Ischemic-Trained Monocytes Improve Arteriogenesis in a Mouse Model of Hindlimb Ischemia.

OBJECTIVE: Monocytes, which play an important role in arteriogenesis, can build immunologic memory by a functional reprogramming that modifies their response to a second challenge. This process, called trained immunity, is evoked by insults that shift monocyte metabolism, increasing HIF (hypoxia-inducible factor)-1α levels. Since ischemia enhances HIF-1α, we evaluate whether ischemia can lead to a functional reprogramming of monocytes, which would contribute to arteriogenesis after hindlimb ischemia. METHODS AND RESULTS: Mice exposed to ischemia by 24 hours (24h) of femoral artery occlusion (24h trained) or sham were subjected to hindlimb ischemia one week later; the 24h trained mice showed significant improvement in blood flow recovery and arteriogenesis after hindlimb ischemia. Adoptive transfer using bone marrow-derived monocytes (BM-Mono) from 24h trained or sham donor mice, demonstrated that recipients subjected to hindlimb ischemia who received 24h ischemic-trained monocytes had remarkable blood flow recovery and arteriogenesis. Further, ischemic-trained BM-Mono had increased HIF-1α and GLUT-1 (glucose transporter-1) gene expression during femoral artery occlusion. Circulating cytokines and GLUT-1 were also upregulated during femoral artery occlusion.Transcriptomic analysis and confirmatory qPCR performed in 24h trained and sham BM-Mono revealed that among the 15 top differentially expressed genes, 4 were involved in lipid metabolism in the ischemic-trained monocytes. Lipidomic analysis confirmed that ischemia training altered the cholesterol metabolism of these monocytes. Further, several histone-modifying epigenetic enzymes measured by qPCR were altered in mouse BM-Mono exposed to 24h hypoxia. CONCLUSIONS: Ischemia training in BM-Mono leads to a unique gene profile and improves blood flow and arteriogenesis after hindlimb ischemia.

Passive administration of purified secretory IgA from human colostrum induces protection against Mycobacterium tuberculosis in a murine model of progressive pulmonary infection.

BACKGROUND: Immunoglobulin A is the most abundant isotype in secretions from mucosal surfaces of the gastrointestinal, respiratory and genitourinary tracts and in external secretions such as colostrum, breast milk, tears and saliva. The high concentration of human secretory IgA (hsIgA) in human colostrum strongly suggests that it should play an important role in the passive immune protection against gastrointestinal and respiratory infections. MATERIALS AND METHODS: Human secretory IgA was purified from colostrum. The reactivity of hsIgA against mycobacterial antigens and its protective capacity against mycobacterial infection was evaluated. RESULTS: The passive administration of hsIgA reduces the pneumonic area before challenge with M. tuberculosis. The intratracheal administration of M. tuberculosis preincubated with hsIgA to mice greatly reduced the bacterial load in the lungs and diminished lung tissue injury. CONCLUSIONS: HsIgA purified from colostrum protects against M. tuberculosis infection in an experimental mouse model.

Dry-reagent gold nanoparticle-based lateral flow biosensor for the simultaneous detection of Vibrio cholerae serogroups O1 and O139.

Cholera is a communicable disease caused by consumption of contaminated food and water. This potentially fatal intestinal infection is characterised by profuse secretion of rice watery stool that can rapidly lead to severe dehydration and shock, thus requiring treatment to be given immediately. Epidemic and pandemic cholera are exclusively associated with Vibrio cholerae serogroups O1 and O139. In light of the need for rapid diagnosis of cholera and to prevent spread of outbreaks, we have developed and evaluated a direct one-step lateral flow biosensor for the simultaneous detection of both V. cholerae O1 and O139 serogroups using alkaline peptone water culture. Serogroup specific monoclonal antibodies raised against lipopolysaccharides (LPS) were used to functionalize the colloidal gold nanoparticles for dual detection in the biosensor. The assay is based on immunochromatographic principle where antigen-antibody reaction would result in the accumulation of gold nanoparticles and thus, the appearance of a red line on the strip. The dry-reagent dipstick format of the biosensor ensure user-friendly application, rapid result that can be read with the naked eyes and cold-chain free storage that is well-suited to be performed at resource-limited settings.

