T Cell Activators Exhibit Distinct Downstream Effects on Chimeric Antigen Receptor T Cell Phenotype and Function.

T cell activation is an essential step in chimeric Ag receptor (CAR) T (CAR T) cell manufacturing and is accomplished by the addition of activator reagents that trigger the TCR and provide costimulation. We explore several T cell activation reagents and examine their effects on key attributes of CAR T cell cultures, such as activation/exhaustion markers, cell expansion, gene expression, and transduction efficiency. Four distinct activators were examined, all using anti-CD3 and anti-CD28, but incorporating different mechanisms of delivery: Dynabeads (magnetic microspheres), TransAct (polymeric nanomatrix), Cloudz (alginate hydrogel), and Microbubbles (lipid membrane containing perfluorocarbon gas). Clinical-grade lentiviral vector was used to transduce cells with a bivalent CD19/CD22 CAR, and cell counts and flow cytometry were used to monitor the cells throughout the culture. We observed differences in CD4/CD8 ratio when stimulating with the Cloudz activator, where there was a significant skewing toward CD8 T cells. The naive T cell subset expressing CD62L+CCR7+CD45RA+ was the highest in all donors when stimulating with Dynabeads, whereas effector/effector memory cells were highest when using the Cloudz. Functional assays demonstrated differences in killing of target cells and proinflammatory cytokine secretion, with the highest killing from the Cloudz-stimulated cells among all donors. This study demonstrates that the means by which these stimulatory Abs are presented to T cells contribute to the activation, resulting in differing effects on CAR T cell function. These studies highlight important differences in the final product that should be considered when manufacturing CAR T cells for patients in the clinic.

CAR-T cell expansion platforms yield distinct T cell differentiation states.

With investigators looking to expand engineered T cell therapies such as CAR-T to new tumor targets and patient populations, a variety of cell manufacturing platforms have been developed to scale manufacturing capacity using closed and/or automated systems. Such platforms are particularly useful for solid tumor targets, which typically require higher CAR-T cell doses. Although T cell phenotype and function are key attributes that often correlate with therapeutic efficacy, how manufacturing platforms influence the final CAR-T cell product is currently unknown. We compared 4 commonly used T cell manufacturing platforms (CliniMACS Prodigy, Xuri W25 rocking platform, G-Rex gas-permeable bioreactor, static bag culture) using identical media, stimulation, culture length, and donor starting material. Selected CD4+CD8+ cells were transduced with lentiviral vector incorporating a CAR targeting FGFR4, a promising target for pediatric sarcoma. We observed significant differences in overall expansion over the 14-day culture; bag cultures had the highest capacity for expansion while the Prodigy had the lowest (481-fold versus 84-fold, respectively). Strikingly, we also observed considerable differences in the phenotype of the final product, with the Prodigy significantly enriched for CCR7+CD45RA+ naïve/stem central memory (Tn/scm)-like cells at 46% compared to bag and G-Rex with 16% and 13%, respectively. Gene expression analysis also showed that Prodigy CAR-Ts are more naïve, less cytotoxic and less exhausted than bag, G-Rex, and Xuri CAR-Ts, and pointed to differences in cell metabolism that were confirmed via metabolic assays. We hypothesized that dissolved oxygen level, which decreased substantially during the final 3 days of the Prodigy culture, may contribute to the observed differences in T cell phenotype. By culturing bag and G-Rex cultures in 1% O2 from day 5 onward, we could generate >60% Tn/scm-like cells, with longer time in hypoxia correlating with a higher percentage of Tn/scm-like cells. Intriguingly, our results suggest that oxygenation is responsible, at least in part, for observed differences in T cell phenotype among bioreactors and suggest hypoxic culture as a potential strategy prevent T cell differentiation during expansion. Ultimately, our study demonstrates that selection of bioreactor system may have profound effects not only on the capacity for expansion, but also on the differentiation state of the resulting CAR-T cells.

No correlative evidence of costs of infection or immunity on leucocyte telomere length in a wild population of Soay sheep.

Telomere length (TL) is a biomarker hypothesized to capture evolutionarily and ecologically important physiological costs of reproduction, infection and immunity. Few studies have estimated the relationships among infection status, immunity, TL and fitness in natural systems. The hypothesis that short telomeres predict reduced survival because they reflect costly consequences of infection and immune investment remains largely untested. Using longitudinal data from a free-living Soay sheep population, we tested whether leucocyte TL was predicted by infection with nematode parasites and antibody levels against those parasites. Helminth parasite burdens were positively associated with leucocyte TL in both lambs and adults, which is not consistent with TL reflecting infection costs. We found no association between TL and helminth-specific IgG levels in either young or old individuals which suggests TL does not reflect costs of an activated immune response or immunosenescence. Furthermore, we found no support for TL acting as a mediator of trade-offs between infection, immunity and subsequent survival in the wild. Our results suggest that while variation in TL could reflect short-term variation in resource investment or environmental conditions, it does not capture costs of infection and immunity, nor does it behave like a marker of an individual's helminth-specific antibody immune response.

