Antibody Response In Man Research Articles

Synthetic peptides deduced from the amino acid sequence of Epstein-Barr virus nuclear antigen 6 (EBNA 6): antigenic properties, production of monoreactive reagents, and analysis of antibody responses in man.

Studies on the antibody responses to various Epstein-Barr virus (EBV) antigens have been instrumental in the understanding of the seroepidemiology and diagnosis of this viral infection and the subsequent carrier state. While antibodies to the viral capsid antigen (VCA), early antigen (EA), and nuclear antigens 1 and 2 (EBNA 1 and 2) have been well characterized, the antibody response to the other nuclear antigens is not well understood. EBNA 6 is expressed by lymphoblasts during acute EBV infection and may be an important antigen for diagnosis and evaluation of the immune response. In order to analyze the antibody response to EBNA 6, ten peptides (20-21 amino acids), deduced from the EBNA 6 coding region, were synthesized and evaluated for antigenicity by ELISA. One peptide (p-63; PAPQAPYQGYQEPPAPQAPY) derived from the amino acid repeats showed the highest specific reactivity with human sera. This peptide was evaluated further for detection of human EBNA 6-reactive antibodies. Forty-two of forty-nine (86%) EBV-seropositive healthy donors had p-63-specific IgG reactivity, while none of 50 EBV-seronegative patients reacted with the p-63 peptide. Twenty-two of fifty-one (43%) patients with ongoing primary EBV infection had detectable p-63-specific IgG. Serum samples drawn sequentially from patients during and after primary EBV infection revealed an increase in p-63-reactive IgG over time.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral immunization with Salmonella typhi Ty21a-based clones expressing Vibrio cholerae O-antigen: serum bactericidal antibody responses in man in relation to pre-immunization antibody levels

Previous studies have shown that oral immunization with Salmonella typhi Ty21a-based clones expressing Vibrio cholerae O-antigen elicits serum antibody responses against the foreign polysaccharide in human volunteers. These responses are conveniently assayed by complement-dependent bacteriolysis of V. cholerae. In this report the bactericidal responses generated by two such clones are analysed in relation to the pre-immunization titres of various serum antibodies. A significant association was found, in that recipients with higher prevaccine titres of anti-V. cholerae bactericidal antibodies were less likely to register significant bactericidal responses following immunization. These results are discussed in relation to the concept of vaccine exclusion.

Immunization of simian immunodeficiency virus-infected rhesus monkeys with soluble human CD4 elicits an antiviral response.

Since the CD4 molecule is a high-affinity cell-surface receptor for the human immunodeficiency virus (HIV), it has been suggested that a soluble truncated form of CD4 may compete with cell-surface CD4 for HIV binding and thus be of use in the therapy of AIDS. We have utilized the simian immunodeficiency virus of macaques (SIVmac)-infected rhesus monkeys to explore another possible therapeutic application of CD4 in AIDS--the use of recombinant soluble CD4 (rsCD4) as an immunogen. SIVmac-infected rhesus monkeys immunized with human rsCD4 developed not only an anti-human CD4 but also an anti-rhesus monkey CD4 antibody response. Coincident with the generation of this antibody response, SIVmac could not be isolated easily from peripheral blood lymphocytes and bone marrow macrophages of these animals. Furthermore, the decreased number of both granulocyte/macrophage and erythrocyte colonies grown from the bone marrow of these immunized monkeys rose to normal levels. These findings suggest that a modified human CD4 molecule serving as an immunogen might elicit an antibody response in man that could induce a beneficial therapeutic response in HIV-infected individuals.

Conformational stability of B cell epitopes on group I and group II Dermatophagoides spp. allergens. Effect of thermal and chemical denaturation on the binding of murine IgG and human IgE antibodies.

