Differential Kinetics and Distribution of Antibodies in Serum and Nasal and Vaginal Secretions after Nasal and Oral Vaccination of Humans

Although nasal vaccination has emerged as an interesting alternative to systemic or oral vaccination, knowledge is scarce about the immune responses after such immunization in humans. In the present study, we have compared the kinetics and organ distribution of the antibody responses after nasal and oral vaccination. We immunized female volunteers nasally or orally with cholera toxin B subunit (CTB) and determined the specific antibody levels in serum and nasal and vaginal secretions, as well as the number of circulating antibody-secreting cells, before immunization and 1, 2, 3, 6, and 26 weeks thereafter. Nasal vaccination induced 9-fold CTB-specific immunoglobulin A (IgA) and 56-fold specific IgG antibody increases in nasal secretions, whereas no significant IgA increase was seen after oral vaccination. Both oral and nasal vaccination resulted in 5- to 6-fold CTB-specific IgA and 20- to 30-fold specific IgG increases in vaginal secretions. Strong serum responses to CTB were also induced by both routes of vaccination. A notable difference between nasal and oral vaccination was that the nasal route elicited a specific antibody response with a later onset but of much longer duration than did the oral route. We conclude from this study that the nasal route is superior to the oral route for administering at least nonliving vaccines against infections in the upper respiratory tract, whereas either oral or nasal vaccination might be used for eliciting antibody responses in the female genital tract.     

Kinetics of Local and Systemic Immune Responses after Vaginal Immunization with Recombinant Cholera Toxin B Subunit in Humans

Vaginal vaccination seems to be the best strategy for inducing specific immunoglobulin A (IgA) and IgG antibody responses in the female genital tract. The relative efficiencies of one, two, and three vaginal doses of recombinant cholera toxin B subunit (CTB) in generating mucosal and systemic immune responses in healthy women were evaluated, and the kinetics of the immune responses were monitored for responding volunteers for up to 12 months after the last vaccination. A single dose of CTB failed to generate CTB-specific IgA antibody responses in cervical secretions. Two vaccinations induced significant increases in IgA antitoxin titers in seven of nine volunteers, and four volunteers also developed IgG antitoxin responses. The magnitudes of the responses were 20-fold for IgA antitoxin and 7.1-fold for IgG antitoxin. A third vaccination did not significantly increase the antitoxin responses, although the frequency of IgG responses was slightly higher than that after the second vaccination. In serum, CTB-specific antibodies were observed already after a single vaccination. However, two vaccinations were required to induce marked IgA as well as IgG antitoxin titer increases in the majority of volunteers. The postvaccination levels of antitoxin antibodies in serum were comparable after two and three vaccinations. At 12 months after vaccination, significantly elevated IgA and IgG antitoxin levels in cervical secretions could still be detected in approximately half of the volunteers who had initially responded to the vaccine. Antitoxin titer increases in serum were found in most of the vaccinees at follow-up.     

Intranasal vaccination of humans with recombinant cholera toxin B subunit induces systemic and local antibody responses in the upper respiratory tract and the vagina.

Forty-five volunteers were vaccinated twice intranasally with 10, 100, or 1,000 microg of cholera toxin B subunit (CTB). Blood and nasal and vaginal secretions were collected before and 1 week after the second vaccination from all volunteers, and the specific and total immunoglobulin A (IgA) and IgG titers were determined by enzyme-linked immunosorbent assay. Samples were also taken 6 months (n = 16) and 1 year (n = 14) after the vaccination. The 10- and 100-microg doses were well tolerated by the volunteers, but the 1,000-microg dose induced increased secretions from the nose and repetitive sneezings for several hours. The CTB-specific serum IgA and IgG increased 21- and 7-fold, respectively, 1 week after vaccination with the medium dose and increased 61- and 37-fold, respectively, after the high dose. In nasal secretions the specific IgA and IgG increased 2- and 6-fold after the medium dose and 2- and 20-fold after the high dose, respectively. In vaginal secretions the specific IgA and IgG increased 3- and 5-fold after the medium dose and 56- and 74-fold after the high dose, respectively. The lowest dose did not induce any significant antibody titer increases in serum or in secretions. The specific IgA and IgG levels in secretions were still elevated after 6 months but were decreasing 1 year after the vaccination. These results show that intranasal vaccination of humans with CTB induces strong systemic and mucosal antibody responses and suggest that CTB may be used as a carrier for antigens that induce protective immunity against systemic as well as respiratory and genital infections.     

