Conhecimento e adesão ao Papanicolau de mulheres de uma rede de Atenção Primária à Saúde / Knowledge and adherence to the Papanicolau of women from a primary health care network

Objetivo Analisar o conhecimento e a adesão ao Papanicolau de mulheres que frequentam Unidades Básicas de Saúde. Métodos Um questionário composto de questões pré-codifi cadas e abertas foi aplicado às usuárias de duas Unidades Básicas de Saúde da cidade de São José do Rio Preto, São Paulo, localizadas em bairros com perfi l socioeconômico distinto. Os dados foram analisados estatisticamente pelo programa Statistical Package for the Social Sciences.Resultados Após a análise de 99 questionários respondidos, ficou evidente um nível de conhecimento melhor sobre o exame de Papanicolau das residentes do bairro com melhores condições socioeconômicas e das mulheres mais jovens. Ficou evidente que muitas fazem esse exame sem saber o devido objetivo desse procedimento. A vergonha e a falta de tempo foram relatadas como motivos relevantes para não realizar o exame. Conclusão A falta de informação sobre o exame de Papanicolau das mulheres com mais de 60 anos e menor nível socioeconômico ficou evidente neste estudo e pode ser considerada um dos aspectos mais relevantes à não adesão à prevenção do câncer do colo de útero. Dessa maneira, ações de saúde alternativas deveriam ser adotadas pelas Unidades Básicas de Saúde para melhor orientar a população e, assim, aumentar a adesão a esse exame.

Objective To analyze the knowledge and adhesion to the Papanicolaou smear test of women attending Basic Health Units. Methods A questionnaire composed of pre-coded and open questions was applied to users of two Basic Health Units of the city of São José do Rio Preto, São Paulo, located in districts with different socioeconomic profiles. The data were statistically analyzed by the Statistical Package for the Social Sciences program. Results After the analysis of 99 questionnaires answered, a better level of knowledge about the Pap smear was found among the residents of the better socioeconomic neighborhood and the younger women. It has become evident that many take this test without knowing the proper purpose of this procedure. Shame and lack of time were reported as relevant reasons for not doing the test. Conclusion The lack of information on the Papanicolaou smear of women over 60 years of age and lower socioeconomic level was evident in this study and may be considered one of the most relevant aspects to non-adherence to cervical cancer prevention. In this way, alternative health actions should be adopted by the Basic Health Units to better guide the population and thus increase adherence to this examination.

CD271+ Mesenchymal Stem Cells as a Possible Infectious Niche for Leishmania infantum.

Visceral leishmaniasis (VL) is a serious and fatal disease. Therapeutic drugs are toxic and non-sterilizing. The etiological agents Leishmania infantum and Leishmania donovani cause active and asymptomatic diseases. Effective drugs to treat VL exist but unfortunately, post-treatment relapses are common. Little is known why drugs are non-sterilizing or how these intracellular pathogens can escape treatment. Here, using a murine model of VL we found that CD271+/Sca1+ bone marrow mesenchymal stem cells (BM-MSCs) are readily infected in vitro and in vivo by L. infantum. Because BM-MSCs express potent drug efflux pumps, e.g., ABCG2 it is possible that this unique intracellular infectious niche could allow L. infantum to escape anti-parasite drugs.

Immunogenicity in dogs and protection against visceral leishmaniasis induced by a 14kDa Leishmania infantum recombinant polypeptide.

