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PubMed2005

Comparison of intranasal and transcutaneous immunization for induction of protective immunity against Chlamydia muridarum respiratory tract infection.

Chlamydia pneumoniae causes a range of respiratory infections including bronchitis, pharyngitis and pneumonia. Infection has also been implicated in exacerbation/initiation of asthma and chronic obstructive pulmonary disease (COPD) and may play a role in atherosclerosis and Alzheimer's disease. We have used a mouse model of Chlamydia respiratory infection to determine the effectiveness of intranasal (IN) and transcutaneous immunization (TCI) to prevent Chlamydia lung infection. Female BALB/c mice were immunized with chlamydial major outer membrane protein (MOMP) mixed with cholera toxin and CpG oligodeoxynucleotide adjuvants by either the IN or TCI routes. Serum and bronchoalveolar lavage (BAL) were collected for antibody analysis. Mononuclear cells from lung-draining lymph nodes were stimulated in vitro with MOMP and cytokine mRNA production determined by real time PCR. Animals were challenged with live Chlamydia and weighed daily following challenge. At day 10 (the peak of infection) animals were sacrificed and the numbers of recoverable Chlamydia in lungs determined by real time PCR. MOMP-specific antibody-secreting cells in lung tissues were also determined at day 10 post-infection. Both IN and TCI protected animals against weight loss compared to non-immunized controls with both immunized groups gaining weight by day 10-post challenge while controls had lost 6% of body weight. Both immunization protocols induced MOMP-specific IgG in serum and BAL while only IN immunization induced MOMP-specific IgA in BAL. Both immunization routes resulted in high numbers of MOMP-specific antibody-secreting cells in lung tissues (IN>TCI). Following in vitro re-stimulation of lung-draining lymph node cells with MOMP; IFNgamma mRNA increased 20-fold in cells from IN immunized animals (compared to non-immunized controls) while IFNgamma levels increased 6- to 7-fold in TCI animals. Ten days post challenge non-immunized animals had >7,000 IFU in their lungs, IN immunized animals <50 IFU and TCI immunized animals <1,500 IFU. Thus, both intranasal and transcutaneous immunization protected mice against respiratory challenge with Chlamydia. The best protection was obtained following IN immunization and correlated with IFNgamma production by mononuclear cells in lung-draining LN and MOMP-specific IgA in BAL.

Administration, Intranasal↗

PubMed1999

Immunization promotion activities: are they effective in encouraging mothers to immunize their children?

Mass media communication is an important strategy for increasing parental uptake and to promote community participation when large-scale immunization activities are carried out. In Mexico, the National Vaccination Council (CONAVA) launches three immunization campaigns every year accompanied by three vaccination promotion campaigns. This study was conducted to assess whether communication activities to promote CONAVA's Second National Health Week (SNHW) were effective in providing information to mothers about the importance of immunizing their children under five years of age and in prompting them to seek immunization services. A probability sample of mothers living in the metropolitan area of Mexico City and having at least one child under five years old was selected for the study. Four outcome variables were defined as measuring the impact of the campaign: (1) mothers' knowledge about the SNHW; (2) mothers' comprehension indicating how well they understood the campaign messages (aware, partly aware and unaware); (3) mothers' motivation, i.e. whether or not they sought out immunizations for their children under the age of five and (4) mothers' opinion of how well they liked the messages. A total of 935 mothers were interviewed; 88.2% knew about the SNHW, 64.3% were aware that the campaign aimed to provide immunizations, and most held a favorable opinion about the messages. Among aware mothers, 87.5% of their children received immunizations. In this group 72.1% were prompted by the information in the campaign to seek immunizations for their children while 27.9% had to be personally invited to participate in the campaign. The latter occurred either when health workers or volunteers visited mothers in their homes or by soliciting mothers' participation as they visited or passed by immunization health posts. In the unaware mothers group, 72.7% of their children received immunizations; 62.5% of the mothers took their children because of information they received through the campaign while 37.5% had to be personally invited to immunize their children. Mothers with better socioeconomic status were more aware of the campaign, but a high percentage of them did not seek immunizations, while mothers with middle and lower socioeconomic status were motivated to immunize their children through the campaign. Promotion activities and messages communicated through the mass media were appropriate to inform and motivate mothers to seek immunization services for their children.

