Showing papers on "Hemagglutination published in 1981"

Adhesion, hemagglutination, and virulence of Escherichia coli causing urinary tract infections.

Abstract: The capacity of 453 Escherichia coli strains to agglutinate erythrocytes and yeast cells and to attach to human urinary tract epithelial cells was tested. The strains were isolated from the urine of patients with acute pyelonephritis, acute cystitis, or asymptomatic bacteriuria and from the stools of healthy school children. Three main patterns of hemagglutination were found: (i) mannose-resistant agglutination of human erythrocytes alone or simultaneously with mannose-sensitive agglutination of guinea pig erythrocytes; (ii) only mannose-sensitive agglutination of guinea pig and other erythrocytes; and (iii) no agglutination. Strains with mannose-resistant agglutination of human erythrocytes alone or in combination with mannose-sensitive hemagglutination attached in high numbers to human urinary tract epithelial cells. Bacteria inducing only mannose-sensitive hemagglutination attached in low numbers, and non-agglutinating strains did not bind to the urinary tract epithelial cells. The bacterial surface antigen(s) mediating mannose-resistant hemagglutination of human erythrocytes and attachment to human urinary tract epithelial cells may be one factor selecting for E. coli from among the fecal flora which infect the urinary tract. The highest proportion of strains with this property was found among acute pyelonephritis isolates (77%), and the lowest proportion of strains with this property was found among normal fecal E. coli (16%).

Antigenic characterization of human and animal rotaviruses by immune adherence hemagglutination assay (IAHA): evidence for distinctness of IAHA and neutralization antigens.

Abstract: An immune adherence hemagglutination assay (IAHA) and a modified enzyme-linked immunosorbent assay for antigenic characterization of human rotaviruses were developed. The designations of type 1 and type 2 were identical to those established previously by specific complement fixation, enzyme-linked immunosorbent assay, and immune electron microscopy. By IAHA (and modified enzyme-linked immunosorbent assay) certain animal rotaviruses were found to be closely related to human rotavirus type 1. The pattern of IAHA reactivity and the cell culture neutralization serotype were found to be distinct properties. The separation of neutralization and IAHA reactivity was apparent when animal rotaviruses which were distinguishable from each other by neutralization assays were found to share IAHA specificity. Further evidence for the dissociation of the neutralization and IAHA specificities was found in studies of human and bovine rotaviruses which underwent genetic reassortment during coinfection. Thus, it appeared that the IAHA and neutralization antigens were coded for by different genes. In view of these findings, we suggest that the term serotype be reversed to identify the antigen that reacts with neutralizing antibodies as is customary for other viruses and that the term subgroup (instead of serotype) be used for the specificity detected by specific complement fixation, enzyme-linked immunosorbent assay, and now IAHA.

Detection of Platelet Antibodies by a Newly Developed Mixed Agglutination with Platelets

Abstract: . We have developed a mixed passive haemagglutination test for the detection of platelet antibodies. This test is essentially a combination of a modified test of mixed agglutination and reversed passive haemagglutination. Using this test, platelet allo-antibodies (HLA antibodies and non-HLA antibodies) were found to be detected with very high sensitivity in the sera of pregnant women and transfused patients. The platelet crossmatch test was performed for patients who had to receive massive platelet transfusion. There was a good correlation between the result of the crossmatch and clinical platelet recovery.

Preparation and characterization of antisera to electrophoretically purified SA11 virus polypeptides.

Abstract: Antisera to SA11 virus proteins were prepared by immunizing rabbits with individual polypeptides separated by polyacrylamide gel electrophoresis under reducing or nonreducing conditions; the resulting antisera were characterized by four immunological methods. Results of complement fixation tests with double-shelled rotavirus particles and sera raised against reduced or unreduced proteins of the outer shell of the virus suggested the presence of common antigenic determinants in the outer capsid layers of SA11 and the Northern Ireland strain of calf rotavirus. In this test, antisera to outer shell polypeptides gp34 (O2) and gp25 (O4) cross-reacted with calf rotavirions, whereas those to p62 (O1) and p26 (O3) reacted only with the homologous virus. Antisera to the reduced outer shell proteins of the virus did not neutralize viral infectivity, nor did they possess hemagglutination inhibition activity. Evidence suggesting the presence of type-specific antigenic determinant(s) in the major inner protein p42 (I4) of SA11 virus, capable of inducing neutralizing antibody, is presented and discussed. Antisera produced against unreduced gp34 and p26 polypeptides of the virus contained type-specific neutralizing antibodies. Polypeptide gp34 was also capable of inducing hemagglutination inhibiting antibody. All of the antisera to unreduced polypeptides had agglutinating activity against double-shelled particles of homologous and heterologous rotaviruses.

