Adjuvant effect of Bordetella pertussis vaccine to sheep erythrocytes: enhancement of antibody formation by using subcutaneous administration of adjuvant and antigen.

The subcutaneous route (s.c.) was used to study the adjuvant effect of Bordetella pertussis vaccine (pv) on the primary antibody response to sheep erythrocytes. The reasons for using the s.c. route are discussed. PV, besides enhancing the hemagglutinin response, also markedly increased the number of plaque-forming cells in the draining lymph nodes. A heated preparation of PV was tested and found to possess significant adjuvant activity. Interestingly, the enhancement occurred in the absence of marked enlargement of the lymph nodes, which was characteristic of the unheated preparation. In addition, a crude solubilized cell-free preparation of PV was tested and also found to possess significant adjuvant activity. The activity was only partially abolished by heat. Hence, it was concluded that both heat-labile as well as heat-stable factors contributed to the adjuvanticity of PV. The studies also support the view that the draining lymph nodes represent a principal locus of action of PV and that the s.c. route of administration of adjuvant and antigen provides a suitable model for studying and assaying the adjuvanticity of PV.     

Resistance to adenovirus infection after administration of Bordetella pertussis vaccine in mice.

Treatment of mice with Bordetella pertussis vaccine rendered mice resistant to mouse adenovirus infection. The resistant state took at least 5 days to develop, and susceptibility returned to a portion of the test population 35 days after treatment. Transient resistance developed in congenitally athymic mice also. Treatment with a dose of 25 micrograms (dry weight) of B. pertussis vaccine protected approximately 50% of the test population. Vaccines prepared from several different strains of B. pertussis were capable of inducing resistance, and the induction of resistance was not dependent on the mouse strain used for testing. Cross-reacting antibodies capable of neutralizing the virus or protecting against a challenging infection were not induced by treatment with B. pertussis vaccine.     

On the mechanism of the adjuvant effect of Bordetella pertussis vaccine

Pertussis vaccine accelerates rather than retards, of antigen from the circulation and enhances the secondary as well as the primary response. Pertussis vaccine alone has an anamnestic effect and is capable of causing the appearance of homocytotropic antibody which reacts with antigens to which the animal has previously made a primary response. The effects of pertussis and Freund's adjuvant are additive. Increased insulin levels are not necessary for the adjuvant effect as alloxan diabetic animals are quite capable of enhanced antibody response after pertussis vaccine. Beta adrenergic blocking drugs increase and adrenergic agonists reduce antibody response slightly. It is concluded that pertussis exerts its effect directly on the precursor of the antibody-forming cells by increasing their rate of cell division Impairment of beta adrenergic receptors may be the mechanism of the effect.     

Effective immunization against Bordetella pertussis respiratory infection in mice is dependent on induction of cell-mediated immunity.

A murine respiratory challenge model was used to examine the induction of cellular and humoral immune responses and their role in protection against Bordetella pertussis following immunization or previous infection. Spleen cells from mice convalescing from a B. pertussis infection exhibited extensive in vitro T-cell proliferation and secreted high levels of interleukin-2 (IL-2) and gamma interferon but not IL-4 or IL-5, a cytokine profile typical of CD4+ Th1 cells. Serum from these mice had low or undetectable anti-B. pertussis antibody levels. In contrast, mice immunized with an acellular pertussis vaccine had high levels of B. pertussis antibodies and spleen cells secreting IL-5 but not gamma interferon, a profile characteristic of CD4+ Th2 cells. Immunization with an inactivated whole-cell vaccine induced both CD4+ Th1 and serum antibody responses. After exposure to a B. pertussis respiratory challenge, the convalescent mice and those immunized with the whole-cell vaccine eliminated the bacterial infection significantly faster than mice immunized with the acellular vaccine. These findings show that the selection of antigens and their form of presentation are important in determining whether the subsequent immune response is cellular, mediated by Th1 cells, or humoral, mediated by Th2 cells. In the murine model, the induction of a Th1-mediated cellular immune response appears to be a key element in acquired immunity to a B. pertussis infection.     