Kinetics of local and systemic immune responses after vaginal immunization with recombinant cholera toxin B subunit in humans

Vaginal vaccination seems to be the best strategy for inducing specific immunoglobulin A (IgA) and IgG antibody responses in the female genital tract. The relative efficiencies of one, two, and three vaginal doses of recombinant cholera toxin B subunit (CTB) in generating mucosal and systemic immune responses in healthy women were evaluated, and the kinetics of the immune responses were monitored for responding volunteers for up to 12 months after the last vaccination. A single dose of CTB failed to generate CTB-specific IgA antibody responses in cervical secretions. Two vaccinations induced significant increases in IgA antitoxin titers in seven of nine volunteers, and four volunteers also developed IgG antitoxin responses. The magnitudes of the responses were 20-fold for IgA antitoxin and 7.1-fold for IgG antitoxin. A third vaccination did not significantly increase the antitoxin responses, although the frequency of IgG responses was slightly higher than that after the second vaccination. In serum, CTB-specific antibodies were observed already after a single vaccination. However, two vaccinations were required to induce marked IgA as well as IgG antitoxin titer increases in the majority of volunteers. The postvaccination levels of antitoxin antibodies in serum were comparable after two and three vaccinations. At 12 months after vaccination, significantly elevated IgA and IgG antitoxin levels in cervical secretions could still be detected in approximately half of the volunteers who had initially responded to the vaccine. Antitoxin titer increases in serum were found in most of the vaccinees at follow-up.     

Influence of exogenous reproductive hormones on specific antibody production in genital secretions after vaginal vaccination with recombinant cholera toxin B subunit in humans

The objective of this study was to investigate the influence of exogenous reproductive hormones on the local and systemic production of specific immunoglobulin A (IgA) and IgG antibodies after vaginal vaccination with recombinant cholera toxin subunit B (CTB). Three groups of women using either progesterone-containing intrauterine devices (n=9), oral contraceptives (n=8), or no hormonal contraceptive methods (n=9) were vaginally immunized twice, 2 weeks apart. Cervical secretions, vaginal fluids, and serum were collected before and after vaccination. Total and CTB-specific IgA and IgG antibodies in genital secretions and serum were analyzed by enzyme-linked immunosorbent assay. A majority of the women presented strong CTB-specific IgA and IgG antibody responses in cervicovaginal secretions after vaccination, whereas the antitoxin responses in serum were weaker. Exogenously administered steroid hormones did not seem to have any impact on the production of specific antibodies. Both the frequencies and the magnitudes of IgA and IgG antitoxin responses in genital secretions were comparable among the three immunization groups. An association, in particular for IgA, was found between the magnitudes of the CTB-specific antibody responses in cervical secretions and vaginal fluids after vaccination. The sensitivities and positive predictive values of vaginal antibody analyses to reflect responses in cervical secretions were also high, suggesting that vaginal fluids alone might be used for evaluation of genital immune responses in large-scale vaccination studies in the future.     

Antibody Responses in the Lower Respiratory Tract and Male Urogenital Tract in Humans after Nasal and Oral Vaccination with Cholera Toxin B Subunit

Nasal vaccine delivery is superior to oral delivery in inducing specific immunoglobulin A (IgA) and IgG antibody responses in the upper respiratory tract. Although an antibody response in the nasal passages is important in protecting against primary colonization with lung pathogens, antibodies in the lungs are usually required as well. We immunized 15 male volunteers twice nasally or orally with cholera toxin B subunit (CTB) and determined the specific antibody levels in serum, bronchoalveolar lavage (BAL) fluid, and urine before and 2 weeks after immunization. Nasal immunization induced fivefold increases in the levels of specific IgA antibodies in BAL fluid of most volunteers, whereas there were no significant specific IgA responses after oral immunization. The specific IgG antibody level increased eightfold in BAL fluid in the nasally vaccinated subjects, and the major part of IgG had most probably been transferred from serum. Since the specific IgG response in serum was lower in the individuals vaccinated orally, the IgG response in BAL fluid in this group was also lower and not significant. In conclusion, nasal immunization is also preferable to the oral route when vaccinating against lower respiratory tract infections, and a systemic immune response is considerably more important in the lower than in the upper respiratory tract. Moreover, both nasal and oral immunizations were able to stimulate 6- to 10-fold specific IgA and IgG responses in urine in about half of the individuals, which indicates that distant mucosal vaccination might be used to prevent adhesion of pathogens to the urogenital tract.     