Binding Specificity of Piliated Strains of Escherichia coli and Salmonella typhimurium to Epithelial Cells, Saccharomyces cerevisiae Cells, and Erythrocytes

Abstract: The binding to mammalian cells of piliated enteric bacteria and the inhibition of the binding by antibodies to purified pili were studied. The target cells were epithelial cells from human bucca and human and rat urinary tracts, erythrocytes from various species, and Saccharomyces cerevisiae cells. The strains were selected to represent the two main agglutination patterns of enteric bacteria: mannose-resistant agglutination of human and other erythrocytes and mannose-sensitive agglutination of guinea pig and other erythrocytes. Escherichia coli 3669 caused only mannose-resistant agglutination, E. coli 6013 caused only mannose-sensitive agglutination, and E. coli 3048 caused both types of agglutination simultaneously. Salmonella typhimurium SH6749 exhibited only mannose-sensitive hemagglutination and was included to allow comparison of its pili with those of E. coli strains. The range of epithelial cells to which the bacteria adhered was related to their agglutination patterns. All four strains attached to human buccal cells. Only E. coli strains 3669 and 3048, which caused mannose-resistant agglutination, adhered to human urinary tract epithelial cells, and only those strains that caused mannose-sensitive agglutination adhered to rat urinary tract epithelial cells. The binding of S. typhimurium SH6749, but not of the other strains with mannose-sensitive agglutination, was significantly inhibited by d-mannose. Globotetraosylceramide, a glycolipid present in the human urinary tract epithelium, inhibited attachment to human uroepithelial cells of the two strains with mannose-resistant hemagglutination. As tested by the enzyme-linked immunosorbent assay, cross-reactions between type 1 pili of the E. coli strains were strong, but those between S. typhimurium and E. coli mannose-sensitive pili were weak. The two pili that induced mannose-resistant hemagglutination on E. coli did not cross-react. Significant inhibition of adhesion of all four strains was obtained with the homologous anti-pilus antiserum. The binding of bacteria to mammalian cells may thus be mediated by several types of bacterial pili reacting with different receptors on mammalian cells.

Antibody capture radioimmunoassay for anti-rubella IgM.

Abstract: An M-antibody capture radioimmunoassay (MACRIA) for anti-rubella IgM was developed. Under optimum conditions positive serum specimens bound up to 20 times as much radioactivity as negative specimens. Positive reactions were expressed in arbitrary units/ml by comparison with a calibration curve derived from results obtained with dilutions of a standard serum. The specificity of the assay was confirmed by testing IgM and IgG rich fractions of positive sera. One hundred and forty specimens from blood donors, patients whose sera contained rheumatoid factor and patients with acute, non-rubella, virus infections were tested by MACRIA. No significant non-specific reactions were detected. Paired sera from acute rubella (25 patients) and individual sera from suspected rubella (69 patients) were tested for anti-rubella IgM by MACRIA and by haemagglutination inhibition following sucrose-density-gradient fractionation. There was close agreement between the two methods. The capture assay was more sensitive and could be used to detect the weak IgM response in women given RA 27/3 vaccine. After the natural infection, the MACRIA was strongly positive for two months and remained weakly so for a further two months. Repeat testing of sera demonstrated good reproducibility of the assay. MACRIA proved a simple, sensitive and specific test for anti-rubella IgM and compared favourably with currently used techniques.

Ether treatment of type B influenza virus antigen for the hemagglutination inhibition test.

Abstract: Ether treatment was studied as a method of increasing the ability of type B influenza antigen to detect antibody by hemagglutination inhibition. Comparisons were made with the untreated antigen, with an eluate made from the same virus, and with a standard type B antigen of an earlier virus. Results were evaluated based on the comparative ability to detect rises in antibody titer, as well as the relative frequency of antibody prevalence determined by each method. The ether-treated antigen was far superior to the untreated antigen in both respects; it was also superior to the eluate, although the difference was less pronounced. The treated antigen performed better than the standard type B antigen in detecting antibody in children, but there was little difference in adults. This pattern was felt to be a result of the closer relation of the treated antigen to the infecting strain. The method is, therefore, proposed as a means of producing more reactive antigens of currently circulating strains of type B influenza virus.