In areas were human visceral leishmaniasis (VL) is endemic, the domestic dog is the main parasite reservoir in the infectious cycle of Leishmania infantum. Development of prophylactic strategies to lower the parasite burden in dogs would reduce sand fly transmission thus lowering the incidence of zoonotic VL. Here we demonstrate that vaccination of dogs with a recombinant 14kDa polypeptide of L. infantum nuclear transport factor 2 (Li-ntf2) mixed with adjuvant BpMPLA-SE resulted in the production of specific anti-Li-ntf2 IgG antibodies as well as IFN-γ release by the animals' peripheral blood mononuclear cells stimulated with the antigen. In addition, immunization with this single and small 14kDa poplypeptide resulted in protracted progression of the infection of the animals after challenging with a high dose of virulent L. infantum. Five months after challenge the parasite load was lower in the bone marrow of immunized dogs compared to non-immunized animals. The antibody response to K39, a marker of active VL, at ten months after challenge was strong and significantly higher in the control dogs than in vaccinated animals. At the study termination vaccinated animals showed significantly more liver granulomas and lymphoid hyperplasia than non-vaccinated animals, which are both histological markers of resistance to infection. Together, these results indicate that the 14kDa polypeptide is an attractive protective molecule that can be easily incorporated in a leishmanial polyprotein vaccine candidate to augment/complement the overall protective efficacy of the final product.

Bone marrow mesenchymal stem cells provide an antibiotic-protective niche for persistent viable Mycobacterium tuberculosis that survive antibiotic treatment.

During tuberculosis (TB), some Mycobacterium tuberculosis bacilli persist in the presence of an active immunity and antibiotics that are used to treat the disease. Herein, by using the Cornell model of TB persistence, we further explored our recent finding that suggested that M. tuberculosis can escape therapy by residing in the bone marrow (BM) mesenchymal stem cells. We initially showed that M. tuberculosis rapidly disseminates to the mouse BM after aerosol exposure and maintained a stable burden for at least 220 days. In contrast, in the lungs, the M. tuberculosis burden peaked at 28 days and subsequently declined approximately 10-fold. More important, treatment of the mice with the antibiotics rifampicin and isoniazid, as expected, resulted in effective clearance of M. tuberculosis from the lungs and spleen. In contrast, M. tuberculosis persisted, albeit at low numbers, in the BM of antibiotic-treated mice. Moreover, most viable M. tuberculosis was recovered from the bone marrow CD271(+)CD45(-)-enriched cell fraction, and only few viable bacteria could be isolated from the CD271(-)CD45(+) cell fraction. These results clearly show that BM mesenchymal stem cells provide an antibiotic-protective niche for M. tuberculosis and suggest that unraveling the mechanisms underlying this phenomenon will enhance our understanding of M. tuberculosis persistence in treated TB patients.

An unbiased peptide-wide discovery approach to select Mycobacterium tuberculosis antigens that target CD8+ T cell response during infection.

Accruing data strongly support the possible role of CD8+ T cells in immunity against tuberculosis (TB). Multivalent vaccines against Mycobacterium tuberculosis (Mtb) that incorporate CD8+ T cell antigens with those that elicit CD4+ T cells are therefore highly desirable. To screen for potential CD8+ T cell antigens that are produced by Mtb during infection, we isolated pathogen-derived peptides that bound to MHC Class I molecules expressed in adherent splenocytes obtained from Mtb-infected mice. Mass spectroscopy analysis revealed the following four nonamer peptides that had 100% homology with Mtb proteins: DGYVGAPAH (MT_0401), TTMPLFAD (MT_1164), RSGAATPVR (MT_2160.1) and LAAVVGVVL (MT_0078). The gene MT_0401 codes the protein 5'-phosphoribosylglycinamide transformylase 2 and the other three genes code for hypothetical proteins with unknown function. The NCBI/Blast analysis showed that among the four peptides DGYVGAPAH had the highest maximum alignment score and lowest E value (number of alignments expected by chance). Therefore, we assessed whether MT_0401 expressed in two genetic vaccine formulations was capable of stimulating CD8+ T cell response that is specific to DGYVGAPAH peptide. When mice were immunized with a recombinant plasmid DNA and an E1/E3-deleted Adenovirus 5 expressing MT0401 protein, using both homologous and heterologous prime-boost protocols, they developed strong DGYVGAPAH-specific CD8+ T cell response as well as antibody and CD4+ specific T cell response to the full length MT0401 protein. Equally important was the observation that mice infected with Mtb developed DGYVGAPAH-specific CD8+ T cell responses in both spleen and lungs. These results demonstrate that Mtb antigens that are processed and presented via MHC Class I machinery can be readily identified by the described approach and may be useful candidate antigens to stimulate specific CD8+ T cell responses in vaccine development programs.