Comparison of the oral, rectal, and vaginal immunization routes for induction of antibodies in rectal and genital tract secretions of women.

To determine which mucosal immunization routes may be optimal for induction of antibodies in the rectum and female genital tract, groups of women were immunized a total of three times either orally, rectally, or vaginally with a cholera vaccine containing killed Vibrio cholerae cells and the recombinant cholera toxin B (CTB) subunit. Systemic and mucosal antibody responses were assessed at 2-week intervals by quantitation of CTB-specific antibodies in serum and in secretions collected directly from mucosal surfaces of the oral cavity, rectum, cervix, and vagina with absorbent wicks. The three immunization routes increased levels of specific immunoglobulin G (IgG) in serum and specific IgA in saliva to similar extents. Rectal immunization was superior to other routes for inducing high levels of specific IgA and IgG in rectal secretions but was least effective for generating antibodies in female genital tract secretions. Only vaginal immunization significantly increased both specific IgA and specific IgG in both the cervix and the vagina. In addition, local production of CTB-specific IgG in the genital tract could be demonstrated only in vaginally immunized women. Vaginal immunization did not generate antibodies in the rectum, however. Thus, generation of optimal immune responses to sexually transmitted organisms in both the rectal and the genital mucosae of women may require local immunization at both of these sites.     

Systemic and mucosal immune responses in mice after mucosal immunization with group B streptococcus type III capsular polysaccharide-cholera toxin B subunit conjugate vaccine

Group B streptococci (GBS) colonize the female genital and rectal tracts and can cause invasive infection in susceptible newborns. An optimally effective GBS vaccine should induce mucosal and systemic immunity. In this study, we investigate the local and systemic immune responses to GBS type III capsular polysaccharide (CPS) after mucosal vaccination of mice via intranasal, peroral, rectal, and vaginal routes, with GBS type III CPS conjugated with recombinant cholera toxin B subunit (GBS III CPS-rCTB). Cholera toxin (CT) was added as an adjuvant. Immunoglobulin G (IgG) and IgA antibodies to the CPS were tested in serum, lungs, and intestinal, rectal, and vaginal extracts by enzyme-linked immunosorbent assay. The conjugated CPS administered by intranasal, peroral, rectal, and vaginal routes was much more effective at inducing both mucosal and systemic antibody responses to GBS III CPS than was unconjugated CPS. The CPS-specific immune responses in various organs were dependent on the route of immunization. Generally, the highest levels of IgA and IgG were generated in the regions or sites of the conjugate exposure. Thus, intranasal vaccination elicited the highest anti-CPS IgA and IgG antibody levels in the lungs, whereas peroral administration in the intestinal site and vaginal vaccination elicited the highest antibody levels in the vagina. Rectal vaccination was superior to the other routes in inducing high antibody levels in the rectum. The four routes of mucosal vaccination also induced distant antibody responses to CPS. Rectal vaccination induced high specific IgA levels in the vagina and intestine, and oral administration induced high specific IgA levels in the lungs and rectum. All four routes of vaccination with the conjugate elicited similarly high levels of anti-CPS IgG in serum. Intranasal vaccination with different doses of the conjugate (10, 30, and 80 microg of CPS) did not have a significant influence on the anti-CPS specific antibody responses. Intranasal immunization induced better antibody responses when one dose of the conjugate was divided and given on three consecutive days compared to administration of the full dose on one occasion. In conclusion, rectal and vaginal vaccination may be the best way of stimulating anti-CPS immune responses in the rectal and vaginal tracts, while high levels of anti-CPS antibodies in the lungs can be achieved after intranasal administration. The vaccination regimen thus might influence the mucosal immune response to CPS. This conjugate may serve as an effective mucosal vaccine for preventing mucosal colonization and invasive infection caused by GBS.     