Preferential induction of cell-mediated immunity by chemically modified sheep erythrocytes

Sheep red blood cells (SRBC) almost exclusively induce humoral antibodies when injected in saline into adult rats. Chemical modification of SRBC by either periodate oxidation or acetoacetylation resulted in preparations which provoked lower antibody responses than did normal SRBC, but induced much higher levels of delayed-type hypersensitivity. Furthermore, SRBC which had been both periodate oxidized and acetoacetylated induced even higher delayed responses, but were unable to stimulate detectable antibody formation. Thus, by two simple chemical treatments, SRBC have been converted from an antigen which predominantly induces humoral antibodies tc an antigen which exclusively provokes cell-mediated immunity. The chemically modified SRBC had some notable immunological properties. (I) Antigenically, they were still strongly agglutinated by anti-SRBC antiserum. (II) They very effectively induced delayed-type hypersensitivity when injected either in saline or Freund's complete adjuvant. (III) They lost their immunogenicity when lysed just prior to injection. (IV) They induced delayed-type hypersensitivity which cross-reacted with goose, rabbit and horse red blood cells, a result consistent with the notion that antigens cross-react more broadly at the cell-mediated immune level than at the antibody level. (V) Comparatively high levels of both humoral and cell-mediated immunity were achieved when a mixture of periodate oxidized SRBC and acetoacetylated SRBC was injected. The theoretical and practical implications of these findings are discussed.     

Stimulation of non-specific resistance by heterologous endotoxins and experimental immunity to Bordetella pertussis in mice

A single intraperitoneal administration of Bordetella pertussis vaccine produced within a few days an increased resistance in mice against intracerebral infection with B. pertussis strain 18–323 such as has previously been described by Evans and Perkins as early or interference immunity.

Intraperitoneal administration of the endotoxin of B. pertussis induced a relatively transient resistance against intracerebral infection with Salmonella typhi strain Ty2, but not against intracerebral infection with B. pertussis organisms.

When the treatment was made intracerebrally however, heterologous and homologous endotoxins as well as a synthetic double-stranded RNA complex of polyriboinosinic and polyribocytidylic acids (poly I.C) could increase the resistance of mice against intracerebral infection with B. pertussis organisms. In brains of animals thus treated, evident suppression of bacterial growth comparable to that in a passive immunity experiment was seen.

By the use of brain extract prepared from mice or rats treated intracerebrally with heterologous endotoxin, the non-specific resistance could be successfully induced in mice.

To substantiate any possible relation of such a non-specific resistance induced by endotoxins to the early immunity seen after the intraperitoneal injection of B. pertussis vaccine further efforts are necessary.

     

The effect of Freund's complete adjuvant on the cellular response in mice to sheep erythrocytes.

The effect of Freund's complete adjuvant on the cellular response in BALB/c mice to SRBC was studied using techniques based on immunocytoadherence (ICA), inhibition of ICA using an antiserum to the theta alloantigen, and immune adherence (IA). Particular attention was paid to the cellular morphology of the responding lymph nodes, details of which are described.     

Preferential enhancement of IgE antibody formation by Bordetella pertussis.

Preferential enhancement of IgE antibody response was observed in BALF/c mice by the administration of Bordetella pertussis with antigen (DNP-Salmonella). Correlation between B cell mitogenic activity and adjuvant action among B. pertussis, Salmonella, lipopolysaccharide of Escherichia coli and Ficoll was examined but was not found. Thymus-derived cells seemed necessary to develop adjuvant action of B. pertussis since antibody response in athymic nude mice was not influenced by B. pertussis. Helper function of adoptively transfered spleen cells was enhanced by immunization of the donor mice with carrier antigen in the presence of B. pertussis. The magnitude of enhancement was greatest in IgE class. The results indicated that preferential enhancement of IgE antibody formation by B. pertussis is mediated by the augmentation of carrier-specific helper function.     

Adjuvant activity of the histamine-sensitizing factor of Bordetella pertussis in different strains of mice.

