Reactions of Monoclonal Antibodies to Human MN Blood Groups with red Blood Cells of Subhuman Primates

All 12 samples of chimpanzee erythrocytes tested were agglutinated by the commercial polyclonal anti-M reagent of rabbit origin, but none was agglutinated by monoclonal anti-M reagent of murine origin. This, as well as results of absorption experiments, showed that the polyclonal and monoclonal anti-M reagents detect different M epitopes. Polyclonal anti-N reagent of rabbit origin and monoclonal reagent of murine origin obtained by immunization with N blood group substance did not react with any chimpanzee erythrocyte samples. On the other hand, monoclonal anti-N reagent originating from immunization with M blood group substance agglutinated two of the 12 tested chimpanzee erythrocyte samples. This and other experimental results strongly suggested that the latter monoclonal anti-N reagent combined with “N” antigen, i.e., an antigen present on glycophorin B of human M as well as N erythrocytes; apparently erythrocytes of some chimpanzees contain also this antigen.     

抗人红细胞M型抗原单克隆抗体的研制及初步应用

应用杂交瘤枝术,用人M型RBC免疫的BALB/c小鼠脾细胞,与小鼠骨髓瘤细胞系NS-1融合,筛选出抗M血型抗原的单克隆抗体杂交瘤细胞株13H_2;经过8个多月连续传代培养增殖良好,仍能稳定分泌效价高、特异性强的单克隆抗体。细胞培养上清效价1∶512,亲和力11s。通过将此株单抗用于血型检测、标准红细胞谱细胞的鉴定和在法医上检测血痕,均证明此株单抗识别的只是红细胞上的M血型抗原,与其它血型抗原无关。较多克隆抗M型抗原血清特异性强,效价高,亲和力好,是检测MN血型的良好诊断试剂。     

A monoclonal antibody directed against the homologous N-terminal domain of glycophorin A and B

A monoclonal antibody (iB5, IgG1 kappa) reacting with human red cells was produced after immunization of BALB/C mice with cord red cells, followed by fusion of the spleen cells with the murine myeloma cell line Ag 8-653. The monoclonal antibody agglutinated blood group N+ much better than M + N-red cells but did not recognize erythrocytes from rare individuals typed as M + N-S-s-U- and those from an En(a-) individual (M.E.P.). However, S-s-U- donors typed as M + N + or M-N+ and En(a-) red cells from donor G.W. were agglutinated. The erythrocyte receptors for iB5 are completely destroyed by papain treatment and significantly decreased by neuraminidase. Interestingly also, the iB5 antibody failed to agglutinate trypsin-treated N+M-S-s-U- erythrocytes. Other investigations have shown that the monoclonal antibody precipitated glycophorin A and B from N+ red cells and only glycophorin B from M+N-erythrocytes. The reactivity of iB5 was further explored by immunostaining following the electrophoretic transfer to nitrocellulose sheets of membrane proteins from common (M and N) and rare erythrocytes [En(a-),S-s-U-, MgMg, McM, St(a+), Mi.V, Mi.III, Tn] separated by SDS-polyacrylamide gel electrophoresis. These studies have clearly demonstrated that the monoclonal iB5 antibody is directed against the homologous N-terminal domain of glycophorin A and B, a specificity which explains the serological reactivity of iB5 against common and rare erythrocytes.     

Negative cross-reactivity of rabbit anti-Malassezia furfur antibodies with other yeasts

Anti-Malassezia furfur monospecific polyclonal antibodies was produced by repeated immunization of rabbit with Malassezia furfur yeast cells mixed with Freud adjuvant. The antibody titres of respective rabbit's serum samples prior to and after each immunization against M. furfur were assayed by indirect immunofluorescence technique using the M. furfur whole yeast antigen fixed in Teflon coated slides. The highest anti-M. furfur antibody titre achieved was 1 in 1280 dilution. At 1:20 dilution, none of the respective serum samples taken at various stages of immunization gave positive immunofluorescent staining against any of the other species of yeasts tested in this study. Anti-M. furfur monospecific polyclonal antibodies produced in rabbit in this study has the potential for diagnostic application in immunohistochemical detection of M. furfur in human tissues.     