Enhancement of Serum and Mucosal Immune Responses to a Haemophilus influenzae Type B Vaccine by Intranasal Delivery

Intranasal (i.n.) vaccination is potentially the most direct method for conveying upper respiratory and mucosal immunity to respiratory pathogens. However, for unclear reasons, vaccines introduced into the nasal sinuses often have lower efficacy than vaccines administered by the more frequently used parenteral routes. We examined i.n. vaccination in a mouse immune-response model with a commonly used Haemophilus influenzae type B vaccine (Hibv) composed of the polyribosylribitol phosphate (PRP) capsule antigen conjugated to tetanus toxoid. Intranasal vaccination with Hibv using a Toll-like receptor 4 (TLR4) agonist as an adjuvant significantly increased the levels of IgA specific for the PRP capsule antigen in blood serum, saliva, and mucosal secretion specimens. In contrast, control mice vaccinated transdermally (t.d.) with Hibv did not produce significant levels of PRP-specific IgA in the blood serum and saliva, and anti-PRP IgG was increased only in serum. The i.n. and t.d. vaccinations resulted in equivalent bactericidal antibody responses in blood serum, suggesting that vaccine-derived IgG is protective against infection. Elevated levels of IgG specific for the tetanus toxoid carrier protein were measured in nasal sinuses and vaginal secretions in mice vaccinated by either the t.d. or i.n. route. Tissue culture studies confirmed that the nasopharynx-associated lymphoid tissue (NALT) was at least one of the sources of PRP-specific IgA and carrier-specific IgG within the nasal sinuses. We conclude that i.n. vaccination aided by a TLR4 agonist results in robust immune responses to both the carrier protein and bacterial polysaccharide components of the Hibv.     

A novel and effective intranasal immunization strategy for respiratory syncytial virus.

In designing subunit vaccination strategies for respiratory syncytial virus (RSV), immunization by mucosal routes may present a realistic alternative to parenteral administration for inducing protective immune responses. To this end, we have utilized the BALB/c mouse model and an adjuvant formulation containing caprylic/capric glycerides (CCG) and polyoxyethylene-20-sorbitan monolaurate (PS). The intranasal (i.n.) delivery of purified natural F protein (3 microg per vaccine) formulated with CCG-PS resulted in the generation of statistically heightened serum anti-F protein immunoglobulin G (IgG), IgG1, IgG2b, and IgA antibodies. In addition, the presence of locally produced anti-F protein IgA was demonstrated in both vaginal and nasal washes of vaccinated mice. That production of specific serum and mucosal immunoglobulins resulted in functional immune responses was shown in neutralizing antibody assays and protection of mouse lungs against subsequent live virus challenge. Consequently, we propose a novel vaccine formulation composed of purified natural RSV F protein in CCG-PS as a viable intranasal immunogen to stimulate anti-RSV immune responses in humans.     

Rectal Immunization for Induction of Specific Antibody in the Genital Tract of Women

The purpose of the current study was to examine potential routes of vaccine administration for the induction of antigen-specific responses in the genital tract of women. Sixteen women were enrolled in this study, and the level of influenza-specific antibodies induced in the genital tract was measured after rectal or intramuscular immunizations. Both methods of administration induced significant increases in the concentration of flu-specific IgA found in cervical secretions within 28 days after vaccination. Initially flu-specific IgG antibodies were not induced in the genital tract by either route. As expected both IgA and IgG flu-specific antibodies were dramatically increased in serum after intramuscular vaccination. In contrast, rectal administration did not induce significant IgA responses, and only small flu-specific IgG increases in serum. Six months after administration, IgA flu-specific antibody concentrations were significantly higher than baseline levels in vaginal secretions and saliva isolated from both subject groups and flu-specific IgG concentrations in cervical secretions were high in the rectal immunization group. The long-term presence of both IgG and IgA antibody in genital secretions suggests that rectal immunization may be an effective method for induction of immune protection in the genital tract of women.     