The effect of an extract of histamine-sensitizing factor (HSF) of Bordetella pertussis on the immune response of different strains of mice to ovalbumin (OA) was investigated with regard to optimal dose of antigen and adjuvant. It was observed that all strains of mice treated with HSF during immunization with OA demonstrated enhanced production of hemagglutinating antibodies, as compared to animals treated with antigen alone. This enhancement was generally not as great as that demonstrated when Al(OH)3 was the adjuvant. HSF also stimulated a reaginic antibody response (IgE) to OA, but not in all strains of mice. In reagin responders optimal responses were observed with high doses of both antigen and adjuvant, whereas low doses of both produced little or no response. Maximal reagin production occurred usually 14-28 days after immunization and persisted for long periods of time. An anamnestic reagin response was elicited upon secondary immunization with antigen alone, not only in mice immunized with OA and HSF but also in animals treated with OA alone. These studies demonstrate the profound effect that a microbial substance such as HSF can have on reaginic antibody production and suggest that the stimulation of IgE antibody production is the net result of a number of factors including genetic capabilities of the host, environmental influence such as adjuvants, and prior exposure to an antigen.     

Pertussis-specific cell-mediated immunity in infants after vaccination with a tricomponent acellular pertussis vaccine.

The aim of this study was to investigate pertussis-specific cell-mediated immunity in infants vaccinated with a tricomponent acellular vaccine. Infants were investigated during a primary vaccination schedule from the third month of life to the sixth month as well as before and after a booster at 15 to 24 months. This is the first report of specific cell-mediated immune responses to pertussis-related antigens in infants below the age of 12 months. Our data show that the vaccine induces T-cell responses specific for the vaccine components, detoxified pertussis toxin, filamentous hemagglutinin, and pertactin, that increase progressively over the course of the vaccination schedule. In contrast to declining antibody titers, cell-mediated immune responses are stable over the postprimary to prebooster period. Vaccination results in a progressive increase in the number of T cells that express activation marker CD45RO preferentially on CD4-positive T cells after stimulation with pertussis antigens. Measurements of cytokine secretion profiles demonstrated a preferential induction of interleukin 2- and gamma interferon-producing T-helper 1 cells and only low production of interleukin 10. The observed persistence of the specific cell-mediated immunity may have a bearing on the protective mechanisms induced by pertussis vaccination. Cell-mediated immunity requires further study, particularly to improve our understanding of the persistence of protection afforded by vaccination up to the administration of booster doses.     

Adjuvant for IgE antibody and islet-activating protein in Bordetella pertussis.

A new purified protein, with a molecular weight of 77,000, isolated from the supernatant of Bordetella pertussis culture fluid and called islet-activating protein (IAP), had adjuvant activity for IgE antibody in addition to leukocytosis-promoting, histamine-sensitizing and islet-activating activities. None of the three subunits (F1, F2 and F3) was biologically active by itself. All of the four activities were recovered in the complexes of subunits F1.3 and F2.3. These results suggest that the activities are brought about by a common factor inherent in B. pertussis.     

Cellular immunity in adolescents and adults following acellular pertussis vaccine administration

Cell-mediated immune (CMI) responses to an acellular pertussis vaccine administered to 49 subjects, a subset of participants in the National Institutes of Health-funded adult acellular pertussis vaccine efficacy trial, were evaluated and compared with antibody responses to vaccine antigens. Levels of proliferation of and cytokine secretion from lymphocytes cultured in the presence of pertussis toxin, filamentous hemagglutinin, or pertactin were measured before vaccination and 1 month and 1 year after vaccination. Statistically significant increases in lymphocyte stimulation indices and cytokine secretion were noted at both 1 month and 1 year after vaccination. Brisk pertussis antigen-specific immunoglobulin G responses were also noted at 1 month after vaccination, but these responses had declined by nearly 50% at 1 year after vaccination. These studies clearly demonstrate that both cellular and humoral immune responses occur after the administration of acellular pertussis vaccines to adolescents and adults but that the CMI responses are of greater magnitude and longer duration. CMI responses may be a better correlate of long-term protection.     

Role for cell-mediated immunity in the resistance of mice to subcutaneous herpes simplex virus infection.

The role of cell-mediated immunity in the resistance of young adult mice to subcutaneous herpes simplex virus (HSV) type I infection was studied in mice receiving immunosuppressive doses of antilymphocyte sera (ALS) or antithymocyte sera (ATS). The effectiveness of these treatments to reduce cell-mediated responses was measured by their ability to prolong the life of allografts transplanted to ALS- or ATS-treated mice. It was found that subcutaneous infection of these mice with HSV resulted in spread of virus from the site of inoculation to the central nervous system. Neutralizing antibody could not be detected in the sera of ALS- or ATS-treated mice after HSV inoculation. Passive transfer of neutralizing antibody to ATS-treated mice did not restore resistance to subcutaneous HSV infection. However, adoptive transfer of HSV-sensitized spleen cells did provide significant protection against infection unless the spleen cells were treated with ATS prior to transfer. These experiments suggest that lymphocytes are involved in a cell-mediated response to subcutaneous HSV infection and demonstrate the importance of a noncompromised immune response in controlling spread of HSV from localized areas of infection.     

