Sulfadoxine- Pyrimethamine: Dead or Alive for Malaria Control? GOSLING RD 1, ROPER C 1, CHANDRAMOHAN D 1 1Department of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
Background: Sulfadoxine-pyrimethamine (SP) has played an important role in malaria control across the world and is currently recommended for prevention as Intermittent Preventive Treatment for pregnant women (IPTp) and is being considered for prevention in infants (IPTi) in sub-Saharan Africa.
Methods: Review of the literature. Comparison of in vivo efficacy studies of SP and SP- IPTi protective efficacies with genetic markers of resistance against SP.
Findings: The molecular mechanism of drug resistance in P. falciparum was identified in the mid nineteen- nineties. Point mutations in the parasite folate pathway genes, namely in the parasite dhfr and dhps were associated with clinical failure of SP in uncomplicated malaria and conferred varying degrees of resistance. Identification of the point mutations and sequencing of microsatellites about the genes has allowed us to trace the spread of resistance from Asia to Africa. The proportion of isolates carrying these genes has risen to levels that some experts think heralds the end of SP. Although in areas of high resistance SP appears to have a continued effect for prophylaxis this is short lived and is not efficacious when the observation period is extended from 1 to 3 months.
Conclusion: Due to the patterns of genetic markers for drug resistance it is likely that SP has a short useful life in Eastern and Southern Africa, however in West Africa rates of mutations are much lower and SP may continue to be useful for some time.
Authors’ disclosure statement
The authors state no conflict of interest. The work was funded by a grant from the Intermittent Preventive Treatment of malaria in infants (IPTi) Consortium supported by the Bill and Melinda Gates Foundation.
Monoclonal Antibodies as Vaccine Adjuvants: From Potential to Protection BITSAKTSIS C, RAWOOL DB, IGLESIAS B, DRAKE JR, GOSSELIN EJ Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY, USA.
Background: Targeting antigen (Ag) to Fc receptors (FcR) on Ag presenting cells enhances humoral and cellular immunity. Thus, we hypothesized that targeting inactivated F. tularensis (iFt) to FcR intranasally (i.n.), would enhance protection against mucosal challenge. We examined: 1) the ability of anti-iFt monoclonal antibody (mAb) plus iFt, to enhance presentation of iFt Ag, 2) the ability of mAb-iFt administered i.n. to enhance protection against i.n. challenge, 3) the ability of an FcR-targeted subunit vaccine to protect against S. pneumoniae.
Methods:First, mouse macrophages and iFt Ag-specific T cells were combined with iFt or iFt plus anti-iFt mAb. Cells were incubated at 37oC, supernatants collected, and cytokine secretion measured. Second, mice were divided into three groups (5-6/group) and immunized i.n. with PBS, iFt, or mAb-iFt. Mice were immunized on day 0, boosted on day 21, challenged i.n. on day 35, and monitored 21 days for survival. Third, mice were divided into three groups consisting of wild-type (WT) mice immunized i.n. with PBS, WT mice immunized with S. pneumoniae Ag (PspA) in the form of anti-human FcγRI (hFcγRI)-PspA subunit vaccine, or transgenic mice expressing hFcγRI immunized with anti-hFcγRI-PspA. Mice were immunized on day 0 and 21 as above, and on day 35 sera were collected, or mice were challenged with S. pneumoniae, to measure Ab production or protection, respectively.
Results: Anti-iFt mAb plus iFt enhanced iFt presentation to Ag-specific T cells. When using mAb-iFt as an i.n. immunogen, increased protection (100%) was achieved compared to iFt alone (50%-65%). In addition, targeting PspA to hFcγRI i.n., in hFcγRI transgenic versus WT mice, enhanced S. pneumoniae-specific IgA and IgG production, and protection against i.n. challenge with S. pneumoniae.
Conclusions: The above studies demonstrate for the first time that targeting infectious disease Ag to FcR at a mucosal site is an effective strategy for enhancing protection against intracellular and extracellular mucosal pathogens. Furthermore, the versatility of this approach is demonstrated, in that mAb to an inactivated infectious agent can be used as an adjuvant, when a protective Ag has not been identified (F. tularensis). Alternatively, a subunit approach can be used when a protective Ag, such as PspA, has been identified (S. pneumoniae).