Antibodies and Antibody-Secreting Cells in the Female Genital Tract after Vaginal or Intranasal Immunization with Cholera Toxin B Subunit or Conjugates

We studied the antibody response including antibody-secreting cells (ASC) in the female genital tract of mice after mucosal immunizations with the recombinant B subunit of cholera toxin (rCTB) perorally, intraperitoneally, vaginally, and intranasally (i.n.). The strongest genital antibody responses as measured with a novel perfusion-extraction method were induced after vaginal and i.n. immunizations, and these routes also gave rise to specific immunoglobulin A (IgA) and IgG ASC in the genital mucosa. Specific ASC in the iliac lymph nodes, which drain the female genital tract, were seen only after vaginal immunization. Progesterone treatment increased the ASC response in the genital tissue after all mucosal immunizations but most markedly after vaginal immunization. We also tested rCTB as a carrier for human gamma globulin (HGG) and the effect of adding cholera toxin (CT) as an adjuvant for the induction of systemic and genital antibody responses to HGG after vaginal and i.n. immunizations. Vaginal immunizations with HGG conjugated to rCTB resulted in high levels of genital anti-HGG antibodies whether or not CT was added, while after i.n. immunization the strongest antibody response was seen with the conjugate together with CT. In summary, vaginal and i.n. immunization give rise to a specific mucosal immune response including ASC in the genital tissue, and vaginal immunization also elicits ASC in the iliac lymph nodes. We have also shown that rCTB can act as an efficient carrier for a conjugated antigen for induction of a specific antibody response in the genital tract of mice after vaginal or i.n. immunization.     

Salivary, nasal, genital, and systemic antibody responses in monkeys immunized intranasally with a bacterial protein antigen and the Cholera toxin B subunit.

Previous attempts to induce mucosal antibodies in rhesus monkeys by enteric immunization have resulted in only modest and short-lived responses, dominated by immunoglobulin M (IgM) antibodies in the plasma. In this study, two groups of rhesus monkeys were immunized intranasally three times at 2-week intervals with a bacterial protein antigen (AgI/II) either chemically coupled to or mixed with the B subunit of cholera toxin (CT), a known potent mucosal immunogen and carrier for other immunogens. Cells secreting antibodies, predominantly of the IgA isotype, to AgI/II and to CT were detected in the peripheral blood 1 week after each immunization, indicating the dissemination of IgA-secreting precursor cells through the mucosal immune system. IgG and, to a lesser extent, IgA antibodies to both proteins were induced in the plasma commencing after the second immunization. Plasma IgE concentrations and IgE antibody levels were not consistently raised during the immunization period. IgA antibodies were found in nasal and vaginal washes. Nasal IgG but not IgA antibodies showed a significant positive correlation with plasma IgG antibody levels, suggesting that they were largely derived by transudation from the circulation. Analysis of the molecular form of vaginal IgA indicated that both secretory and monomeric forms of IgA were present in various proportions. Furthermore, neither IgG nor IgA antibodies in vaginal washes were correlated with plasma antibody responses, suggesting the contribution of locally synthesized antibodies of both isotypes. Comparison of the responses between the two groups of animals showed only sporadic significant differences, indicating that intranasal immunization with AgI/II either coupled to or mixed with the B subunit of CT was equally effective at inducing generalized IgA antibody responses in the mucosal immune system and predominantly IgG antibodies in the plasma.     

A nasal whole-cell pertussis vaccine induces specific systemic and cross-reactive mucosal antibody responses in human volunteers

A whole-cell pertussis vaccine, each dose consisting of 250 microg of protein, was given intranasally four times at weekly intervals to six adult volunteers. All vaccinees responded with increases in nasal fluid IgA antibodies to Bordetella pertussis whole-cell antigen. Three vaccinees with high nasal antibody responses also developed increased serum IgA and IgG antibodies to this antigen. Salivary antibody responses to the whole-cell antigen, as well as antibodies in serum and secretions to pertussis toxin (PT) and filamentous haemagglutinin (FHA) were negligible, except for a moderate increase in nasal fluid antibodies to FHA. Unexpectedly, the same vaccinees developed significant rises in nasal and salivary IgA antibodies to meningococcal outer-membrane antigens, whereas corresponding serum IgA and IgG antibodies were unchanged. Thus it appears that mucosal immunisation may induce secretory antibodies with broader specificities than can be found in serum.     