Nonimmunoglobulin fraction of human milk inhibits bacterial adhesion (hemagglutination) and enterotoxin binding of Escherichia coli and Vibrio cholerae.

Abstract: Human milk and colostrum samples were divided into an immunoglobulin and a nonimmunoglobulin fraction by immunosorbent chromatography. The ability of these fractions to inhibit bacterial cell adhesion and enterotoxin receptor binding of Vibrio cholerae and various Escherichia coli isolates was then tested by in vitro assays. The strongest effect was generally seen with the nonimmunoglobulin fractions, which were shown to significantly inhibit E. coli cell adhesion (hemagglutination) mediated by CFA/I, CFA/II, or K88 fimbriae (but not type 1 pili) and V. cholerae hemagglutination, as well as the binding of cholera toxin and E. coli heat-labile enterotoxin to GM1 ganglioside. Also, the immunoglobulin fractions had significant inhibitory activity in some of these systems. The results are interpreted to suggest that human milk and colostrum may contain secreted structure analogs of the cell receptors for some bacterial adhesions and enterotoxins; this might contribute to the protective effect of milk against enteric infections.

Analysis of Antigenic Drift in the Haemagglutinin Molecule of Influenza B Virus with Monoclonal Antibodies

Abstract: Summary Antigenic drift in the haemagglutinin (HA) molecule of influenza B viruses was studied with monoclonal antibodies. Antigenic drift occurred in each of the 12 different epitopes studied and there was evidence that at least two antigenically distinguishable influenza B virus strains can co-circulate during an epidemic. The frequency of antigenic variation in the HA of influenza B viruses was frequently less than 1 in 108 and was approx. 1000-fold below that found in influenza A strains. Haemagglutination inhibition (HI) tests on antigenic variants selected with 12 different monoclonal antibodies suggested that the antigenic determinants could be subdivided into three partially overlapping groups. Many of the antigenic variants selected with monoclonal antibodies were distinguishable from the parental virus with post-infection ferret sera, suggesting that the majority of the variants that do occur could have epidemiological potential.

Blood group A-like glycolipid and a novel Forssman antigen in the hepatocarcinoma of a blood group O individual.

Abstract: Two glycolipid fractions that inhibit Blood Group A hemagglutination were isolated from hepatocarcinoma tissue of a Blood Group O individual. One fraction corresponding to a ceramide penta- to hexasac-charide weakly inhibited hemagglutination caused by blood group anti-A sera and gave a precipitin reaction with Rana catesbiana lectin. The fraction had no Forssman activity, showed a single spot on thin-layer chromatography, and was degraded by hog liver α- N -acetylgalactosaminidase to a glycolipid with a higher thin-layer chromatography mobility than that of the original glycolipid. The enzyme-treated product had no A-like activity. The direct probe mass spectrometry of the fraction after permethylation indicated the presence of the immunodominant sugar sequence GalNAc→Hex→HexN, but the absence of a tetrasaccharide A determinant, HexN→[Fuc→]Hex→HexN,and a fucosyl residue. The other fraction corresponding to a ceramide di- to trisaccharide showed only a very low A-like inhibition but showed a strong Forssman activity (inhibition of sheep erythrocyte hemolysis by anti-Forssman antibodies and complement). The activity was completely abolished by hog liver α- N -acetylgalactosaminidase with a simultaneous elimination of thin-layer chromatography spots, one corresponding to ceramide trisaccharide and the other with slightly higher mobility. The presence of the Forssman determinant, HexN→HexN, in this fraction was clearly indicated by direct-probe mass spectrometry with a selected ion recording during continuous-temperature-gradient evaporation. Although the supply of the tumor tissue in this case was extremely limited, the above information clearly indicates the presence of an aberrant A determinant and an unusual short-chain Forssman determinant in the hepatocarcinoma of the Blood Group O individual. The tissue did not contain normal Forssman glycolipid with a ceramide pentasaccharide structure.

Properties of monoclonal antibodies to human immunoglobulin kappa and lambda chains.

