Mucosal and systemic immune responses induced by a single time vaccination strategy in mice.

Vaccination is considered by the World Health Organization as the most cost-effective strategy for controlling infectious diseases. In spite of great successes with vaccines, many infectious diseases are still leading killers, because of the inadequate coverage of many vaccines. Several factors have been responsible: number of doses, high vaccine reactogenicity, vaccine costs, vaccination policy, among others. Contradictorily, few vaccines are of single dose and even less of mucosal administration. However, more common infections occur via mucosa, where secretory immunoglobulin A plays an essential role. As an alternative, we proposed a novel protocol of vaccination called Single Time Vaccination Strategy (SinTimVaS) by immunizing 2 priming doses at the same time: one by mucosal route and the other by parenteral route. Here, the mucosal and systemic responses induced by Finlay adjuvants (AF Proteoliposome 1 and AF Cochleate 1) implementing SinTimVaS in BALB/c mice were evaluated. One intranasal dose of AF Cochleate 1 and an intramuscular dose of AF Proteoliposome 1 adsorbed onto aluminum hydroxide, with bovine serum albumin or tetanus toxoid as model antigens, administrated at the same time, induced potent specific mucosal and systemic immune responses. Also, we demonstrated that SinTimVaS using other mucosal routes like oral and sublingual, in combination with the subcutaneous route elicits immune responses. SinTimVaS, as a new immunization strategy, could increase vaccination coverage and reduce time-cost vaccines campaigns, adding the benefits of immune response in mucosa.

Inmunopotenciadores para la acuicultura / Immune–potentiators for the Aquaculture

La acuicultura es una de las actividades económicas de mayor crecimiento para la producción de alimentos. Unode sus principales retos es la obtención de grandes volúmenes de producción con la mayor calidad posible. Esto conlleva a una reducción de la aplicación de antibióticos y productos quimioterapéuticos. Una de las estrategias más prometedoras es la aplicación de inmunopotenciadores, principalmente en los cultivos intensivos. El objetivode este trabajo fue revisar los principales inmunopotenciadores, así como las tendencias y retos de su uso mundial. Se resumen las particularidades moleculares y funcionales de los mismos y se hace énfasis en los más estudiados: levamisol, ß-glucanos, lipopolisacárido, vitamina C, extractos de plantas y hormonas. Todos estos compuestos de naturaleza heterogénea inciden mayoritariamente en los componentes de la inmunidad innata de los peces, fortaleciendo y potenciando la resistencia a enfermedades; adicionalmente algunos de ellostienen funciones antiestrés y favorecen su crecimiento. Se concluye que los inmunopotenciadores constituyen una estrategia viable para reducir las pérdidas por problemas sanitarios en el sector de la acuicultura; pero aún quedan por solucionar aspectos como la vía de administración y la etapa de inmunización adecuada para cadaespecie y tipo de cultivo(AU)

Aquaculture represents one of the fastest–growing animal food–producing sectors worldwide. One of the mainchallenges is to obtain high–volume production with the highest possible quality, this leads to reduce the use ofantibiotics and chemotherapeutics. A promising solution to these problems is the application of immune–potentiatiors mainly in intensive farming. This article aims to review the main immune–potentiators, as well as thetrends and challenges of global use of them. It summarizes the main molecular and functional characteristics withemphasis on those most studied such as levamisole, ß-glucans, lipopolysaccharide, vitamin C, plant extracts andhormones. All these heterogeneous compounds, mostly affect the innate immunity of fish, strengthening andenhancing disease resistance and some of them additionally have anti–stress effect and promote fish growth. Weconclude that immune–potentiators are a viable strategy to reduce losses for health problems in aquaculture field,however, aspects such as administration route and appropriate immunization phase for each species remains tobe solved(AU)

Adjuvants are Key Factors for the Development of Future Vaccines: Lessons from the Finlay Adjuvant Platform.