Mucosal vaccination with recombinantly attenuated staphylococcal enterotoxin B and protection in a murine model

Previous work in our laboratory revealed that mice parenterally vaccinated with recombinantly attenuated staphylococcal enterotoxin (SE) or toxic shock syndrome toxin 1 develop protective antibodies against a lethal intraperitoneal (i.p.) toxin challenge. This study investigated the efficacy of nasal and oral immunizations with an SEB vaccine (SEBv) toward an i.p. or mucosal (via an aerosol) toxin challenge. Both vaccination routes, with the immunoadjuvant cholera toxin (CT), elicited comparable SEB-specific immunoglobulin A (IgA) and IgG levels in saliva. Nasal or oral inoculations also generated SEB-specific IgA, IgG, and IgM in the serum, but the nasal route yielded higher specific IgG titers. SEBv alone, when given nasally or orally, did not induce any detectable SEB-specific antibody. Mice vaccinated mucosally were protected against a 50% lethal dose of wild-type SEB given i.p. or mucosally, thus demonstrating that nasal or oral administration of this SEBv, with CT, elicits systemic and mucosal antibodies to SEB that protect against SEB-induced lethal shock.     

Effect of age and maternal antibodies on the systemic and mucosal immune response after neonatal immunization in a porcine model

Newborn mammals are highly susceptible to respiratory infections. Although maternal antibodies (MatAb) offer them some protection, they may also interfere with their systemic immune response to vaccination. However, the impact of MatAb on the neonatal mucosal immune response remains incompletely described. This study was performed to determine the effect of ovalbumin (OVA) ‐specific MatAb on the anti‐OVA antibody response in sera, nasal secretions and saliva from specific pathogen‐free Vietnamese miniature piglets immunized at 7 or 14 days of age. Our results demonstrated that MatAb increased antigen‐specific IgA and IgG responses in sera, and transiently enhanced an early secretory IgA response in nasal secretions of piglets immunized at 7 days of age. In contrast, we detected a lower mucosal (nasal secretion and saliva) anti‐OVA IgG response in piglets with MatAb immunized at 14 days of age, compared with piglets with no MatAb, suggesting a modulatory effect of antigen‐specific maternal factors on the isotype transfer to the mucosal immune exclusion system. In our porcine model, we demonstrated that passive maternal immunity positively modulated the systemic and nasal immune responses of animals immunized early in life. Our results, therefore, open the possibility of inducing systemic and respiratory mucosal immunity in the presence of MatAb through early vaccination.     

Generation of female genital tract antibody responses by local or central (common) mucosal immunization

Genital antibody responses were compared in female mice immunized intravaginally (i.vag.) or intranasally (i.n.) with a bacterial protein antigen (AgI/II of Streptococcus mutans) coupled to the B subunit of cholera toxin. Serum and salivary antibodies were also evaluated as measures of disseminated mucosal and systemic responses. Although i.vag. immunization induced local vaginal immunoglobulin A (IgA) and IgG antibody responses, these were not disseminated to a remote secretion, the saliva, and only modest levels of serum antibodies were generated. In contrast, i.n. immunization was substantially more effective at inducing IgA and IgG antibody responses in the genital tract and in the circulation, as well as at inducing IgA antibodies in the saliva. Moreover, mucosal and systemic antibodies induced by i.n. immunization persisted for at least 12 months. Analysis of the molecular form of genital IgA indicated that the majority of both total IgA and specific IgA antibody was polymeric, and likely derived from the common mucosal immune system.     

Local Intravaginal Vaccination of the Female Genital Tract

In a clinical trial the authors tested whether local intravaginal or oral vaccination would stimulate a mucosal immune response in the female genital tract. The whole cell/B subunit (CTB) oral cholera vaccine was used. Two groups of previously unimmunized volunteers were given three doses of vaccine at 2-week intervals: a first group of seven women received oral immunizations and a second group of seven women were immunized locally in the genital tract by mixing the vaccine with a well defined gel, eldexomer, and applying it directly in the fornix of the vagina. The women were given the first vaccination on day 10 of the menstrual cycle. Sampling of peripheral blood and of cervical mucus (CM) using an Aspiglaire syringe was performed immediately prior to the first dose and at 8–10 days following the last immunization. The study showed that while only three of the seven orally immunized women responded with detectable IgA and IgG anti-CTB antibodies in the genital tract, six out of the seven women in the locally vaccinated group responded with genital tract antibodies. The responses were also generally stronger and CM contained higher specific IgA and secretory component containing anti-CTB titres in the locally vaccinated group. Of the orally vaccinated individuals all responded with increases in serum anti-CTB IgG and 4/7 also exhibited specific IgA serum titres. By contrast, only 3/7 in the intravaginal group responded with increases in serum IgG and IgA anti-CTB titers following immunization. The authors conclude that local intravaginal vaccination using a well-defined gel appears to be the route of choice to stimulate immunity in the female genital tract.     

