Enhancement of primary and secondary cellular immune responses against human immunodeficiency virus type 1 gag by using DNA expression vectors that target Gag antigen to the secretory pathway

In this study, we have investigated the influence of antigen targeting after DNA vaccination upon the induction of cellular immune responses against human immunodeficiency virus type 1 (HIV-1) Gag. In addition to the standard version of HIV-1 Gag, we constructed Gag expression vectors that encode a secreted (Sc-Gag) and a cytoplasmic (Cy-Gag) Gag molecule. Although all three HIV-1 Gag expression vectors induced detectable humoral and cellular immune responses, after intramuscular injection the DNA vector encoding the Sc-Gag generated the highest primary cytotoxic T-lymphocyte (CTL) and T-helper responses. Mice immunized with one of the HIV-1 Gag DNA vectors (but not with the control vector pcDNA3. 1) developed a protective immune response against infection with recombinant vaccinia virus expressing HIV-1 Gag, and this response persisted for 125 days. The magnitude of the protection correlated with the levels of Gag-specific ex vivo CTL activity and the number of CD8(+) T cells producing gamma interferon. The DNA vector encoding the Sc-Gag induced higher levels of protection and greater secondary CTL responses than did the DNA vector encoding Cy-Gag.     

Earliest Mexican Turkeys (Meleagris gallopavo) in the Maya Region: Implications for Pre-Hispanic Animal Trade and the Timing of Turkey Domestication

Late Preclassic (300 BC-AD 100) turkey remains identified at the archaeological site of El Mirador (Petén, Guatemala) represent the earliest evidence of the Mexican turkey (Meleagris gallopavo) in the ancient Maya world. Archaeological, zooarchaeological, and ancient DNA evidence combine to confirm the identification and context. The natural pre-Hispanic range of the Mexican turkey does not extend south of central Mexico, making the species non-local to the Maya area where another species, the ocellated turkey (Meleagris ocellata), is indigenous. Prior to this discovery, the earliest evidence of M. gallopavo in the Maya area dated to approximately one thousand years later. The El Mirador specimens therefore represent previously unrecorded Preclassic exchange of animals from northern Mesoamerica to the Maya cultural region. As the earliest evidence of M. gallopavo found outside its natural geographic range, the El Mirador turkeys also represent the earliest indirect evidence for Mesoamerican turkey rearing or domestication. The presence of male, female and sub-adult turkeys, and reduced flight morphology further suggests that the El Mirador turkeys were raised in captivity. This supports an argument for the origins of turkey husbandry or at least captive rearing in the Preclassic.     

The discovery of SB-435495. A potent,orally active inhibitor of lipoprotein-associated phospholipase A(2) for evaluation in man

The introduction of a functionalised amido substituent into a series of 1-(biphenylmethylacetamido)-pyrimidones has given a series of inhibitors of recombinant lipoprotein-associated phospholipase A(2) with sub-nanomolar potency and very encouraging developability properties. Diethylaminoethyl derivative 32, SB-435495, was selected for progression to man.     

Functional differences between two classes of oncogenic mutation in the PIK3CA gene

PIK3CA codes for the p110α isoform of class-IA PI 3-kinase and oncogenic mutations in the helical domain and kinase domain are common in several cancers. We studied the biochemical properties of a common helical domain mutant (E545K) and a common kinase domain mutant (H1047R). Both retain the ability to autophosphorylate Ser608 of p85α and are also inhibited by a range of PI 3-kinase inhibitors (Wortmannin, LY294002, PI-103 and PIK-75) to a similar extent as WT p110α. Both mutants display an increased V_max but while a PDGF derived diphosphotyrosylpeptide caused an increase in V_max for WT p85α/p110α it did not for the E545K variant and actually decreased V_max for the H1047R variant. Further, the E545K mutant was activated by H-Ras whereas the H1047R mutant was not. Together these results suggest helical domain mutants are in a state mimicking activation by growth factors whereas kinase domain mutants mimic the state activated by H-Ras.     

