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Biology subjects

Abegglen, L. M.

Publications and source records attributed to Abegglen, L. M..

5 recordsLinked to original sources

Immune-cancer analyses across mammals reveal a potential trophic level and platelet-linked tradeoff between cancer and trauma mortality

There may be fitness tradeoffs between wound healing, immune responses, and cancer development due to shared pathways, limited resources and conflicting selective pressures. The immune system is important in both response to injury and carcinogenesis. We initially investigated correlations between cancer prevalence and immune cells, controlling for known associations with body mass and lifespan. We analyzed data from 216 mammalian species from at least 20 individuals per species. Body mass correlated positively with segmented neutrophil-to-lymphocyte ratios and negatively with lymphocyte concentrations. However, only platelet concentration correlated (negatively) with cancer prevalence (P-value = 0.006). To further understand this association, we investigated whether a fitness tradeoff could exist between preventing death from cancer versus injury. We discovered a negative correlation between cancer and trauma mortalities (P-value [≤] 0.0006), even when we accounted for the fact that different causes of death must sum to 100%. Platelet size and trophic level negatively correlated with trauma mortality, but not when controlling for cancer mortality (P-value = 0.06). If trauma mortality is an indirect measure of wound healing, this suggests a fitness tradeoff may exist between cancer suppression and wound healing across mammals, mediated in part through platelet size and trophic level.

evolutionary biology↗

Neutrophil extracellular traps offer a new therapeutic target for elephant endotheliotropic herpes hemorrhagic disease (EEHV-HD)

Elephant survival is threatened by a devastating hemorrhagic disease called elephant endotheliotropic herpes virus-hemorrhagic disease (EEHV-HD). Once clinical signs are observed in elephants, the disease progresses rapidly and frequently results in death. EEHV-HD negatively impacts elephant conservation because very young, reproductively immature elephants are most at risk for death. Ongoing efforts to understand disease pathogenesis and progression may identify treatment targets and improve clinical outcomes. In some lethal EEHV-HD cases, microthrombosis has been observed in organ tissues similar to other hemorrhagic diseases in humans and animals where sticky webs of protein-coated DNA strands called neutrophil extracellular traps (NETs) exacerbate thrombosis and hemorrhage associated with disseminated intravascular coagulation (DIC). In this study, we sought to identify if NET formation occurs in elephants and could contribute to poor outcomes in EEHV-HD. Our study demonstrated NET release for the first time from elephant heterophils (neutrophils) that occurred in response to various stimuli, including plasma from EEHV-HD affected elephants. EEHV-HD affected tissues contained extensive NETs suggesting that dysregulated NET formation contributes to pathogenesis of this disease. Importantly, elephant neutrophils were blocked from releasing NETs in response to EEHV-HD plasma using known NET inhibitors. The ability to stop NETs in EEHV-HD offers a new therapeutic approach that could be combined with current therapies to improve survival for affected elephants and to positively impact conservation efforts.

immunology↗

AI-powered pan-species computational pathology: bridging clinic and wildlife care

Cancers occur across species. Understanding what is consistent and varies across species can provide new insights into cancer initiation and evolution, with significant implications for animal welfare and wildlife conservation. We built the pan-species cancer digital pathology atlas (PANCAD) and conducted the first pan-species study of computational comparative pathology using a supervised convolutional neural network algorithm trained on human samples. The artificial intelligence algorithm achieves high accuracy in measuring immune response through single-cell classification for two transmissible cancers (canine transmissible venereal tumour, 0.94; Tasmanian devil facial tumour disease, 0.88). Furthermore, in 18 other vertebrate species (mammalia=11, reptilia=4, aves=2, and amphibia=1), accuracy (0.57-0.94) was influenced by cell morphological similarity preserved across different taxonomic groups, tumour sites, and variations in the immune compartment. A new metric, named morphospace overlap, was developed to guide veterinary pathologists towards rational deployment of this technology on new samples. This study provides the foundation and guidelines for transferring artificial intelligence technologies to veterinary pathology based on a new understanding of morphological conservation, which could vastly accelerate new developments in veterinary medicine and comparative oncology.

cancer biology↗

What p53 sees: ATM and ATR activation through crosstalk between DNA damage response pathways

1Cells losing the ability to self-regulate in response to damage is a hallmark of cancer. When a cell encounters damage, regulatory pathways estimate the severity of damage and promote repair, cell cycle arrest, or apoptosis. This decision-making process would be remarkable if it were based on the total amount of damage in the cell, but because damage detection pathways vary in the rate and intensity with which they promote pro-apoptotic factors, the cells real challenge is to reconcile dissimilar signals. Crosstalk between repair pathways, crosstalk between pro-apoptotic signaling kinases, and signals induced by damage byproducts complicate the process further. The cells response to{gamma} and UV radiation neatly illustrates this concept. While these forms of radiation produce lesions associated with two different pro-apoptotic signaling kinases, ATM and ATR, recent experiments show that ATM and ATR react to both forms of radiation. To simulate the pro-apoptotic signal induced by{gamma} and UV radiation, we construct a mathematical model that includes three modes of crosstalk between ATM and ATR signaling pathways: positive feedback between ATM/ATR and repair proteins, ATM and ATR mutual upregulation, and changes in lesion topology induced by replication stress or repair. We calibrate the model to agree with 21 experimental claims about ATM and ATR crosstalk. We alter the model by adding or removing specific processes, then examine the effects of each process on ATM/ATR crosstalk by recording which claims the altered model violates. Not only is this the first mathematical model of ATM/ATR crosstalk, its implications provide a strong argument for treating pro-apoptotic signaling as a holistic effort rather than attributing it to a single dominant kinase.

systems biology↗

Elephant genomes reveal insights into differences in disease defense mechanisms between species

Disease susceptibility and resistance comprise important factors in conservation, particularly in elephants. To determine genetic mechanisms underlying disease resistance and other unique elephant traits, we estimated 862 and 1,017 potential regulatory elements in Asian and African elephants, respectively. These elements are significantly enriched in both species with differentially expressed genes involved in immunity pathways, including tumor-necrosis factor which plays a role in the response to elephant endotheliotropic herpesvirus (EEHV). Population genomics analyses indicate that amplified TP53 retrogenes are maintained by purifying selection and may contribute to cancer resistance in elephants, including less malignancies in African vs. Asian elephants. Positive selection scans across elephant genomes revealed genes that may control iconic elephant traits such as tusk development, memory, and somatic maintenance. Our study supports the hypothesis that interspecies variation in gene regulation contributes to differential inflammatory responses leading to increased infectious disease and cancer susceptibility in Asian versus African elephants. Genomics can inform functional immunological studies which may improve both conservation for elephants and human therapies.

evolutionary biology↗