The development of effective vaccines against neglected diseases, especially those associated with poverty and social deprivation, is urgently needed. Modern vaccine technologies and a better understanding of the immune response have provided scientists with the tools for rational and safer design of subunit vaccines. Often, however, subunit vaccines do not elicit strong immune responses, highlighting the need to incorporate better adjuvants; this step therefore becomes a key factor for vaccine development. In this review we outline some key features of modern vaccinology that are linked with the development of better adjuvants. In line with the increased desire to obtain novel adjuvants for future vaccines, the Finlay Adjuvant Platform offers a novel approach for the development of new and effective adjuvants. The Finlay Adjuvants (AFs), AFPL (proteoliposome), and AFCo (cochleate), were initially designed for parenteral and mucosal applications, and constitute potent adjuvants for the induction of Th1 responses against several antigens. This review summarizes the status of the Finlay technology in producing promising adjuvants for unsolved-vaccine diseases including mucosal approaches and therapeutic vaccines. Ideas related to adjuvant classification, adjuvant selection, and their possible influence on innate recognition via multiple toll-like receptors are also discussed.

Reducción de la toxicidad del lipopolisacárido de Neisseria meningitidis serogrupo B y estudio de su estabilidad estructural / Reduction of the toxicity of the lipopolysaccharide from Neisseria meningitidis serogroup B and study of its structural stability

La búsqueda de adyuvantes está dentro de las líneas de investigación más importantes para el desarrollo de vacunas en las últimas décadas. Uno de los adyuvantes, en etapa de investigación en el Instituto Finlay, tiene en su composición al lipopolisacárido (LPS) de Neisseria meningitidis serogrupo B, el cual es altamente tóxico. Por ello nos propusimos modificarlo estructuralmente, para reducir su toxicidad y evaluar su estabilidad durante tres meses. Se utilizó un LPS purificado por el método de extracción con agua y fenol y se modificó estructuralmente por una hidrólisis básica controlada. El LPS resultante fue evaluado en el momento de la hidrólisis, al mes y a los tres meses. Se midió la concentración de grupos amino generados y la toxicidad por el método del lisado de amebocitos del limulus (LAL); se determinó el patrón electroforético y la constante de distribución (Kd) por cromatografía de exclusión molecular, como parámetros indicativos de la integridad estructural. Los resultados mostraron un aumento de los grupos amino, una reducción de la toxicidad en más de cinco mil veces que la inicial del LPS nativo y un incremento de la Kd, determinada por cromatografía. Todos los parámetros estudiados durante los tres meses se mantuvieron constantes. Se puede concluir que el LPS, modificado estructuralmente por medio de una hidrólisis básica controlada y almacenado en solución acuosa a temperaturas entre 2 y 8 °C, permaneció sin cambios en su estructura al menos por tres meses(AU)

The search of adjuvants has been one of the most important lines of the research in the development of vaccines in the last decades. One of the adjuvants under research at Finlay Institute uses lipopolysaccharide (LPS) from Neisseria meningitidis serogroup B in its composition and it is very toxic. For this reason we aim to make a structural modification of LPS from N. meningitidis serogroup B to reduce its toxicity and to study its stability for three months. A LPS purified by water and phenol extraction method was modified structurally by a controlled basic hydrolysis. The modified LPS was controlled at moment of the hydrolysis, a month and three months later. The evaluations consisted on the determination the concentrations of amine groups generated, the toxicity by Limulus Amoebocyte Lysate (LAL), the determination of the electrophoretic pattern and the constant of distribution (Kd) by chromatography of molecular exclusion as indicative parameters of structural integrity. The obtained results showed an increase of amine groups, a reduction of more than 5 000 times of the initial toxicity of native LPS and an increase of the Kd determined by chromatography. Studied parameters remained constant in the three studied months. In summary, modified structurally LPS by means of a controlled basic hydrolysis and stored in watery solution and temperatures from 2 to 8 °C remains without changes in their structure at least for three months(AU)

[In silico identification of molecular mimicry between T-cell epitopes of Neisseria meningitidis B and the human proteome]. / Identificación In Silico del mimetismo molecular entre epitopes T de Neisseria meningitidis B y el proteoma humano.

