Groups Of Immunized Mice Research Articles

Humoral immunity through immunoglobulin M protects mice from an experimental actinomycetoma infection by Nocardia brasiliensis.

An experimental model of infection with Nocardia brasiliensis, used as an example of a facultative intracellular pathogen, was tested. N. brasiliensis was injected into the rear foot pads of BALB/c mice to establish an infection. Within 30 days, infected animals developed a chronic actinomycetoma infection. Batch cultures of N. brasiliensis were used to purify P61, P38, and P24 antigens; P61 is a catalase, and P38 is a protease with strong caseinolytic activity. Active and passive immunizations of BALB/c mice with these three purified soluble antigens were studied. Protection was demonstrated for actively immunized mice. However, immunity lasted only 30 days. Other groups of immunized mice were bled at different times, and their sera were passively transferred to naive recipients that were then infected with N. brasiliensis. Sera collected 5, 6, and 7 days after donor immunization conferred complete, long-lasting protection. The protective effect of passive immunity decreased when sera were collected 2 weeks after donor immunization. However, neither the early sera (1-, 2-, and 3-day sera) nor the later sera (30- or 45-day sera) prevented the infection. Hyperimmune sera with the highest levels of immunoglobulin G (IgG) to N. brasiliensis antigens did not protect at all. The antigens tested induced two IgM peaks. The first peak was present 3 days after immunization but was not antigen specific and did not transfer protection. The second peak was evident 7 days after immunization, was an IgM response, was antigen specific, and conferred protection. This results clearly demonstrate that IgM antibodies protect the host against a facultative intracellular bacterium.

Differential immune response to B:9-23 insulin 1 and insulin 2 peptides in animal models of type 1 diabetes

Mice have two insulin genes that differ in the insulin sequence by two amino acids, including the B9 position. Given prior studies of the B:9-23 insulin peptide in NOD mice, a fundamental question is whether the immune response to the B:9-23 peptide of the two insulins is identical. We investigate responses to the immunization with B:9-23 insulin 1 and 2 peptides in NOD and RIP-B7.1 Balb/c mice. NOD and F1 (Balb/c × C57/Bl6) B7.1 transgenic mice were given either B:9-23 insulin 1, B:9-23 insulin 2 or tetanus toxoid (TT) control peptide. Insulin autoantibodies (IAA), and anti-B:9-23 antibodies (IgG 1 and IgG 2c) were measured. Subcutaneous injection of the insulin 2 but not the insulin 1 peptide significantly protected NOD mice from diabetes. Conceptually similar, insulin 1 peptide immunization accelerated diabetes in the B7.1 mice compared with insulin 2 peptide. Insulin 1 and 2 peptides induced similar levels of IAA in the NOD mice except at week 26, where insulin 2 induced higher levels of IAA. Anti-IgG 1 B:9-23 peptide antibodies were higher in the insulin 2 immunized group of NOD mice, while IgG 2c anti-B:9-23 peptide antibodies were higher in the insulin 1 group. Adoptive transfer of splenocytes from insulin 1 immunized mice to NOD. scid mice demonstrated accelerated diabetogenicity. The protection afforded by insulin 2 peptide but not insulin 1 peptide in the NOD mouse is reflected by its predominant Th2 humoral response. This may relate to the protection conferred by the insulin 1 knockout when bred onto NOD mice in contrast to acceleration of disease with an insulin 2 knockout.

Immunogenicity of polyepitope libraries assembled by epitope shuffling: an approach to the development of chimeric gene vaccination against malaria