Adult↗

PubMed1999

Mucosal vaccination overcomes the barrier to recombinant vaccinia immunization caused by preexisting poxvirus immunity.

Overcoming preexisting immunity to vaccinia virus in the adult population is a key requirement for development of otherwise potent recombinant vaccinia vaccines. Based on our observation that s.c. immunization with vaccinia induces cellular and antibody immunity to vaccinia only in systemic lymphoid tissue and not in mucosal sites, we hypothesized that the mucosal immune system remains naive to vaccinia and therefore amenable to immunization with recombinant vaccinia vectors despite earlier vaccinia exposure. We show that mucosal immunization of vaccinia-immune BALB/c mice with recombinant vaccinia expressing HIV gp160 induced specific serum antibody and strong HIV-specific cytotoxic T lymphocyte responses. These responses occurred not only in mucosal but also in systemic lymphoid tissue, whereas systemic immunization was ineffective under these circumstances. In this context, intrarectal immunization was more effective than intranasal immunization. Boosting with a second dose of recombinant vaccinia was also more effective via the mucosal route. The systemic HIV-specific cytotoxic T lymphocyte response was enhanced by coadministration of IL-12 at the mucosal site. These results also demonstrate the independent compartmentalization of the mucosal versus systemic immune systems and the asymmetric trafficking of lymphocytes between them. This approach to circumvent previous vaccinia immunity may be useful for induction of protective immunity against infectious diseases and cancer in the sizable populations with preexisting immunity to vaccinia from smallpox vaccination.

AIDS Vaccines↗

PubMed2005

The influence of immunizing dose size and schedule on immunity to subsequent challenge with antigenically distinct strains of Eimeria maxima.

Eimeria maxima, the most immunogenic of the Eimeriidae that infect the chicken, is characterized by the presence of antigenic diversity within field isolates. In priming/challenge experiments immunity to homologous infection is essentially complete while immunity against challenge by a heterologous strain is often only partial. The phenotype "escape from immune protection" is known to be influenced by both host and parasite genotypes but the impact of varied immunization dose and schedule remains poorly documented. In this manuscript we report that an immunizing dose between 99.99%) protective immunity against challenge by 100 oocysts of a homologous strain. In contrast, complete immunity against a heterologous strain was never observed, although increasing the immunizing dose size did frequently reduce oocyst production arising from subsequent heterologous challenge. Differences in cross-protective immunizing capacity between two strains of E. maxima were evident as the H strain consistently stimulated a more potent protective immune response than the W strain. Similarly, increasing the number of immunizing doses of the E. maxima W strain (but not the H strain) increased immune protection against subsequent heterologous challenge. When combined with previously published data the results described here suggest that the E. maxima genome encodes a pool of antigens that are capable of stimulating an immune response cross-protective against more than one strain. These antigens supplement a separate restricted pool of antigens that are capable of stimulating stronger, but strain-specific, protective immune responses.

Animals↗

PubMed2006

Influenza immunization in nursing homes: who does not get immunized and whose status is unknown?