The objective of the study was to determine the T-cell epitopes of four of the most frequent antigenic proteins of the outer membrane of Neisseria meningitidis B, and to identify the most relevant sites for molecular mimicry with T-cell epitopes in humans. In order to do so, an in silico study -a type of study that uses bioinformatic tools- was carried out using SWISS-PROT/TrEMBL, SYFPEITHI and FASTA databases, which helped to determine the protein sequences, CD4 and CD8 T-cell epitope prediction, as well as the molecular mimicry with humans, respectively. Molecular similarity was found in several human proteins present in different organs and tissues such as: liver, skin and epithelial tissues, brain, lymphatic system and testicles. Of these, those found in testicles were more similar, showing the highest frequency of mimetic sequences. This finding shed light on the success of N. meningitidis B to colonize human tissues and the failure of certain vaccines against this bacterium, and it even helps to explain possible autoimmune reactions associated with the infection or vaccination.

Identificación In Silico del mimetismo molecular entre Epitopes T de Neisseria meningitidis B y el proteoma humano / In Silico identification of molecular mimicry between T-Cell Epitopes of Neisseria meningitidis B and the human proteome

El objetivo del estudio fue determinar los epítopes T de cuatro de las proteínas antigénicas más frecuentes de la membrana externa de Neisseria meningitidis B e identificar los sitios más relevantes donde existe mimetismo molecular para estos epítopes en seres humanos. Para ello se realizó un estudio in silico (estudios que usan herramientas bioinformáticas) usando las bases de datos SWISS-PROT/TrEMBL SYFPEITHI y FASTA, las cuales se emplearon para la determinación de las secuencias proteicas, la predicción de los epítopes T CD4 y CD8, y la determinación del mimetismo molecular en humanos, respectivamente. Se encontró similitud molecular en varias proteínas humanas presentes en diferentes órganos y tejidos, entre ellos: hígado, piel y epitelios, cerebro, sistema linfático y testículos, destacando las encontradas en estos últimos, ya que ellas mostraron la frecuencia más alta de secuencias miméticas. Este hallazgo ayuda a comprender el éxito de N. meningitidis B para colonizar tejidos humanos, el fracaso de ciertas vacunas contra esta bacteria e incluso ayuda a explicar posibles reacciones autoimmunes asociadas a la infección o vacunación.

The objective of the study was to determine the T-cell epitopes of four of the most frequent antigenic proteins of the outer membrane of Neisseria meningitidis B, and to identify the most relevant sites for molecular mimicry with T-cell epitopes in humans. In order to do so, an in silico study -a type of study that uses bioinformatic tools- was carried out using SWISS-PROT/TrEMBL, SYFPEITHI and FASTA databases, which helped to determine the protein sequences, CD4 and CD8 T-cell epitope prediction, as well as the molecular mimicry with humans, respectively. Molecular similarity was found in several human proteins present in different organs and tissues such as: liver, skin and epithelial tissues, brain, lymphatic system and testicles. Of these, those found in testicles were more similar, showing the highest frequency of mimetic sequences. This finding shed light on the success of N. meningitidis B to colonize human tissues and the failure of certain vaccines against this bacterium, and it even helps to explain possible autoimmune reactions associated with the infection or vaccination.

Pilot scale production of the vaccine adjuvant Proteoliposome derived Cochleates (AFCo1) from Neisseria meningitidis serogroup B.