Developing a polyepitope vaccine which contains diverse antigenic types is a promising strategy to cope with the problem of malaria variation and diversity. However, arranging the peptides to produce the most effective immunogenicity remains a hurdle. In an attempt to develop an effective complex antigenic gene vaccine, we constructed a polyepitope library by randomly assembling epitopes using the epitope shuffling technique. The polyepitope library, which contains epitopes from different antigens of Plasmodium falciparum, was divided into five sub-libraries based on the size of chimeric genes. Here we report that higher antibody titers were observed in mice with immunized with sub-libraries containing genes >1200 bp, using enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IFAT) assay to determine both individual epitope peptides and the natural parasites at the erythrocyte stage. Different levels of IgG subtypes and cytokines were elicited by different sub-library and administration times. In a rodent malaria model, some groups of immunized mice were partially cross-protected against a lethal challenge from Plasmodium yoelii. These results suggest that the immunogenicity of a polyepitope chimeric antigen is essentially conformation- and length-dependent, and demonstrates that the promising advantage of epitope shuffling technology is that it allows us to randomly assemble many polyepitope molecules in tandem format. This finding also indicates that polyepitope library vaccination is a suitable approach for screening optimized chimeric gene vaccines against malaria and other diseases.

Treatment of bladder carcinomas using recombinant BCG DNA vaccines and electroporative gene immunotherapy.

Intravesical immunotherapy with live Mycobacterium bovis bacillus Calmette-Guérin (BCG) is the treatment of choice for superficial bladder cancers. Nevertheless, a significant proportion of patients do not respond to this therapy, and adverse effects are common. Here, we report the cloning of recombinant mycobacterial DNA vaccines and demonstrate the ability of multicomponent and multisubunit DNA vaccines to enhance Th1-polarized cytokine-mediated responses as well as effector cell responses. Splenocytes from immunized groups of mice were restimulated in vitro and examined for cytotoxicity against murine bladder tumur (MBT-2) cells. We used four combined recombinant BCG DNA vaccines (poly-rBCG) for electroporative gene immunotherapy (EPGIT) in vivo, and found that tumor growth was significantly inhibited and mouse survival was prolonged. Increased immune cell infiltration and induction of apoptosis were noted after treatment with poly-rBCG alone, with the murine interleukin-12 (mIL-12) vaccine alone, and-most significantly-with the poly-rBCG+mIL-12 vaccine combination. Electroporation of poly-rBCG+mIL-12 resulted in complete tumor eradication in seven of eight mice (P<.01) within 28 days. Thus, EPGIT using multicomponent multisubunit BCG is highly effective in the treatment of bladder cancer. This approach presents new possibilities for the treatment of bladder cancer using recombinant BCG DNA vaccines.

A novel DNA vaccine containing endosome-fusogenic peptide prevents CVB3-induced myocarditis in mice

To enhance the effect of chitosan-pcDNA3-VP1 DNA vaccine to prevent onset of coxsackievirus B3 (CVB3)-induced myocarditis. HA-pLys16 "carrier peptide" containing "endosome fusogenic peptide" and poly-Lysine was synthesized and complexed with DNA and chitosan sequentially, resulting chitosan-pcDNA3-VP1-HApLys16 vaccine. It was administrated to BALB/c mice with a total dose of 200 micro g pcDNA3-VP1. Mice were infected with 3 (LD(50) CVB3 3 weeks later to induce myocarditis. Loss of body weight, body/heart weight ratio, outlook and HE staining of heart tissues was observed and compared as an indicative of severity of myocarditis. chitosan-pcDNA3-VP1-HApLys16 vaccine intranasal immunization enhanced secretion of mucosal sIgA. After 3 x LD(50) CVB3 infection, pcDNA3 immunized mice groups lost their 5.75% weight following CVB3 infection, while chitosan-pcDNA3-VP1 and chitosan-pcDNA3-VP1-HApLys16 immunized mice increased their body weight by 1.75% and 5.44%. Body/heart weight ratio of chitosan-pcDNA3-VP1-HAplys16 group reached 193.77 suggesting lightened myocarditis. No myonecrosis or infiltrating immune cells existed in heart of chitosan-pcDNA3-VP1-HAplys16 immunized mice, and 1/6 of incidence and very light myocarditis were seen in chitosan-pcDNA3-VP1 immunized mice. While in pcDNA3 immunized mice 6/6 incidence and extremely severe myocarditis were observed. Heart from pcDNA3-immunized mice was bigger than normal ones and had a lot of white stripes, which were not observed in that of chitosan-pcDNA3-VP1 and chitosan-pcDNA3-VP1-HApLys16 immunized mice. Novel chitosan-pcDNA3-VP1-HApLys16 vaccine containing "endosome fusogenic peptide" could more effectively prevent CVB3-induced myocarditis than chitosan-pcDNA3-VP1 vaccine.