Intraspecific phylogeny and lineage group identification based on the prfA virulence gene cluster of Listeria monocytogenes

Listeria monocytogenes is a serious food-borne pathogen that can cause invasive disease in humans and other animals and has been the leading cause of food recalls due to microbiological concerns in recent years. In order to test hypotheses regarding L. monocytogenes lineage composition, evolution, ecology, and taxonomy, a robust intraspecific phylogeny was developed based on prfA virulence gene cluster sequences from 113 L. monocytogenes isolates. The results of the multigene phylogenetic analyses confirm that L. monocytogenes comprises at least three evolutionary lineages, demonstrate that lineages most frequently (lineage 1) and least frequently (lineage 3) associated with human listeriosis are sister-groups, and reveal for the first time that the human epidemic associated serotype 4b is prevalent among strains from lineage 1 and lineage 3. In addition, a PCR-based test for lineage identification was developed and used in a survey of food products demonstrating that the low frequency of association between lineage 3 isolates and human listeriosis cases likely reflects rarity of exposure and not reduced virulence for humans as has been previously suggested. However, prevalence data do suggest lineage 3 isolates may be better adapted to the animal production environment than the food-processing environment. Finally, analyses of haplotype diversity indicate that lineage 1 has experienced a purge of genetic variation that was not observed in the other lineages, suggesting that the three L. monocytogenes lineages may represent distinct species within the framework of the cohesion species concept.     

Does the Chemotherapy Backbone Impact on the Efficacy of Targeted Agents in Metastatic Colorectal Cancer? A Systematic Review and Meta-Analysis of the Literature

ImportanceThe EGFR inhibitors (EGFR-I) cetuximab and panitumumab and the angiogenesis inhibitors (AIs) bevacizumab and aflibercept have demonstrated varying efficacy in mCRC.ObjectiveTo document the overall impact of specific chemotherapy regimens on the efficacy of targeted agents in treating patients with mCRC. Data sources: MEDLINE, EMBASE and Cochrane databases were searched to 2014, supplemented by hand-searching ASCO/ESMO conference abstracts.ResultsEGFR-I added to irinotecan-based chemotherapy modestly improved OS with HR 0.90 (95% CI 0.81–1.00, p = 0.04), but more so PFS with HR 0.77 (95% CI 0.69–0.86, p<0.00001). No benefit was evident for EGFR-I added to oxaliplatin-based chemotherapy (OS HR 0.97 (95% CI 0.87–1.09) and PFS HR 0.92 (95% CI 0.83–1.02)). Significant oxaliplatin-irinotecan subgroup interactions were present for PFS with I² = 82%, p = 0.02. Further analyses of oxaliplatin+EGFR-I trials showed greater efficacy with infusional 5FU regimens (PFS HR 0.82, 95% CI 0.72–0.94) compared to capecitabine (HR 1.09; 95% CI 0.91–1.30) and bolus 5FU (HR 1.07; 95% CI 0.79–1.45); subgroup interaction was present with I² = 72%, p = 0.03. The oxaliplatin-irinotecan interaction was not evident for infusional 5FU regimens. For AIs, OS benefit was observed with both oxaliplatin-based (HR 0.83) and irinotecan-based (HR 0.77) regimens without significant subgroup interactions. Oxaliplatin+AI trials showed no subgroup interactions by type of FP, whilst an interaction was present for irinotecan+AI trials although aflibercept was only used with infusional FP (I² = 89.7%, p = 0.002).

Conclusion and Relevance

The addition of EGFR-I to irinotecan-based chemotherapy has consistent efficacy, regardless of FP regimen, whereas EGFR-I and oxaliplatin-based regimens were most active with infusional 5FU. No such differential activity was observed with the varying chemotherapy schedules when combined with AIs.     

The retinal pigment epithelium as a gateway for monocyte trafficking into the eye

The choroid plexus epithelium within the brain ventricles orchestrates blood‐derived monocyte entry to the central nervous system under injurious conditions, including when the primary injury site is remote from the brain. Here, we hypothesized that the retinal pigment epithelium (RPE) serves a parallel role, as a gateway for monocyte trafficking to the retina following direct or remote injury. We found elevated expression of genes encoding leukocyte trafficking determinants in mouse RPE as a consequence of retinal glutamate intoxication or optic nerve crush (ONC). Blocking VCAM‐1 after ONC interfered with monocyte infiltration into the retina and resulted in a local pro‐inflammatory cytokine bias. Live imaging of the injured eye showed monocyte accumulation first in the RPE, and subsequently in the retina, and peripheral leukocytes formed close contact with the RPE. Our findings further implied that the ocular milieu can confer monocytes a phenotype advantageous for neuroprotection. These results suggest that the eye utilizes a mechanism of crosstalk with the immune system similar to that of the brain, whereby epithelial barriers serve as gateways for leukocyte entry.