CD271(+) bone marrow mesenchymal stem cells may provide a niche for dormant Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb) can persist in hostile intracellular microenvironments evading immune cells and drug treatment. However, the protective cellular niches where Mtb persists remain unclear. We report that Mtb may maintain long-term intracellular viability in a human bone marrow (BM)-derived CD271(+)/CD45(-) mesenchymal stem cell (BM-MSC) population in vitro. We also report that Mtb resides in an equivalent population of BM-MSCs in a mouse model of dormant tuberculosis infection. Viable Mtb was detected in CD271(+)/CD45(-) BM-MSCs isolated from individuals who had successfully completed months of anti-Mtb drug treatment. These results suggest that CD271(+) BM-MSCs may provide a long-term protective intracellular niche in the host in which dormant Mtb can reside.

A clinical trial to evaluate the safety and immunogenicity of the LEISH-F1+MPL-SE vaccine when used in combination with meglumine antimoniate for the treatment of cutaneous leishmaniasis.

Forty-four adult patients with cutaneous leishmaniasis (CL) were enrolled in a randomized, double-blind, controlled, dose-escalating clinical trial and were randomly assigned to receive three injections of either the LEISH-F1+MPL-SE vaccine (consisting of 5, 10, or 20 µg recombinant Leishmania polyprotein LEISH-F1 antigen+25 µg MPL-SE adjuvant) (n=27), adjuvant alone (n=8), or saline placebo (n=9). The study injections were given subcutaneously on Days 0, 28, and 56, and the patients were followed through Day 336 for safety, immunological, and clinical evolution endpoints. All patients received chemotherapy with meglumine antimoniate starting on Day 0. The vaccine was safe and well tolerated. Nearly all vaccine recipients and no adjuvant-alone or placebo recipients demonstrated an IgG antibody response to LEISH-F1 at Day 84. Also at Day 84, 80% of vaccine recipients were clinically cured, compared to 50% and 38% of adjuvant-alone and placebo recipients. The LEISH-F1+MPL-SE vaccine was safe and immunogenic in CL patients and appeared to shorten their time to cure when used in combination with meglumine antimoniate chemotherapy.

Initiation of acquired immunity in the lungs of mice lacking lymph nodes after infection with aerosolized Mycobacterium tuberculosis.

Recent evidence points to lung draining lymph nodes as the site that initiates the immune response in mice infected with aerosolized Mycobacterium tuberculosis. Here we expanded these studies and showed that infection of mice that lack lymph nodes with aerosolized M. tuberculosis results in a massive mononuclear cell infiltrate in the lungs within 14 days postinfection. This infiltration clearly resembles an expansion of the bronchus-associated lymphoid tissue. As expected, no bronchus-associated lymphoid tissue was observed in M. tuberculosis-infected wild-type control mice. Importantly, acquired specific immune response to M. tuberculosis antigens could be detected in lung lymphocytes harvested from mice lacking lymph nodes as early as 14 days postinfection. In addition, the bacterial burden in these mice was indistinguishable from that observed in wild-type C57BL/6 control mice. These results indicate that in the absence of lymph nodes, priming of the immune response occurs in the lung tissues after infection of mice with aerosolized M. tuberculosis and clearly illustrate the enormous plasticity of the immune system to develop resistance to foreign pathogens.

Evaluation of an immunochemotherapeutic protocol constituted of N-methyl meglumine antimoniate (Glucantime) and the recombinant Leish-110f + MPL-SE vaccine to treat canine visceral leishmaniasis.

