Expression of heterophile, Paul-Bunnell and Hanganutziu-Deicher antigens on human melanoma cell lines

Expression of heterophile antigens was studied on 6 human melanoma cell lines. Paul-Bunnell and Hanganutziu-Deicher (H-D) antigens, but not Forssman antigen, were demonstrated on these cell lines. H-D antigen was also demonstrated on melanoma cells isolated from primary and metastatic lesions. Evidence was also presented that HLA class I but not class II (DR and DQ) molecules are expressed on these cell lines. H-D antibodies of IgG class were detected in 10 of 23 (42%) melanoma patients suggesting the possibility that H-D antigen might have been expressed in an immunogenic form in the patients.

IgM antibodies recognizing carbohydrate epitopes shared between schistosomula and miracidia of Schistosoma mansoni that block in vitro killing

A series of monoclonal antibodies (mAb) was raised in mice against Schistosoma mansoni, which recognized a carbohydrate determinant on a major Mr greater than 200,000 schistosomulum surface antigen. These mAb cross-reacted with the surface of cercariae and miracidia and with schistosomula of S. haematobium and S. bovis. Other mAb were generated that only recognized a Mr 20,000 schistosomulum surface antigen; they did not cross-react with eggs or miracidia and were species specific. The anti-Mr 20,000 mAb of the IgG1 isotype exhibited high levels of complement-dependent cytotoxicity to schistosomula in vitro. IgM mAb that recognized carbohydrate epitopes of the Mr greater than 200,000 surface antigen blocked the lethal activity of the anti-Mr 20,000 mAb. The IgM anti-Mr greater than 200,000 mAb also reduced complement-dependent cytotoxicity of serum from mice vaccinated with irradiated cercariae.

A syngeneic monoclonal antibody to murine Meth-A sarcoma (HepSS-1) recognizes heparan sulfate glycosaminoglycan (HS-GAG): cell density and transformation dependent alteration in cell surface HS-GAG defined by HepSS-1

We have isolated a syngeneic monoclonal antibody (HepSS-1) reactive to a murine methylcholanthrene-induced fibrosarcoma, Meth-A. HepSS-1 also bound to a wide variety of established and fresh normal cells derived from not only mice but also other species such as human, monkey, rat, hamster, and chicken. Immunoprecipitation of surface iodinated Meth-A cell extract with HepSS-1, as well as Sepharose 4B gel chromatography of Meth-A cell extract and detection of antigens recognized by HepSS-1 by a sandwich-type radioimmunoassay revealed that the HepSS-1 antigens were composed of several molecular species, with one as large as approximately 10(6) daltons. The following evidence indicates that HepSS-1 specifically recognizes an epitope present in heparan sulfate glycosaminoglycan (HS-GAG). First, treatment of Meth-A cells with heparitinase or heparinase, but not with chondroitinase ABC or hyaluronidase, resulted in the loss of HepSS-1 binding. Second, HS-GAG but not seven other types of GAG (hyaluronic acid, heparin, chondroitin, chondroitin 4-sulfate, chondroitin 6-sulfate, dermatan sulfate, and keratan sulfate) inhibited HepSS-1 binding to Meth-A cells. Third, HepSS-1 bound with HS-GAG but not with the seven other types of GAG. From the binding analysis of HepSS-1 to various modified HS-GAG and whale omega-heparin, it is additionally suggested that HepSS-1 recognizes an epitope closely related to O-sulfated and N-acetylated glucosamine. We found that NIH 3T3 cells expressed more HepSS-1 epitopes at a low cell density than at confluency and in G2 + M than in G1, whereas NIH 3T3 cells transformed with Kirsten-ras oncogene or SV-40 expressed high levels of HepSS-1 epitopes and ceased to show the density-dependent change in the amount of HepSS-1 epitopes. These observations were also reproduced by using NIH 3T3 cells transformed with a temperature sensitive Kirsten murine sarcoma virus maintained at permissive and non-permissive temperatures. Thus HepSS-1 is a first monoclonal antibody to HS-GAG and seems to be useful to elucidate changes in cell surface HS-GAG in normal cell growth and cell transformation.

Homotypic and heterotypic antibodies for prevention of experimental rotavirus gastroenteritis

We investigated the abilities of homologous and heterologous antibody preparations to neutralize murine rotavirus in a mouse model of rotavirus infection. We found that incubation of virus with murine sera obtained from animals experimentally infected with the homologous epizootic diarrhea of infant mice strain of rotavirus resulted in inability of the virus to cause symptomatic disease in infant mice. Sera from nonimmune mice and mice infected or immunized with a heterotypic strain of rotavirus did not effectively neutralize virus in this system. On the other hand, neutralization was noted after incubation of virus with a number of immunoglobulins from other animal and human sources. The neutralizing activity of the preparations in the murine model correlated partially, but not completely, with the level of in vitro neutralizing antibody to the murine strain of rotavirus measured in a tissue culture system. In most cases, asymptomatic infection after feeding of the virus and the antibody preparation resulted in subsequent generation of an active immune response in infected animals.

