973 resultados para Prime-boost immunization
Resumo:
Cervical cancer is a public health concern as it represents the second cause of cancer death in women worldwide. High-risk human papillomaviruses (HPV) are the etiologic agents, and HPV E6 and/or E7 oncogene-specific therapeutic vaccines are under development to treat HPV-related lesions in women. Whether the use of mucosal routes of immunization may be preferable for inducing cell-mediated immune responses able to eradicate genital tumors is still debated because of the uniqueness of the female genital mucosa (GM) and the limited experimentation. Here, we compared the protective activity resulting from immunization of mice via intranasal (i.n.), intravaginal (IVAG) or subcutaneous (s.c.) routes with an adjuvanted HPV type 16 E7 polypeptide vaccine. Our data show that s.c. and i.n. immunizations elicited similar frequencies and avidity of TetE71CD81 and E7-specific Interferon-gamma-secreting cells in the GM, whereas slightly lower immune responses were induced by IVAG immunization. In a novel orthotopic murine model, both s.c. and i.n. immunizations allowed for complete long-term protection against genital E7-expressing tumor challenge. However, only s.c. immunization induced complete regression of already established genital tumors. This suggests that the higher E7-specific systemic response observed after s.c. immunization may contribute to the regression of growing genital tumors, whereas local immune responses may be sufficient to impede genital challenges. Thus, our data show that for an efficiently adjuvanted protein-based vaccine, parenteral vaccination route is superior to mucosal vaccination route for inducing regression of established genital tumors in a murine model of HPV-associated genital cancer.
Resumo:
BACKGROUND: Therapeutic cancer vaccines aim to boost the natural immunity against transformed cancer cells, and a series of adjuvants and co-stimulatory molecules have been proposed to enhance the immune response against weak self-antigens expressed on cancer cells. For instance, a peptide/CpG-based cancer vaccine has been evaluated in several clinical trials and was shown in pre-clinical studies to favor the expansion of effector T versus Tregs cells, resulting in a potent antitumor activity, as compared to other TLR ligands. Alternatively, the adjuvant activity of CD1d-restricted invariant NKT cells (iNKT) on the innate and adaptive immunity is well demonstrated, and several CD1d glycolipid ligands are under pre-clinical and clinical evaluation. Importantly, additive or even synergistic effects have been shown upon combined CD1d/NKT agonists and TLR ligands. The aim of the present study is to combine the activation and tumor targeting of activated iNKT, NK and T cells. METHODS: Activation and tumor targeting of iNKT cells via recombinant α-galactosylceramide (αGC)-loaded CD1d-anti-HER2 fusion protein (CD1d-antitumor) is combined or not with OVA peptide/CpG vaccine. Circulating and intratumoral NK and H-2Kb/OVA-specific CD8 responses are monitored, as well as the state of activation of dendritic cells (DC) with regard to activation markers and IL-12 secretion. The resulting antitumor therapy is tested against established tumor grafts of B16 melanoma cells expressing human HER2 and ovalbumin. RESULTS: The combined CD1d/iNKT antitumor therapy and CpG/peptide-based immunization leads to optimized expansion of NK and OVA-specific CD8 T cells (CTLs), likely resulting from the maturation of highly pro-inflammatory DCs as seen by a synergistic increase in serum IL-12. The enhanced innate and adaptive immune responses result in higher tumor inhibition that correlates with increased numbers of OVA-specific CTLs at the tumor site. Antibody-mediated depletion experiments further demonstrate that in this context, CTLs rather than NK cells are essential for the enhanced tumor inhibition. CONCLUSIONS: Altogether, our study in mice demonstrates that αGC/CD1d-antitumor fusion protein greatly increases the efficacy of a therapeutic CpG-based cancer vaccine, first as an adjuvant during T cell priming and second, as a therapeutic agent to redirect immune responses to the tumor site.
Resumo:
The EORTC 22881-10882 trial in 5178 conservatively treated early breast cancer patients showed that a 16 Gy boost dose significantly improved local control, but increased the risk of breast fibrosis. To investigate predictors for the long-term risk of fibrosis, Cox regression models of the time to moderate or severe fibrosis were developed on a random set of 1797 patients with and 1827 patients without a boost, and validated in the remaining set. The median follow-up was 10.7 years. The risk of fibrosis significantly increased (P<0.01) with increasing maximum whole breast irradiation (WBI) dose and with concomitant chemotherapy, but was independent of age. In the boost arm, the risk further increased (P<0.01) if patients had post-operative breast oedema or haematoma, but it decreased (P<0.01) if WBI was given with >6 MV photons. The c-index was around 0.62. Nomograms with these factors are proposed to forecast the long-term risk of moderate or severe fibrosis.