The use of new adjuvants in vaccine formulations is a subject of current research. Only few parenteral adjuvants have been licensed. We have developed a mucosal and parenteral adjuvant known as AFCo1 (Adjuvant Finlay Cochleate 1, derived from proteoliposomes of N. meningitidis B) using a dialysis procedure to produce them on lab scale. The immunogenicity of the AFCo1 produced by dialysis has been already evaluated, but it was necessary to demonstrate the feasibility of a larger-scale manufacturing process. Therefore, we used a crossflow diafiltration system (CFS) that allows easy scale up to obtain large batches in an aseptic environment. The aim of this work was to produce AFCo1 on pilot scale, while conserving the adjuvant properties. The proteoliposomes (raw material) were resuspended in a buffer containing sodium deoxycholate and were transformed into AFCo1 under the action of a calcium forming buffer. The detergent was removed from the protein solution by diafiltration to a constant volume. In this CFS, we used a hollow fiber cartridge from Amicon (polysulfona cartridge of 10 kDa porosity, 1mm channel diameter of fiber and 0.45 m² area of filtration), allowing production of a batch of up to 20 L. AFCo1 were successfully produced by tangential filtration to pilot scale. The batch passed preliminary stability tests. Nasal immunization of BALB/c mice, induced specific saliva IgA and serum IgG. The induction of Th1 responses were demonstrated by the induction of IgG2a, IFNγ and not IL-5. The adjuvant action over Neisseria (self) antigens and with co-administered (heterologous) antigens such as ovalbumin and a synthetic peptide from haemolytic Streptococcus B was also demonstrated.

La gD2 coadministrada con el AFCo1 por vía intranasal induce inmunidad protectora contra virus de herpes simple tipo 2 en ratones / gD2 coadministered with AFCo1 by intranasal route induces protective immunity against Virus Herpes Simplex type 2 in mice

La infección por virus herpes simple tipo 2 (VHS-2) continúa siendo un problema de salud mundial. Esta infección es transmitida sexualmente y es la principal causa de úlceras genitales. La prevención de esta enfermedad requiere de la utilización de vacunas mucosales, pues las vacunas parenterales no han sido exitosas. Por otra parte, no existen adyuvantes mucosales, por lo que el desarrollo de estos es esencial para la estrategia de estas vacunas. La administración intranasal (IN) de la glicoproteína D del VHS-2 (gD2), coadministrada con el cocleato (AFCo1+gD2) sería igualmente efectiva con la gD2 incluida (AFCo1-gD2). Se inocularon ratones hembras C57BL/6 por la vía IN con gD2, contenida dentro del cocleato, coadministrada con el cocleato o gD2 sola. Se determinaron los niveles de IgG anti gD2 en suero y lavado vaginal, así como las subclases de IgG anti gD2 por ELISA. Se determinó la respuesta linfoproliferativa en células de bazo, el perfil de citoquinas Th1/Th2, los signos de la enfermedad y la protección frente al reto viral. Se observaron altos títulos de IgG e IgG2c anti gD2 en el suero de los animales inoculados con la gD2 y el AFCo1 como adyuvante. No se observaron diferencias significativas (p>0,05) entre los grupos que recibieron AFCo1+gD2 y los que recibieron AFCo1-gD2. Se observó un perfil de citoquinas tipo Th1 y un 100 por ciento de sobrevida en los grupos que recibieron el AFCo1 como adyuvante de la gD2, mientras que en el grupo que recibió la gD2 sola no se observó protección. Estos resultados indican que la gD2 puede ser utilizada coadministrada con AFCo1 por vía IN como un potencial candidato vacunal contra VHS-2(AU)