The conformational stability of B cell epitopes on the 25-kDa group I and 14-kDa group II mite allergens was compared by using heat-treated or chemically denatured allergens to inhibit the binding of native 125I allergens to murine mAb or to human IgE antibodies. Structural changes after treatment were assessed by SDS-PAGE and circular dichroism spectroscopy. Heating for 1 h at greater than 75 degrees C, treatment at pH 2.0 or pH 12.0, or with 6M guanidine or 6M urea, reduced the binding of the group I allergens to mAb or IgE antibodies by 10- to 1000-fold. The group II allergens were heat stable and even after prolonged heat treatment (5 h at 75 degrees C or 30 min at 100 degrees C) their antibody binding activity was reduced by less than twofold. The group II allergens were also resistant to pH and to denaturation with 6M guanidine. However, after reduction and alkylation, antibody binding sites on both the group I and group II allergens were destroyed. Reduction of disulfide bonds with 2-ME caused a marked shift in the molecular mass of group I allergens on SDS-PAGE, from 25 kDa to 28-31 kDa. Reduction and alkylation also generated two high m.w. forms of Der p I and Der f I. After heating (100 degrees for 30 min), both Der f I and Der f II retained significant secondary structure, as judged by circular dichroism spectroscopy, but on reduction they showed the typical spectra of fully denatured proteins (greater than 85% random structure). The results show clear differences between the susceptibility of B cell epitopes on the group I and group II allergens to denaturation. Despite these differences in stability, both allergens are equally potent immunogens for IgE antibody responses in man. The results support the view that the physical properties of allergens (low m.w. and solubility), limiting low dose exposure (1 to 10 ng/day), and host genetic and immunoregulatory processes, are more important than gross structural features in the induction and maintenance of IgE antibody responses.

Quantitation of mouse monoclonal antibody and human anti-mouse antibody response in serum of patients.

The assays required to study pharmacokinetics of monoclonal antibodies and human anti-mouse antibody response in man, utilizing enzyme linked immunosorbent assay, have been at best semi-quantitative. We have developed and well characterized a quantitative assay for measurement of murine monoclonal antibodies and human anti-mouse antibody in circulation of patients injected with murine monoclonal antibodies. The sensitivity of mouse IgG assay is approximately 1 ng/ml and cross reactivity of IgG's from other species were less than 0.01%. The pre-therapy samples from 30 patients treated with monoclonal antibody CO17-1A as well as serum from 54 individuals had no detectable human anti-mouse antibody indicating specificity. The sensitivity of this assay was approximately 10 mg/ml. The utility of these assays was demonstrated in a group of patients receiving 400 mg of monoclonal antibody CO17-1A. The half-life and the degree of immune response can be measured using these assays.

Pathogenetic and serological aspects of pulmonary aspergillosis.

Af is an important pathogen of the bronchopulmonary system, and the clinical spectrum encompasses aspergilloma, CNPA, IPA, ABPA, bronchial asthma, and allergic alveolitis. Bronchial carriage may, however, not always be associated with pathological effects. The polymorphism of the aspergillus-related disorders seems mostly to depend upon the different responses of the hosts. This review considers the antigenic composition of Af and specific antibody responses in man in relation to the pathogenesis and diagnosis of the various forms of pulmonary aspergillosis. More than 200 macromolecular components have been listed for Af and more than 30 antigens found to react with human sera. Serum antibodies to Af are common in healthy subjects. Schønheyder and his associates (A-L) have shown that IgG, IgA and IgM antibodies in healthy subjects are directed towards antigens to which also patients with aspergillosis strongly react. With immunofluorescent staining these antigens were found to be associated with hyphal walls, and a MW 470,000 fraction from ruptured mycelium was most reactive in ELISA. The respiratory tract appears to be the major route for exposure since the humoral responses include IgA class antibodies, and sIgA antibodies are found in bronchial secretions. Moreover, IgG antibody levels to the MW 470,000 fraction correlate with occupational exposure and smoking habits. In patients with cystic fibrosis high IgG antibody levels to MW 470,000 and MW 25,000-50,000 antigen fractions were associated with the carriage of Af in the sputum. An individual patient's level of IgA antibodies to the MW 470,000 fraction was inversely related to the Af carrier rate, and this was also true for IgE dependent reactivity to Af antigens. These observations indicate that IgG antibodies to some antigens mirror the extent of antigenic exposure, whereas some IgA and IgE antibodies may play a protective role against bronchial colonization with Af. IgG antibody determinations by ELISA were found to provide a higher diagnostic efficacy in pulmonary aspergillosis than IgA antibody assays. With IgG antibodies there were statistically significant differences between patients and the controls and there was little overlap of ELISA values between the groups. The fractions of MW 250,000 with catalase activity and MW 25,000-50,000 with protease activity, were most suitable for serological diagnosis. A gel immunoelectrophoretic assay proved Af catalase to be a major diagnostic antigen in patients with aspergilloma or with an apical aspergillus lung infiltrate.(ABSTRACT TRUNCATED AT 400 WORDS)

B cell development and regulation after T cell-depleted marrow transplantation.