The evaluation of the efficacy of an immunochemotherapy protocol to treat symptomatic dogs naturally infected with Leishmania chagasi was studied. This clinical trial had the purpose to test the combination of N-methyl meglumine antimoniate (Glucantime and the second generation recombinant vaccine Leish-110f plus the adjuvant MPL-SE to treat the canine leishmaniasis (CanL). Thirty symptomatic naturally infected mongrel dogs were divided into five groups. Animals received standard treatment with Glucantime or treatment with Glucantime Leish-110f + MPL-SEas immunochemotherapy protocol. Additional groups received Leish-110f + MPL-SE only, MPL-SE only, or placebo. Evaluation of haematological, biochemical (renal and hepatic function) and plasmatic proteins, immunological (humoral and cellular immune response) and the parasitological test revealed improvement of the clinical parameters and parasitological cure in dogs in both chemotherapy alone and immunochemotherapy cohorts. However, the immunotherapy and immunochemotherapy cohorts had reduced number of deaths, higher survival probability, and specific cellular reactivity to leishmanial antigens, in comparison with chemotherapy cohort only and control groups (adjuvant alone and placebo). These results support the notion of using well-characterized recombinant vaccine as an adjunct to improve the current chemotherapy of CanL.

Th1 immune response promotes severe bone resorption caused by Porphyromonas gingivalis.

Bacterial infections of the dental pulp result in soft tissue and alveolar bone destruction. It has been suggested that Th1 responses promote disease, whereas Th2 responses are protective. However, other studies have challenged this notion. To address this question, bone destruction was evaluated in mice immunized to develop strong and polarized Th1- or Th2-biased responses to the oral pathogen Porphyromonas gingivalis. Th1 bias was confirmed by the presence of high titers of serum IgG2a and the production of high levels of interferon (IFN)-gamma and no interleukin (IL)-4 by lymph node cells stimulated with P. gingivalis antigens. In contrast, Th2-biased animals had high titer IgG1 and no IgG2a, and their lymph node cells produced high levels of IL-4 but no IFN-gamma. Subsequent infection of the dental pulp with P. gingivalis caused extensive inflammation and alveolar bone destruction in Th1-biased mice, whereas Th2-biased mice and controls developed minimal lesions. Inflammatory granulomas in Th1-biased mice were heavily infiltrated with osteoclasts and had high local expression of IFN-gamma, IL-1alpha, and IL-1beta. Little or no IFN-gamma/IL-1alpha/IL-1beta and no obvious osteoclasts were detected in lesions of Th2-biased and control groups. These results directly demonstrate that specific Th1 responses promote severe infection-stimulated alveolar bone loss.

Immunotherapy for drug-refractory mucosal leishmaniasis.

BACKGROUND: Pentavalent antimony (Sb(v)) is the mainstay therapy for mucosal leishmaniasis (ML), but it is toxic, and relapses are common. Immunotherapy using a mixture of killed parasites, with or without bacille Calmette-Guerin, is an alternative but is used sporadically because of inconsistent results. METHODS: We developed a defined immunotherapeutic antigen preparation for use in an observational, open-label trial to treat 6 patients with ML with a history of Sb(v) therapy failure. All patients were treated with the antigens thiol-specific antioxidant, Leishmania major stress inducible protein 1, Leishmania elongation initiation factor, and Leishmania heat shock protein 83, plus granulocyte-macrophage colony-stimulating factor. Patients underwent clinical and pathological evaluations before the initiation of immunotherapy and at 3, 6, 9, 12, 18, 24, and 60 months after. RESULTS: One month after the third injection, 1 patient showed complete clinical remission (CC) and remained disease free for the duration of the study. At the 9-month follow-up examination, 5 patients showed CC, and all patients were asymptomatic at a subsequent 5-year follow-up examination. CONCLUSIONS: These data support the concept that vaccine therapy with a defined antigen combination, used with standard chemotherapy, is a safe and effective approach to treat drug-refractory ML.

Unique model of dormant infection for tuberculosis vaccine development.