Artefactual increase in serum thyrotropin concentration caused by heterophilic antibodies with specificity for IgG of the family Bovidea

A 19-year-old white woman presented with symptoms compatible with mild hyperthyroidism and biochemical evidence suggestive of autonomous thyrotropin (TSH) secretion. Intensive investigation of the pituitary-thyroid axis suggested that the basal concentrations of TSH were artefactually increased owing to heterophilic antibodies in the patient's serum with a broad specificity for immunoglobulin class G of the family Bovidea. These heterophilic antibodies complexed with the ovine antisera to human thyrotropin that are used in the RIA system, in particular blocking the binding of TSH but also partly blocking interaction with the second antibody. When TSH was measured immunometrically or by an RIA with TSH-specific antisera of rabbit origin, the concentrations measured were within the appropriate reference intervals. The blocking effect can be overcome by including large quantities of non-TSH-specific ovine IgG in assay incubation mixtures. Interference of this type is generally not appreciated and its incidence is poorly characterized, but it may have implications for any method in which antibodies are used as reagents.

Heteroclitic antibodies in Fischer 344 rats to a synthetic encephalitogenic myelin basic protein peptide

Fischer 344 rats, immunized with the synthetic encephalitogenic myelin basic protein peptide YS49 (YGSLPQKAQRPQDENG), produced heteroclitic antibodies that reacted much more extensively and with a much higher affinity with the cross-reacting encephalitogenic guinea pig sequence S49S (GSLPQKSQRSQDENG) than they did with the immunogenic YS49. On the other hand, antisera against S49S reacted in a normal manner with homologous S49S and cross-reacted only poorly with YS49. The phenomenon of heteroclisis in Fischer 344 rats correlated with the greater encephalitogenic potency of the cross-reacting entity. Kibler et al. (J. Exp. Med., 146 (1977) 1323-1331), by comparing the encephalitogenic guinea pig sequence to a less potent analog, had also previously observed what now would be termed a heteroclitic phenomenon at the T cell level in Lewis rats. In their hands, however, as well as in ours Lewis rat antisera against the encephalitogenic peptide region were much too complex to be analyzed with respect to heteroclisis. It was shown in the present experiments that by utilizing the Fischer 344 system one may also readily obtain heteroclisis at the B cell level against encephalitogenic peptides. Neither YS49 nor S49S as immunogen produced detectable antibody in Brown Norway (BN) rats with exception of two immunized with YS49. In those two cases heteroclitic antibodies were obtained that had a very low significant (greater than 3 SD above baseline) antigen binding capacity for S49S and no detectable reactivity for the homologous YS49 ligand.

Computer modeling of the reaction between antigen and heterogeneous antibody in fixed antigen excess: a new method for measuring antibody affinity

Antigen-antibody binding experiments were performed by choosing antigen excess starting conditions and then diluting both the 125I-BSA antigen and anti-BSA proportionately so that the ratio between the reactants remained constant. The fraction antigen bound was measured at each dilution. Binding data were analyzed by computer using non-linear least squares regression to determine the affinity and affinity distribution of different antisera. Early anti-BSA was found to have a unimodal distribution with a binding constant in the range of 10(6)M-1. Intermediate anti-BSA had a bimodal distribution: 1/3 high affinity (1.0 X 10(9] and 2/3 low affinity (3.4 X 10(6)M-1). Late and hyperimmune rabbit BSA antibodies had unimodal affinity distributions with binding constants varying between 1.7 and 2.9 X 10(10)M-1. Antibody affinity can be readily determined by computer analysis of binding curves obtained in constant antigen excess conditions.

Protective effect of naturally acquired homotypic and heterotypic rotavirus antibodies

To assess serotype specificity of immune resistance to rotavirus gastroenteritis, the relation between pre-existing neutralising antibodies to homotypic and heterotypic rotaviruses and protection against infection or clinical illness was investigated. The subjects were 44 orphans exposed once or twice to consecutive outbreaks of gastroenteritis due to type 3 rotavirus in an orphanage in Sapporo. Sera were collected throughout these outbreaks and the serum levels of neutralising antibodies against four different serotypes of group A human rotavirus were measured before and after the outbreaks. Protection against rotavirus gastroenteritis seemed to be serotype specific and to be related to levels of antibody against homotypic virus. A neutralising antibody level of 1/128 or greater seemed to be protective. The protective effect was of short duration, which was probably the explanation for recurrent attacks of gastroenteritis due to a rotavirus of the same serotype. Seroconversions or concomitant antibody responses to type 1 or 4 rotavirus in most children with type 3 rotavirus infection suggested that immunity to heterotypic virus can be induced by a rotavirus vaccine.