Sexually transmitted infections by Herpes Simplex Virus type 2 (HSV-2) are the leading cause of genital ulcers and a major public health problem worldwide. This requires the use of mucosal vaccines, because parenteral vaccines have not been successful. Presently, there are not mucosal adjuvants, for this reason the development of adjuvants is essential for mucosal vaccine strategies. The intranasal (IN) immunizations using HSV-2 glycoprotein D (gD2), coadministered with cochleate (AFCo1+gD2), would be an efficient candidate for future vaccines against HSV2, similar to the gD2 incorporated into AFCo1(AFCo1-gD2). Female C57Bl/6 mice were inoculated with AFCo1-gD2, AFCo1+gD2 or gD2 alone by IN route. The anti gD2 IgG in sera and vaginal fluids and IgG subclasses were measured by ELISA. The lymphoproliferative response in spleen cells, the Th1/Th2 cytokine profile, the protection and the signs of disease against viral challenge were measured. High titers of IgG and IgG2c subclasses were observed in sera of mice that received the gD2 and AFCo1 as adjuvant. No significant differences (p>0.005) were observed in the animals that received AFCo1+gD2 or AFCo1-gD2. a preferential Th1 cytokine profile and 100 percent of survival after challenge were observed in both groups that received the gD2 and AFCo1, while no survival was observed in the group that only received the gD2. These results showed that the gD2 can be used coadministered with AFCo1 by IN route as a potential vaccine candidate against HSV-2(AU)

Influencia de las vías de inmunización mucosales sobre la protección contra herpes simple tipo 2 con el AFCo1 como adyuvante / Influence of mucosal immunization routes on herpes simplex virus type 2 protection with AFCol as adjuvant

Las vacunas mucosales se han planteado como una estrategia prometedora para inducir protección mucosal. El virus herpes simple tipo 2 es uno de los patógenos más frecuentes en el humano transmitidos por vía sexual. Varios candidatos vacunales contra este patógeno se han evaluado, pero no han sido efectivos, por lo que aún no se cuenta con una vacuna profiláctica ni terapéutica. La gD2 es una glicoproteína recombinante y está reportada como uno de los antígenos de importancia vacunal contra este germen. Contamos con el cocleato derivado del proteoliposoma de Neisseria meningitidis serogrupo B (AFCo1) que ha mostrado capacidades adyuvantes por varias vías de inmunización. El objetivo de este trabajo fue evaluar la protección inducida en ratones por el AFCo1-gD2, administrada por diferentes vías mucosales. Se utilizaron ratones hembras C57BL6, los cuales fueron inmunizados por vía intranasal (IN), intravaginal (IVag) o intrarrectal (IR) con AFCo1-gD2 o gD2 sola. Se determinó la IgG anti gD2, la proliferación celular específica, la replicación viral en lavado vaginal, los signos de la enfermedad y la protección frente al reto viral. Se obtuvo respuestas significativas de IgG anti gD2 por todas las vías, aunque la IN mostró los valores más elevados. Se observó proliferación celular en células de animales inmunizados IN e IVag, pero no por vía IR. Se observó la mayor protección (100 por ciento) en los animales inmunizados por vía IN. Se concluye que la vía nasal es la más prometedora en la inducción de protección contra este reto viral(AU)

Mucosal vaccines are a promising strategy to induce mucosal protection. Herpes simplex virus type 2 is the commonest pathogens in the human transmitted by exposure at the genital mucosal surfaces. Many vaccine candidates against this pathogen have been evaluated; but they have not been effective, and neither a prophylactic nor a therapeutic vaccine has been yet obtained. The gD2 is a recombinant glycoprotein and it is reported as one of the antigens of importance for vaccine against this virus. There is the cochleate (AFCo1) derived from proteoliposome of Neisseria meningitidis serogroup B. This cochleate has shown potentialities as adjuvant for several immunization routes. The objective of this study was to evaluate the protection induced in mice by the AFCo1-gD2 administered by different mucosal routes. Female mice C57BL/6 were used and immunized by: intranasal (IN), intravaginal (IVag), or intrarectal (IR) routes with AFCo1-gD2 or gD2 alone. The anti-gD2 IgG and specific cellular proliferation were determined and the viral replication in vaginal wash, the signs of disease and the protection against the viral challenge, were measured too. A significant anti-gD2 IgG response was obtained by all routes, although the IN route showed the highest values. Cellular proliferation was observed in cells of animals immunized IN and IVag route; but not by IR route. In addition, a higher protection (100 percent) in the animals immunized with AFCo1-gD2 by IN route was observed. In conclusion the intranasal is the most promising route in the protection induction against this viral challenge(AU)

The golden era of vaccine adjuvants.