Antibody secreting B lymphocytes from immunized donors can be adoptively transferred after T cell-depleted marrow transplantation to produce protective levels of antibody in the recipient. We have investigated whether these transferred lymphocytes remain subject to continued clonal selection and subsequently became memory B cells even in the initial absence of T cells. Twenty-eight donor/recipient pairs were randomized pretransplant to be immunized or not with tetanus toxoid (TT). The recipients were then vaccinated with TT at 3, 6, and 12 mo posttransplant, and the anti-TT antibody response (IgG and IgM) was measured. Only when both donor and recipient were immunized pretransplant could the recipient respond to antigen challenge within the first year posttransplant. Examination of the spectrotype pattern of the recipient anti-TT antibody shows that selection of B cell clones continues, so that T cell depletion does not prevent the appearance of oligoclonal antibody responses. However, because the spectrotype pattern of the recipient did not match the donors, B cell regulatory mechanisms in donor and recipient are nonidentical. These data contrast with observations made in recipients of non-T cell-depleted marrow and serve to illustrate the role of T lymphocytes in the induction and regulation of secondary antibody responses in man. The results also suggest that optimal humoral responses to any antigen after T cell depletion can only occur when both donor and recipient are immunized pretransplant, a prediction borne out by studies on the influence of donor cytomegalovirus status on the severity of cytomegalovirus infection in the recipient.

The interference of antibiotics with antigen-specific antibody responses in man

The effect of a series of antimicrobial drugs on human antigen-specific primary antibody response in vitro was investigated. Of the five agents tested, only streptomycin and gentamicin induced an appreciable reduction in the antibody response; penicillin G, rifampin and amikacin had a poor or irregular effect. The precise mechanisms of action of these substances on mammalian cells remain to be elucidated since an assessment of their capacity to interfere with the immune system is of particular importance in those patients with induced or acquired immunodeficiencies. In this respect, we provide an inexpensive and sensitive method for the preliminary screening of potentially immunosuppressive drugs.

Specific antibody responses in man after immunostimulation with bacterial ribosomal fractions: Preliminary report

Specific antibody responses in man after immunostimulation with bacterial ribosomal fractions: Preliminary report

Dose response of IgE and IgG antibodies during ragweed immunotherapy

We studied the detailed dose-response relationship for ragweed (RW) antibody responses in 51 patients who received maximal-dose immunotherapy with crude RW extract. Serum RW-IgG and RWIgE levels were determined by solid-phase radioimmunoassay at frequent intervals during initiation and maintenance of immunotherapy. Pretreatment RWIgE ranged from 0.94 to 974 ng/ml (median 105); 45 51 patients had insignificant levels (<250 ng/ml) of RWIgG. The maximal doses given ranged from 0.19 to 93.5 μg of RW antigen E per injection. All patients produced a significant IgG response (medium peak 3462 ng/ml, range 689 to 24,395), and 46 51 had significant increases in IgE antibody (median peak 231 ng/ml, range 12 to 1528). A threshold dose was defined for each patient's IgG and IgE response as that dose level which initiated a persistent increment in immunoglobulin to ≥25% of pretreatment levels. The median for IgE was 0.13 μg of antigen E, which was achieved in a medium time of 42 days. The threshold dose for IgG was significantly higher (medium 0.56 μg of antigen E; p = 0.001) and occurred significantly later (median 79 days; p = 0.003). Despite variability over 3 orders of magnitude, the thresholds for IgE and IgG responses were significantly correlated for individual patients (r = 0.487; p = 0.002). The maximum RWIgE response occurred in a median of 107 days, after which IgE antibodies declined in 46 of 49 patients. The maximal IgG response occurred significantly later (median 245 days; p < 0.001) and then plateaued or declined modestly. The doses required to achieve maximal IgE and IgG responses were significantly correlated (r = 0.638; p <0.001). The maximum IgG response was positively correlated with the maximal dose of RW antigen E received (r = 0.592; p <0.001). In 28 of the 51 patients, the incremental rise in total serum IgE was more than twice that observed for RWIgE at the time of the maximum response, suggesting a nonspecific effect of RW immunotherapy on total serum IgE levels. This discrepancy could not be accounted for by environmental stimulation from other known allergens, as assessed by skin testing, or by pretreatment levels of RWIgE or total IgE. These observations indicate that the human IgE antibody response during high-dose RW immunotherapy is more sensitive to both stimulation and suppression by continuous allergen administration than is the IgG response. This finding may have implication both for our understanding of the in vivo regulation of immune response during allergen immunotherapy and for future attempts to modify specific IgE antibody responses in man.