Idiotypic analysis of five xenogeneic antisera to anti-human thyroglobulin monoclonal antibodies

Five xenogeneic anti-idiotypic antisera (anti-id) were produced against individual BALB/c-derived monoclonal antibodies (mAb) which bound to different peptidic determinants on the human thyroglobulin molecule (Tg). Idiotypic analysis performed using sensitive radioimmunoassays revealed that: (1) the anti-id highly precipitated their homologous ligands; (2) two anti-id displayed minor cross-reactivities with one or two heterologous mAb; (3) each unlabelled homologous mAb was able to inhibit the idiotype binding of the corresponding anti-id; (4) no significant inhibition of homologous idiotype binding was observed with large excess of heterologous mAb; (5) efficient inhibition of mAb binding to Tg was observed only when homologous anti-id served as inhibitor. The data support the conclusion that xenogeneic anti-id may detect on their corresponding ligands individual idiotypic specificities that can be located at the mAb-combining site. Such reagents may constitute appropriate probes for further studies on anti-Tg autoimmunity.

Very late activation antigens (VLA) are human leukocyte-neuronal crossreactive cell surface antigens

The antigenic relationship between human neuronal and lymphocyte cell surface antigens has been analyzed using heteroantisera raised against human peripheral blood mononuclear cells (PBMC). The specificities of the crossreactive antigens were examined by immunoprecipitation of 125I-labeled SK-N-SH cultured neuronal cells using rabbit anti-PBMC (RAPBMC) sera and compared to known specificities using mAb. The predominant reactivity of each rabbit antiserum tested against SK-N-SH cells was with three molecules of 130,000, 160,000, and 180,000 Mr. These three chains comigrated with three molecules precipitated with the very late activation antigen (VLA)-specific mAb A-1A5. Sequential precipitations with mAb A-1A5 established that the three RAPBMC-precipitated bands were members of the VLA complex. This was confirmed by two-dimensional PAGE of the RAPBMC and A-1A5 immunoprecipitates, which were indistinguishable from one another. The two-dimensional pattern was more complex than was anticipated from the heterodimeric model of VLA chain association, and suggests an additional 130,000 Mr component of VLA. The three chains of the VLA complex precipitated by RAPBMC or mAb A-1A5 from SK-N-SH neurons closely resembled the VLA pattern present on activated T cells, including the 180,000 Mr activation-specific alpha 1 chain recognized by mAb TS2/7. Normal brain cell membranes also contain VLA molecules that are precipitated by RAPBMC and mAb A-1A5. Thus the VLA complex provides potentially important shared immunogens on human neurons and T cells.

Microstructure of the sialic acid moiety of N-glycolylneuraminyllactosylceramide and the elucidation of Hanganutziu and Deicher (HD) antigenicity

The carboxyl (-COOH) group of heterophile Hanganutziu and Deicher (HD) antigen-active ganglioside (N-glycolylneuraminyllactosylceramide) was esterified (-CO2CH3) by methyl iodide and then reduced to a primary alcohol (-CH2OH) by sodium borohydride. The intact molecule (commonly known as HD3) as well as its two derivatives were tested for HD antigen potency using four human pathologic sera containing HD antibodies. The methyl ester derivative (1-methyl-HD3) gave the same inhibition potency as HD3, but the reduced HD3 gave poor inhibition (1/66) compared to the intact HD3. The results show that reduction of the carboxyl group diminishes the inhibitory potency of HD3. This suggests that although the N-glycolyl (-CH2OH) group of HD3 is the most important determinant for manifestation of HD antigenicity, it is likely that the antibody recognizes both the N-glycolyl and carboxyl groups together when they form a hydrogen bond (-CH2OH---OOC-), aided by their possible proximity, and that substitution of either group therefore reduces the reaction of HD3 with HD antibody dramatically.

Studies on Hanganutziu-Deicher antigens-antibodies. I. Hanganutziu-Deicher antibodies of IgG class in liver diseases

Sera of patients with various liver diseases were examined for the presence of Hanganutziu-Deicher (H-D) antibodies by enzyme immunoassay with high-molecular weight glycoprotein (HMWGP) isolated from bovine red blood cell stromata. IgG class H-D antibodies were demonstrated in sera of 5.9% of acute hepatitis, 28.1% of chronic hepatitis and 21.9% of liver cirrhosis patients. H-D specificity of the antibodies under investigation was determined by absorption experiments. Evidence was also presented that the H-D antibodies in the liver disease sera are directed to N-glycolyl neuraminic acid (NGNA) and/or NGNA-dependent determinants of HMWGP.

Theoretical considerations of the ability of monoclonal antibodies to detect antigenic differences between closely related variants, with particular reference to heterospecific reactions

In theory monoclonal antibodies can be used to analyse antigenic determinants in great detail by correlating differences in antibody affinity for variant antigens with their amino acid differences. In particular, heteroclitic antibodies should be detected, which would normally be masked in a polyclonal antiserum. Recognition of such antibodies may be important for our understanding of the scope of antibody repertoires particularly when the immunogen is closely related to a component of the immunised animal. In practice the immunoassays commonly used to measure affinity differences between different antigens fall short of these capabilities. Mathematical studies were carried out to identify factors controlling the sensitivity of 4 types of assay to differences in affinities for different antigens. The most important factors controlling assay sensitivity were found to be the ratio of antibody affinity (K) to epitope density in direct binding assays, the ratio of K to antibody concentration in liquid phase competition assays, and the ratio of solid phase to liquid phase values of K for solid-phase competition assays. It is predicted that a combination of solid-phase competition assay with high epitope density and direct binding assay with low epitope density would result in optimal detection of heteroclitic antibodies and small differences in antibody affinity for cross-reactive antigens.