Manufacture of CD22 CAR T cells following positive versus negative selection results in distinct cytokine secretion profiles and γδ T cell output.

Chimeric antigen receptor T cells (CART) have demonstrated curative potential for hematological malignancies, but the optimal manufacturing has not yet been determined and may differ across products. The first step, T cell selection, removes contaminating cell types that can potentially suppress T cell expansion and transduction. While positive selection of CD4/CD8 T cells after leukapheresis is often used in clinical trials, it may modulate signaling cascades downstream of these co-receptors; indeed, the addition of a CD4/CD8-positive selection step altered CD22 CART potency and toxicity in patients. While negative selection may avoid this drawback, it is virtually absent from good manufacturing practices. Here, we performed both CD4/CD8-positive and -negative clinical scale selections of mononuclear cell apheresis products and generated CD22 CARTs per our ongoing clinical trial (NCT02315612NCT02315612). While the selection process did not yield differences in CART expansion or transduction, positively selected CART exhibited a significantly higher in vitro interferon-γ and IL-2 secretion but a lower in vitro tumor killing rate. Notably, though, CD22 CART generated from both selection protocols efficiently eradicated leukemia in NSG mice, with negatively selected cells exhibiting a significant enrichment in γδ CD22 CART. Thus, our study demonstrates the importance of the initial T cell selection process in clinical CART manufacturing.

Breast, Prostate, Colorectal, and Lung Cancer Incidence and Risk Factors in Women Who Have Sex with Women and Men Who Have Sex with Men: A Cross-Sectional and Longitudinal Analysis Using UK Biobank.

BACKGROUND: There is limited evidence about cancer incidence for lesbian, gay and bisexual women and men, although the prevalence of cancer risk factors may be higher. AIM: To describe cancer incidence for four common cancers (breast, lung, colorectal and prostate). METHODS: This project used UK Biobank participant data. We explored risk factor prevalence (age, deprivation, ethnicity, smoking, alcohol intake, obesity, parity, and sexual history), and calculated cancer risk, for six groups defined based on sexual history; women who have sex exclusively with men (WSEM), or women (WSEW), women who have sex with men and women (WSWM); men who have sex exclusively with women (MSEW), or men (MSEM), and men who have sex with women and men (MSWM). RESULTS: WSEW, WSWM, MSEM, and MSMW were younger, more likely to smoke, and to live in more deprived neighbourhoods. We found no evidence of an association between sexual history and breast, colorectal, or prostate cancer in age-adjusted models. Lung cancer incidence was higher for WSWM compared with WSEM, HR (95%CI) 1.78 (1.28-2.48), p = 0.0005, and MSWM compared with MSEW, 1.43 (1.03-1.99), p = 0.031; after adjustment for smoking, this difference was no longer significant. CONCLUSIONS: Sexual minority groups have a higher risk for lung cancer, due to greater exposure to smoking.

Optimizing a fully automated and closed system process for red blood cell reduction of human bone marrow products.