抗血型M、N及抗血型糖蛋白A/B单克隆抗体的制备及其特性鉴定

目的:制备抗血型M、N及抗血型糖蛋白A/B(GPA/GPB)的单克隆抗体(mAb),并进行特性鉴定。方法:用人“O”型血红细胞作为免疫源,免疫BALB/c小鼠。采用淋巴细胞杂交瘤技术制备mAb,用谱红细胞筛选阳性克隆;采用直接、间接血凝试验检测杂交瘤细胞培养上清及腹水中mAb的效价。分别用快速定性试纸和酶处理红细胞检测mAb的Ig亚类及抗原表位。用Western blot鉴定抗GPA/GPB mAb的特异性。结果:获得4株分泌抗M、1株抗N及3株抗GPA/GPB mAb的杂交瘤细胞株。杂交瘤细胞培养上清mAb的效价介于1×2-4~1×2-8之间,腹水mAb的效价在1×2-7~1×2-12之间。除1株mAb 1C1C9C4为IgM外,其他7株mAb均为IgG。通过杂交瘤细胞培养上清与谱红细胞的反应格局,结合mAb抗原表位的检测,确定4株和1株mAb可分别特异性结合于GPA的M、N抗原表位;另3株mAb 6D7C9、7C9H4和7C9G11与“O”型血红细胞膜的Western blot结果显示,均可结合GPA、GPB蛋白。结论:成功地建立了4株分泌抗M、1株分泌抗N及3株分泌抗GPA/GPB mAb的杂交瘤细胞株,可用于MNSs血型系统的研究及鉴定,并为制备双功能抗体用于病毒、肿瘤疾病的诊断和治疗打下了坚实的基础。     

Immunodominant Nocardia asteroides antigens: isolation and characterisation by enzyme-linked immunoelectrotransfer blotting, and the value of immunoblot strips.

Concentrated cell-free filtrates (nocardins) were prepared from Nocardia asteroides cultures grown on Sauton's synthetic broth. Nocardins from 10 strains of six N. asteroides serotypes were produced and the proteins separated by isoelectric focusing. N. asteroides antigens among these proteins were tested for specificity using rabbit antisera and monoclonal antibodies (MAbs) against N. asteroides and Mycobacterium tuberculosis by the enzyme-linked immunoelectrotransfer blot test. At least 15 protein antigens were identified from each of the 10 nocardins. The immunodominant antigens were one serotype-specific N. asteroides protein with an isoelectric point (pI) of 4.0 (factor 1) and two group antigens with pIs of 4.43 (factor 6) and 4.68 (factor 8). The nitrocellulose strips prepared with these antigens did not react with antibodies to M. tuberculosis, nor with normal sera from humans, rabbits, or mice, but reacted specifically with anti-N. asteroides MAbs and polyclonal antibodies. Four purified protein derivatives of tuberculin were tested and did not cross-react with the three anti-N. asteroides MAbs. These reactions suggest that the antigens identified as factors 1, 6 and 7 are specific to N. asteroides and that factor 1 is specific for serotype 2, while factors 6 and 8 are species-specific.     

Production and Characterisation of Murine Monoclonal Antibodies to Feline Erythrocyte A and B Antigens

Anti-A antiserum from blood type B cats, the current reagent used to detect blood type A cats, is expensive, labour intensive to produce, and can vary in sensitivity between preparations. In contrast, monoclonal antibodies are produced easily in large quantities and pure form. We produced six IgM class murine monoclonal antibodies, four specific for feline blood type A and two that detect feline blood type B, by injection of mice with liposomes incorporating type A or B erythrocyte membrane antigens. Specificities of each monoclonal antibody were characterised by high performance thin layer chromatography of feline erythrocyte membrane glycolipids and by immunoblotting of feline erythrocyte membrane proteins separated by SDS-PAGE. The anti-A monoclonal antibodies specifically detected feline blood type A by direct agglutination of blood-typed samples from many cats. Each anti-A monoclonal antibody agglutinated some, but not all, feline blood type AB samples. Two anti-A monoclonal antibodies appeared identical and recognised [NeuGc]₂G_D3, the major glycolipid antigen of type A blood. The other two also appeared identical to each other and recognised a slower migrating glycolipid band, which may be [NeuGc]G_T3. The two anti-B monoclonal antibodies detected feline blood type B by direct agglutination and both recognised [NeuAc]₂G_D3, the major glycolipid antigen of type B blood. None of the monoclonal antibodies recognised erythrocyte membrane glycoproteins specific for either feline type A or type B blood. The ability of the anti-A monoclonal antibodies produced in this study to specifically detect feline blood type A makes them useful replacements for anti-A antiserum for blood typing of cats. The inability of each anti-A antibody to agglutinate blood from every type AB cat suggests a difference between the A antigen of some type A and some type AB cats.     