A 5-day workshop on adjuvant for vaccines was held in Trinidad, Cuba, on the 16-21 May 2010. Organized by the Latin American Association for Immunology and the Cuban Society for Immunology, the workshop attracted more than 60 scientists from different parts of the world. The meeting summarizes current knowledge regarding vaccine adjuvants, including delivery systems and parasitic vaccines. Main discussion topics were the discovery of new adjuvant formulations, action mechanisms for adjuvants, adjuvants for a different route of immunization, focused on mucosal vaccines, and nano- and micro-particles as a delivery system. This article highlights the most important issues presented.

AFCo1 as nasal adjuvant of capsular polysaccharide from Neisseria meningitidis serogroup C induces systemic and mucosal immune responses.

Increasing emphasis is being placed on the mucosal administration of vaccines in order to stimulate mucosal as well as systemic responses. Findings from our group suggest that proteoliposome-derived cochleate (AFCo1) acts as a potent mucosal adjuvant. As an alternative to chemical conjugation, the current study aimed to determine the benefit of using AFCo1 to improve the mucosal and systemic immune responses to capsular polysaccharide of Neisseria meningitidis serogroup C (PsC), a model of a thymus-independent (TI) antigen. Therefore, intranasal (i.n.) immunization of 3 doses 1 week apart with AFCo1 plus PsC in mice was conducted. Highly specific anti-PsC IgA responses and an anti-PsC IgG response were obtained. The subclass pattern induced against PsC was similar to that induced with the meningococcal vaccine. In summary, AFCo1 as nasal adjuvant was demonstrated to be capable of eliciting mucosal and systemic specific responses against a TI antigen.

Mucosal and systemic immune responses of mice to tetanus toxoid coadministered nasally with AFCo1.

Mucosal immune responses are an early and important line of defense against pathogens. The current understanding of the mucosal immune system allows us to consider the use of nasal immunization for induction of antigen-specific immune responses at the mucosal surface and the systemic compartment. Mucosal adjuvants are key for developing novel mucosal vaccines and represent 1 approach to improving mucosal and systemic immunity. However, few mucosal vaccine adjuvants are currently approved for human use. Neisseria meningitidis B proteoliposome-derived cochleate (AFCo1 - Adjuvant Finlay Cochleate 1) has been demonstrated to be a potent mucosal adjuvant. The present work demonstrates that intranasal immunization of 3 doses of tetanus toxoid (TT) coadministered with AFCo1 in mice promotes high systemic and mucosal responses. The anti-TT IgG serum titers and the mucosal anti-TT IgA in saliva and vaginal wash were significantly higher than TT alone. The analysis of antibody subclasses showed that intranasal administration of AFCo1 + TT induced not only IgG1 but also IgG2a anti-TT antibodies at levels comparable to those obtained with TT vaccine (vax-TET). These data support the fact that AFCo1 is a potent mucosal adjuvant in nasal immunization to a coadministered protein antigen.

Adjuvantes: un componente esencial de las vacunas de Neisseria

Adjuvants may be classified into delivery systems and immune potentiator or modulator molecules based on their mechanism of action. Neisseria vaccines containing traditional adjuvants such as aluminium salts have existed for long time, but meningitis caused by Neisseria meningitidis serogroups, particularly serogroup B, continues to be a global health problem. Novel strategies have applied in silico and recombinant technologies to develop universal antigens (e.g. proteins, peptides and plasmid DNA) for vaccines, but these antigens have been shown to be poorly immunogenic even when alum adjuvanted, implying a need for better vaccine design. In this work we review the use of natural, detoxified, or synthetic molecules in combination with antigens to activate the innate immune system and to modulate the adaptive immune responses. In the main, antigenic and imune potentiator signals are delivered using nano-, micro-particles, alum, or emulsions. The importance of interaction between adjuvants and antigens to activate and target dendritic cells, the bridge between the innate and adaptive immune systems, will be discussed. In addition, nasal vaccine strategies based on the development of mucosal adjuvants and Neisseria derivatives to eliminate the pathogen at the site of infection provide promising adjuvants effective not only against respiratory pathogens, but also against pathogens responsible for enteric and sexually transmitted diseases(AU)