OBJECTIVE: To identify nursing home resident and facility characteristics associated with patients not receiving influenza immunization and having unknown immunization status. DESIGN: Secondary data analysis using multinomial logistic regression of data from the National Nursing Home Survey, a nationally representative establishment-based survey. SETTING: A total of 1,423 nursing facilities of all ownerships and certifications systematically sampled with probability proportional to number of beds. PATIENTS: A total of 7,350 randomly sampled people aged 65 years or older residing in nursing homes between July and December 1999 (approximately 6 per facility). MAIN OUTCOME MEASURE: Immunization status of residents. RESULTS: Fifteen percent of residents were not immunized and 19% had unknown immunization status. In multivariate analysis, lack of immunization and unknown immunization status were each separately associated with being newly admitted, with no or unknown pneumococcal immunization, and with facility failures to screen for immunization and to record inoculation in the medical record. High-risk status and staff immunization requirements had no effect. Separate analyses showed that residents with unknown immunization status are statistically significantly different from both those vaccinated and those not vaccinated. CONCLUSION: This study indicates that both resident and facility characteristics are associated with failure to be immunized for influenza. Facilities should consider targeting younger, newly admitted, and residential care residents for influenza immunization, since they are more likely to be missed. Further research into the barriers to immunization specific to nursing home resident choice or opportunity may be warranted.

Aged↗

PubMed2002

Production of antibodies by single DNA immunization: comparison of various immunization routes.

DNA immunization is a recent vaccination method that induces humoral and cellular immune responses in a range of hosts. Different immunization routes induce a different degree of the immune response. In the present report, we demonstrate that multiple intramuscular immunizations of plasmid DNA encoding various leukocyte surface molecules induced a specific antibody response. In contrast, a single intramuscular immunization could not induce antibody production. To study the induction of antibody response after a single immunization of plasmid DNA, mice were single-dose intramuscularly, intraperitoneally, intravenously and intrasplenically immunized, simultaneously, with the same preparation of plasmid DNA encoding CD147 membrane protein. We observed that only the intrasplenic route induced specific antibody production. The induction of antibody by intrasplenic immunization was confirmed by using plasmid DNA encoding CD54 molecule. By this single-dose DNA intrasplenic immunization, the generated antibodies could be detected in mice up to 6 months. These results suggest that the injected DNA is expressing the relevant protein antigen in the spleen for several months after injection. Our results demonstrate that direct immunization of antigen-encoding DNA into the spleen is a more effective method for induction of antibody production. This finding may support future investigations of DNA vaccination strategies that specifically promote the uptake of plasmid by splenocytes. Intrasplenic immunization may also be helpful in the understanding of the early events of the immune response to DNA vaccine and be useful as an effective route for the induction of immune responses.

Animals↗

PubMed2002

Immune cells in the anterior chamber of patients with immune reactions after penetrating keratoplasty.

PURPOSE: Lymphocytes, monocytes, and macrophages are the predominating immune cells in graft rejection after keratoplasty in animal models. This study focuses on the isolation of immune cells from the anterior chamber of patients with slight, moderate, and severe endothelial immune reactions after penetrating keratoplasty. METHODS: Anterior chamber puncture was performed in five patients with cataract without inflammation and without penetrating keratoplasty (C1), in three patients undergoing penetrating keratoplasty without immune reactions (C2), in four patients undergoing penetrating keratoplasty after complete resolution of endothelial immune reactions (C3), in seven patients undergoing penetrating keratoplasty with slight endothelial immune reactions (IMI), in 10 patients undergoing penetrating keratoplasty with moderate endothelial immune reactions (IM2), and in eight patients undergoing penetrating keratoplasty with severe endothelial immune reactions (IM3). In each patient, approximately 0.1 mL of aqueous humor was examined. Cells in suspension were directly centrifuged on glass slides using a Cytospin centrifuge, stained, and evaluated under the light microscope. RESULTS: Groups C1, C2, and C3 did not contain cells. Immune cells were identified in three of seven patients in IM1, in eight of 10 patients in IM2, and in eight of eight patients in IM3. Predominating cells were macrophages and monocytes followed by lymphocytes. Regarding all patients in IMI, IM2, and IM3, a statistically significant correlation between detected cells and patient age, period between penetrating keratoplasty and anterior chamber puncture, or period between first symptoms and anterior chamber puncture could not be revealed. Granulocytes were found statistically significantly less often in patients with high-risk indications, in patients with a history of immune reactions and under immunosuppression. Lymphocytes were found statistically significantly less often in patients with a history of immune reactions. CONCLUSIONS: The probability to isolate immune cells from the anterior chamber of patients undergoing penetrating keratoplasty correlates with the severity of the endothelial immune reactions. This study is a first step to evaluate how detailed immunologic findings from animal keratoplasty models fit to clinical reality in patients undergoing keratoplasty. In the next step, cells found in the aqueous humor of patients with endothelial immune reactions should be further characterized directly (determination of molecules on the surface of the cells) or indirectly (determination of cytokine levels in the aqueous humor).