Production and Characterisation of Murine Monoclonal Antibodies to Feline Erythrocyte A and B Antigens

Anti-A antiserum from blood type B cats, the current reagent used to detect blood type A cats, is expensive, labour intensive to produce, and can vary in sensitivity between preparations. In contrast, monoclonal antibodies are produced easily in large quantities and pure form. We produced six IgM class murine monoclonal antibodies, four specific for feline blood type A and two that detect feline blood type B, by injection of mice with liposomes incorporating type A or B erythrocyte membrane antigens. Specificities of each monoclonal antibody were characterised by high performance thin layer chromatography of feline erythrocyte membrane glycolipids and by immunoblotting of feline erythrocyte membrane proteins separated by SDS-PAGE. The anti-A monoclonal antibodies specifically detected feline blood type A by direct agglutination of blood-typed samples from many cats. Each anti-A monoclonal antibody agglutinated some, but not all, feline blood type AB samples. Two anti-A monoclonal antibodies appeared identical and recognised [NeuGc]₂G_D3, the major glycolipid antigen of type A blood. The other two also appeared identical to each other and recognised a slower migrating glycolipid band, which may be [NeuGc]G_T3. The two anti-B monoclonal antibodies detected feline blood type B by direct agglutination and both recognised [NeuAc]₂G_D3, the major glycolipid antigen of type B blood. None of the monoclonal antibodies recognised erythrocyte membrane glycoproteins specific for either feline type A or type B blood. The ability of the anti-A monoclonal antibodies produced in this study to specifically detect feline blood type A makes them useful replacements for anti-A antiserum for blood typing of cats. The inability of each anti-A antibody to agglutinate blood from every type AB cat suggests a difference between the A antigen of some type A and some type AB cats.     

A mouse monoclonal antibody against glycophorin A produced by in vitro stimulation with human red cell membranes

Human erythrocyte membranes were used as antigen for production of mouse monoclonal antibodies against blood group related structures by in vitro immunization. Culture medium supernatant of PHA and PMA stimulated mouse thymus cells was used as source of cytokines. The selected antibody designated 124,D-7 (isotype IgM) was found to directly agglutinate all human red cells, except the rare erythrocytes En(a-) which lack glycophorin A. Immunoblotting showed faint bands in the positions of glycophorin A, whereas no binding occurred to glycophorin B. Inhibition of agglutination with purified glycophorin A and peptides suggests that the epitope is located within the amino acid residues 35-40. Rat and chicken erythrocytes also reacted with the antibody, whereas mouse erythrocytes were only agglutinated at very low dilutions of ascitic fluid.     

Monoclonal antibodies directed against human Rh antigens in tests with red cells of non-human primates

Human anti-D (Rh_o) monoclonal antibodies (Mabs) of the IgG (70) and IgM (27) classes were tested with red blood cells (RBCs) of various non-human primates, from anthropoid apes to New World monkeys. Significant differences in reactivity were observed among antibodies of two classes depending on taxonomic position of primate animals. Only IgM Mabs gave positive reactions (9 out of 18 Mabs) with blood of Old World monkeys. Allotypic reactions with RBCs of African apes were produced by a majority of IgG Mabs but by very few IgM reagents, most of the latter reacting with RBCs of all chimpanzees and all gorillas tested. Eight out of 70 IgG anti-D defined chimpanzee polymorphisms related to chimpanzee R^c antigen which is the chimpanzee counterpart of human D antigen. Most of IgG anti-D Mabs (61/70) were found specific of D^gor antigen (gorilla counterpart of human antigen D). Most of anti-D which were found negative with all chimpanzee RBCs were also negative with human D^IVb RBCs and most of anti-D which agglutinated human D^IVb RBCs were positive with some or all chimpanzee blood samples. Differences among Mabs evidenced in tests with non-human primate RBCs reflect the complexity of the immune reactions to the human D antigen. The results obtained with anti-Rh Mabs of specificities other than D confirmed that chimpanzee, gorilla and gibbon express c-like epitopes and that antigens C, E, e are absent in non-human primates.     