Inmunización intranasal con AFCo1 induce respuesta inmune de memoria, sistemica y mucosal en ratones neonatal

Neonates have a poorly developed immune system. Respiratory pathogens cause disease during early periods of live. Consequently, it is important to develop protective vaccines that induce immunity and immunological memory against respiratory pathogens early in life. Intranasal (i.n.) route could be an effective via for immunization. Therefore, we explored the effectiveness of AF (Adjuvant Finlay) PL1 (Proteoliposome) from Neisseria meningitidis serogroup B and its derivate Cochleate (AFCo1) by nasal route in neonatal mice. They were immunized i,n, 3 times 7 days apart and anti PL systemic and mucosal antibody response were measured by ELISA. In addition, a prime-boost strategy was used to evaluate the humoral immune response in neonate mice. The 3 doses of AFPL1 or AFCo1 induced significant levels of anti PL IgG antibodies in comparison whit control, but AFCo1 (2017 U/mL) was significantly higher than AFPL1 (1107 U/mL). AFCo1 and AFPL1 induced a predominant Th1 pattern with IgG2a/IgG1 >1 by i,n, immunization and AFCo1 induced a high anti PL IgA saliva response in saliva. Interestingly, one nasally prime at 7 days of born and a memory one boost i,n, dose 9 weeks later with AFCo1 or AFPL1 showed similar specific IgG levels and IgG2a/IgG1 relation than 3 i.n. doses in adult mice. In conclusion, these results represent the first report of neonatal intranasal vaccination using AFCo1 capable to induce systemic and mucosal immunity and priming for memory(AU)

Respuesta inmune mucosal inducida por proteoliposoma y cocleato derivados de N meningitidis serogrupo B

Mucosal vaccination offers attractive advantages to conventional systemic vaccination. Most pathogens enter or establish infection at mucosal surfaces. This represents an enormous challenge for vaccine development. Nevertheless, the availability of safe and effective adjuvants that function mucosally is the major limitation. Therefore, we investigated the impact of mucosal immunization with the Neisseria meningitidis B proteoliposome (AFPL1, Adjuvant Finlay Proteoliposome 1) and its-derived cochleate (Co, AFCo1). They contain multiple PAMPs as immunopotentiators and have delivery system ability as well as Th1 polarization activity. Groups of female mice were immunized by nasal, oral, intravaginal, or intramuscular routes with three doses with AFPL1/AFCo1 alone or containing ovalbumin or glycoprotein (g) D2 from Herpes Simplex Virus type 2 (HSV-2). High levels of specific IgG antibodies were detected in sera of mice vaccinated with either route. However, specific IgA antibodies were produced in saliva and vaginal wash only following mucosal delivering. The polarization to a Th1 pattern was confirmed by testing the induction of IgG2a/IgG2c antibody, positive delayed-type hypersensitivity reactions, and gIFN production. Additionally, AFCo1gD2 showed practically no vaginal HSV-2 replication and 100 percent protection against lethal vaginal HSV-2 challenge. In conclusion, the results support the use of AFCo1 as potent Th1 adjuvant for mucosal vaccines, particularly for nasal route(AU)

Mucosal immunization using proteoliposome and cochleate structures from Neisseria meningitidis serogroup B induce mucosal and systemic responses.