Antigenicidad e inmunogenicidad de una cepa inactivada de Vibrio cholerae O1 El Tor Inaba / Antigenicity and immunogenicity of inactivated Vibrio cholerae 01 El Tor Inaba

INTRODUCCIÓN: el cólera continúa siendo problema de salud, principalmente en las zonas más pobres. La mayoría de los aislamientos que se realizan al nivel mundial pertenecen a Vibrio cholerae O1 biotipo El Tor serotipo Ogawa, aunque se han reportado brotes causados por el serotipo Inaba, por lo que se aconseja que una vacuna efectiva contra la enfermedad deberá contener células o antígenos de ambos serotipos. OBJETIVO: describir las características de la cepa de V. cholerae O1 El Tor Inaba C6706 como posible cepa para la obtención de vacunas inactivadas contra el cólera. MÉTODOS: se elaboró un lote de siembra de trabajo crioconservado a - 70 ºC, se evaluó su identidad, pureza y viabilidad. La cepa fue cultivada en caldo triptona soya y su inactivación se realizó a 56 ºC durante 20 min. Se evaluó la capacidad antigénica del producto obtenido mediante western blot y ELISA de inhibición de lipopolisacárido. La inmunogenicidad en conejos, inoculados por vía intraduodenal, se determinó mediante la cinética de anticuerpos vibriocidas. RESULTADOS: el lote de siembra de trabajo mantuvo su identidad, pureza y viabilidad durante 18 meses de estudio. Se observó la presencia de los antígenos lipopolisacárido, hemaglutinina sensible a manosa y proteína de membrana externa U, en las suspensiones de células inactivadas de V. cholerae O1, no así de las subunidades A y B de la toxina colérica (CTA y CTB, respectivamente) o pilli corregulado con la toxina (TCP). Por otra parte, se obtuvieron títulos vibriocidas en los sueros de conejos, similares a la respuesta inducida por la cepa viva atenuada 638 de V. cholerae O1, candidata a vacuna oral. CONCLUSIONES: la cepa de V. cholerae O1 El Tor Inaba C6706 mostró características culturales, antigénicas e inmunogénicas que permiten considerarla como posible cepa para la obtención de vacunas inactivadas contra el cólera(AU)

INTRODUCTION: cholera continues being a serius health problem, mainly in the poorest areas. Most of the isolations worldwide belong to Vibrio cholerae O1 biotype El Tor serotype Ogawa, although there have been reported outbreaks caused by serotype Inaba, that is why it is recommended that an effective vaccine against the illness should contain cells or antigens of both serotypes. OBJECTIVE: to describe the characteristics of the strain C6706 of V. cholerae O1 El Tor Inaba as a likely strain for the obtaining of inactivated vaccines for cholera. METHODS: a criopreserved working culture batch was made up at - 70 ºC to evaluate identity, purity and viability. The strain was cultured in tryptone soy broth and was inactivated at 56º C for 20 minutes. Antigenicity of this preparation was tested by Western Blot and ELISA inhibition test. Immunogenicity in adult rabbits, inoculated intraduodenally, was determined by means of kinetics of vibriocidal antibodies. RESULTS: the working culture batch kept their identity, purity and viability during 18 months of study. The results confirmed the presence of relevant antigens as lipopolysaccharide (LPS), mannose-sensitive hemagglutinin (MSHA) and outer membrane protein U (OmpU) in the suspension of inactivated V. cholerae O1 cells, but not cholera toxin subunits (CTA, CTB) or toxin-coregulated pili (TCP).On the other hand, vibriocidal titers were found in rabbit sera, which were similar to those previously reported for the live V. cholerae O1 strain 638, an attenuated oral vaccinal candidate CONCLUSIONS: the V. cholerae O1 El Tor Inaba C6706 strain showed cultural, antigenic and immunogenic characteristics that allow us to consider it as a possible strain for the obtaining of inactivated vaccines for cholera(AU)

Antigenicidad e inmunogenicidad de una cepa inactivada de Vibrio cholerae O1 El Tor Inaba / Antigenicity and immunogenicity of inactivated Vibrio cholerae 01 El Tor Inaba

INTRODUCCIÓN: el cólera continúa siendo problema de salud, principalmente en las zonas más pobres. La mayoría de los aislamientos que se realizan al nivel mundial pertenecen a Vibrio cholerae O1 biotipo El Tor serotipo Ogawa, aunque se han reportado brotes causados por el serotipo Inaba, por lo que se aconseja que una vacuna efectiva contra la enfermedad deberá contener células o antígenos de ambos serotipos. OBJETIVO: describir las características de la cepa de V. cholerae O1 El Tor Inaba C6706 como posible cepa para la obtención de vacunas inactivadas contra el cólera. MÉTODOS: se elaboró un lote de siembra de trabajo crioconservado a - 70 ºC, se evaluó su identidad, pureza y viabilidad. La cepa fue cultivada en caldo triptona soya y su inactivación se realizó a 56 ºC durante 20 min. Se evaluó la capacidad antigénica del producto obtenido mediante western blot y ELISA de inhibición de lipopolisacárido. La inmunogenicidad en conejos, inoculados por vía intraduodenal, se determinó mediante la cinética de anticuerpos vibriocidas. RESULTADOS: el lote de siembra de trabajo mantuvo su identidad, pureza y viabilidad durante 18 meses de estudio. Se observó la presencia de los antígenos lipopolisacárido, hemaglutinina sensible a manosa y proteína de membrana externa U, en las suspensiones de células inactivadas de V. cholerae O1, no así de las subunidades A y B de la toxina colérica (CTA y CTB, respectivamente) o pilli corregulado con la toxina (TCP). Por otra parte, se obtuvieron títulos vibriocidas en los sueros de conejos, similares a la respuesta inducida por la cepa viva atenuada 638 de V. cholerae O1, candidata a vacuna oral. CONCLUSIONES: la cepa de V. cholerae O1 El Tor Inaba C6706 mostró características culturales, antigénicas e inmunogénicas que permiten considerarla como posible cepa para la obtención de vacunas inactivadas contra el cólera.