Resumo:
Résumé Le but de cette étude est d'évaluer la faisabilité et l'efficacité d'un traitement des carcinomes pharyngo-laryngés avancés par combinaison de chimiothérapie intensive associé à une radiothérapie accélérée. Vingt-trois patients ont été inclus (age médian 54 ans, entre 35 et 70 ans). Les localisations tumorales étaient l'hypopharynx (n=7), base de langue (n=10), nasopharynx (n=2) ou l'oesophage proximal (n.1), ou sans porte d'entrée (n=3). Le traitement comprend trois cycles de chimiothérapie (cisplatin 100mg/m2 à J1 ; 5-FU 1000mg/m2 par jour pendant 5 jours en perfusion continue, précédé par de l'amifostine 910mg/m2 ; répété toutes les trois semaines). La radiothérapie concomitante, accélérée (dose totale de 70Gy en 6 semaines) a été débuté au premier jour du deuxième cycle de chimiothérapie. Vingt et un patients ont pu achever la radiothérapie. Dix-huit patients étaient en rémission complète à la fin du traitement. Avec un suivi médian de 45 mois, le taux de survie globale atteint 56% (95% Cl, 32-79%). Le contrôle loco-régional était de 71% (95% CI, 52-91%). La toxicité associée au traitement consistait en une insuffisance rénale réversible (≥grade II) chez 9 patients (43%) et une agranulocytose fébrile chez 9 patients (43%). Tous les patients ont présenté une mucite modérée à sévère (grade II/III) et 19 patients ont montré une toxicité cutanée de grade III. En conclusion, le traitement combiné de radiothérapie accélérée avec une chimiothérapie concomitante à base de Cisplatin/5-FU full-dose avec amifostine est faisable. La toxicité est importante mais reste maîtrisable dans le cadre d'un centre multidisciplinaire. Le taux de survie globale à 4 ans est prometteur, la recherche en vue de traitements moins toxiques doit se poursuivre. Abstract The purpose of this study was to evaluate the feasibility and efficacy of a treatment concept combining three cycles of full-dose chemotherapy (CT) with concomitant accelerated uninterrupted radiotherapy (RI). Twenty- three patients (median age: 54 years, range: 35-70) with locally advanced squamous cell carcinoma of the head and neck (SCCHN) were included. The primary tumor involved the hypopharynx (n=7), base of the tongue (n=10), nasopharynx (n=2) or upper esophagus (n=1) or its location was unknown (n=3). Treatment consisted of three cycles of chemotherapy (cisplatin 100 mg/m2 on day 1; 5-FU 1,000 mg/m2 per day for 5 days as a continuous infusion, preceded by amifostine 910 mg/m2). repeated every 3 weeks. Uninterrupted concomitant boost-accelerated RI (total dose of 70 Gy in 6 weeks) started together on day 1 of the second cycle. All but two patients received the full course of RT. Eighteen patients achieved complete remission (78%). At a median follow-up of 45 months the overall survival was 56% (95% c.i. 32-79%) and the loco-regional control 71% (95% c.i. 52-91%). Toxicity involved reversible renal insufficiency of grade II in 9 patients (39%) and neutropenic fever in 9 patients (39%). All patients suffered from moderate to severe mucositis (grade HMI), and 19 patients presented cutaneous toxicity grade III. Concomitant boost-accelerated RI combined with concurrent full-dose cisplatin/5-FU chemotherapy and amifostine is feasible with manageable, although substantial, toxicity. The overall survival of 4 years is promising. Newer regimens causing less acute mucosal and skin toxicity are needed.
Resumo:
Agro-ecosystems have recently experienced dramatic losses of biodiversity due to more intensive production methods. In order to increase species diversity, agri-environment schemes provide subsidies to farmers who devote a fraction of their land to ecological compensation areas (ECA). Several studies have shown that invertebrate biodiversity is actually higher in ECA than in nearby intensively cultivated farmland. It remains poorly understood, however, to what extent ECA also favour vertebrates, such as small mammals and their predators, which would contribute to restore functioning food chains within revitalized agricultural matrices. We studied small mammal populations among eight habitat types - including wildflower areas, a specific ECA in Switzerland - and habitat selection (radiotracking) by the barn owl Tyto alba, one of their principal predators. Our prediction was that habitats with higher abundances of small mammals would be more visited by foraging Barn owls during the period of chicks' provisioning. Small mammal abundance tended to be higher in wildflower areas than in any other habitat type. Barn owls, however, preferred to forage in cereal fields and grassland. They avoided all types of crops other than cereals, as well as wildflower areas, which suggests that they do not select their hunting habitat primarily with respect to prey density. Instead of prey abundance, prey accessibility may play a more crucial role: wildflower areas have a dense vegetation cover, which may impede access to prey for foraging owls. The exploitation of wildflower areas by the owls might be enhanced by creating open foraging corridors within or around wildflower areas. Wildflower areas managed in that way might contribute to restore functioning food chains within agro-ecosystems.