Immunoglobulin E is not required for but enhances airway inflammation and hyperresponsiveness.

The aim of this study was to investigate the role of immunoglobulin E (IgE) in the late phase reaction (LPR) of murine experimental asthma. Our model consisted of an implant of DNP-conjugated, heat-coagulated hen's egg white (DNP-EWI), followed 14 days later by an intratracheal challenge with aggregated DNP-ovalbumin. Airway inflammation was analyzed 48 h after challenge and compared with a similarly immunized group of mice with highly suppressed humoral response due to anti-micro and anti-delta antibody treatment. Total number of cells in the bronchoalveolar lavage (BAL) (with predominance of eosinophils) and EPO activity in the lung homogenate were increased in the DNP-EWI-immunized group compared with immunosuppressed or nonimmunized mice. However, the cellular infiltration and EPO activity observed in the immunosuppressed group were still significantly above those obtained in the nonimmunized group, indicating that inhibition of antibody production did not completely prevent the inflammatory manifestations in BAL and lung. Airway hyperresponsiveness to methacoline was obtained in DNP-EWI-immunized mice, but the respiratory mechanical parameters returned to normal levels in the immunosuppressed group. When these mice were reconstituted with monoclonal anti-DNP antibodies, only IgE, but not IgG1, restored lung inflammation and decreased the conductance of the respiratory system, therefore, increasing hyperresponsiveness. These results indicate that antibodies are not essential for induction of LPR in the lung. However, IgE enhances pulmonary inflammation and hyperresponsiveness.

Effect of surgical trauma on epithelial cell adhesion molecule (GA-733) vaccine-induced tumor resistance.

Surgical trauma inhibits immune function. Our goal was to study the effect of surgical intervention on the development of the immune response to epithelial cell adhesion molecule (EpCAM [GA-733]), a tumor-associated protein used for vaccination in colon cancer. Recombinant GA-733 and monophosphoryl-lipid A (MPLA) were incorporated into biodegradable beads and implanted in the following groups of mice: control, insufflation, and laparotomy. After surgery, the mice were inoculated with GA-733-transfected C26 cells (C26-EpCAM). Plasma anti-GA733 IgG antibodies were detected in enzyme-linked immunoassay (ELISA). Killing specific to GA-733 was assayed by C26-EpCAM-killing assay. The difference in tumor size between immunized and nonimmunized animals was statistically significant only in control mice (p < 0.05). Greater cytotoxic response to C26-GA733 developed in all immunized mice groups than in their respective controls. However, anti-GA733 IgG increased significantly in the control and insufflation groups, but not in the laparotomy group. Combined GA-733 vaccine allows reduction of tumor growth in control but not in surgically managed animals. This vaccine can induce a specific-cell and antibody-mediated immune response. Open surgery leads to a decreased antibody response to the GA-733 tumor vaccine.

MODULATORY EFFECTS OF SALMONELLA LAP-LPS ON MURINE MACROPHAGES

Purpose: To study the modulatory effects of Salmonella lipid associated protein - lipopolysaccharides (LAP-LPS) on murine macrophages as the intracellular survival within the host macrophages is an important feature for a number of gram-negative pathogens like S.typhi. Methods: Macrophage functions were studied in two groups of mice immunized with either LPS or LAP-LPS. Results: Comparison of protective efficacy of mice preimmunized with LPS based preparations, against challenge infectious doses, showed higher protection in LAP-LPS complex immunized mice group as compared to the mice group immunized with LPS alone. Aggregation of S.typhi cells was lesser with intestinal mucus extracted from LAP-LPS immunized mice as compared to LPS immunized challenged group. A significant increase in the number of macrophages in LAP-LPS immunized mice was also observed in comparison to control and LPS immunized mice groups. Nitric oxide (NO) and superoxide dismutase (SOD) production were also more in macrophages derived from LAP-LPS immunized mice group. Phagocytic uptake studies showed that there was enhanced uptake of bacteria in the LAP-LPS immunized animals in comparison to LPS immunized and controls. Similar trend was observed in intracellular killing of bacteria by the macrophages. Conclusions: The results indicated the involvement of protein moiety in LAP on modulation of effects of LPS on macrophages.