INTRODUCTION: cholera continues being a serius health problem, mainly in the poorest areas. Most of the isolations worldwide belong to Vibrio cholerae O1 biotype El Tor serotype Ogawa, although there have been reported outbreaks caused by serotype Inaba, that is why it is recommended that an effective vaccine against the illness should contain cells or antigens of both serotypes. OBJECTIVE: to describe the characteristics of the strain C6706 of V. cholerae O1 El Tor Inaba as a likely strain for the obtaining of inactivated vaccines for cholera. METHODS: a criopreserved working culture batch was made up at - 70 ºC to evaluate identity, purity and viability. The strain was cultured in tryptone soy broth and was inactivated at 56º C for 20 minutes. Antigenicity of this preparation was tested by Western Blot and ELISA inhibition test. Immunogenicity in adult rabbits, inoculated intraduodenally, was determined by means of kinetics of vibriocidal antibodies. RESULTS: the working culture batch kept their identity, purity and viability during 18 months of study. The results confirmed the presence of relevant antigens as lipopolysaccharide (LPS), mannose-sensitive hemagglutinin (MSHA) and outer membrane protein U (OmpU) in the suspension of inactivated V. cholerae O1 cells, but not cholera toxin subunits (CTA, CTB) or toxin-coregulated pili (TCP).On the other hand, vibriocidal titers were found in rabbit sera, which were similar to those previously reported for the live V. cholerae O1 strain 638, an attenuated oral vaccinal candidate CONCLUSIONS: the V. cholerae O1 El Tor Inaba C6706 strain showed cultural, antigenic and immunogenic characteristics that allow us to consider it as a possible strain for the obtaining of inactivated vaccines for cholera.

Induction of a protective response with an IgA monoclonal antibody against Mycobacterium tuberculosis 16kDa protein in a model of progressive pulmonary infection.

Mycobacterium tuberculosis is a facultative intracellular pathogen for which cell-mediated immunity is considered the major component of the immune response. For many decades, the prevailing scientific view has been the antibodies have little or no role in modifying the course of M. tuberculosis infection. In recent years, several studies have challenged this dogma, and there is a body of evidence that supports a role of antibodies against M. tuberculosis. In the present work, we evaluated the protective activity of two monoclonal antibodies (TBA61 and TBA84). Here, we chose the intratracheal model of pulmonary infection to evaluate bacterial load and morphometric and histological changes in the lungs of treated mice. Data obtained revealed the reduction of bacterial load and milder morphometric and histopathological changes in mice treated with TBA61 at 21 days post-infection with M. tuberculosis H37Rv compared to those treated with TBA84 and control mice. These results allow continuing exploring the potential use of monoclonal antibodies as prophylactic and therapeutic agents against intracellular pathogens such as M. tuberculosis.

Passive protection with immunoglobulin A antibodies against tuberculous early infection of the lungs.

We report on a new approach toward protection against tuberculosis, based on passive inoculation with immunoglobulin A (IgA) antibodies. In a mouse model of tuberculous lung infection, intranasal inoculations of mice with an IgA monoclonal antibody (mAb) against the alpha-crystallin antigen of Mycobacterium tuberculosis reduced up to 10-fold the lung bacterial counts at nine days after either aerosol- or intranasal challenge. This effect involved synergism between mAb inoculations shortly before and 3 days after infection. Monomeric IgA reduced the colony-forming unit counts to the same extent as the polymeric IgA, suggesting antibody targeting to Fcalpha, rather than poly-immunoglobulin receptors on infected lung macrophages. The protective effect was of short duration, presumably due to the rapid degradation of the intranasally applied IgA. Our results provide evidence of an alternative approach which could be further developed toward immunoprophylaxis against tuberculosis in immunocompromised subjects.