Generation of human long-lived plasma cells by developmentally regulated epigenetic imprinting

Antibody secreting cells (ASCs) circulate after vaccination and infection and migrate to the BM where a subset known as long-lived plasma cells (LLPCs) persists and secrete antibodies for a lifetime. The mechanisms by which circulating ASCs become LLPCs are not well elucidated. Here, we show that human blood ASCs have distinct morphology, transcriptomes, and epigenetics compared with BM LLPCs. Compared with blood ASCs, BM LLPCs have decreased nucleus/cytoplasm ratio but increased endoplasmic reticulum and numbers of mitochondria. LLPCs up-regulate pro-survival genes MCL1, BCL2, and BCL-XL while simultaneously down-regulating pro-apoptotic genes HRK1, CASP3, and CASP8. Consistent with reduced gene expression, the pro-apoptotic gene loci are less accessible in LLPCs. Of the pro-survival genes, only BCL2 is concordant in gene up-regulation and loci accessibility. Using a novel in vitro human BM mimetic, we show that blood ASCs undergo similar morphological and molecular changes that resemble ex vivo BM LLPCs. Overall, our study demonstrates that early-minted blood ASCs in the BM microniche must undergo morphological, transcriptional, and epigenetic changes to mature into apoptotic-resistant LLPCs.

Dental Anthropology-A Revolutionary Tool in Forensic Science

Dental anthropology is a field of physical anthropology that studies the origin, development, and evolution of anthropoid dentitions, as well as their relationship to social, physical, and cultural factors. Teeth have their own distinct morphology and physiology, which is in stark contrast to the body's genetic structure. Teeth are also unique among the resistant elements of archaeological and fossil remains in that they have been exposed on the body's surface throughout their lives. As a result, dental anthropology may be assessed in the mouth cavity of living humans using similar methods to those used for prehistoric relics. As a result, it's no surprise that practising dental surgeons have historically ranked well among dental anthropologists. This review’s initial purpose is to provide an overview of the morphological and non-morphological properties of animate dentitions that aid in the indirect identification of prehistoric remains and the understanding of their cultural, social, and physical relationships, as well as to assist forensic odontologists with craniofacial identification and skull bone reconstruction.

Characterization of the Flagellar Collar Reveals Structural Plasticity Essential for Spirochete Motility

Many spirochetes cause serious human diseases. They are well recognized by their distinct morphology and motility.

Characterization of the flagellar collar reveals structural plasticity essential for spirochete motility

Spirochetes are a remarkable group of bacteria with distinct morphology and periplasmic flagella that enable motility in viscous environments, such as host connective tissues. The collar, a spirochete-specific complex of the periplasmic flagellum, is required for the unique spirochete motility, yet it has not been clear how the collar assembles and enables spirochetes to transit between complex host environments. Here, we characterize the collar complex in the Lyme disease spirochete Borrelia burgdorferi. We discover as well as delineate the distinct functions of two novel collar proteins, FlcB and FlcC, by combining subtractive bioinformatic, genetic, and cryo-electron tomography approaches. Our high-resolution in-situ structures reveal that the multi-protein collar has a remarkable structural plasticity essential not only for assembly of flagellar motors in the highly curved membrane of spirochetes but also for generation of the high torque necessary for spirochete motility.

Exogenous pigments shield microorganisms from spaceflight-induced changes

Research has indicated that pigments commonly produced by microorganisms may be protective against the environmental stresses inherent to spaceflight. However, few studies have directly tested the protective capabilities of microbial pigments applied externally as shielding materials. In this study, liquid cultures of Bacillus subtilis were shielded by various pigment solutions, and solid media cultures of Bacillus subtilis were co-inoculated with the highly pigmented microorganisms Aspergillus niger and Neurospora crassa. These experiments were conducted in a compact, automated payload aboard the International Space Station (ISS) interior for 30 days. Post-flight phenotypic analyses of liquid cultures showed that solutions of carotenoid pigments were effective at minimizing detrimental effects of spaceflight. Elevated growth rate was observed for solid cultures, and distinct morphology changes were identified in both liquid and solid samples and quantified as markers of spaceflight-induced stress. These findings collectively progress our understanding of microbial pigments for the development of space-related applications.

A new species of Lepiota (Agaricaceae) from Punjab, Pakistan

During our surveys of fungi of some areas adjacent to the Cholistan desert, Punjab, Pakistan, we collected a new species in Lepiota sect. Echinatae. It was found on loamy soil under Vachellia nilotica and is described and illustrated as new based on the distinct morphology and ITS nrDNA analysis. The new species, Lepiota haroonabadensis, is characterized macroscopically by a light yellowish orange pileus covered with brown squarrose scales, bright yellowish to yellowish red stipe with pale yellow spiny scales, and rudimentary annulus; and microscopically by ellipsoid basidiospores, narrowly clavate to clavate cheilocystidia, cylindrical to sub-cylindrical or ellipsoidal elements of the pileus covering and cylindrical to globose elements of the stipe covering. A full description, color photos, line illustrations and a phylogenetic tree to show the position of the new species are provided.

Arachis inflata: A New B Genome species of Arachis (Fabaceae)

Great efforts have been done to collect germplasm of the Arachis genus in South America, however, many regions still remain underexplored. Under the hypothesis that these regions have new and diverse populations/species of Arachis, several expeditions were carried out since 2000 in Bolivia, to increase the documentation of the genus diversity. As a first result of these explorations, a new species of section Arachis with B genome is formally described. Arachis inflata is closely related to A. magna and A. ipaënsis, but it can be clearly distinguished from them, and from any other species of the genus, for having a type of fruit with a completely distinct morphology. The fruit has a smooth epicarp, but shows a bullated aspect, due to the presence of air chambers in the mesocarp.

Retroperitoneal Sclerosing Angiomyolipoma with Long-Term Follow up: A Case Report with Unique Clinicopathologic and Genomic Profile

Sclerosing angiomyolipoma (sAML) is a rare variant of the perivascular epithelioid tumors exhibiting distinct morphology with extensive stromal hyalinization, which makes it challenging to recognize. It often lacks an adipose tissue component and melanocytic markers may be expressed only focally, further posing a diagnostic challenge. Here, we report a case of sAML of the left pararenal retroperitoneum in a 52-year-old woman with 92 months of clinical follow up and discuss the histologic features, immunoprofile, molecular alterations, and differential diagnoses that can aid in the diagnosis of this unique and rare entity.

Maturation of Human Long-lived Plasma Cells Results in Resistance to Apoptosis by Transcriptional and Epigenetic Regulation

Antibody secreting cells (ASC) circulate after vaccination and migrate to the bone marrow (BM) where a subset known as long-lived plasma cells (LLPC) persist and secrete antibodies for a lifetime. The mechanisms of how circulating ASC become LLPC are not well elucidated. Here, we show that human blood ASCs have distinct morphology, transcriptomes, and epigenetics compared to BM LLPC. LLPC acquire transcriptional and epigenetic changes in the apoptosis pathway to support their survival. Upregulation of pro-survival gene expression accompanies downregulation of pro-apoptotic gene expression in LLPC. While pro-apoptotic gene loci are less accessible, pro-survival gene loci are not always accompanied by accessibility changes. Importantly, we show similar LLPC morphological and transcriptional maturation of blood ASC in response to the novel in vitro BM mimetic. In all, our study demonstrates that blood ASC in the BM microniche must undergo morphological and molecular changes to mature into apoptotic-resistant LLPC.