Effect of uterine immunization and oestradiol on specific IgA and IgG antibodies in uterine, vaginal and salivary secretions.

Levels of IgA and IgG antibodies were measured in uterine and vaginal secretions to examine the effect of uterine immunization on the genital tract humoral immune system. When ovariectomized animals were immunized on Day 0 and boosted 13 days later by placing sheep erythrocytes (SRBC) directly in the uterine lumen (UT/UT) immunization), a pronounced IgA and IgG antibody response was detected in uterine secretions measured on Day 26. This response was 20-30-fold greater than that measured following Peyer's patch immunization and boosting (PP/PP) and Peyer's patch immunization followed by uterine boosting (PP/UT). In contrast to uterine antibody responses that were oestradiol-dependent following PP/PP and PP/UT immunization, UT/UT immunization resulted in IgA and IgG antibody responses that were hormonally independent. To determine whether immunological information is distributed beyond the immediate site of immunization, ovariectomized rats were immunized and boosted by injection of SRBC into one uterine horn. When uterine secretions from the contralateral (non-immune) horns were analysed, IgA and IgG antibodies were found in uterine secretions after oestradiol stimulation. IgA and IgG antibodies were also present in vaginal secretions following UT/UT immunization and ligation of uteri at the utero-cervical junction. This response was hormonally dependent in that vaginal antibody levels were lowered by oestradiol treatment. IgG but not IgA antibodies were also found in saliva of UT/UT immunized animals. Oestradiol had no effect on salivary IgG levels in contrast to those of the genital tract. In summary, these experiments indicate that immunization of uteri can elicit pronounced IgA and IgG antibody responses in uterine secretions and this response is not altered by oestradiol. Moreover, immunization at one site in the genital tract results in the appearance of antibodies at other uterine sites (the contralateral-non-immunized horn), in vaginal secretions, in serum and at other mucosal sites, such as the salivary glands.     

Effect of sublingual administration with a native or denatured protein allergen and adjuvant CpG oligodeoxynucleotides or cholera toxin on systemic T(H)2 immune responses and mucosal immunity in mice.

BACKGROUND: Sublingual immunotherapy has been recently used for allergic diseases, but its mechanisms are still unclear. OBJECTIVE: To examine the effect of sublingual administration of a native or denatured allergen alone or plus adjuvant on systemic T(H)2 responses and mucosal immunity in mice. METHODS: Naive or sensitized BALB/c mice were sublingually vaccinated biweekly for 3 weeks with ovalbumin (OVA) or urea-denatured OVA (CM-OVA) only or plus adjuvant CpG oligodeoxynucleotides (CpG) or cholera toxin (CT). Two weeks later, their specific serum IgG, IgG1, IgG2a, IgE, and saliva secretory IgA (SIgA) antibody responses and the cytokine profiles of spleen and cervical lymph node cells were investigated. RESULTS: Specific SIgA antibody responses were induced by vaccination with CM-OVA plus CpG or CT. Whereas vaccination with CM-OVA and CpG enhanced T(H)1 responses but inhibited IgE production, vaccination with CT and CM-OVA or OVA increased cervical lymph node cell production of interleukin (IL) 4, IL-5, and IL-6 and serum IgG1 antibody responses. In previously sensitized mice, sublingual vaccination with OVA or CM-OVA plus CT or CpG stimulated mucosal SIgA antibody responses, but did not enhance ongoing IgE antibody responses. CONCLUSIONS: Sublingual vaccination with OVA or CM-OVA plus adjuvant CT or CpG all can induce systemic and mucosal immunity, but CM-OVA plus CpG had the best prophylactic and therapeutic effects on IgE antibody production. It is likely that sublingual vaccines may have a role for the prophylaxis and immunotherapy of allergic reactions.