Most pathogens either invade the body or establish infection in mucosal tissues and represent an enormous challenge for vaccine development by the absence of good mucosal adjuvants. A proteoliposome-derived adjuvant from Neisseria meningitidis serogroup B (AFPL1, Adjuvant Finlay Proteoliposome 1) and its derived cochleate form (Co, AFCo1) contain multiple pathogen-associated molecular patterns as immunopotentiators, and can also serve as delivery systems to elicit a Th1-type immune response. The present studies demonstrate the ability of AFPL1and AFCo1 to induce mucosal and systemic immune responses by different mucosal immunizations routes and significant adjuvant activity for antibody responses of both structures: a microparticle and a nanoparticle with a heterologous antigen. Therefore, we used female mice immunized by intragastric, intravaginal, intranasal or intramuscular routes with both structures alone or incorporated with ovalbumin (OVA). High levels of specific IgG antibody were detected in all sera and in vaginal washes, but specific IgA antibody in external secretions was only detected in mucosally immunized mice. Furthermore, antigen specific IgG1 and IgG2a isotypes were all induced. AFPL1 and AFCo1 are capable of inducing IFN-gamma responses, and chemokine secretions, like MIP-1alpha and MIP-1beta. However, AFCo1 is a better alternative to induce immune responses at mucosal level. Even when we use a heterologous antigen, the AFCo1 response was better than with AFPL1 in inducing mucosal and systemic immune responses. These results support the use of AFCo1 as a potent Th1 inducing adjuvant particularly suitable for mucosal immunization.

New meningococcal C polysaccharide-tetanus toxoid conjugate Physico-chemical and immunological characterization.

The polysaccharides (Ps) are thymus-independent 2 (TI-2) antigens and poor immunogens in infants and young children; as a result of this delayed response to Ps antigens during ontogeny, infants and young children are highly susceptible to infections caused by encapsulated bacteria. Meningococcal group C polysaccharide (PsC)-proteins conjugate vaccines have been reported to induce significant serum IgG antibodies and immunologic memory in infants resulting in very effective vaccines. We describe here the obtainment, by a new method, of a neoglycoconjugate intended to immunize against Neisseria meningitidis serogroup C, its characterization by physico-chemical methods, including (1)H NMR and fluorescence spectroscopy methods, as well as the characterization of the immune response induced in mice by such conjugate. Amine groups generated by basic hydrolysis in the PsC were successfully conjugated to carboxyl groups of tetanus toxoid (TT), using carbodiimide-mediated coupling. The specific anti-Ps IgG and anti-Ps IgG subclasses (IgG1 and IgG2a) were measured by ELISA methods, the bactericidal activity in sera and the cytokines response (IFNgamma or IL5) in spleen cell of mice immunized with conjugated and native Ps were evaluated. The (1)H NMR spectra and the result obtained by the fluorescence spectroscopy method showed that the PsC and TT maintained structural identity after conjugation process. Conjugated PsC elicited an increase of anti-PsC IgG responses, anti-PsC IgG subclass (IgG1, IgG2a), an eight-fold increase in bactericidal activity in sera of mice immunized with conjugate compared with native PsC, was also observed. Higher titres of IFNgamma were observed in mice immunized with conjugated Ps. These results indicated that, the PsC and TT maintained its chemical and antigenic structure after the conjugation process. A change in the immunological pattern of responses of PsC, from TI-2 to a thymus-dependent (TD) pattern, was also demonstrated.

Adjuvant properties of lipopolysaccharide from Neisseria meningitidis serogroup B detoxified and conjugated with tetanus toxoid.

We evaluated the adjuvant properties and toxicity of purified Neisseria meningitidis serogroup B lipopolysaccharide (LPS) conjugated with tetanus toxoid (TT) using a new method of conjugation to obtain amine groups in the polysaccharide structure. The endotoxic activity of treated LPS was reduced 2400 times as determined by Limulus amoebocyte assay and no mortality was observed in Balb/c mice inoculated with detoxified LPS versus 100% mortality in native LPS inoculated mice. The conjugated LPS-TT elicited in mice higher anti-TT IgG2a and IgG1 than unconjugated TT. In addition, high levels of anti-LPS IgG and IgG subclasses were detected in sera. These results evidence the adjuvant activity of detoxified LPS and may suggest that the conjugation to TT changes the LPS immune response from thymus-independent to thymus-dependent.