Specific in vitro antimannan-rich antigen of Candida albicans antibody production by sensitized human blood lymphocytes.

We have developed a new antigenic system for the induction of specific in vitro antibody response in man. The antigen used was purified from the cell wall of Candida albicans strain A and contained greater than 96% polysaccharide mannan. Peripheral blood mononuclear cells from Candida-sensitized donors produced specific antimannan antibodies during a 7-d culture in the presence of mannan absorbed with methylated bovine serum albumin. Two methods were used to detect antimannan antibody responses. Antimannan antibody-producing cells were identified by radioautography with tritiated mannan. Antibody concentration in culture supernatants was measured by an enzyme-linked immunosorbent assay. In both methods, specific IgM and IgG (but not IgA) antibodies were detected. The antibody production to mannan was specific, since an antigenically unrelated polysaccharide (pneumococcal antigen S III) did not bind to methylated bovine serum albumin-mannan-induced blast cells and did not induce antimannan antibody-containing cells. Furthermore, a pulse with an excess of unlabeled mannan abolished [3H]mannan binding, whereas an excess of unlabeled S III did not. Similarly, no antimannan antibody was obtained in influenza virus-stimulated cultures and mannan-stimulated cultures were not inducing antiinfluenza antibodies. The antimannan antibody production was shown to be a T cell-dependent phenomenon. The T helper effect appeared to be radiosensitive. It was under a genetic restriction as it occurred only in autologous or semi-identical but not in allogeneic situations. This system is relatively simple, reproducible, and well suited for the study of specific secondary in vitro antibody responses to polysaccharide antigens in humans.

Elicitation of the prausnitz-kustner reaction by antiidiotypic antibodies.

Rabbit antiidiotypic IgG directed against IgG F(ab')2 anti-tetanus toxoid (TT) antibodies ("idiotype") elicited a Prausnitz-Kustner reaction in normal skin sites sensitized 48 h earlier with the serum of the idiotype donor that contained IgE anti-TT antibodies. The serum moiety that caused the sensitization was heat sensitive (56 degrees C, 1 h), and was specifically removed by passage over immunosorbents containing rabbit antihuman IgE or TT antigen. The data obtained indicate that human IgG and IgE antibodies share idiotypic determinants and raise the possibility that idiotypic interactions may play a role in the regulation of the IgE antibody response in man.

The in vivo antibody responses to polymerized flagellin (POL) in man

The capacity of antibody response in man was evaluated by a single intradermal injection of polymerized flagellin (POL) from Salmonella adelaide. The antibody was titrated in sera (with or without treatment with 2-mercaptoethanol) by microhemaglutination using antigen-sensitized group O red blood cells (RBC). The naturally occurring antibody to POL was detected in 64% of 190 nonimmunized healthy subjects. Its frequency and titer gradually increased with age. In 10 healthy adult subjects and 15 patients with miscellaneous diseases, a good response with both IgM and IgG antibody was induced. The IgM to IgG switch-over was more clearly elucidated in subjects without the natural antibody. In 12 immunodeficient patients, the subjects with T- and/or B-cell dysfunction did not produce or poorly produced the antibody. Four subjects with Wiscott-Aldrich syndrome (WAS) revealed a comparatively high antibody response; two of them became significantly responsive to POL after administration of transfer factor and reimmunization with POL. POL is one of the best applicable test antigens and appears to act as a T-independent immunogen in man.