Most individuals exposed to Mycobacterium tuberculosis become infected but hinder the infectious process in dormant foci, known as latent tuberculosis. This limited infection usually stimulates strong T-cell responses, which provide lifelong resistance to tuberculosis. However, latent tuberculosis is still poorly understood, particularly because of the lack of a reliable animal model of dormant infection. Here we show that inoculation of mice with a unique streptomycin-auxotrophic mutant of Mycobacterium tuberculosis recapitulates dormant infection. The mutant grows unimpaired in the presence of streptomycin and no longer grows but remains viable for long periods of time after substrate removal, shifting from the log growth phase to the latent stage, as indicated by augmented production of alpha-crystallin. Mice challenged with the mutant and inoculated with streptomycin for approximately 3 weeks developed a limited infection characterized by a low bacteriological burden and the presence of typical granulomas. After substrate withdrawal, the infection was hindered but few microorganisms remained viable (dormant) in the animals' tissues for at least 6 months. In addition, the animals developed both potent T-cell responses to M. tuberculosis antigens, such as early culture filtrate, Ag85B, and ESAT-6, and resistance to reinfection with virulent M. tuberculosis. Therefore, infection of mice or other animals (e.g., guinea pigs) with M. tuberculosis strain 18b constitutes a simple and attractive animal model for evaluation of antituberculosis vaccines in the context of an M. tuberculosis-presensitized host, a prevailing condition among humans in need of a vaccine.

Skin test performed with highly purified Mycobacterium tuberculosis recombinant protein triggers tuberculin shock in infected guinea pigs.

Tuberculin shock due to inoculation of Mycobacterium tuberculosis antigens in patients with tuberculosis is a serious syndrome originally described over 100 years ago by Robert Koch. Here, we present experimental evidence that a single M. tuberculosis recombinant protein, CFP-10, triggers this syndrome. Intradermal inoculation of CFP-10 elicits in M. tuberculosis-infected mice high levels of serum tumor necrosis factor alpha and causes tuberculin shock in infected guinea pigs characterized by hypothermia and death within 6 to 48 h after the antigen inoculation. Autopsies of these animals revealed intense polycythemia and hemorrhagic patches in the lung parenchyma, a pathological observation consistent with tuberculin shock. These results point to the possible occurrence of tuberculin shock in sensitive individuals inoculated with highly purified M. tuberculosis recombinant proteins as vaccine candidates or skin test reagents.

Differential immune responses and protective efficacy induced by components of a tuberculosis polyprotein vaccine, Mtb72F, delivered as naked DNA or recombinant protein.

Key Ags of Mycobacterium tuberculosis initially identified in the context of host responses in healthy purified protein derivative-positive donors and infected C57BL/6 mice were prioritized for the development of a subunit vaccine against tuberculosis. Our lead construct, Mtb72F, codes for a 72-kDa polyprotein genetically linked in tandem in the linear order Mtb32(C)-Mtb39-Mtb32(N). Immunization of C57BL/6 mice with Mtb72F DNA resulted in the generation of IFN-gamma responses directed against the first two components of the polyprotein and a strong CD8(+) T cell response directed exclusively against Mtb32(C). In contrast, immunization of mice with Mtb72F protein formulated in the adjuvant AS02A resulted in the elicitation of a moderate IFN-gamma response and a weak CD8(+) T cell response to Mtb32c. However, immunization with a formulation of Mtb72F protein in AS01B adjuvant generated a comprehensive and robust immune response, resulting in the elicitation of strong IFN-gamma and Ab responses encompassing all three components of the polyprotein vaccine and a strong CD8(+) response directed against the same Mtb32(C) epitope identified by DNA immunization. All three forms of Mtb72F immunization resulted in the protection of C57BL/6 mice against aerosol challenge with a virulent strain of M. tuberculosis. Most importantly, immunization of guinea pigs with Mtb72F, delivered either as DNA or as a rAg-based vaccine, resulted in prolonged survival (>1 year) after aerosol challenge with virulent M. tuberculosis comparable to bacillus Calmette-Guérin immunization. Mtb72F in AS02A formulation is currently in phase I clinical trial, making it the first recombinant tuberculosis vaccine to be tested in humans.

Expression and purification of immunologically reactive DPPD, a recombinant Mycobacterium tuberculosis skin test antigen, using Mycobacterium smegmatis and Escherichia coli host cells.