Abstract: Hybridomas have been produced from mice immunized with human IgG. Culture supernates were assayed for the presence of antibody-producing cells by passive haemagglutination. Hybridomas producing antibodies to human kappa (kappa) and lambda (lambda) light chains have been cloned and grown as ascitic tumours in BALB/c mice. The antigen-binding characteristics of the monoclonal antibodies, contained in the ascitic fluid, were assessed by haemagglutination inhibition, ELISA and radioimmunoassay systems and by the binding of radiolabelled antigen in analytical flat-bed iso-electric focussing gels. One monoclonal anti-kappa reacted better with free than with combined kappa chains; for another the reverse was true. Antibody fractions separated by DEAE chromatography of ascitic fluids were coupled to ox red cells with chromic chloride and compared with polyclonal antibodies for the detection of cell-surface immunoglobulins.

Specificity, sensitivity, and reproducibility among the fluorescent treponemal antibody-absorption test, the microhemagglutination assay for Treponema pallidum antibodies, and the hemagglutination treponemal test for syphilis.

Abstract: Using 920 sera, we compared the specificity and reproducibility of the hemagglutination treponemal test for syphilis with those of the fluorescent treponemal antibody-absorption test and the microhemagglutination assay for Treponema pallidum antibodies; we found all three tests to be comparable. However, the hemagglutination treponemal test for syphilis, like the microhemagglutination assay for T. pallidum antibodies, lacked sensitivity in sera from patients with primary syphilis.

Hemagglutination method for detection of freshwater cyanobacteria (blue-green algae) toxins.

Abstract: Strains of the freshwater cyanobacteria (blue-green algae) Anabaena flosaquae and Microcystis aeruginosa produced toxins that caused intermittent but repeated cases of livestock, waterfowl, and other animal deaths. They also caused illness, especially gastrointestinal, in humans. The most common group of toxins produced by these two species were peptide toxins termed microcystin, M. Aeruginosa type c, and anatoxin-c. A method was found to detect the toxins which utilizes their ability to cause agglutination of isolated blood cells from mice, rats, and humans. The method could detect the toxin in samples from natural algal blooms, laboratory cultures, and toxin extracts. The method consists of: (i) washing lyophilized cyanobacteria cells with physiological saline (0.9% NaCl), (ii) centrifuging the suspension and then mixing portions of the cell-free supernatant with equal volumes of saline-washed erythrocytes in V-shaped microtiter plates, (iii) allowing the mixture to stand for 3 to 4 h, and (iv) scoring the presence of the toxin as indicated by blood cell agglutination. Nontoxic strains, as determined by intraperitoneal mouse bioassay of cyanobacteria or green algae, did not produce an agglutination response.

Hemadsorption immunosorbent technique for determination of rubella immunoglobulin M antibody.

Abstract: We used hemadsorption immunosorbent technique (HIT) to detect mumps immunoglobulin M (IgM) antibody. IgM from human sera was adsorbed into anti-human IgM-coated wells in plates, and mumps-specific IgM was detected by adding mumps virus hemagglutinin and guinea pig erythrocytes consecutively. Specific IgM-positive sera showed hemadsorption, whereas negative sera showed hemagglutination. All 81 patients with current mumps infections tested showed mumps-specific IgM antibody, with titers ranging from 160 to 327,680. In most cases IgM antibody was already present on day 1 or 2 after the onset of illness. IgM antibody persisted for 6 to 10 weeks. Of 57 patients with acute respiratory illnesses caused by parainfluenza virus, 5 showed cross-reactions in the hemadsorption immunosorbent technique assay for mumps IgM. The hemadsorption immunosorbent technique assay is specific for the IgM class of antibody and avoids false-positive results due to rheumatoid factor. This test is an efficient and sensitive method for rapid and early diagnosis of mumps infections.

Immune reactivity of the purified hemagglutinin of measles virus.

Abstract: The role of the immune response to measles virus in acute infection or in disease states associated with this virus is of major interest. The viral genome-specified surface antigens of measles, the hemagglutinin and fusion proteins, are likely to be of paramount importance with respect to the host immune response to the virus. This report describes initial studies aimed at assessing the immune response to the major surface glycoprotein, the hemagglutinin. This antigen was purified by affinity chromatography, using a monoclonal anti-hemagglutinin immobilized on Sepharose. The purified protein retained biological activity in hemagglutination assays. This activity could be specifically inhibited with a human antimeasles serum and with monoclonal antibody to the hemagglutinin. Lymphocytes from individuals known to proliferate to measles-infected monolayers also proliferated to the purified hemagglutinin. Thus, the immune-response to measles virus is, in part, directed to this surface antigen.