BACKGROUND AIMS: Hematopoietic stem cell transplantation using bone marrow as the graft source is a common treatment for hematopoietic malignancies and disorders. For allogeneic transplants, processing of bone marrow requires the depletion of ABO-mismatched red blood cells (RBCs) to avoid transfusion reactions. Here the authors tested the use of an automated closed system for depleting RBCs from bone marrow and compared the results to a semi-automated platform that is more commonly used in transplant centers today. The authors found that fully automated processing using the Sepax instrument (Cytiva, Marlborough, MA, USA) resulted in depletion of RBCs and total mononuclear cell recovery that were comparable to that achieved with the COBE 2991 (Terumo BCT, Lakewood, CO, USA) semi-automated process. METHODS: The authors optimized the fully automated and closed Sepax SmartRedux (Cytiva) protocol. Three reduction folds (10×, 12× and 15×) were tested on the Sepax. Each run was compared with the standard processing performed in the authors' center on the COBE 2991. Given that bone marrow is difficult to acquire for these purposes, the authors opted to create a surrogate that is more easily obtainable, which consisted of cryopreserved peripheral blood stem cells that were thawed and mixed with RBCs and supplemented with Plasma-Lyte A (Baxter, Deerfield, IL, USA) and 4% human serum albumin (Baxalta, Westlake Village, CA, USA). This "bone marrow-like" product was split into two starting products of approximately 600 mL, and these were loaded onto the COBE and Sepax for direct comparison testing. Samples were taken from the final products for cell counts and flow cytometry. The authors also tested a 10× Sepax reduction using human bone marrow supplemented with human liquid plasma and RBCs. RESULTS: RBC reduction increased as the Sepax reduction rate increased, with an average of 86.06% (range of 70.85-96.39%) in the 10×, 98.80% (range of 98.1-99.5%) in the 12× and 98.89% (range of 98.80-98.89%) in the 15×. The reduction rate on the COBE ranged an average of 69.0-93.15%. However, white blood cell (WBC) recovery decreased as the Sepax reduction rate increased, with an average of 47.65% (range of 38.9-62.35%) in the 10×, 14.56% (range of 14.34-14.78%) in the 12× and 27.97% (range of 24.7-31.23%) in the 15×. COBE WBC recovery ranged an average of 53.17-76.12%. Testing a supplemented human bone marrow sample using a 10× Sepax reduction resulted in an average RBC reduction of 84.22% (range of 84.0-84.36%) and WBC recovery of 43.37% (range of 37.48-49.26%). Flow cytometry analysis also showed that 10× Sepax reduction resulted in higher purity and better recovery of CD34+, CD3+ and CD19+ cells compared with 12× and 15× reduction. Therefore, a 10× reduction rate was selected for the Sepax process. CONCLUSIONS: The fully automated and closed SmartRedux program on the Sepax was shown to be effective at reducing RBCs from "bone marrow-like" products and a supplemented bone marrow product using a 10× reduction rate.

The association between female reproductive performance and leukocyte telomere length in wild Soay sheep.

Telomere length (TL), typically measured across a sample of blood cells, has emerged as an exciting potential marker of physiological state and of the costs of investment in growth and reproduction within evolutionary ecology. While there is mounting evidence from studies of wild vertebrates that short TL predicts raised subsequent mortality risk, the relationship between reproductive investment and TL is less clear cut, and previous studies report both negative and positive associations. In this study, we examined the relationship between TL and different aspects of maternal reproductive performance in a free-living population of Soay sheep. We find evidence for shorter TL in females that bred, and thus paid any costs of gestation, compared to females that did not breed. However, we found no evidence for any association between TL and litter size. Furthermore, females that invested in gestation and lactation actually had longer TL than females who only invested in gestation because their offspring died shortly after birth. We used multivariate models to decompose these associations into among- and within-individual effects, and discovered that within-individual effects were driving both the negative association between TL and gestation, and the positive association between TL and lactation. This suggests that telomere dynamics may reflect recent physiologically costly investment or variation in physiological condition, depending on the aspect of reproduction being investigated. Our results highlight the physiological complexity of vertebrate reproduction, and the need to better understand how and why different aspects of physiological variation underpinning life histories impact blood cell TL.

Heritable variation in telomere length predicts mortality in Soay sheep.

Telomere length (TL) is considered an important biomarker of whole-organism health and aging. Across humans and other vertebrates, short telomeres are associated with increased subsequent mortality risk, but the processes responsible for this correlation remain uncertain. A key unanswered question is whether TL-mortality associations arise due to positive effects of genes or early-life environment on both an individual's average lifetime TL and their longevity, or due to more immediate effects of environmental stressors on within-individual TL loss and increased mortality risk. Addressing this question requires longitudinal TL and life history data across the entire lifetimes of many individuals, which are difficult to obtain for long-lived species like humans. Using longitudinal data and samples collected over nearly two decades, as part of a long-term study of wild Soay sheep, we dissected an observed positive association between TL and subsequent survival using multivariate quantitative genetic models. We found no evidence that telomere attrition was associated with increased mortality risk, suggesting that TL is not an important marker of biological aging or exposure to environmental stress in our study system. Instead, we find that among-individual differences in average TL are associated with increased lifespan. Our analyses suggest that this correlation between an individual's average TL and lifespan has a genetic basis. This demonstrates that TL has the potential to evolve under natural conditions, and suggests an important role of genetics underlying the widespread observation that short telomeres predict mortality.

Telomere attrition rates are associated with weather conditions and predict productive lifespan in dairy cattle.

