Personalized RNA neoantigen vaccines stimulate T cells in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is lethal in 88% of patients1, yet harbours mutation-derived T cell neoantigens that are suitable for vaccines 2,3. Here in a phase I trial of adjuvant autogene cevumeran, an individualized neoantigen vaccine based on uridine mRNA-lipoplex nanoparticles, we synthesized mRNA neoantigen vaccines in real time from surgically resected PDAC tumours. After surgery, we sequentially administered atezolizumab (an anti-PD-L1 immunotherapy), autogene cevumeran (a maximum of 20 neoantigens per patient) and a modified version of a four-drug chemotherapy regimen (mFOLFIRINOX, comprising folinic acid, fluorouracil, irinotecan and oxaliplatin). The end points included vaccine-induced neoantigen-specific T cells by high-threshold assays, 18-month recurrence-free survival and oncologic feasibility. We treated 16 patients with atezolizumab and autogene cevumeran, then 15 patients with mFOLFIRINOX. Autogene cevumeran was administered within 3 days of benchmarked times, was tolerable and induced de novo high-magnitude neoantigen-specific T cells in 8 out of 16 patients, with half targeting more than one vaccine neoantigen. Using a new mathematical strategy to track T cell clones (CloneTrack) and functional assays, we found that vaccine-expanded T cells comprised up to 10% of all blood T cells, re-expanded with a vaccine booster and included long-lived polyfunctional neoantigen-specific effector CD8+ T cells. At 18-month median follow-up, patients with vaccine-expanded T cells (responders) had a longer median recurrence-free survival (not reached) compared with patients without vaccine-expanded T cells (non-responders; 13.4 months, P = 0.003). Differences in the immune fitness of the patients did not confound this correlation, as responders and non-responders mounted equivalent immunity to a concurrent unrelated mRNA vaccine against SARS-CoV-2. Thus, adjuvant atezolizumab, autogene cevumeran and mFOLFIRINOX induces substantial T cell activity that may correlate with delayed PDAC recurrence.

Dietary EPA and DHA prevent changes in white adipose tissue omega-3 PUFA and oxylipin content associated with a Fads2 deficiency.

Fatty acid desaturase 2 (Fads2) encodes the delta-6 desaturase (D6D) enzyme, which is rate-limiting for the endogenous production of omega-3 long-chain polyunsaturated fatty acids (LC-PUFA). Numerous studies have reported the cardiometabolic health benefits of omega-3 LC-PUFA. Humans carrying genetic variants in the FADS2 gene have reduced levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), as well as oxylipins, in blood, erythrocytes and white adipose tissue (WAT). Similar findings have been reported in whole-body Fads2-/- mice fed a diet deficient in omega-3 LC-PUFA. The objective of this study was to determine if a diet containing EPA and DHA would prevent the deficiencies in WAT lipid profiles seen in Fads2-/- mice fed a diet containing only ALA. Male C57BL/6 J Fads2-/- and wild type (WT) mice were fed a low fat (7% w/w) diet for 9 weeks containing either flaxseed oil + ARASCO (FD, containing~53% ALA) or menhaden oil (MD, containing~14% EPA and 10% DHA). Fads2-/- mice fed an ALA-enriched diet had reduced body weight, little-to-no omega-3 LC-PUFA and a near complete loss of all omega-3 derived oxylipins in both epididymal and inguinal WAT (P<.05) compared to their WT counterparts, as well as altered expression of key regulators of the fatty acid desaturase pathway. However, Fads2-/- mice fed a diet containing EPA and DHA prevented most of these changes. This study provides evidence that a diet containing EPA and DHA provides a nutritional strategy to prevent alterations in WAT lipid content caused by reduced D6D activity.

Neither linoleic acid nor arachidonic acid promote white adipose tissue inflammation in Fads2-/- mice fed low fat diets.