The effect of pertussis vaccine on the immune response of mice to sheep red blood cells

Bordetella pertussis is an adjuvant when given to mice immunized with sheep RBC. The adjuvant activity of pertussis is reflected in an increase in the number of cells producing antibody as measured by the localized haemolysis in gel technique. γG-PFC have a more marked response to pertussis than do γM-PFC, and in general γG-PFC are more sensitive than γM to variations in dose or injection schedule of pertussis organisms. Pertussis increases the response to doses of antigen which previously were considered to be maximal. The distribution of PFC between spleen, blood and lymph nodes is altered by pertussis injections.     

Validation of nested Bordetella PCR in pertussis vaccine trial.

A nested PCR, using a 239-bp sequence in the pertussis toxin promoter region, was developed and evaluated. The assay differentiates Bordetella pertussis, Bordetella parapertussis, and Bordetella bronchiseptica by restriction enzyme analysis of the amplified fragments. The diagnostic performance of the PCR was evaluated in a Swedish pertussis vaccine efficacy trial which took place from 1992 to 1995, including study children and household members and using culture and serology for laboratory confirmation of suspected cases. In total 2,421 nasopharyngeal aspirates were analyzed. The total diagnostic sensitivity for B. pertussis was 90.2% (194 of 215). During the study period samples were processed with and without the cation-exchange resin Chelex. The PCR diagnostic sensitivity for B. pertussis among the Chelex-treated aspirates was 94.9% (75 of 79), and that for B. pertussis among 124 aspirates in a consecutive non-Chelex-treated material was 89.5% (111 of 124). After Chelex treatment of the 13 PCR-negative samples, an additional six became PCR positive, giving a final sensitivity of 94.3%. In addition, PCR was positive for B. pertussis with 57 of 1,744 samples negative by culture but with available serological data. The specificity of PCR with these samples was supported by a significant increase in antibody levels between acute and convalescent sera in 45 cases and by epidemiological or clinical data in all but two of the remaining cases. PCR was also positive for B. pertussis with 26 of 415 aspirates from episodes lacking serology. The diagnostic sensitivity of PCR for B. parapertussis was 74.0% (37 of 50). There were an additional seven culture-negative B. parapertussis PCR findings, six from cases with significant antibody increases against filamentous hemagglutinin only and one from a case lacking serology. There were no samples positive for B. bronchiseptica. In conclusion, PCR detection of B. pertussis and/or B. parapertussis enabled us to identify 90 positive nasopharyngeal aspirates, in addition to the 262 culture-positive samples (an increase of 34%). Relating these cases to serology and clinical data indicated a PCR specificity approaching 100%.     

Synergistic effect of Bordetella pertussis lymphocytosis-promoting factor on protective activities of isolated Bordetella antigens in mice.

The effect of low levels of added lymphocytosis-promoting factor (LPF) on the ability of several antigenic preparations isolated from Bordetella pertussis and other bacteria to protect mice against intracerebral infection with B. pertussis was examined. LPF was found to enhance the protective activities of filamentous hemagglutinin, 22S antigen, and fimbriae isolated from B. pertussis. Outer membrane protein preparations from phase I B. pertussis which had LPF removed by haptoglobin affinity columns or inactivated by glutaraldehyde, sodium dodecyl sulfate, or Formalin had reduced protective activities but were made fully protective by the readdition of LPF. Similarly, outer membrane protein preparations from Bordetella bronchiseptica, Bordetella parapertussis, or phase IV B. pertussis lacking LPF were protective only when low levels of LPF were added to the preparations. Outer membrane protein preparations from Neisseria gonorrhoeae or Escherichia coli were nonprotective even in the presence of added LPF. The purified LPF by itself was nonprotective unless treated with glutaraldehyde. LPF that had been detoxified with glutaraldehyde was, however, ineffective at enhancing the protective activity of antigenic preparations. The synergistic effect of LPF is discussed in relation to its known biological properties.