Telomere length is predictive of adult health and survival across vertebrate species. However, we currently do not know whether such associations result from among-individual differences in telomere length determined genetically or by early-life environmental conditions, or from differences in the rate of telomere attrition over the course of life that might be affected by environmental conditions. Here, we measured relative leukocyte telomere length (RLTL) multiple times across the entire lifespan of dairy cattle in a research population that is closely monitored for health and milk production and where individuals are predominantly culled in response to health issues. Animals varied in their change in RLTL between subsequent measurements and RLTL shortened more during early life and following hotter summers which are known to cause heat stress in dairy cows. The average amount of telomere attrition calculated over multiple repeat samples of individuals predicted a shorter productive lifespan, suggesting a link between telomere loss and health. TL attrition was a better predictor of when an animal was culled than their average TL or the previously for this population reported significant TL at the age of 1 year. Our present results support the hypothesis that TL is a flexible trait that is affected by environmental factors and that telomere attrition is linked to animal health and survival traits. Change in telomere length may represent a useful biomarker in animal welfare studies.

Short-term telomere dynamics is associated with glucocorticoid levels in wild populations of roe deer.

While evidence that telomere length is associated with health and mortality in humans and birds is accumulating, a large body of research is currently seeking to identify factors that modulate telomere dynamics. We tested the hypothesis that high levels of glucocorticoids in individuals under environmental stress should accelerate telomere shortening in two wild populations of roe deer (Capreolus capreolus) living in different ecological contexts. From two consecutive annual sampling sessions, we found that individuals with faster rates of telomere shortening had higher concentrations of fecal glucocorticoid metabolites, suggesting a functional link between glucocorticoid levels and telomere attrition rate. This relationship was consistent for both sexes and populations. This finding paves the way for further studies of the fitness consequences of exposure to environmental stressors in wild vertebrates.

The Genetic Architecture of Bovine Telomere Length in Early Life and Association With Animal Fitness.

Health and survival are key goals for selective breeding in farm animals. Progress, however, is often limited by the low heritability of these animal fitness traits in addition to measurement difficulties. In this respect, relevant early-life biomarkers may be useful for breeding purposes. Telomere length (TL), measured in leukocytes, is a good candidate biomarker since TL has been associated with health, ageing, and stress in humans and other species. However, telomere studies are very limited in farm animals. Here, we examined the genetic background, genomic architecture, and factors affecting bovine TL measurements in early life, and the association of the latter with animal fitness traits expressed later in life associated with survival, longevity, health, and reproduction. We studied two TL measurements, one at birth (TLB) and another during the first lactation (TLFL) of a cow. We performed a genome-wide association study of dairy cattle TL, the first in a non-human species, and found that TLB and TLFL are complex, polygenic, moderately heritable, and highly correlated traits. However, genomic associations with distinct chromosomal regions were identified for the two traits suggesting that their genomic architecture is not identical. This is reflected in changes in TL throughout an individual's life. TLB had a significant association with survival, length of productive life and future health status of the animal, and could be potentially used as an early-life biomarker for disease predisposition and longevity in dairy cattle.

Bovine telomere dynamics and the association between telomere length and productive lifespan.

Average telomere length (TL) in blood cells has been shown to decline with age in a range of vertebrate species, and there is evidence that TL is a heritable trait associated with late-life health and mortality in humans. In non-human mammals, few studies to date have examined lifelong telomere dynamics and no study has estimated the heritability of TL, despite these being important steps towards assessing the potential of TL as a biomarker of productive lifespan and health in livestock species. Here we measured relative leukocyte TL (RLTL) in 1,328 samples from 308 Holstein Friesian dairy cows and in 284 samples from 38 female calves. We found that RLTL declines after birth but remains relatively stable in adult life. We also calculated the first heritability estimates of RLTL in a livestock species which were 0.38 (SE = 0.03) and 0.32 (SE = 0.08) for the cow and the calf dataset, respectively. RLTL measured at the ages of one and five years were positively correlated with productive lifespan (p < 0.05). We conclude that bovine RLTL is a heritable trait, and its association with productive lifespan may be used in breeding programmes aiming to enhance cow longevity.

Longitudinal changes in telomere length and associated genetic parameters in dairy cattle analysed using random regression models.