Resumo:
Glioblastoma multiforme (GBM) is the most aggressive brain tumor that, by virtue of its resistance to chemotherapy and radiotherapy, is currently incurable. Identification of molecules whose targeting may eliminate GBM cells and/or sensitize glioblastoma cells to cytotoxic drugs is therefore urgently needed. CD44 is a major cell surface hyaluronan receptor and cancer stem cell marker that has been implicated in the progression of a variety of cancer types. However, the major downstream signaling pathways that mediate its protumor effects and the role of CD44 in the progression and chemoresponse of GBM have not been established. Here we show that CD44 is upregulated in GBM and that its depletion blocks GBM growth and sensitizes GBM cells to cytotoxic drugs in vivo. Consistent with this observation, CD44 antagonists potently inhibit glioma growth in preclinical mouse models. We provide the first evidence that CD44 functions upstream of the mammalian Hippo signaling pathway and that CD44 promotes tumor cell resistance to reactive oxygen species-induced and cytotoxic agent-induced stress by attenuating activation of the Hippo signaling pathway. Together, our results identify CD44 as a prime therapeutic target for GBM, establish potent antiglioma efficacy of CD44 antagonists, uncover a novel CD44 signaling pathway, and provide a first mechanistic explanation as to how upregulation of CD44 may constitute a key event in leading to cancer cell resistance to stresses of different origins. Finally, our results provide a rational explanation for the observation that functional inhibition of CD44 augments the efficacy of chemotherapy and radiation therapy.
Resumo:
In 1875, 7 years prior to the description of the Koch bacillus, Klebs visualized the first Streptococcus pneumoniae in a pleural fluid. Since then, this organism has played a determinant role in biomedical science. From a biological point of view, it was largely implicated in the development of passive and active immunization by serotherapy and vaccination, respectively. Genetic transformation was also first observed in S. pneumoniae, leading to the discovery of DNA. From a clinical point of view, S. pneumoniae is still today a prime cause of otitis media in children and of pneumonia in all age groups, as well as a predominant cause of meningitis and bacteremia. In adults, bacteremia is still entailed with a mortality of over 25%. Although S. pneumoniae remained very sensitive to penicillin for many years, penicillin-resistance has emerged and increased dramatically over the last 15 years. During this period of time, the frequency of penicillin-resistant isolates has increased from < or = 1% to frequencies varying from 20 to 60% in geographic areas as diverse as South Africa, Spain, France, Hungary, Iceland, Alaska, and numerous regions of the United States and South America. In Switzerland, the current frequency of penicillin-resistant pneumococci ranges between 5 and > or = 10%. The increase in penicillin-resistant pneumococci correlates with the intensive use of beta-lactam antibiotics. The mechanism of resistance is not due to bacterial production of penicillinase, but to an alteration of the bacterial target of penicillin, the so-called penicillin-binding proteins. Resistance is subdivided into (i) inter mediate level resistance (minimal inhibitory concentration [MIC] of penicillin of 0.1-1 mg/L) and (ii) high level resistance (MCI > or = 2 mg/L). The clinical significance of intermediate resistance remains poorly defined. On the other hand, highly resistant strains were responsible for numerous therapeutical failures, especially in cases of meningitis. Antibiotics recommended against penicillin-resistant pneumococci include cefotaxime, ceftriaxone, imipenem and in some instances vancomycin. However, penicillin-resistant pneumococci tend to present cross-resistances to all the antibotics of the beta-lactam family and could even become resistant to the last resort drugs mentioned above. Thus, in conclusion, the explosion of resistance to penicillin in pneumococci is a ubiquitous phenomenon which must be fought against by (i) a strict utilization of antibiotics, (ii) the practice of microbiological sampling of infected foci before treatment, (iii) the systematic surveillance of resistance profiles of pneumococci against antibiotics and (iv) the adequate vaccination of populations at risk.
Resumo:
PURPOSE: Vaccines targeting tumor associated antigens are in development for bladder cancer. Most of these cancers are nonmuscle invasive at diagnosis and confined in the mucosa and submucosa. However, to our knowledge how vaccination may induce the regression of tumors at such mucosal sites has not been examined previously. We compared different immunization routes for the ability to induce vaccine specific antitumor CD8 T cells in the bladder and bladder tumor regression in mice. MATERIALS AND METHODS: In the absence of a murine bladder tumor model expressing a tumor antigen relevant for human use we established an orthotopic model expressing the HPV-16 tumor antigen E7 as a model. We used an adjuvant E7 polypeptide to induce CD8 T cell mediated tumor regression. RESULTS: Subcutaneous and intravaginal but not intranasal vaccination induced a high number of TetE7(+)CD8(+) T cells in the bladder as well as bladder tumor regression. The entry of vaccine specific T cells in the bladder was not the only key since persistent regression of established bladder tumors by intravaginal or subcutaneous immunization was associated with tumor infiltration of total CD4 and CD8 T cells. This resulted in an increase in TetE7(+)CD8(+) T cells and a decrease in T regulatory cells, leading to an increased number of effector interferon-γ secreting vaccine specific CD8 T cells in the regressing bladder tumor. CONCLUSIONS: These data show that immunization routes should be tailored to each mucosal tumor site. Subcutaneous or intravaginal vaccination may be of additional value to treat patients with bladder cancer.