Adult↗

PubMed2005

A preliminary study to evaluate the immune responses induced by immunization of dogs with inactivated Ehrlichia canis organisms.

Ehrlichia canis is an intracellular pathogen that causes canine monocytic ehrlichiosis. Although the role of antibody responses cannot be discounted, control of this intracellular pathogen is expected to be by cell mediated immune responses. The immune responses in dogs immunized with inactivated E. canis organisms in combination with Quil A were evaluated. Immunization provoked strong humoral and cellular immune responses, which were demonstrable by Western blotting and lymphocyte proliferation assays. By Western blotting antibodies to several immunodominant E. canis proteins were detected in serum from immunized dogs and antibody titres increased after each immunization. The complement of immunogenic proteins recognized by the antisera were similar to those recognized in serum from infected dogs. Upon challenge with live E. canis, rapid anamnestic humoral responses were detected in the serum of immunized dogs and primary antibody responses were detected in the serum from control dogs. Following immunization, a lymphocyte proliferative response (cellular immunity) was detected in peripheral blood mononuclear cells (PBMNs) of immunized dogs upon stimulation with E. canis antigens. These responses were absent from non-immunized control dogs until after infection with live E. canis, when antigen specific-lymphocyte proliferation responses were also detected in the PBMNs of the control dogs. It can be thus concluded that immunization against canine monocytic ehrlichiosis may be feasible. However, the immunization regimen needs to be optimized and a detailed investigation needs to be done to determine if this regimen can prevent development of acute and chronic disease.

Animals↗

PubMed2003

Therapeutic manipulation of the immune system: enhancement of innate and adaptive mucosal immunity.

The mucosal immune system has evolved alongside, but separate, from the general systemic immune system. As a major consequence of this dichotomy, only immune responses initiated in mucosal inductive sites can result in effective immunity in mucosal tissues themselves. Oral tolerance, as usually assessed as orally-induced systemic unresponsiveness, contributes to mucosal homoeostasis by preventing unwanted immune reactions to food or environmental antigens. It is now established that tolerance can also be induced by the nasal route and mucosally-induced tolerance is being actively investigated for immune therapy against a number of diseases. Nontoxic derivatives of cholera toxin and the heat labile toxin of Escherichia coli as well as chimeric enterotoxins have been developed. These molecules retain the mucosal adjuvant activity of native enterotoxins and are effective at inducing targeted Th1 or Th2- type immune responses. Mucosal delivery of cytokines as adjuvants represents a safer alternative to parenteral cytokine injection. Nasally administered cytokines such as IL-1 and IL-12 or chemokines including RANTES, lymphotactin, MIP-1 beta, all act as mucosal adjuvants for co-administered antigens. Each of these cytokines promote specific pattern of CD4(+) T helper cell cytokine responses that could be exploited for targeted immune therapy. Although GALT and NALT are both parts of the Common Mucosal Immune System, there are major differences between orally and nasally induced immune responses. Nasal vaccines more effectively promote protective immunity in the genitourinary tract than do oral vaccines. In addition, aging affects mucosal tolerance or immunity in GALT more than is seen in NALT. Therapeutic manipulation of mucosal immunity involves regulation of CD4(+) T cell cytokine responses and thus, should require a careful examination of the host status, including the occurrence of inflammatory bowel diseases.