The efficacy of a DNA vaccine encoding herpes simplex virus type 1 (HSV-1) glycoprotein D in decreasing ocular disease severity following corneal HSV-1 challenge.

Antiviral effects of a DNA vaccine against herpes simplex virus 1 (HSV-1) glycoprotein D (gD) were evaluated in eight week-old female BALB/c mice. The nuclease-insensitive construct (gD-ASOR) consisted of an HSV-1 gD encoding plasmid coupled to asialo orosomucoid (ASOR), targeting it to cells bearing ASOR receptors. Mice were immunized on day 0 and 7 with 10 microg doses of gD-ASOR or control substances. Fourteen days later, mice were infected by the corneal route with 10(5) pfu or 10(6) pfu HSV-1, strain 17syn+. Immunized mice showed a significant decrease in ocular disease severity over a 21-day observation period following infection compared to sham-immunized mice. Acute replication kinetic assays demonstrated a 100-fold decrease in viral titers on day 6 in trigeminal ganglia from immunized BALB/c mice compared to sham-immunized mice. Immunized mice showed a significant increase in numbers of CD4(+)T cells infiltrating the trigeminal ganglia at day 6 post infection compared to sham-immunized mice. Significant differences were not seen in latent viral reservoir between immunized and unimmunized mouse groups. Immunization with gD-ASOR decreased the severity of acute ocular HSV-1 infection, induced a CD4(+) T cell response, decreased the viral load in the trigeminal ganglia, but did not diminish viral latency.

The effects of immunization with recombinant Sm14 (rSm14) in reducing worm burden and mortality of mice infected with Schistosoma mansoni.

To investigate whether mice immunization with the recombinant form of a 14.7 KDa Schistosoma mansoni protein (rSm14) confers protection against a S. mansoni lethal challenge infection, rSm14-immunized mice were challenged with different cercarial burdens. A significant protection was detected in immunized mice challenged with 100 or 1,000 S. mansoni cercariae when compared with their controls (p< 0.004 and p< 0.01 respectively). Differently from previous report, none of the mice from the control group (not immunized and infected with 1000 cercariae) died before the 30th day post-infection. A direct correlation between the number of challenge cercariae and the precocity of mice death was found. IgM anti-rSm14 antibodies were significantly produced (p< 0.05) mainly in the groups of immunized mice infected with 500 or 1000 cercariae. IgG and IgA anti-rSm14 antibodies were not significantly detected. In Western immunoblots, all mice sera showed a specific antibody response with a 14.7 KDa antigen being reacted with particular intensity in sera from immunized mice. The results show that immunization with rSm14 reduced mice worm burden independently of the cercariae load of challenge infection. No correlation was found between serum antibodies and worm burden reduction. In relation to cercarial load and the rate and precocity of mice mortality a direct correlation was found.

Low-Protein Diet Induces Oral Tolerance to Ovalbumin in Mice.