Resumo:
This paper breaks new ground toward contractual and institutional innovation in models of homeownership, equity building, and mortgage enforcement. Inspired by recent developments in the affordable housing sector and in other types of public financing schemes, this paper suggests extending institutional and financial strategies such as timeand place-based division of property rights, conditional subsidies, and credit mediation to alleviate the systemic risks of mortgage foreclosure. Alongside a for-profit shared equity scheme that would be led by local governments, we also outline a private market shared equity model, one of bootstrapping home buying with purchase options.
Resumo:
The protective capabilities of three Leishmania recombinant proteins - histone 1 (H1) and hydrophilic acylated surface protein B1 (HASPB1) immunized singly, or together as a protein cocktail vaccine with Montanide, and the polyprotein MML immunized with MPL-SE adjuvant - were assessed in beagle dogs. Clinical examination of the dogs was carried out periodically under blinded conditions and the condition of the dogs defined as asymptomatic or symptomatic. At the end of the trial, we were able to confirm that following infection with L. infantum promastigotes, five out of eight dogs immunized with H1 Montanide, and four out of eight dogs immunized with either the combination of HASPB1 with Montanide or the combination of H1+HASPB1 with Montanidetrade mark, remained free of clinical signs, compared with two out of seven dogs immunized with the polyprotein MML and adjuvant MPL-SE, and two out of eight dogs in the control group. The results demonstrate that HASPB1 and H1 antigens in combination with Montanide were able to induce partial protection against canine leishmaniasis, even under extreme experimental challenge conditions.
Resumo:
This Article breaks new ground toward contractual and institutional innovation in models of homeownership, equity building, and mortgage enforcement. Inspired by recent developments in the affordable housing sector and other types of public financing schemes, we suggest extending institutional and financial strategies such as time- and place-based division of property rights, conditional subsidies, and credit mediation to alleviate the systemic risks of mortgage foreclosure. Two new solutions offer a broad theoretical basis for such developments in the economic and legal institution of homeownership: a for-profit shared equity scheme led by local governments alongside a private market shared equity model, one of "bootstrapping home buying with purchase options".
Resumo:
Human papillomavirus (HPV) vaccines based on L1 virus-like particle (VLP) can prevent genital HPV infection and associated lesions after three intramuscular injections. Needle-free administration might facilitate vaccine implementation, especially in developing countries. Here we have investigated rectal and vaginal administration of HPV16 L1 VLPs in mice and their ability to induce anti-VLP and HPV16-neutralizing antibodies in serum and in genital, rectal and oral secretions. Rectal and vaginal immunizations were not effective in the absence of adjuvant. Cholera toxin was able to enhance systemic and mucosal anti-VLPs responses after rectal immunization, but not after vaginal immunization. Rectal immunization with Resiquimod and to a lesser extent Imiquimod, but not monophosphoryl lipid A, induced anti-HPV16 VLP antibodies in serum and secretions. Vaginal immunization was immunogenic only if administered in mice treated with nonoxynol-9, a disrupter of the cervico-vaginal epithelium. Our findings show that rectal and vaginal administration of VLPs can induce significant HPV16-neutralizing antibody levels in secretions, despite the fact that low titers are induced in serum. Imidazoquinolines, largely used to treat genital and anal warts, and nonoxonol-9, used as genital microbicide/spermicide were identified as adjuvants that could be safely used by the rectal or vaginal route, respectively.
Resumo:
Some chronic diseases--like renal failure, liver insufficiency, chronic lung disease, cardiac involvement, diabetes mellitus, asplenia--present limited defects of the immune system and/or a higher risk of infection; therefore, patients with such pathologies should get selective vaccinations. The efficacy of immunization decreases with disease progression; for this reason, these patients should be immunized as soon as possible. At the beginning of their disease, these patients do not need a specialized treatment and are followed by the general practitioner alone who is in charge of immunizing them as well as contact people of any immunocompromised patient. OFSP's regular vaccinations programme is recommended, as well as selective vaccinations against influenza, pneumococci and viral hepatitis, depending on the underlying chronic disease.