Persistent Clonotypes Associated with Group A Streptococcal Polysaccharide Antibody Response in Man

Elevated anti-streptococcal group A polysaccharide antibodies are present in the sera of acute rheumatic fever patients. Analytical isoelectric focusing of sera taken in the acute phase of the disease and sequentially for up to 2 years later reveals a stable clonotype pattern of anti-group A polysaccharide antibodies. In addition, with reinfection and recurrence of the rheumatic fever, the same clonotype pattern of antibodies is present. This finding indicates that naturally acquired immunity is associated with persistence of clonotype expression.

Boosting of secretory IgA antibody responses in man by parenteral cholera vaccination.

The occurrence of specific antibodies to Vibrio cholerae lipopolysaccharide in serum, milk, and saliva of Pakistani women from a very low socioeconomic group was studied before and after a single subcutaneous cholera vaccination. Before immunization all women had low levels of specific antibodies in serum, primarily of IgM class, and in many cases cholera IgA angibodies were found in milk and saliva as well, indicating earlier natural exposure. The vaccination consistently induced a marked rise in serum antibody titer, and notably also produced significant titer increases in 70% of the milk and in 45% of the saliva samples. Whereas the serum antibodies induced were predominantly of the IgG class, secretory IgA was responsible for most of the titer increase in the secretions. The results indicate that parenteral cholera vaccination can boost local secretory IgA antibody responses in intestinally primed individuals.

The antibody respones in man to infection with different serotypes of group-A streptococci.

SUMMARY The influence of the infecting serotype on streptococcal antibody response in man was investigated in a series of twelve incidents of streptococcal infection due to nine different M-types. The percentage of patients who developed type-specific M antibody after throat infection with opacity-factor-negative M-types varied between 64 and 100% and was in general three times greater than the percentage who developed this antibody to opacity-factor-positive M types. The type-specific antibody response was poor after skin infection with both opacity-factor-positive and opacity-factor-negative serotypes and varied between 0 and 33%. Antistreptolysin O and anti-deoxyribonuclease B titres were on the whole similar in the different outbreaks, except that anti-streptolysin O titres were low and anti-deoxyribonuclease B titres were high in patients with skin infection. The antibody response to M-associated protein varied widely between outbreaks. In incidents due to opacity-factor-positive serotypes, the titres were generally low, but opacity-factor-negative serotypes showed great variation in their ability to cause production of the antibody. In outbreaks of tonsillitis in which some of the patients later suffered from rheumatic fever, many persons formed large amounts of the antibody in response to an uncomplicated infection. Because high titres of antibody against M-associated protein are almost invariable in rheumatic fever it seems possible that the “rheumatogenic” strains of group-A streptococci are to be found among the opacity-factor-negative serotypes.

Human cell culture rabies vaccine. Antibody response in man

Human cell culture rabies vaccine. Antibody response in man

Antibody response in man to influenza virus neuraminidase following influenza.

Antibody response in man to influenza virus neuraminidase following influenza.

Heterotypic Antibody Responses in Man Following Vaccination with Adenovirus Type 1 Hexon Antigen

Vaccination of 11 adult male volunteers with adenovirus type 1 hexon antigen resulted in the formation of heterotypic as well as homotypic serum neutralizing antibody responses. The relative frequency of responses to serotypes belonging to immunologic group 3, which includes type 1, was significantly higher than those which occurred to serotypes in group 1 or group 2.

Comparison of HI and HAdI Antibody Response of Military Recruits to Monovalent Vaccines.

SummaryA comparison of the antibody response of humans vaccinated with either A2/Japan/305/57 or A2/Japan/170/62 monovalent vaccine as measured by HAdI and HI techniques has been presented. Although the HAdI antibody titers were higher the information obtained from comparisons of the frequency of antibody response and of mean fold titer increases was the same for both methods. Thus, it would appear from this experience that the HAdI technique offers no great advantage for the selection of vaccine strains when the criterion is the antibody response in man. In addition, it should be pointed out that the HAdI test is a more laborious, expensive and time consuming procedure than the HI method.