The suitable development of oral tolerance against ingested dietary foods is of critical importance to escaping food allergy. Using mice as an animal model for oral tolerance against ovalbumin (OVA) as a dietary antigen, we investigated the effects of dietary protein on their immunological tolerance. Female BALB/c mice fed either a 20% or 5% protein diet were orally administered 5 mg of OVA for four consecutive days, then immunized intraperitoneally with 100 microg of OVA. The immunized group of mice were fed and treated in the same manner, except that they received orally distilled water for four consecutive days before receiving intraperitoneal immunization with the antigen. Immunization alone with OVA elevated the total IgE and induced the production of OVA-specific antibodies IgE, IgG, IgG1, and IgG2a in the sera of both the 20% and 5% protein diet groups. The oral administration of OVA to mice before intraperitoneal immunization significantly reduced the total IgE and OVA-specific antibodies in mice fed 5% protein diet, but it had hardly any effect on those in mice fed a 20% protein diet. When spleen cells from these groups of mice were cultured with OVA as a mitogen, they responded substantially to OVA in the immunized groups fed 20% and 5% protein diets and in the presensitized group fed 20% protein, but those from the presensitized group fed a 5% protein diet did not respond. Furthermore, when IL-4 was assayed in the spleen cell cultures of the 20% and 5% groups, mice in the presensitized group fed a 5% protein diet produced a significantly less amount of IL-4 than those fed a 20% protein diet. Moreover, irrelevant to the protein amount in the diet, the production of IFN-gamma from spleen cell cultures dramatically decreased in the group without presensitization and profoundly increased in the presensitized group of mice fed a 5% protein diet. These findings suggest that a low-protein diet leads to an induction of oral tolerance against dietary antigens; this appears to involve a clear down-regulation of Th2 cytokine, IL-4.

Humoral and cell-mediated immunity to Vero cell-derived influenza vaccine

A candidate trivalent influenza whole virus vaccine produced in a continuous mammalian cell line (Vero), and analogous commercially available egg-derived vaccines, were compared for their ability to induce humoral and cell-mediated immunity in Balb/c mice. Substantial haemagglutination-inhibition titre and high levels of influenza virus-specific IgG were found in all groups of immunized mice, irrespective of the vaccine formulation. The IgG responses were predominantly of IgG1 and IgG2a/2b isotypes. Virus-specific secretory IgA antibodies were detected only in mice immunized intranasally with a live virus, derived either from Vero cells or eggs. T-cell proliferative responses and T-helper 1 type cytokine release was significantly higher in mice immunized with Vero cell-derived influenza vaccine compared to egg-derived vaccine formulations. We have demonstrated that the immunogenicity of the trivalent Vero cell-derived whole influenza virus vaccine was comparable to that of the equivalent egg-derived vaccine, with respect to humoral immune response and was superior with respect to cellular response.

Immune responses to third stage larvae of Onchocerca volvulus in interferon-gamma and interleukin-4 knockout mice.

To shed clarity on the dichotomy of reported results relative to the significance of T helper-1 vs T helper-2 immune responses in onchocerciasis, we compared the survivability of Onchocerca volvulus third-stage larvae (L3) in immunized mice that had either a targeted disruption of the Interleukin-4 or Interferon-gamma gene. Treatment groups consisted of control mice and mice immunized with irradiated O. volvulus L3. All mice were challenged with diffusion chambers containing viable L3. Vaccinated IL-4-/- were unable to kill this larval target. In contrast, vaccinated INF-gamma-/- and C57BL/6 mice, exhibited high levels of killing, had elevated levels of IL-4 and significantly greater numbers of eosinophils in their diffusion chambers than the IL-4-/-. Whereas, levels of IFN-gamma in all three groups of immunized mice were equivalent to those of control mice, levels of IL-5 were elevated, even in the IL-4-/-, indicating that cytokines other than IL-4 were involved in its production. The protective immune response to third-stage larvae of O. volvulus in mice vaccinated with irradiated larvae has an absolute IL-4 requirement.

Trypanosoma cruzi: The major cysteinyl proteinase (cruzipain) is a relevant immunogen of parasite acidic antigens (FIII)

This study examined the immune responses induced by cruzipain, a well-characterized T. cruzi antigen, to determine whether it is a relevant immunogen among the parasite acidic antigens (FIII), for which some biological properties have been studied previously. Humoral and cellular immune responses were investigated in BALB C mice after immunization with cruzipain or FIII. Skin tests revealed immediate type-hypersensitivity (ITH) and delayed-type hypersensitivity (DTH) reactions to cruzipain in both groups of immunized mice. IgG1 and IgE isotypes against cruzipain were detected by ELISA in both groups and immunoblot studies showed that these antibodies recognized a major protein band of 50 kDa, cruzipain. The antigen-specific proliferative responses of spleen lymphocytes from both groups of immunized mice were also increased. Immunization with cruzipain or FIII antigen significantly enhanced the percentage survival of mice challenged with 10 3 trypomastigotes. The results revealed high cross-reactivity between cruzipain and FIII, suggesting that cruzipain is a relevant immunogen among the parasite acidic antigens.