DPPD is a Mycobacterium tuberculosis recombinant antigen that elicits specific delayed type hypersensitivity reactions similar in size and morphological aspects to that elicited by purified protein derivative, in both guinea pigs and humans infected with M. tuberculosis. In addition, earlier clinical studies with DPPD suggested that this molecule could improve the specificity of the tuberculin skin test, which is used as an important aid for the diagnosis of tuberculosis. However, these studies could only be performed with DPPD engineered as a fusion molecule with another Mycobacterium spp. protein because no expression of DPPD could be achieved as a single molecule or as a conventional fusion protein in any commercial system. Although recombinant fusion proteins are in general suitable for several biological studies, they are by definition not ideal for studies involving highly purified and defined polypeptide sequences. Here, we report two alternative approaches for the expression of immunologically reactive recombinant genuine DPPD. The first approach used the rapidly growing, nonpathogenic Mycobacterium smegmatis as host cells transformed with the pSMT3 plasmid vector containing the full-length DPPD gene. The second approach used Escherichia coli transformed with the pET-17b plasmid vector containing the DPPD gene engineered in a three-copy fusion manner in tandem with itself. Though at low levels, expression and purification of immunologically reactive DPPD in M. smegmatis could be achieved. More abundant expression and purification of DPPD as a homo-trimer molecule was achieved in E. coli (> or =2 mg/L of bacterial broth cultures). Interestingly, expression could only be achieved in host cells transformed with the DPPD gene containing its leader peptide. However, the expressed proteins lacked the leader sequence, which indicates that processing of the M. tuberculosis DPPD gene was accurately achieved and necessary in both M. smegmatis and E. coli. More importantly, the delayed type hypersensitivity reactions elicited by purified molecules in guinea pigs infected with M. tuberculosis were indistinguishable from that elicited by purified protein derivative. Because the DPPD gene is present only in the tuberculosis-complex organisms of the Mycobacterium genus, these highly purified molecules should be helpful in identifying individuals sensitized with tubercle bacilli.

Cloning and characterization of a gene encoding an immunoglobulin-binding receptor on the cell surface of some members of the family Trypanosomatidae.

Several members of the Trypanosomatidae family, when freshly isolated from their mammalian hosts, have immunoglobulins adsorbed to their cell surfaces. However, a significant portion of these antibody molecules is not parasite specific, i.e., the immunoglobulins are bound to the parasite's cell surface molecules via noncognitive interactions. It has been proposed that this noncognitive adsorption of immunoglobulins to the parasite is mediated by an Fc-like receptor present in several members of the Trypanosomatidae family. However, the molecular identification of this receptor has never been defined. Here, we describe the cloning of a gene encoding a protein that might represent this molecule. The gene, named Lmsp1, was cloned by screening a Leishmania major cDNA expression library using a rabbit antiserum. Lmsp1 is present in both Leishmania and Trypanosoma and is expressed in all developmental stages of these parasites. The predicted protein has a molecular mass of 16.6 kDa and contains an RGD sequence starting at residue 104 and three cysteine residues at positions 55, 74, and 116. The purified recombinant protein strongly binds to normal immunoglobulins of various animal species (humans, rabbits, sheep, goats, guinea pigs, donkeys, rats, and mice) and the binding to human immunoglobulins appears to be immunoglobulin G (IgG) and IgM isotype specific. Moreover, Lmsp1 binds to both purified Fc and Fab fragments of IgG from both humans and rabbits. The mapping of the Lmsp1 epitopes that bind human IgG revealed that different sequences of the molecule bind to Fc or Fab. In addition, fluorescence-activated cell sorter analyses with a specific rabbit anti-Lmsp1 antiserum showed that Lmsp1 is associated with the parasite's cell surface. Finally, inhibition experiments point to an active role of this molecule in the immunoglobulin-mediated attachment and penetration of Trypanosoma cruzi in its macrophage host cells, thus suggesting that Lmsp1 is a putative Trypanosomatidae immunoglobulin receptor.