Characterization of a murine monoclonal antibody specific for the human P1 blood group antigen

Four monoclonal antibodies (MAbs) directed against the P1 blood group antigen were produced by hybridomas obtained from mouse immunized with turtle-dove avomucoid. One of the MAb (154 IX B6) selected as a blood typing reagent agglutinated native P1 and Pk1 red cells with a high titer but was inactive against native P2, Pk2 and p erythrocytes. After papain treatment the reactivity towards P1 and Pk1 erythrocytes was enhanced whereas p erythrocytes remained unreactive. A weak cross-reactivity of the MAb with the Pk antigen was suspected since enzyme-treated Pk2 erythrocytes became significantly agglutinated. Further analysis of the antibody specificity was established by binding studies using neutral glycolipids prepared from P1 and P2 erythrocytes, affinity immunoabsorbents carrying known oligosaccharide structures and hapten inhibition with synthetic oligosaccharides. The MAb bound weakly to the Gal alpha 1-4Gal structure common to P1 and Pk antigens but had a marked preference for the P1 determinant (Gal alpha 1-4 Gal beta 1-4 GlcNAc) and the binding was abolished by prior treatment of oligosaccharide antigens by alpha(not beta)-galactosidase, which supports evidence that a terminal alpha-galactose residue is involved in the blood group P1 and Pk specificities. The MAb has a slightly broader specificity than the human anti-P1 counterpart but can be used safely for routine blood typing.     

The erythrocyte and epithelial cell receptors for Haemophilus influenzae are expressed independently.

The Anton blood group antigen has been shown to be the erythrocyte receptor for Haemophilus influenzae. Cord erythrocytes, which lack the Anton antigen, were not agglutinated by H. influenzae (L. van Alphen, J. Poole, and M. Overbecke, FEMS Microbiol. Lett. 37:69-71, 1986). Twenty-eight erythrocyte suspensions from newborns less than 4 days old were also not agglutinated, but 23 of 56 erythrocyte suspensions from 4- to 50-day-old newborns and 23 of 35 erythrocyte suspensions from older infants were agglutinated. Positive hemagglutination correlated with the presence of the Anton antigen on the erythrocytes for 163 of 173 (P less than 0.0001). Adherence of H. influenzae to buccal epithelial cells obtained from six newborns within 3 days after birth was as strong as that found with adult epithelial cells, whereas the erythrocytes from five of six of these newborns were not agglutinated by the bacteria. Adherence of H. influenzae to epithelial cells of 15 donors was not inhibited by anti-Anton serum. Moreover, H. influenzae carrying fimbriae adhered to epithelial cells of an Anton-negative donor. From these results we conclude that the age at which the erythrocyte receptor for H. influenzae is expressed is the same as for the Anton antigen, but that the receptor on the epithelial cells is already expressed at birth and is not identical to the Anton antigen.     

Reactivity of monoclonal antibodies against human leucocyte antigens with lymphocytes of non-human primate origin

The phylogenetic distribution of antigens present on human lymphocytes was investigated by incubating human or simian cells with murine anti-human monoclonal antibodies and then determining the level of reactivity with a radiolabelled anti-murine IgG reagent. The monoclonal antibodies used were specific for a T-cell antigen, lymphoid and lymphoid:myeloid antigens, Ia antigens, and beta 2 microglobulin. The cells examined included B- and T-lymphoblastoid cell lines and fresh peripheral blood lymphocytes separated by sheep erythrocyte rosetting into T-cell and non T-cell fractions. Results of these studies showed that the antibodies gave complete cross-reactivity with gorilla and chimpanzee cells while B-cell lines of orangutan origin had lost lymphoid and beta 2 microglobulin markers. Gibbon cells and cells of Old World and New World monkeys reacted strongly only with monoclonal antibodies against Ia antigenic determinants. These Ia antigens were found on the non T-cell fraction of fresh peripheral lymphocytes, on B-cell lines and on some virus induced T-cell tumour lines. Immunoprecipitation analysis using the anti-Ia antibodies showed a degree of molecular diversity on owl monkey and marmoset cells compared to the Ia antigens associated with human cells.     