Naturally occurring human "antigalactosyl" IgG antibodies are heterophile antibodies recognizing blood-group-related substances

IgG autoantibodies in human serum bind selectively to a new antigen that appears on senescent erythrocytes, thereby initiating their removal from the circulation. We tested the hypothesis that these IgG molecules recognize terminal galactose residues, thought by some investigators to become exposed as cells age. Results revealed that human antibodies with an "antigalactosyl" specificity are heterophile antibodies directed against rabbit and not human red cells. This was demonstrated using hemagglutination assays and immunoblotting. Immunoblots performed with affinity purified antigalactosyl antibodies revealed binding of the antibodies to rabbit, but not human, erythrocyte membrane proteins. They have a broad range of specificities including anti-B, anti-I, and possibly anti-P1 and Pk. These heterophile antibodies are not involved in the physiological removal of senescent human RBC by macrophages as indicated by the data demonstrating that incubation of senescent red cells aged in situ with galactose prior to incubation with macrophages does not alter their phagocytosis. Senescent cell IgG does not have an antigalactosyl specificity because IgG eluted from senescent cells aged in situ does not bind to rabbit red cells that have exposed alpha-galactosyl moieties.

Development of subtype-specific and heterosubtypic antibodies to the influenza A virus hemagglutinin after primary infection in children

Children undergoing primary infection with an H1N1 or H3N2 influenza A virus developed subtype-specific hemagglutination inhibition antibodies and enzyme-linked immunosorbent assay antibodies to purified hemagglutinin (HA) of the infecting virus subtype. They also developed lower titered ELISA antibodies to the noninfecting H1 or H3 HA and to H8 (an avian strain) HA. Thus, after primary infection with an influenza A virus, children develop enzyme-linked immunosorbent assay, but not hemagglutination inhibition, antibodies reactive with heterosubtypic HAs. These heterosubtypic antibodies could influence the response to infection with other wild-type or attenuated vaccine strains of influenza A virus.

[Heterogeneity of monoclonal antibody affinity]

In experiments with Pasteurella pestis monovalent capsular antigen and hybridoma monoclonal antibodies obtained after cloning and recloning the heterogeneity of the active centers of antibodies with respect to their affinity was revealed. In ascitic fluids obtained from the animals inoculated with different hybridoma clones 5 groups of antibodies, differing in their affinity, were determined in each fluid sample.

Characteristics of the anti-sheep red blood cell heterophile antibodies produced during Schistosoma japonicum infection in mice

Heterophile antibodies (Ab) against sheep red blood cells were shown to have developed in mice experimentally infected with Schistosoma japonicum (SJ). Incidence of the elevated Ab levels was markedly high in the period of 6-10 weeks following infection. By means of absorption tests, the heterophile Ab could be distinguished from classical human heterophile Ab of Paul-Bunnell, Hanganutzui-Deicher, and Forssman types. Antigen(s) cross-reactive with the heterophile Ab was found only in goat red blood cells (RBC) but absent on RBC of other species, in various tissue homogenates of syngeneic mice, or in SJ parasites and their eggs. The Ab activity seems to be mainly localized in immunoglobulin classes other than IgM.

Cellular characteristics of neoplastic angioendotheliosis. An immunohistological marker study of 6 cases

Neoplastic angioendotheliosis (NAE) is a rare, mostly fatal disease characterized by proliferation of large blastoid cells in small vessels of various organs. The origin of neoplastic cells remain undetermined. In this study, cell markers were studied immunohistologically on paraffin sections of six cases of NAE, by applying avidin-biotin-peroxidase (ABC) method and five antibodies which can demonstrate marker antigens on formalin fixed and paraffin embedded specimens. It was shown that the neoplastic cells were heavily stained with an anti-B lymphocyte monoclonal antibody LN-1 (6/6), moderately stained with another anti-B lymphocyte antibody LN-2 (5/6) and heavily stained with a monoclonal antibody which reacts with all levels of leukocytes (Dako-LC) (6/6). The cells did not show positive reaction with an anti-myelomonocytic antibody anti-Leu M1. The reaction against anti-Factor VIII, which can depict endothelial cells, was mostly negative, and if positive, was faint and indefinite, leading to an assumption that the reaction was against antigens in serum and not against neoplastic cells. These results suggest that the neoplastic cells of NAE are in the B lymphocyte lineage.

Immunological study of heart diseases with special reference to the cytotoxicity of the heterophile antibody against cultured myocardial cells

In our previous study, a high rate of "heterophile antibody" was found in idiopathic cardiomyopathy. In the present investigation the cytotoxic activity of this antibody was examined in cultured myocardial cells. Trypsin treated cells cultured for 3 days were used in the two-step method of the complement dependent cytotoxicity test. The trypan blue dye-exclusion method was utilized to determine the percentage of surviving cells, and the cytotoxic effect was expressed by the cytotoxic index (CI). With fresh rabbit serum as complement, the mean CI value of the heterophile antibody positive sera was 20.7, which was in contrast to the value of anti-heart antibodies negative sera (p less than 0.01). As the cytotoxic effect to the heterophile antibody was absent without the complement, it may be complement dependent. Thus, our results suggest that the heterophile antibody may play a role in the pathogenesis or be an incremental factor of idiopathic cardiomyopathy.