Adjuvants, Immunologic↗

PubMed2005

A model of immunity to Burkholderia pseudomallei: unique responses following immunization and acute lethal infection.

Burkholderia pseudomallei, the etiological agent of melioidosis, causes significant mortality in endemic regions, but little is known regarding the immune mechanisms required for successful protective immunity. To establish a model of immunization that could be used to study this we screened a library of B. pseudomallei strains for immunogenicity in mice. BALB/c mice were immunized with test strains, and 2 weeks later were given a lethal challenge (LC) of virulent B. pseudomallei. Among 49 strains tested, a single strain, CL04, exhibited strong immunoprotective capacity. Interestingly, CL04 had been cultured from a patient with chronic colonization of B. pseudomallei, which is a rare phenomenon. Mice immunized with 0.1 x LD50 (5 x 10(3) CFU) of CL04 had significantly better survival and lower bacterial loads after LC compared to naïve controls. Dose-response analysis demonstrated more robust immunity after higher immunizing doses, and bacterial inactivation by gamma irradiation diminished the protective effect, indicating a requirement for viable organism for immunity. CL04-induced immunity was demonstrated both in B. pseudomallei-susceptible BALB/c and -resistant C57BL/6 mice. We investigated the gene profile of CL04-induced immunity by analyzing responses to immunization using cDNA microarray. Unique responses involving granulocyte macrophage colony stimulating factor (GM-CSF), the proapoptotic regulator Bad and cyclin-dependent kinase (CDK5) were detected in immunized mice, but these responses were absent in naïve-LC mice. Further, responses differed between mouse strains, indicating dependence on host genetic background. This model will be useful in identifying elements of the immune response required for successful adaptive immunity against B. pseudomallei.

Animals↗

PubMed1986

Comparison of cell-mediated and humoral immunity in the dog lung after localized lung immunization.

This study evaluated cell-mediated immunity (CMI) and antibody production serially in control and immunized lung lobes of beagle dogs. A fiberoptic bronchoscope was used to immunize selected airways in the left cardiac lung lobe with 10(10) sheep red blood cells (SRBC); the right cardiac lobe received saline as control. The immune responses produced by this localized lung immunization were evaluated in cells and fluids obtained from blood and serial bronchial washings of the immunized and control lung lobes from 5 to 21 days after immunization. The antigen-specific production of procoagulant activity (LPCA) and inhibition of migration of alveolar macrophages by SRBC antigen were used to measure CMI in lavage cells from immunized and control lung lobes. The level of specific IgM and IgG antibody in lavage fluid from the control and immunized lung lobes was evaluated with the enzyme-linked immunosorbent assay (ELISA). The results of this study showed a significantly greater percentage of neutrophils and lymphocytes in the lavage fluid from the immunized lung lobes than from the control lung lobes. The increased number of lymphocytes in the immunized lung lobes showed a positive correlation with increased antibody concentrations. In contrast to the antibody response, CMI as measured by LPCA and MIF assays was positive, with nearly equal responses in control and immunized lung lobes. Even though there were only a few lymphocytes in the control lung lobes, there were apparently enough specific immune lymphocytes present that produced mediators after antigen stimulation to result in positive CMI responses.

Animals↗

PubMed2003

CpG immuno-stimulatory motifs enhance humoral immune responses against hepatitis C virus core protein after DNA-based immunization.