Modulation of DNA binding in vivo by specific humoral immunological response: a novel host factor in environmental carcinogenesis?

To investigate the possible modulatory effect of the immune response induced by recurrent carcinogen exposure, a specific humoral immune response toward 2-acetylaminofluorene (2-AAF) was elicited in Swiss mice with repeated intraperitoneal injections of a 2-AAF-gelatin conjugate. The immunization procedure resulted in the production of specific anti-2-AAF antibodies in all treated animals. Groups of immunized and nonimmunized mice were subsequently fed 2-AAF pelleted in the diet at 50 and 150 ppm for 4 weeks. At the end of 2-AAF administration, animals were sacrificed and the content of 2-AAF-adducts in liver DNA was determined by enzyme-linked immunoadsorbent assay using a polyclonal rabbit antiserum. The comparison of the adducts levels in immunized and nonimmunized mice (receiving either the vehicle or the adjuvant alone during pretreatment) demonstrates a highly significant (p < 0.001) difference among groups, with far lower adduct levels in immunized animals. No significant difference in food consumption or liver metabolic activities was observed among experimental groups, suggesting the absence of external bias. The mechanism underlying the result observed is not yet clear; however, the experimental data strongly suggest that the specific immunological response induced by recurrent carcinogen exposure may exert a modulatory effect and act as a relevant host factor in chemical carcinogenesis.

Protective efficacy of a parenterally administered MOMP-derived synthetic oligopeptide vaccine in a murine model of Chlamydia trachomatis genital tract infection: serum neutralizing IgG antibodies do not protect against chlamydial genital tract infection

The protective efficacy of an alum-adsorbed, parenterally administered synthetic oligopeptide immunogen corresponding to antigenically common T-helper and neutralizing B-cell epitopes of the Chlamydia trachomatis major outer membrane protein was studied in a murine model of chlamydial genital tract infection. Mice produced high levels of anti-chlamydial serum IgG neutralizing antibodies following subcutaneous immunization with the alum-adsorbed oligopeptide. Lower but detectable levels of chlamydial specific IgG antibodies were found in vaginal washes. IgG1 was the predominant isotype present in sera and vaginal washes. Chlamydial-specific IgA was not present in either the sera or vaginal washes of immunized mice. Vaccinated and control mice were challenged intravaginally or intrauterinally with low, medium, or high doses of C. trachomatis serovar D challenge inocula. Protection was assessed by performing quantitative chlamydial cervico-vaginal cultures over the course of the infection period. There were no statistically significant differences between groups of immunized and control mice in either colonization, shedding, or duration of infection. These findings demonstrate that parenteral immunization with the oligopeptide (serum-neutralizing antibodies) is ineffective in preventing chlamydial genital tract infection. It is possible, since chlamydial infection is restricted to the genital tract mucosae, that a more accurate evaluation of the oligopeptide vaccine potential will require local rather than systemic immunization.

Mechanism of the protective immunity against murine typhoid: persistence of Salmonella L forms in the liver after immunization with live-cell vaccines.

Live-cell vaccines of Salmonella typhimurium, either a sub-lethal dose of a wild-type (strain LT2) or a high dose of its two-heptose Rd1 mutant (strain SL1004), induced acquired resistance to murine typhoid, which remained 180 days after immunization. Growth of S. typhimurium as a bacillary form ceased between days 30 and 60 of immunization, but L forms of this bacterium colonized the liver (the mean number of L forms in the liver: 600 L-forming units) even at 180 days post-immunization. In contrast, a high inoculum of either a Ra mutant (strain TV148) of strain LT2 or S. schottmülleri 8006 sharing the same O antigenic components with those of S. typhimurium induced only a short-lived protection in proportion to the number of L forms in the liver, and the protective immunity was lost before day 180. However, there was no significant difference in the salmonella-specific T-cell responses among groups of immunized mice on day 180 of immunization. A lethal infection with strain LT2 in mice which had been immunized 75 days previously with living cells of strain SL1004 resulted in a rapid clearance of the challenge inoculum, together with a rapid elevation of anti-S. typhimurium antibody responses. Thus, the present data suggest that the long-lived immunity conferred upon live S. typhimurium vaccines is attributable to the colonization of this bacterium in the liver as L forms and the ability to colonize the liver as L forms is independent of the chain length of salmonella O-antigens.