The presence of anti-sheep red blood cell heterophile antibodies and their characteristics in murine schistosomiasis japonica

Sensitive methods of an enzyme-linked immunosorbent assay (ELISA) using red blood cells (RBC) have been developed and were applied to the detection of anti-sheep red blood cell (SRBC) heterophile antibodies (Ab) present in sera of Schistosoma japonicum (SJ)-infected mice. The indirect hemagglutination test (IHA) was used for the purpose as well. By these methods a significant increase in the heterophile Ab levels was demonstrated in the mice particularly after 6-10 weeks of infection. The heterophile Ab in SJ-infected mice were predominantly immunoglobulins resistant to 2-mercaptoethanol treatment and had temperature-independent reactivity. In an attempt to investigate the immunological specificity of the heterophile Ab, various absorption tests were performed; Davidsohn's differential absorption test revealed that the heterophile Ab were distinct from Forssman antibody, Paul-Bunnell antibody and heterophile agglutinins known to appear in serum sickness. The heterophile Ab were absorbed only with SRBC and goat red blood cells, not with other species of RBC such as human O Rh-, O Rh+, A Rh+, B Rh+, mouse, ox, chicken, horse, rabbit, guinea pig, and rat RBC, or syngeneic tissue homogenates including brain, lung, liver, spleen, kidney, muscle, and thymus. This heterophile antibody response is not a consequence of a specific immune response directed to the antigens of SJ parasites, since absorption of the heterophile Ab with SJ adult worms or an egg preparation did not reduce the heterophile Ab level.

Stimulation of Na+-K+ pump in sheep red blood cells by heteroimmune anti-sheep red cell antibodies

In the HK-LK polymorphism of sheep red blood cells, alloimmune antiserum against the L antigen on LK cells is known to stimulate the Na+-K+ pump in low K+ (LK) cells, but alloimmune antiserum against the M antigen of high K+ (HK) cells does not. We have shown for the first time that heteroimmune antibodies against sheep red blood cells raised in mice can stimulate the pump. Heteroimmune antibodies against both LK(L) cells and HK(M) cells stimulated active K+ transport in LK cells. Furthermore heteroimmune antibodies against LK(L) cells also stimulated the pump in HK cells. As expected, alloimmune and heteroimmune antibodies acted at different sites in stimulating transport in LK cells.

Specificity of transplantation heterophile antibodies

Sera of 154 recipients of renal allografts were studied for transplantation heterophile (T-H) antibodies by means of immunodiffusion, mixed agglutination (MA) and enzyme immunoassay (EIA). T-H antibodies were found by immunodiffusion against bovine red blood cell (BRBC) extracts (15%) and sheep red blood cell (SRBC) extracts (12%): The specificity of antibodies to BRBC was shown to be distinct from that of antibodies to SRBC. Both of these T-H antibody types were absorbable by guinea pig kidney ( GPK ) tissue sediments and, therefore, they could be classified into the GPK -positive group of heterophile antibodies. The MA test was successfully employed to demonstrate directly T-H antibodies combining with antigens of GPK . Results of the MA inhibition studies and those of EIA indicated that some of the BRBC antibodies are directed to antigens of asialo-high molecular-weight glycoprotein of BRBC.

Heterophile antibodies in sera of patients with Chediak-Higashi syndrome

Sera of 6 patients with Chediak-Higashi syndrome and sera of their mothers were studied for heterophile antibodies. Sera of 5 patients as well as 5 sera of their mothers contained antibodies against trypsinized bovine erythrocytes, tissue sediments of guinea pig kidney or high molecular weight glycoprotein (HMWGP) of bovine erythrocyte stromata. The antibodies combining with HMWGP in enzyme immunoassay belonged to IgM and IgG classes. Although none of the sera had significant titer of agglutinins against sheep erythrocytes, on the basis of absorption and inhibition studies, these antibodies seemed to belong to the Hanganutziu-Deicher group of antibodies.