Chronic HCV infection is associated with a high morbidity and mortality rate, and currently a prophylactic or therapeutic vaccine is not available. DNA-based immunization is a powerful method to generate cellular and humoral immune responses. However, DNA immunization against HCV core results only in a weak humoral immune response demonstrated in several studies. Therefore, co-immunization with a novel adjuvant may enhance such potentially important immune responses. We examined whether unmethylated CpG motifs in the form of oligodeoxynucleotides (ODN) or E. coli DNA can act as adjuvants for a DNA vaccination approach, since CpG motifs have been shown to stimulate the innate immune system as well as B and T cell immune reactivity. The present study demonstrates that CpG motifs enhance in vivo antibody levels after DNA immunization against HCV core. However, despite some in vitro activity of CpG motifs, no enhancement of T cell responses in vivo was observed after immunization with HCV plasmid DNA and CpG motifs in mice. Our results suggest that co-immunization with CpG-ODN may strengthen humoral immune responses but show no potential effect as an adjuvant to induce cellular immunity against HCV core.

Adjuvants, Immunologic↗

PubMed1991

Effector phenotypes and mechanisms of antitumor immune reactivity of tumor-immunized and tumor-bearing mice in two syngeneic tumors.

By using two different syngeneic tumors, Meth A sarcoma and RL male 1 lymphoma of BALB/c origin, the present study was designed to investigate the subset(s) of T cells mediating in vivo antitumor immune responses and some of the effector mechanisms of in vivo protective immunity in BALB/c mice immunized against tumor or bearing tumor. Spleen cells from the mice immunized against Meth A tumor or bearing Meth A tumor inhibited the growth of Meth A tumor in the Winn assay. In the Meth A-immunized mice, L3T4+ (CD4+) cells played a major role in mediating the inhibitory activity against Meth A tumor growth, whereas in the Meth A-bearing mice, the antitumor protective immunity was mediated by both L3T4+ and Lyt-2+ (CD8+) cells. Spleen cells from the Meth A-immunized or Meth A-bearing mice were not able to generate cytotoxic T lymphocytes (CTL) directed against Meth A tumor after the in vitro restimulation of spleen cells with mitomycin C (MMC)-treated Meth A cells, while fresh spleen cells from the Meth A-immunized or Meth A-bearing mice were able to induce the strong delayed-type hypersensitivity (DTH) responses to Meth A tumor. The DTH response to Meth A tumor was mediated by L3T4+ cells in the Meth A-immunized mice and by both L3T4+ and Lyt-2+ cells in the Meth A-bearing mice. In the similar experiments performed in the RL male 1 lymphoma, the antitumor activity in spleen cells from the RL male 1-immunized or RL male 1-bearing mice depended on Lyt-2+ but not L3T4+ cells in the Winn assay. When spleen cells from the RL male 1-immunized or RL male 1-bearing mice were cultured with MMC-treated RL male 1 cells for 5 days, an appreciable CTL response to RL male 1 tumor was induced. These results suggest that the nature of tumor and/or tumor antigens determines which T cell subset is required to exhibit the protective immunity against tumor and thus the different effector mechanisms could be induced in the different tumor models. Furthermore, these data support the conclusion that antitumor T cell responses are affected by the immune state of host to tumor.

Animals↗

PubMed2005

A DNA vaccine coding for gB and gD of pseudorabies virus (suid herpes type 1) primes the immune system in the presence of maternal immunity more efficiently than conventional vaccines.

DNA vaccines are capable of priming the immune system of neonates in the presence of maternal antibodies. However, it is still not clear whether the extent of priming and protection against challenge infections induced by a DNA vaccine in maternally immune newborns is better than that induced by conventional vaccines. To study this, we used the pseudorabies virus (PRV) infection model in the natural host, the pig. We compared the efficacy of a DNA vaccine with the efficacy of a conventional modified live vaccine (MLV) and an inactivated vaccine (IV) in maternally immune newborn piglets. We measured the priming of the immune response and the degree of protection against challenge infection for all vaccine types. We vaccinated piglets with or without maternal immunity twice, at the age of 5 and 9 weeks, and we assessed protection by challenge infection with virulent PRV at the age of 15 weeks. Vaccination with DNA or conventional vaccines induced both humoral and cell-mediated immune responses in maternally immune animals. DNA vaccination seemed not to suffer from suppression by maternal immunity and resulted in similar or stronger immune responses in maternally immune piglets as compared in naïve piglets. In contrast, vaccination with conventional vaccines resulted in weaker immune responses in maternally immune piglets than in naïve piglets. Moreover, DNA vaccination provided better protection against challenge infection in maternally immune piglets than in naive piglets, whereas vaccination with conventional vaccines did not.