The effect of sperm immunization in the gastrointestinal tract on anti-sperm antibody production and fertility in female mice

The present investigation studied the effects of sperm immunization in the gastrointestinal tract on anti-sperm antibody production and fertility in female mice. For comparative purposes, mice were also immunized with sperm intraperitoneally. Intraperitoneal immunization with 5 × 10 6 washed epididymal and vas deferens sperm 3 times per week for 7 wk produced anti-sperm IgG in plasma at 1:20,000 and in vaginal washings at 1:100 as determined by ELISA. Such mice have been shown previously to have reduced fertility. In comparison, mice immunized intragastrically with 5 × 10 6 sperm once per week for 11–14 wk had anti-sperm IgA in vaginal washings at only about 1:8 as determined by ELISA. After mating at the 14th wk these mice delivered 6.5 ± 1.4 pups, which was not significantly different from the 7.1 ± 1.1 pups delivered by an untreated control group. Mice immunized twice intragastrically and once intravaginally during a 25-day period had no detectable anti-sperm IgA in vaginal washings by ELISA. These mice delivered 9.7 ± 1.2 pups after mating beginning on day 32, as compared to 9.7 ± 0.8 pups in a PBS-sham immunized group. Mice immunized once intraduodenally and then once intraperitoneally 14 days later delivered 10.4 ± 0.9 pups after mating 10–14 days after the second immunization, while a similar group of mice whose primary sperm immunization was directly into Peyer's patches delivered 9.0 ± 1.4 pups. We could not detect anti-sperm IgG or IgA bound to sperm in the uterine or oviduct lumen using immunohistochemical labeling after any of the groups of immunized mice were mated. Our studies suggest that sperm immunization in the female mouse gastrointestinal tract elicited no, or only a weak, secretory antibody response in the reproductive tract lumen and did not reduce fertility.

Intestinal resistance to cholera toxin in mouse. Antitoxic antibodies and desensitization of adenylate cyclase.

Mice were immunized perorally with cholera toxin (CT), cholera B-subunit (CB), or buffer as control. The response of anti-CT antibodies of the IgG, IgA and IgM class in bile, IgA being predominating, were similar in both immunized groups. The same number of anti-CT containing plasma cells (ACC) were determined in the intestinal lamina propria of CT - as well as of CB-immunized mice 20 days after the last immunization, while ACC at day 4 in the CB group were 50% higher than in the CT group. In contrast to the vigorous antibody response to CT in both groups of immunized mice, only animals immunized with CT displayed resistance to CT-induced intestinal hypersecretion and to CT stimulation of adenylate cyclase. The CB-treated group responded to CT with fluid accumulation and enzyme activation similar to controls. The results suggest that intestinal resistance to CT in mouse is due to desensitization of adenylate cyclase rather than to CT-neutralizing antibodies.

The demonstration of pre-hepatic immune response to Fasciola hepatica in the mouse

Harness E., Hughes D. L. and Doy T. G. 1976. The demonstration of a pre-hepatic immune response to Fasciola hepatica in the mouse. International Journal for Parasitology 6: 15–17. Two groups of mice were immunized with either one oral dose of 20 irradiated metacercariae per mouse or 2 such doses given 7 days apart. Twenty-one days after immunization these mice together with non immunized controls were orally dosed with 100 normal metacercariae. Two days later immature flukes were recovered from the peritoneal cavity and counted. The numbers of flukes recovered from both immunized groups of mice were significantly lower than those obtained from the controls; this is taken to indicate that a protective mechanism operates at the intestinal wall.