Virologic, immunologic, and clinical observations on a patient during the incubation, acute, and convalescent phases of infectious mononucleosis

One patient with infectious mononucleosis (IM) was studied from the probable time of Epstein-Barr virus (EBV) infection (38 days before the onset of clinically overt disease), during the incubation and acute phases, until 6 months after clinical remission. Analysis of spontaneous outgrowth of EBV-carrying lymphoblastoid cells, by limiting dilution on feeder layer cultures, showed that virus containing B lymphocytes are already present early during the incubation period. Also low interferon serum levels were detected early after infection, and only before the onset of clinical disease. All other studied clinical laboratory and virus-associated variables were within normal range during the incubation phase, but changed to a pattern characteristic of IM in parallel to the clinical symptoms. During the acute disease EBV-associated nuclear antigen (EBNA)-positive cells could be directly detected among the lymphocytes, and antibodies to EBV antigens appeared. Lymphocytes stained by monoclonal antibodies, detecting Ia-like determinants (activated cells) and suppressor cells, increased dramatically, in parallel to a strong increase of functional suppressor cell activity, measured by inhibition of blastogenesis and PWM-induced immunoglobulin production. During the acute phase there was also a decrease of spontaneous cytotoxicity against the NK-sensitive cell line K562, while cytotoxicity (spontaneous) against an autologous EBV-positive lymphoblastoid cell line (LCL) was detected only during this phase. These reactions correlated to the presence of blasts, and the autologous reaction was exerted mainly by Fc-receptor-negative cells. Lymphokine production in response to EBV antigens was also initiated during the acute phase. During the convalescence period the serological and cellular immune parameters adjusted to the pattern of a normal EBV-seropositive person.

Biotechnological approach to a new foot-and-mouth disease virus vaccine

Major contributions towards the development of an absolutely safe FMDV vaccine are evident. With the identification of VP1 as the immunogenic protein, it is possible to manufacture a subunit vaccine via biotechnology. DNA sequences encoding the VP1 protein can be introduced into a bacterium with ease; under the appropriate conditions, large amounts of VP1 can be produced in a short time. The accumulation of amino acid sequences generated by recombinant DNA techniques allows identification of antigenic domains, which are the basis of variability among serotype and subtype viruses. As a result, vaccine production by chemical synthesis of short peptides corresponding to the antigenic determinants is greatly facilitated. At present, results from experimental vaccines employing genetically engineered or chemically synthesized VP1 antigens against homologous virus infection are encouraging. The current approach of preparing vaccine is to utilize the antigenic specificity of the virus. Since FMDV undergoes antigenic drift, variants not neutralized by type-specific serum will arise. An alternative approach is to prepare vaccines based on antigenic sites shared among all serotype and subtype viruses.

Non-cytotoxic alloantibodies defined by the EA rosette inhibition assay

Sera from both transfused individuals and pregnant women mediated inhibition of Fc-rosette formation. Both normal blood B lymphocytes and chronic lymphocytic leukemia cells were used as targets. Inhibition was not related to the presence or absence of lymphocytotoxic antibodies. When tested against a panel of B lymphocytes these sera displayed selective reactivity in keeping with the recognition of allospecific determinants. No association between the target antigen(s) and classically defined MHC-coded structures was evident. Heteroantibodies to both class I and class II MHC structures as well as beta 2-microglobulin also mediated FcR blockade. However, unlike the alloantisera tested, these antibodies displayed no restriction in their reactivity toward individual target cells.

Circulating human antibodies as a cause of falsely depressed ferritin values

We have previously reported spuriously elevated values for serum thyrotropin (TSH) measured by immunoradiometric assay (IRMA). We tested those sera showing interference with the TSH assay in a ferritin IRMA which used 125I-rabbit antiferritin antibody and solid phase goat antiferritin antibody as reagents and spleen ferritin as standard. In this assay, we obtained falsely low ferritin values that were corrected by addition of 0.2% non-immune rabbit serum to the labelled antibody. Two other radioimmunoassays gave results with these sera that were not falsely lowered. The interference was shown to be due to human IgG reactive with rabbit serum, the specificity of the interfering antibody being similar in all affected sera. Human antibodies directed against immunoassay reagents may lead to spuriously increased or decreased immunoassay results depending on the specific reagents involved.

[The Paul-Bunnell test of maternal and cord sera]

In this study, heterophil antibodies are measured from the cord sera of the 100 newborns who were born normally at term from the healthy females. These results compared with the heterophil agglutinins levels of the mother's sera.

Studies on Paul--Bunnell (P-B) antigen--antibody system. IV. Unresponsiveness to one of P-B antigens in infectious mononucleosis

Sera of 198 patients with infectious mononucleosis (IM), which were obtained during the 3rd or 4th week of the disease, were studied for the presence of antibodies to BS and B antigens of the Paul--Bunnell (P-B) antigenic complex. Six of these IM patients had anti-B antibodies without or with very low-titer anti-BS antibodies and the remaining patients had both types of antibodies at high titers. These 6 IM patients would have been misdiagnosed as seronegative if the traditional P-B tests with sheep erythrocytes had been employed. BS antigen was demonstrated in a large amount in chloroform-methanol extracts of peripheral blood buffy coat and of erythrocytes obtained from 1 of the 6 patients during the 3rd week of the disease and right after recovery.

Heterophil nature of EVI antibody in Trypanosoma cruzi infection

Previous findings implying the autoreactive capability of circulating complement-fixing (EVI) antibodies in patients with Chagas' disease (American trypanosomiasis), under both in vitro and in vivo conditions have been irreproducible. The presence of the tissue antigens involved in the reactivity with EVI antibodies is exclusively confined to nonhuman substrates, suggesting the heterophil nature of these antibodies which, on the other hand, have also been described in human sera collected in areas free from Chagas' disease. This would preclude any direct pathogenic effect of EVI antibodies when present in the circulation, though they may be useful immunological markers of unsuspected Trypanosoma cruzi infection in endemic areas.