Enzyme-linked immunosorbent assay (ELISA) for IgM, IgG and IgA class antibodies against Candida albicans antigens: Development and comparison with other methods

Abstract: An extract of Candida albicans was used as an antigen on microtitre plates in the enzymelinked immunosorbent assay (ELISA) to measure IgM, IgG and IgA class antibodies in the sera of hospitalized patients It was found that of those patient sera that reacted positively in Ouchterlony immunodiffusion (ID) when undiluted, 58% were also positive in the ELISA against the same antigen preparation However, all the sera with an ID titre of 1:2 or higher were ELISA-positive, demonstrating especially IgG and IgA of the sera positive by counterimmunoeletrophoresis against somatic and metabolic antigens of C albicans, 86% were positive by ELISA Reactions in precipitin-negative sera, if they occurred, usually demonstrated IgM or IgA The sera with high passive haemagglutination or indirect immunofluorescence titres against surface antigens of C albicans were positive in the IgG and IgA assays, while approximately one third were positive in the IgM assay

Virus yield-reduction assay for interferon by titration of Sindbis virus hemagglutinin.

Abstract: Publisher Summary The basic steps in a hemagglutination (HA) reduction assay for interferon are (1) incubation of interferon (IF) dilutions on cultures, (2) challenge of the cultures with a high input multiplicity (MOI) of hemagglutinating virus, and (3) measurement of the reduction of hemagglutinin yield The chapter presents the rationale for performing such an assay and a detailed description of the procedures Some of the advantages of the HA reduction assay over the infectious virus yield-reduction assay are that HA titrations are simpler, more rapid, and less expensive than infectious virus titrations and hemagglutinin is usually more stable than infectivity, hence the time of collection of the samples after maximum virus production for HA titration is not as critical as it is for infectivity titrations The major disadvantages usually encountered are (1) the preparation of reagents needed to obtain the proper pH for optimal HA activity, (2) inhibitors of HA activity that may be present in serum or culture fluids, and (3) the availability of male goose erythrocytes

Candida antigenemia, as detected by passive hemagglutination inhibition, in patients with disseminated candidiasis or Candida colonization.

Abstract: A passive hemagglutination inhibition assay was studied by using a hyperimmune serum from rabbits immunized with whole yeast cells (Candida albicans group A). This technique was effective at detecting small amounts of laboratory-prepared mannan or a whole-cell extract of C. albicans. Of 32 patients with documented disseminated candidiasis that were tested, 19 showed evidence of circulating antigen by passive hemagglutination inhibition. Three of these patients showed only partial, rather than complete, inhibition. Among 22 colonized patients, 4 showed partial inhibition, and none of 49 normal controls demonstrated inhibition. All of the sera were tested for antibody by agglutination, immunodiffusion, and passive hemagglutination. This last technique added increased sensitivity, but not specificity, to the standard tests already in use. Fourfold or greater titer rises by passive hemagglutination occurred in fewer than one-third of patients with invasive candidiasis and developed in more than one-half of patients who were colonized and did not require systemic anticandida therapy.

Immunodiagnosis of recently acquired Schistosoma mansoni infection. A comparison of various immunological techniques.

Abstract: A group of Dutch tourists, who became infected with Schistosoma mansoni in Ethiopia, was investigated in a serological follow-up study, during 8-50 weeks after infection. The following immunodiagnostic tests were applied: (1) the immunofluorescent antibody (IFA) test, both on frozen sections of adult worms, and in a modification for the detection of antibodies against gut-associated polysaccharide antigens; (2) the enzyme-linked immunosorbent assay (ELISA) with as antigens: adult worm antigens (AWA), cercarial antigens (CA), soluble egg antigens (SEA), and the purified antigens CAA and MSA1; (3) the defined antigen substrate spheres system with AWA as antigen in an immunofluorescence and immunoperoxidase modification; (4) the indirect haemagglutination reaction with AWA; and (5) the immunoelectrophoresis with AWA and antigens of the intermediate host. With these techniques it could be shown that in all persons which had been in contact with S. mansoni infected water, also in those not excreting schistosome eggs or not showing clinical symptoms of infection, specific anti-schistosome antibodies were present. No false-negative reactions were found with the ELISA with cercarial antigens, MSA1, or AWA-TCA, with the IFA detecting gut-associated polysaccharide antigens and with the immunoelectrophoresis. The highest titres were observed with the two techniques (IFA and ELISA) detecting antibodies against the gut-associated polysaccharide antigen CAA.