Animals↗

PubMed1987

The effects of Clostridium difficile crude toxins and toxin A on ileal and colonic loops in immune and non-immune rabbits.

Rabbits were solidly immunised by parenteral injection of purified Clostridium difficile toxin A such that they resisted an intravenous challenge with a normally lethal dose of toxin A. Ileal and colonic loops constructed in non-immune and immune animals received challenge injections of crude culture filtrate or purified toxin A of C. difficile. Protection of ileum was manifest after sufficient initial mucosal damage resulted in release of high levels of antitoxin A into the loop lumen of immune animals. There was less fluid accumulation in ligated ileal loops of immune than of non-immune rabbits. Less protection was observed when loops were challenged with crude culture filtrate containing toxins A and B than when challenged with purified toxin A. In-vitro studies with Ussing chambers yielded no evidence for tissue-localised immunity as judged by electrical responses and histology of toxin-treated tissue from non-immune and immune animals. No differences were found in the degree of epithelial damage, or volume or composition of fluid accumulating in colonic loops of non-immune and immune rabbits challenged with toxin A or crude culture filtrate. However, in colonic loops of immune rabbits there was no overt tissue-localised haemorrhage, whereas in those of non-immune rabbits tissue-localised haemorrhage was marked. In contrast to our findings with ileal loops, fluid accumulating in colonic loops was watery and contained substantially less total protein and (in immune animals) antitoxin A.

Animals↗

PubMed1995

Effects of single or primary plus booster prostaglandin F2 alpha immunization regimens on immune, ovarian, and growth responses of heifers.

Growth rate of heifers is reduced by prostaglandin F2 alpha (PGF) immunization following a primary and booster regimen. The objective was to attenuate the immune response with or without a booster immunization; specifically, the effects of booster interval, dose of PGF-human serum albumin (HSA) conjugate at booster, adjuvant type, or single immunization with one or two adjuvants were examined. Three experiments were conducted using 175 cyclic heifers. Plasma PGF antibody titers were measured every 2 wk and progesterone concentrations every 3 to 4 d. In Exp. 1, single immunization with one adjuvant (3.3 mg of PGF-HSA in either DEAE-dextran [DEAE] or non-ulcerative Freund's adjuvant [NUFA]; or 10.0 mg of PGF-HSA in NUFA) did not induce sufficient antibody titers to consistently induce persistent corpora lutea (CL). Booster intervals of either 14, 21, or 28 d increased titers sufficiently to induce persistent CL (34/35 heifers), but ADG of heifers was less (P < .05) than for those given a single immunization. In Exp. 2, 1.0 mg of conjugate for booster immunization induced a greater (P < .05) immune response than 3.3 mg, and both doses decreased (P < .05) ADG. Single immunization, with half the conjugate dose in DEAE and half in NUFA injected separately, induced persistent CL in 7/8 heifers without decreasing ADG compared with controls. In Exp. 3, single immunization, with half the conjugate dose in DEAE and half in NUFA injected separately, prolonged (P < .05) the intervals to peak titer compared with the booster treatment, but the incidence (13/15 vs 8/8) and duration (120 +/- 4.8 vs 111 +/- 7.9 d) of persistent CL were similar, and ADG was greater (P < .05). In conclusion, attempts to attenuate the immune response following booster immunization were unsuccessful. Single immunization, using two adjuvants separately, induced persistent CL for at least 120 d without decreasing ADG compared with the primary and booster regimen.