Evaluation of usefulness of 2-mercapto-ethanol treatment in serodiagnosis of swine leptospirosis

Serum samples of piglets infected artificially or naturally, respectively, with Leptospira pomona were treated with 2-mercapto-ethanol (ME) and tested in the microscopic agglutination test in comparison with untreated sera. Serum-treatment with ME showed two beneficial effects, one being the total elimination of heterotypic reactions, the other the reduction or elimination, respectively, of early antibodies, presumably belonging to the IgM class. Accordingly, two practical implications can be derived from our results. The ratio of ME-sensitive and ME-resistant antibody titers allows the recognition of early leptospira infections. The total suppression by ME of heterotypic agglutination eliminates the danger of determining the wrong leptospira type as causative agent, a crucial problem encountered not infrequently with agglutination testing of untreated sera. Recognition of early cases of swine leptospirosis by ME-treatment of sera is particularly useful, as the complement fixative reaction, successfully used in other species for the same purpose, is inappropriate in swine sera owing to their autolytic properties. Furthermore by elimination of all heterotypic reactions the ME-method gives better chances for the determination of the causative agent and hence for correct interpretation of serological results. ME-treatment is considered as a useful help in serodiagnosis of field samples, in which determination of duration of infection is essential or in which heterotypic agglutination is obscuring the etiological leptospira type.

Immunochemical studies of infectious mononucleosis--XI. comparison of heterophile antibody inhibitors from the erythrocyte membranes of four mammalian species

Immunochemical comparisons were made of the reactivity of membrane glycoproteins from horse, bovine, sheep and goat erythrocytes with heterophile antibodies of infectious mononucleosis. The four receptors were tested as competitive inhibitors of a sandwich-type solid-phase radioimmunoassay and of agglutination of glycoprotein-latex reagents by infectious mononucleosis serum. The results of this study showed that the bovine glycoprotein had a superior reactivity with this heterophile antibody system and sheep erythrocyte glycoprotein was the least reactive. The latter had negligible ability to displace 125I-bovine glycoprotein and was a very poor inhibitor of the agglutination of a bovine glycoprotein-latex reagent by infectious mononucleosis serum. Horse and goat glycoproteins were more efficient inhibitors than sheep glycoprotein but less active than the preparation from bovine red cells. All of the inhibitory activity of sheep, horse and goat glycoproteins, and a major portion of that of the bovine glycoprotein was destroyed by neuraminidase treatment. We have termed this receptor--shared by all four species--the Paul-Bunnell receptor, since by definition Paul-Bunnell antibody is a sheep erythrocyte agglutinin which is also reactive with horse, bovine and goat erythrocytes. The neuraminidase (and alkaline borohydride) resistant receptor of bovine glycoprotein has been designated the Bo receptor because it is not common to the other three species.

Relationship between type specific antibodies to herpes simplex virus and type specificity in human sera

A quantitative analysis was carried out on the relationship between type specific neutralizing antibodies to herpes simplex virus and the type specificity, using a mutual absorbing procedure. Forty-two samples were selected among human sera, on the basis of type specificity expressed by the value of II/I index. All sera with values of less than 90 of II/I index contained only type 1 specific antibody, while those with values over 111 contained only type 2 specific antibody. When the values were between 90 and 110, type 1 specific antibody was present in all, and type 2 specific antibody was present in some serum samples.

[Can growth-stimulating immunoglobulins (TGI) explain sporadic euthyroid goiters?]

IgGs capable of stimulating thyroid growth have been demonstrated (thyroid growth stimulating IgG-TGI) using a cytochemical bioassay based upon measurement of DNA synthesis in slices of guinea-pig thyroid. This activity has been confirmed by measurement of 3H-thymidine incorporation into DNA, in rat dispersed thyroid follicles cultured in suspension. Circulating TGI has been observed in patient with "simple" goitre, Graves' disease and more rarely in Hashimoto's thyroiditis. TGI titers are correlated with goitre size or lack of suppressibility by exogenous thyroid hormones rather than with thyroid function as assessed by circulating hormone levels. In patients with primary myxoedema and thyroid atrophy, existence of TGI-blocking IgGs has also been demonstrated. Existence of natural TGI has been corroborated by experimental production of a monoclonal anti-TSH receptor antibody with thyroid growth activity. These observations raise several points: --relationship of TGI to other thyroid antibodies, specially to anti-TSH receptor antibodies; --is "simple" goitre, either diffuse or nodular, an auto-immune thyroid disorder? How to explain the usual functional and structural heterogeneity of these goitres?; --metabolic relationship between DNA synthesis and activity of glucose-6-phosphate deshydrogenase involved in hormonogenesis; mechanism of the apparent uncoupling between cell multiplication and secretory activity.