Production of antibodies against measles virions by use of the mouse hybridoma technique

Abstract: Mouse hybridoma cell lines were produced by fusion of P3 × 63 Ag8 myeloma cells with spleen cells from BALB/c mice immunized with purified measles virions. About 60 per cent of single cell colonies in wells were found to produce measles antibodies as determined by a radioimmune assay. Selected measles antibody producing hybridoma cell lines were passaged intraperitoneally in mice and ascites fluids were collected. This material contained 20–200 times higher antibody titers than unconcentrated medium from hybridoma cell lines propagated in tissue culture. The ascites fluid antibody products of 23 hybridoma cell lines were characterized by different measles serological tests. Seventeen lines produced high titers of hemagglutination inhibiting (HI) and hemolysis-inhibition (HLI) antibodies. One hybridoma cell line produced Ig with low HI but high HLI activity and the remaining 5 hybridoma cell line products only carried HLI activity. Unexpectedly it was found in radioimmune precipitation assays that all hybridomas studied, including those showing HLI but no HI antibody activity, gave a selective precipitation of the 79K measles hemagglutinin polypeptide. Radioimmune precipitation assays with sera from immunized animals showed that they contained high titers of antibodies precipitating the 79 K polypeptide but in addition also somewhat lower titers of antibodies precipitating the 60 K nucleoprotein, 40 K fusion and 36 K matrix polypeptides. Homogeneous Ig products carrying measles antibody activity were demonstrated by imprint immunoelectrophoresis of ascites materials.

Herpesviruses and parkinsonism. Herpes simplex virus types 1 and 2, and cytomegalovirus antibodies in serum and CSF.

Abstract: • Antibodies against herpes simplex virus (HSV) types 1 and 2 and cytomegalovirus (CMV) were assayed with a microindirect hemagglutination (IHA) test in the serum of 67 pairs of patients with Parkinson's disease and controls. Cerebrospinal fluid from 30 pairs was assayed. All patient and control serum was tested with a radioimmunoassay (RIA) for antibodies against HSV type 1 subunit antigens. Serum IHA antibody level against HSV type 1 was increased in patients with Parkinson's disease and RIA antibody levels against the same viral antigen were significantly higher in the patients than controls. Herpes simplex virus type 2 and CMV serum antibodies were equal in the patient and control groups. Most of the CSF samples tested negatively for IHA; small and comparable numbers of the patients and controls had low antibody levels against HSV and CMV antigens.

Effect of enzymes on the attachment of influenza and encephalomyocarditis viruses to erythrocytes.

Abstract: Encephalomyocarditis (EMC) and influenza viruses attach to human erythrocytes causing haemagglutination of the cells. Sialoglycoproteins, containing predominantly glycophorin A, from these cells behave as soluble virus receptors and inhibit haemagglutination by both viruses. Removal of 43% of the sialic acid from erythrocytes with neuraminidase prevented their haemagglutination by EMC virus loss of 40% of glycophorin sialic acid destroyed its inhibitory properties against this virus. However, about 80% of the sialic acid had to be removed from erythrocytes or from glycophorin to achieve the same results for influenza virus. Trypsin treatment of erythrocytes or glycophorin had little effect on haemagglutination or inhibition involving either virus, although the glycopeptides released contain up to 70% of the total sialic acid, and despite the fact that glycophorin was drastically reduced in size as shown by SDS--polyacrylamide gel electrophoresis. It is concluded that not all of the sialic acid present in erythrocyte sialoglycoprotein receptors is involved in attachment of EMC or influenza viruses and that the attachment sites on erythrocytes for these viruses are not identical.

Mitogenicity and binding properties of beta-galactoside-binding lectin from chick-embryo kidney.

Abstract: THe beta-galactoside-binding lectin binds to glucosamine, mannosamine and galactosamine in addition to beta-galactoside, as determined by the inhibition of haemagglutination. Haemagglutination is further extended to examine the interaction of the binding sites for hexosamines and beta-galactosides, indicating that the binding of hexosamine and beta-galactoside is competitive. The lectin also shows strong mitogenic activity toward lymphocytes from mouse lymph node, as determined by the stimulation of thymidine incorporation.