Animals↗

PubMed1971

Cell-mediated immunity and antibody responses in the respiratory tract after local and systemic immunization.

The cell-mediated immune response on the secretory surface of the lower respiratory tract was investigated and compared to the systemic cell-mediated immune response and to the secretory and systemic antibody responses. Guinea pigs were immunized either parenterally or locally with dinitrophenylated human IgG. The effect of rendering animals tolerant on the local cell-mediated response and on the local antibody response was also studied. The antibody response in the bronchial washing fluids was predominantly of the IgA class. In the animals rendered tolerant by administering large doses of the antigen intravenously, the secretory antibody response was significantly reduced to about 40% of the levels in the animals which were not tolerant. Cellular immunity was assayed using the inhibition of macrophage migration. In animals which were immunized subcutaneously, splenic lymphocytes strongly inhibited the migration of normal guinea pig macrophages; however cells obtained from bronchial washings from the same animals exhibited little or no inhibition of macrophage migration in the presence of antigen. In the animals which were immunized by nose drops, splenic lymphocytes showed virtually no inhibition of macrophage migration; however, bronchial washing lymphocytes strongly inhibited the migration of normal macrophages. Thus, nose drop immunization gave rise to a significantly greater local cellular immune response than did parenteral immunization. In those animals which were immunized by nose drops after a tolerizing dose of antigen, there was virtually no inhibition of macrophage migration by either the cells from the spleens or bronchial washings. Studies were done which demonstrated that a substance similar to macrophage-inhibition factor was liberated by the bronchial washing cells on incubation with the antigen. Studies were also done which indicated that secretory antibody played no role in the inhibition of macrophage migration when bronchial washing lymphocytes were used. Lymphocytes were purified from bronchial washings and were found to inhibit normal macrophage migration in the presence of antigen to the same extent that the mixed population of lymphocytes and pulmonary macrophages did. Thus this study supports the concept that local cellular immunity can be initiated independently of systemic cellular immunity.

Animals↗

PubMed1992

Immunity to B16 melanoma in mice immunized with IL-2-secreting allogeneic mouse fibroblasts expressing melanoma-associated antigens.

Co-presentation of weak tumour-associated antigens along with strongly immunogenic determinants leads to the development of an anti-tumour immune response in recipients syngeneic with the tumour. Tumour immunity develops in mice immunized with tumour cells modified by the introduction of cDNA for interleukin-2 (IL-2). Here, we report the anti-tumour response following immunization with an IL-2-secreting cell construct that expresses tumour-associated antigens, along with allogeneic major histocompatibility antigens. The construct was prepared by transfecting LM(TK-) mouse fibroblasts (H-2k) with genomic DNA from B16 melanoma cells syngeneic in C57BL/6J mice (H-2b). Transfectants expressing melanoma-associated antigens (MAA) were then infected with an expression-competent retroviral vector containing a cDNA specifying human IL-2. Cytotoxicity toward B16 cells was detected for as long as 5 months in both spleen and macrophage cell populations in C57BL/6J mice immunized with the IL-2-secreting cells. Mice immunized with non-IL-2-secreting, MAA-positive allogeneic cells developed melanoma immunity as well, but to a lesser extent. Immunity to 2 tumour-cell lines expressing the H-2d haplotype and to YAC-1 cells was detected in peritoneal macrophages, but not in spleen cells from C57BL/6J mice immunized with the cell construct, indicating that the response to B16 cells was only partially specific. C57BL/6J mice immunized with the IL-2-secreting cell construct survived significantly longer, following an injection of viable B16 cells, than mice in various control groups. The contribution of allogeneic antigens to the melanoma immunity was indicated by the failure of mice syngeneic with LM(TK-) cells to develop melanoma immunity following immunization with non-IL-2-secreting, MAA-positive cell constructs. The formation of IL-2 partially compensated for the lack of allogeneic antigens.

Animals↗