans were different from each other and from those of Salmonella sp. and E. coli. The results suggest that although classified under the general term "mannose-specific," bacterial lectins in the form of type 1 fimbriae on different genera exhibit differences in sugar spe...

Research paper thumbnail of Identification of the leukocyte adhesion molecules CD11 and CD18 as receptors for type 1-fimbriated (mannose-specific) Escherichia coli

Infection and Immunity, 1991

Attachment of bacteria to phagocytic cells may be mediated by lectin-carbohydrate interactions, r... more Attachment of bacteria to phagocytic cells may be mediated by lectin-carbohydrate interactions, resulting in lectinophagocytosis. The best-studied system is the interaction of type 1-fimbriated (mannose-specific) Escherichia coli with human phagocytic cells. Here we demonstrate that the leukocyte integrins CD11 and CD18 (CD11/CD18) constitute the major receptors for type 1-fimbriated E. coli. Bacteria were bound in a dose-dependent and saturable manner to CD11/CD18, which was immobilized to microwells, whereas nonfimbriated E. coli cells failed to bind. The binding was efficiently inhibited (82 to 85%) by methyl-alpha-mannoside but not by galactose, and it was reduced by treatment of the immobilized CD11/CD18 with sodium metaperiodate, endoglycosidase H, or a mixture of endoglycosidase F and N-glycosidase. The fimbriated bacteria also bound to CD11a,b,c and CD18 separated by polyacrylamide gel electrophoresis with sodium dodecyl sulfate and blotted onto nitrocellulose paper. This bi...

Research paper thumbnail of Membrane glycoproteins of human polymorphonuclear leukocytes that act as receptors for mannose-specific Escherichia coli

Infection and Immunity, 1987

Type 1 fimbriated (mannose-specific) Escherichia coli cells bind to mannose residues on human pol... more Type 1 fimbriated (mannose-specific) Escherichia coli cells bind to mannose residues on human polymorphonuclear leukocytes (PMN); this leads to phagocytosis of the bacteria. To identify the mannose-containing receptors on the PMN, the cells were surface labeled with 125I and lysed in 0.5% Nonidet P-40, and the lysate was fractionated by affinity chromatography on a column of Sepharose-bound fimbriae. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography of the material eluted from the column with 500 mM methyl-alpha-mannoside revealed two radioactive bands of Mr 70,000 to 80,000 (gp70-80) and 100,000 (gp100). Another weak band of Mr 150,000 (gp150) was observed after prolonged exposure of the gel. Upon blotting of the glycoproteins separated by polyacrylamide gel electrophoresis and overlaying of the blots with concanavalin A, gp150 appeared as the major band. Membrane preparations of the PMN were enriched in gp70-80, gp100, and gp150, in comparis...

Research paper thumbnail of Adherence of Acinetobacter calcoaceticus RAG-1 to human epithelial cells and to hexadecane

Infection and Immunity, 1981

The ability of Acinetobacter calcoaceticus RAG-1 to adhere to human epithelial cells was investig... more The ability of Acinetobacter calcoaceticus RAG-1 to adhere to human epithelial cells was investigated and compared with its ability to adhere to a test hydrocarbon (hexadecane). RAG-1, a microorganism originally isolated for growth on hydrocarbon, adhered to epithelial cells when grown under conditions which promote its adherence to hexadecane; similarly, RAG-1 cells adhered poorly to epithelial cells when grown under conditions which cause the cells to possess low affinity towards hexadecane. A mutant derived from RAG-1, MR-481, deficient in its ability to adhere to hydrocarbon, was similarly unable to adhere to epithelial cells. RAG-1 adherence to epithelial cells was not blocked by a number of sugars tested. Streptococcus pyogenes, whose adherence to epithelial cells has been previously attributed to hydrophobic interactions, was also able to adhere to hexadecane. Results suggest that hydrophobic interactions mediate adherence of the strains studied to both epithelial cells and h...