In vivo effects of anti-idiotype on Plasmodium chabaudi infection in mice.

A polyclonal anti-idiotype was raised in rabbits following immunization with a murine monoclonal antibody which recognized a 250,000 MW antigen of Plasmodium chabaudi-infected erythrocytes. The monoclonal antibody, NIMP M23 (clone 3,) has been shown to protect mice against homologous parasite challenge. Following purification, the anti-idiotype was shown to bind only the immunizing idiotype and to recognize antigen-binding site-associated anti-idiotype. Mice primed with anti-idiotype and challenged with live parasites had an altered course of infection, with significant reduction in their peak parasitaemia levels. Anti-idiotype priming did not induce an antigen-reactive antibody response in vivo but a population of T cells capable of proliferating in vitro to P. chaubaudi-infected red cells was stimulated. These data are discussed in the context of possible idiotypic interaction in murine malaria.     

A unique epitope on human serum albumin recognized by monoclonal antibody HSA-1: a probe for identification of the human origin of blood or tissue

A panel of monoclonal antibodies was raised against human serum albumin from fusions of BALB/c splenocytes and SP2/0-Ag14 murine myeloma cells. This panel was screened against purified albumins from 21 species including chimpanzee, gorilla, and orangutan. A monoclonal antibody (HSA-1) specific for human albumin was identified. The epitope recognized by HSA-1 was shown to be conserved in all human blood samples tested. A double antibody ELISA assay was developed using biotinylated HSA-1 as the specific probe for human albumin. This assay was capable of detecting as little as 30 nanograms or less albumin/ml. This assay was used to verify the presence of human albumin in blood, tissue extracts, and other body fluids. These results show that the HSA-1 monoclonal antibody can be used in determining the human origin of blood, tissue, and a variety of other body fluids.     

Further evidence that carbohydrates are the immunodeterminant structures of blood group M and N specificities

Terminal beta-D-galactopyranosyl (Gal) groups are implied in blood group N but not M specificity by the following findings: (a) Rabbit anti-asialoganglioside sera specific for terminal beta-Gal-(1 leads to 3)-GalNac agglutinate human group 0 M and N erythrocytes, the latter to a significantly higher titer, while rabbit anti-ganglioside GMl sera, whereas sialic acid modifies the antibody specificity, do not. The agglutination score with N erythrocytes was about twice that with M red blood cells. The asialoganglioside antibodies were readily absorbed by group 0 N erythrocytes, which were up to 10 times more efficient than group 0 M erythrocytes. Erythrocyte agglutination by the anti-asialoganglioside sera was inhibited by M and N antigen preparations isolated from group 0 red cells ghosts. N antigen was a better inhibitor. Asialoganglioside effectively inhibited the red cell agglutinations by anti-asialoganglioside serum. Ganglioside GMl did not inhibit. (b) Horse anti-pneumococcus Type XIV serum, which has anti-beta-Gal specificity, precipitated highly active N but not M substances. This precipitation was specifically inhibitable by oligosaccharides with terminal beta-Gal. (c) Beta galactosidase specifically inactivated native N and "acid-produced' N substances with the release of about three moles Gal per subunit of N antigen. It did not affect M antigen.     

Biochemical characterization of a monoclonal antibody to the H type-2 antigen: comparison to other ABH antibodies

Monoclonal and polyclonal antibodies to the ABH blood group antigens were tested for their specificity to glycoproteins with ABH activity on immunoblots of solubilized erythrocyte membranes. Immunoblots were stained with monoclonal antibody G10 to the H type-2 carbohydrate structure or with commercially prepared monoclonal and polyclonal antibodies to A, B, and H blood group antigens. G10 antibody specifically stained antigens in the regions that contain the erythrocyte membrane bands 3 and 4.5; the staining was proportional to the expected H content of the erythrocytes (O greater than A2 greater than B greater than A2B greater than A1 greater than A1B). No specific staining was observed with membranes derived from Oh (Bombay) erythrocytes which lack the H type-2 structure. A commercially prepared monoclonal anti-H did not specifically stain erythrocyte membrane antigens. Monoclonal and polyclonal anti-A specifically stained bands from A and AB but not O, B, or Oh erythrocytes (A1 greater than A1B greater than A2 greater than A2B). Polyclonal anti-B serum specifically stained bands from B and AB but not O, A, or Oh erythrocytes (B greater than A2B greater than A1B). However, no specific staining was observed in tests with monoclonal anti-B. Monoclonal antibodies G10 and anti-A and polyclonal anti-A and -B blood typing sera will be useful in the further characterization of the molecular nature of the ABH antigens.     