TLN-4601, a novel anticancer agent, inhibits Ras signaling through c-Raf degradation
Gourdeau H, Boufaied N, Wioland M-A, Desrochers F, Falardeau P
Background: TLN-4601 is a structurally novel farnesylated dibenzodiazepinone discovered though Thallion’s DECIPHER® technology platform. The compound has demonstrated broad anti-tumor activity in vitro and in vivo. As TLN-4601 was identified through in vitro cytotoxic assays, its molecular target(s) was unknown at the time of discovery. Related to its farnesylated moiety, the effect of TLN-4601 on the Ras-MAPK signaling pathway was assessed.
Methods: Downstream Ras signaling events, Raf-1 and ERK1/2 phosphorylation, were evaluated by immunoblots in human breast (MCF7), glioma (U-87 MG), and prostate (PC-3) tumor cell lines. Cells were treated with 10 mM TLN-4601 in RPMI/0.1% FBS for 30 min, 1h, 4h and 6h, and subsequently exposed 10 min to EGF at 50 ng/mL. Cells were then lysed in ice-cold RIPA buffer extracts separated on SDS-PAGE. To study the effect of TLN-4601 on protein prenylation, exponentially growing cells were exposed to TLN-4601 or lovastatin (positive control) at 3, 10 and 30 µM for 24h. Cells were processed as above and immunoblots probed for RAP1A, HDJ2 and Ras.
Results: TLN-4601 exposure prevented EGF-induced phosphorylation of Raf-1 and ERK1/2. This effect was time and dose dependent with complete inhibition of protein phosphorylation within 6h at 10 µM. The inhibition of Ras-signaling was not mediated by inhibiton of protein prenylation, documented by the lack of effect of TLN-4601 on prenylation of HDJ2 or RAP1A, specific substrates of FTase and GGTase I, respectively. TLN-4601 treatment reduced Ras-GTP levels but did not inhibit EGFR, Raf-1, MEK or ERK1/2 kinase activities. Interestingly, we also noted that TLN-4601 induced Raf-1 proteosomal-dependent degradation.
Conclusions: Our data indicate that TLN-4601 inhibits the Ras-MAPK signaling pathway by two mechanisms: reducing Ras activation and depleting Raf-1 protein.
GRABHERR S1, THALI M2, BERNHARD W2, AUGSBURGER M1, MANGIN P1 1Institute of Forensic Medicine, University of Lausanne, Rue du Bugnon 21, CH-1005 Lausanne;
2Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, CH-3012 Bern
Background:Smuggling dissolved drugs, especially cocaine, in bottled liquids is an ongoing problem at borders. Common fluoroscopy of packages at the border cannot detect contaminated liquids. To find out if the liquids are contaminated, packages and bottles have to be opened, so that an immunologic test by the use of a drug test panel can be performed. Once opened, the cargo can not be delivered and tracked without arousing the suspicion of smugglers. The objective of our study was to develop a non-invasive MDCT (multi-detector computed tomography) screening method to detect cocaine-containing vessels that are hidden between uncontaminated ones in a shipment.
Methods: Studies were performed on three wine bottles containing cocaine solutions that were confiscated at the Swiss border. Reference values were obtained by scans of different sorts of commercially available wines and aqueous solutions of dissolved sugar. All bottles were scanned using MDCT, and data evaluation was performed by measuring the mean peak of Hounsfield units. To verify the method, simulated testing on twelve wine bottles including six contaminated bottles were performed.
Results: Using measurements of the mean peak of Hounsfield units, enables the detection of dissolved cocaine in wine bottles in a non-invasive and rapid fashion. Increasing opacity of the liquid corresponds well with the concentration of dissolved cocaine. Simulated testing showed, that it is possible to distinguish between cocaine-contaminated and uncontaminated wine bottles.
Conclusions: 1.) The described method is an efficacious screening method to detect cocaine-contaminated bottles that are hidden between untreated bottles in cargos. 2.) The non-invasive examination of cargo allows a questionable delivery to be tracked without arousing the suspicion of the smugglers.