Dietary n-6 polyunsaturated fatty acids (PUFA) are widely perceived to promote inflammation and contribute to the development of chronic diseases. This dogma has been recently questioned due to evidence that n-6 PUFA, specifically linoleic acid (LA, 18:2n-6) and arachidonic acid (AA, 20:4n-6), do not appear to activate inflammatory signalling pathways when consumed in moderate amounts. However, delineating the independent roles of different dietary n-6 PUFA in vivo is challenging because LA is continuously converted into AA in a pathway regulated by the fatty acid desaturase 2 (Fads2) gene. The objective of this study was to investigate the independent roles of LA and AA on white adipose tissue (WAT) inflammatory signalling pathways using Fads2-/- mice. We hypothesized that dietary LA would not induce WAT inflammation, unless it was endogenously converted into AA. Male C57BL/6 wild-type (WT) and Fads2-/- mice were fed low-fat isocaloric diets containing either 7% corn oil w/w (CD, containing ~42% LA) or 7% ARASCO oil w/w (AD, containing ~27% AA) for 9 weeks. WAT inflammatory gene expression, protein levels, as well as phospholipid (PL) and triacylglycerol (TAG) fatty acid composition, were analyzed by RT-qPCR, western blots, and gas chromatography, respectively. Fads2-/- mice fed CD had high LA, but little-to-no GLA (18:3n-6), DGLA (20:3n-6), and AA in PLs and TAGs compared to their WT counterparts. In comparison, Fads2-/- and WT mice fed AD showed minimal differences in n-6 PUFA content in serum and WAT, despite having significantly more AA than CD-fed mice. No differences in gene expression for common inflammatory adipokines (e.g. Mcp-1, Ccl5, Tnfα) or key regulators of eicosanoid production (e.g. Cox-2, Alox-12, Alox-15) were detected in WAT between any of the diet and genotype groups. Furthermore, no differences in MCP-1, and total or phosphorylated STAT3 and p38 inflammatory proteins, were observed. Collectively, these results demonstrate that neither LA nor AA promote WAT inflammation when consumed as part of a low-fat diet. Therefore, the existing dogma surrounding n-6 PUFA and inflammation needs to be reconsidered.

[A study of the nutritional status and food habits of Otomi Indians in the Mezquital Valley of Mexico. 1946]. / Estudio del estado de nutrición y los hábitos alimentarios de comunidades otomíes en el Valle del Mezquital de México. 1946.

Publicado originalmente en American Journal of Public Health: Anderson RK, Calvo J, Serrano G, Payne GC. A study of the nutritional status and food habits of Otomi Indians in the Mezquital Valley of Mexico. Am J Public Health 1946;36:883-903.

Estudio del estado de nutrición y los hábitos alimentarios de comunidades otomíes en el Valle del Mezquital de México

Se presentan los resultados de un estudio nutriológico en grupos de indígenas otomíes del Valle del Mezquital de México. La región es árida, estéril y económica y culturalmente una de las más deprimidas del país. Los habitantes comían muy pocos de los alimentos considerados comúnmente como esenciales para lograr una buena nutrición. Su consumo de carne, leche y sus derivados, frutas y verduras es extremadamente bajo. Sin embargo, por el consumo de tortillas, pulque y todas las plantas disponibles que se pueden considerar comestibles, se logra una dieta suficientemente adecuada.

Application of a recA gene-based identification approach to the maize rhizosphere reveals novel diversity in Burkholderia species.

Burkholderia species are widely distributed in the natural environment. We evaluated the use of the recA gene in a cultivation-independent approach to examine the Burkholderia diversity associated with the maize rhizosphere. Two types of recA gene library were constructed, one with broad-specificity recA primers (BUR1 and BUR2) and a second from the products of nested PCRs using Burkholderia-specific primers (BUR3 and BUR4). The broad-specificity primer set provided near full-length recA sequences (869 bp) suitable for the creation of robust environmental sequence data sets; however, the nested PCR approach demonstrated the greatest specificity (84%) for detection of Burkholderia species recA genes. In addition, the screening approach was able to identify recA phylotypes matching Burkholderia cepacia complex species previously cultivated from the maize samples and discriminate these from other Burkholderia. The ecological benefit of Burkholderia species cultivated from maize rhizosphere is well documented, however, the fact that the majority of Burkholderia recA genes detected in this study (90%) were suggestive of novel taxa indicates that a wealth of potentially important interactions with uncultivated Burkholderia species remain unstudied in this habitat.

Development of a recA gene-based identification approach for the entire Burkholderia genus.

Burkholderia is an important bacterial genus containing species of ecological, biotechnological, and pathogenic interest. With their taxonomy undergoing constant revision and the phenotypic similarity of several species, correct identification of Burkholderia is difficult. A genetic scheme based on the recA gene has greatly enhanced the identification of Burkholderia cepacia complex species. However, the PCR developed for the latter approach was limited by its specificity for the complex. By alignment of existing and novel Burkholderia recA sequences, we designed new PCR primers and evaluated their specificity by testing a representative panel of Burkholderia strains. PCR followed by restriction fragment length polymorphism analysis of an 869-bp portion of the Burkholderia recA gene was not sufficiently discriminatory. Nucleotide sequencing followed by phylogenetic analysis of this recA fragment differentiated both putative and known Burkholderia species and all members of the B. cepacia complex. In addition, it enabled the design of a Burkholderia genus-specific recA PCR that produced a 385-bp amplicon, the sequence of which was also able to discriminate all species examined. Phylogenetic analysis of 188 novel recA genes enabled clarification of the taxonomic position of several important Burkholderia strains and revealed the presence of four novel B. cepacia complex recA lineages. Although the recA phylogeny could not be used as a means to differentiate B. cepacia complex strains recovered from clinical infection versus the natural environment, it did facilitate the identification of clonal strain types of B. cepacia, B. stabilis, and B. ambifaria capable of residing in both niches.