Heterophilic antibodies interfering with radioimmunoassay. A false-positive pregnancy test

A young man with amenorrhea had a consistently positive pregnancy test result (serum radioimmunoassay measurement of beta-human chorionic gonadotropin hormone). No fetal or placental tissue was found after uterine curettage and exploratory laparotomy. The false-positive pregnancy test result was due to heterophilic antibovine and antigoat antibodies in the patient's serum. These antibodies interfered with radioimmunoassays using goat antibodies. This case shows that serum heterophilic antibodies can interfere with immunoassays and result in unnecessary diagnostic procedures and/or unnecessary treatment.

Xenoantisera directed against the proliferating T-cells of MRL/Mp-lpr/lpr mice

MRL/Mp-lpr/lpr (lpr/lpr) mice develop a generalized lymph node (LN) hypertrophy reflecting the expansion of a T-cell subset that seems to act as an accelerating factor for autoimmunity. In an attempt to produce antisera specific for this T-cell subset, NZW rabbits and Lewis rats were hyperimmunized with cells from hypertrophied lpr/lpr LN. The resulting xenoantisera were extensively absorbed with lymphoid cells from the congenic MRL/Mp +/+ (+/+) strain. As assessed by complement-dependent microcytotoxicity and indirect immunofluorescence using flow cytofluorometry analysis, these xenoantisera reacted with 70-90% of the cells in the enlarged LN of 4-month-old lpr/lpr mice but only with 10-35% of the cells in the normal-sized LN of age-matched +/+ mice or of 2-month-old lpr/lpr mice. These xenoantisera which appear to identify surface antigens associated with the proliferating lpr/lpr T-cells may prove useful to investigate the mechanism by which these cells contribute to the autoimmune disease of lpr/lpr mice.

Human antibodies recognizing the envelope glycoprotein of the baboon endogenous virus BaEV are of heterophil origin

Human sera were previously shown to possess antibodies capable of recognizing purified retrovirus envelope glycoproteins. In an extension of earlier studies we investigated sera from various groups of patients for an immune reaction against purified glycoprotein of the baboon endogenous virus BaEV. Reproducible demonstrations of oncovirus-like particles in human teratocarcinomas focused our main interest on sera from patients with testicular tumors. The specificity of the positive immune reaction of sera from these patients against BaEV gp 70 was analyzed in a competition RIAs with haptens and different cell lysates and experiments employing deglycosylated BaEV envelope antigen. From these experiments we conclude that the sera from teratocarcinoma patients contain naturally occurring, heterophil antibodies that react with the carbohydrate moieties of retrovirus envelope antigens.

In vivo tumor localization using tumor-specific monkey xenoantibody, alloantibody, and murine monoclonal xenoantibody

Specific in vivo localization of antibodies reactive with human melanoma cell membrane tumor associated antigens (TAA) has been attempted using congenitally athymic nude mice bearing subcutaneous human melanoma tumor xenografts as the experimental model. IgG fractions were prepared from each of several immune and control sera. Antimelanoma antibody sources included human alloantibody obtained from melanoma patients immunized against allogeneic melanoma cells, a monkey antiserum raised by immunization against a single human melanoma cell line, and a murine monoclonal antimelanoma antibody-secreting hybridoma cell line. Localization of these radiolabeled antibodies and of control IgG preparations to tumor tissue was determined by whole body scintigraphy and by differential tissue counting. Compared with the different control IgG preparations, each of the antimelanoma IgG preparations exhibited significant specific accumulation within the melanoma tissue. However, variation existed in the ability of each antimelanoma IgG to tumor preparation to localize despite attempts to control model parameters such as tumor source, in vivo passage number and mass. This variation appears to reflect basic biologic differences between tumors in different animals and possibly differences in the antigen-binding capacities of each IgG preparation following radioiodination. This technique for tumor localization is very promising and has obvious potential for clinical application.

[Serum antibody and splenocyte immunoglobulin receptor affinity in multiply immunized mice]

In the process of repeated immunization of CBA mice with soluble Pasteurella pestis capsular antigen the concentration of antibodies in the blood increased, but the dynamics of antibody affinity in the serum did not correlate with this process. For the first time the average splenocyte receptor affinity was measured, and this characteristics was found to exceed that of the corresponding serum antibodies. To explain the heterogeneity of antibodies, two hypotheses have been proposed. One hypothesis states that the heterogeneity of antibodies is determined by the cyclic character of antigen concentration at the site of injection, while according to the other hypothesis, it is determined by the interaction of immunoglobulins of different idiotypes with idiotypic antibodies.

Heterophile antibodies in the serum of children with nephrotic syndrome

Serum of children with the nephrotic syndrome contained high titers of a (19S) IgM antibody against sheep, horse, guinea pig, rat, and rabbit red blood cells but not against cow red blood cells. There was high correlation between high titers of antisheep antibodies and active nephrotic syndrome in the children with minimal change nephrotic syndrome. The antibody differed from the Paul-Bunnell antibody found in patients with infectious mononucleosis and from the anti-Forssman, Hangautziu-Deicher antibody found in patients with horse serum sickness. Rabbit red blood cells completely absorbed the antibody, but horse or guinea pig red blood cells removed only the anti-Forssman activity.