Antibody responses to the blood group antigen D in SCID mice reconstituted with human blood mononuclear cells.

Mice with severe combined immunodeficiency (SCID) were reconstituted with peripheral blood mononuclear cells (PBMC) obtained from D-negative individuals who had been sensitized to D-positive erythrocytes. Anti-D was spontaneously secreted in mice reconstituted with PBMC obtained from donors within 14 days of re-immunization with D-positive erythrocytes, but was not detected in murine plasma when mice were reconstituted with PBMC obtained from the same donors many years after sensitization, even though anti-D was still present in the serum of these donors. In the murine plasma the anti-D titres were not related to the total human immunoglobulin concentrations. SCID mice reconstituted with PBMC from some donors immune to D-positive erythrocytes (but not immunized within 34 days of donating the sample) made a recall response to the D antigen, which in some cases was maintained for at least 84 days. Depletion of adherent cells from the reconstituting PBMC reduced the total concentration of human IgG obtained. These results show that SCID mice reconstituted with human PBMC (Hu PBMC-SCID) can make a recall response to the D antigen which cannot be attributed to non-specific polyclonal B-lymphocyte activation, and that efficient antigen processing and presentation of the integral erythrocyte membrane D polypeptide occurs in the Hu PBMC-SCID model.     

A and B Antigenicity of Human Spermatozoa and Buccal Epithelial Cells

The source of A and B antigens on the surface of erythrocytes, spermatozoa and buccal epithelial cells was studied using two kinds of monoclonal antibodies of differing specificity. The first, anti-Ar, reacts with the erythrocyte A antigen but not with the soluble A antigen found in secretions such as saliva. Similarly, anti-Br reacts with the erythrocyte B antigen but not with the soluble B antigen present in secretions. The second type of monoclonal antibody, anti-A_r+s, reacts with both the erythrocyte A antigen and with the soluble A blood group substance. Similarly, the anti-B_r+s reacts with both the erythrocyte B antigen and with the soluble B blood group substance. The spermatozoal A antigen reacts only with the anti-A_r+s monoclonal antibody whereas buccal epithelial A antigen reacts with both anti-A_r and with anti-A_r+s. Spermatozoal B antigen reacts only with anti-B_r+s whereas buccal epithelial B antigen reacts with both anti-B_r and anti-B_r+s. Buccal cell A and B antigens appear to be integral to the membrane or at least tightly bound whereas the spermatozoal A and B antigens are adsorbed from seminal plasma and loosely bound.     

Incidence of weak D in blood donors typed as D positive by the Olympus PK 7200

The incidence of weak D has been reported to be between 0.23 and 0.5 percent in Europe and 3.0 percent in the United States. All studies were performed before the introduction of monoclonal anti-D reagents. Using current commercial reagents, this study evaluated D+ samples for the presence of weak D. D+ donors, typed by the Olympus PK 7200, using diluted monoclonal blend anti-D and diluted polyclonal anti-D, were selected by sampling batches of 100 to 200 samples from the previous day's collection. Anti-D reagents used on the Olympus PK 7200 are required to detect RBCs with the weak D phenotype which do not agglutinate at immediate spin (IS) when tested with polyclonal anti-D by manual tube methods. More than 95 percent of donors tested were Caucasian. Using tube tests with two different monoclonal blend anti-D reagents and one polyclonal anti-D typing reagent, the presence or absence of the D antigen was evaluated after the IS reading. Donors found negative or weakly positive (< 2+) at IS were further typed for weak D by the IAT. The weak D samples were RHD genotyped by allele-specific PCR. Of 1,005 donors tested, 4 (0.4%) were classified as weak D by one or more anti-D reagents. Polyclonal anti-D reagent demonstrated weaker reactions when compared with the monoclonal blends. All weak D samples were found positive for exon 4, intron 4, and exon 10, a finding consistent with most D+ samples. The incidence of weak D found in this study is not significantly different from that found in earlier studies using polyclonal anti-D reagents.