Protective efficacy of a tandemly linked, multi-subunit recombinant leishmanial vaccine (Leish-111f) formulated in MPL adjuvant.

Three immunodominant leishmanial antigens (TSA, LmSTI1 and LeIF) previously identified in the context of host response to infection in infected donors and BALB/c mice, as well as their ability to elicit at least partial protection against Leishmania major infection in the BALB/c mouse model, were selected for inclusion into a subunit based vaccine. This is based on the premise that an effective vaccine against leishmaniasis (a complex parasitic infection) would require a multivalent cocktail of several antigens containing a broader range of protective epitopes that would cover a wide range of MHC types in a heterogeneous population. For practical considerations of vaccine development, we report on the generation of a single recombinant polyprotein comprising the sequences of all three open reading frames genetically linked in tandem. The resulting molecule, Leish-111f, comprises an open reading frame that codes for a 111kDa polypeptide. Evaluation of the immunogenicity and protective efficacy of Leish-111f formulated with IL-12 revealed that the immune responses to the individual components were maintained and as well, rLeish-111f protected BALB/c mice against L. major infection to a magnitude equal or superior to those seen with any of the individual components of the vaccine construct or SLA, a soluble Leishmania lysate. But because rIL-12 is expensive and difficult to manufacture and its efficacy and safety as an adjuvant for human use is questionable, we screened for other adjuvants that could potentially substitute for IL-12. We report that monophosphoryl lipid A (MPL) plus squalene (MPL-SE) formulated with rLeish-111f elicited protective immunity against L. major infection. The demonstrated feasibility to manufacture a single recombinant vaccine comprising multiple protective open reading frames and the potential use of MPL-SE as a substitute for IL-12, takes us closer to the realization of an affordable and safe Leishmania vaccine.

Immunization with a polyprotein vaccine consisting of the T-Cell antigens thiol-specific antioxidant, Leishmania major stress-inducible protein 1, and Leishmania elongation initiation factor protects against leishmaniasis.

Development of an effective vaccine against Leishmania infection is a priority of tropical disease research. We have recently demonstrated protection against Leishmania major in the murine and nonhuman primate models with individual or combinations of purified leishmanial recombinant antigens delivered as plasmid DNA constructs or formulated with recombinant interleukin-12 (IL-12) as adjuvant. In the present study, we immunized BALB/c mice with a recombinant polyprotein comprising a tandem fusion of the leishmanial antigens thiol-specific antioxidant, L. major stress-inducible protein 1 (LmSTI1), and Leishmania elongation initiation factor (LeIF) delivered with adjuvants suitable for human use. Aspects of the safety, immunogenicity, and vaccine efficacy of formulations with each individual component, as well as the polyprotein referred to as Leish-111f, were assessed by using the L. major challenge model with BALB/c mice. No adverse reactions were observed when three subcutaneous injections of the Leish-111f polyprotein formulated with either MPL-squalene (SE) or Ribi 529-SE were given to BALB/c mice. A predominant Th1 immune response characterized by in vitro lymphocyte proliferation, gamma interferon production, and immunoglobulin G2A antibodies was observed with little, if any, IL-4. Moreover, Leish-111f formulated with MPL-SE conferred immunity to leishmaniasis for at least 3 months. These data demonstrate success at designing and developing a prophylactic leishmaniasis vaccine that proved effective in a preclinical model using multiple leishmanial antigens produced as a single protein delivered with a powerful Th1 adjuvant suitable for human use.

Antibody-dependent cellular lysis of 3H-labelled Leishmania donovani by human peripheral blood cells

Células mononucleares e polimorfonucleares, obtidas de sangue humano, foram testadas quanto à capacidade de destruir formas promastigotas de Leishmania donovani, num sistema dependente de anticorpos. A morte do parasita foi verificada pela liberaçäo de -3H--uridina previamente incorporada. Neutrófilos e eosinófilos foram as principais populaçöes celulares responsáveis pelo processo, sendo eficazes, inclusive, quando empregadas em baixa relaçäo célula efetora/célula alvo