Telomeres cap the ends of linear chromosomes and shorten with age in many organisms. In humans short telomeres have been linked to morbidity and mortality. With the accumulation of longitudinal datasets the focus shifts from investigating telomere length (TL) to exploring TL change within individuals over time. Some studies indicate that the speed of telomere attrition is predictive of future disease. The objectives of the present study were to 1) characterize the change in bovine relative leukocyte TL (RLTL) across the lifetime in Holstein Friesian dairy cattle, 2) estimate genetic parameters of RLTL over time and 3) investigate the association of differences in individual RLTL profiles with productive lifespan. RLTL measurements were analysed using Legendre polynomials in a random regression model to describe TL profiles and genetic variance over age. The analyses were based on 1,328 repeated RLTL measurements of 308 female Holstein Friesian dairy cattle. A quadratic Legendre polynomial was fitted to the fixed effect of age in months and to the random effect of the animal identity. Changes in RLTL, heritability and within-trait genetic correlation along the age trajectory were calculated and illustrated. At a population level, the relationship between RLTL and age was described by a positive quadratic function. Individuals varied significantly regarding the direction and amount of RLTL change over life. The heritability of RLTL ranged from 0.36 to 0.47 (SE = 0.05-0.08) and remained statistically unchanged over time. The genetic correlation of RLTL at birth with measurements later in life decreased with the time interval between samplings from near unity to 0.69, indicating that TL later in life might be regulated by different genes than TL early in life. Even though animals differed in their RLTL profiles significantly, those differences were not correlated with productive lifespan (p = 0.954).

Sex differences in leucocyte telomere length in a free-living mammal.

Mounting evidence suggests that average telomere length reflects previous stress and predicts subsequent survival across vertebrate species. In humans, leucocyte telomere length (LTL) is consistently shorter during adulthood in males than in females, although the causes of this sex difference and its generality to other mammals remain unknown. Here, we measured LTL in a cross-sectional sample of free-living Soay sheep and found shorter telomeres in males than in females in later adulthood (>3 years of age), but not in early life. This observation was not related to sex differences in growth or parasite burden, but we did find evidence for reduced LTL associated with increased horn growth in early life in males. Variation in LTL was independent of variation in the proportions of different leucocyte cell types, which are known to differ in telomere length. Our results provide the first evidence of sex differences in LTL from a wild mammal, but longitudinal studies are now required to determine whether telomere attrition rates or selective disappearance are responsible for these observed differences.

Descriptive study of older adults encountered by crisis intervention team (CIT) law enforcement officers.

Increasingly, older adults who experience a mental health crisis come to the attention of crisis intervention team (CIT) law enforcement officers. These encounters are due largely to a lack of local mental health care resources. With few options available, individuals call 911 for assistance when an older adult exhibits alarming behavior. This article provides a profile of older adults encountered by CIT officers, identifies the reasons for the 911 call for assistance, and finds what predictors are associated with outcomes of those encounters. We found that these older adults were mostly female, Caucasian, diagnosed with depression, and attempting or threatening suicide.

Method Specific Calibration Corrects for DNA Extraction Method Effects on Relative Telomere Length Measurements by Quantitative PCR.

Telomere length (TL) is increasingly being used as a biomarker in epidemiological, biomedical and ecological studies. A wide range of DNA extraction techniques have been used in telomere experiments and recent quantitative PCR (qPCR) based studies suggest that the choice of DNA extraction method may influence average relative TL (RTL) measurements. Such extraction method effects may limit the use of historically collected DNA samples extracted with different methods. However, if extraction method effects are systematic an extraction method specific (MS) calibrator might be able to correct for them, because systematic effects would influence the calibrator sample in the same way as all other samples. In the present study we tested whether leukocyte RTL in blood samples from Holstein Friesian cattle and Soay sheep measured by qPCR was influenced by DNA extraction method and whether MS calibration could account for any observed differences. We compared two silica membrane-based DNA extraction kits and a salting out method. All extraction methods were optimized to yield enough high quality DNA for TL measurement. In both species we found that silica membrane-based DNA extraction methods produced shorter RTL measurements than the non-membrane-based method when calibrated against an identical calibrator. However, these differences were not statistically detectable when a MS calibrator was used to calculate RTL. This approach produced RTL measurements that were highly correlated across extraction methods (r > 0.76) and had coefficients of variation lower than 10% across plates of identical samples extracted by different methods. Our results are consistent with previous findings that popular membrane-based DNA extraction methods may lead to shorter RTL measurements than non-membrane-based methods. However, we also demonstrate that these differences can be accounted for by using an extraction method-specific calibrator, offering researchers a simple means of accounting for differences in RTL measurements from samples extracted by different DNA extraction methods within a study.

Riverine Bacterial Communities Reveal Environmental Disturbance Signatures within the Betaproteobacteria and Verrucomicrobia.

Riverine bacterial communities play an essential role in the biogeochemical coupling of terrestrial and marine environments, transforming elements and organic matter in their journey from land to sea. However, precisely due to the fact that rivers receive significant terrestrial input, the distinction between resident freshwater taxa vs. land-derived microbes can often become ambiguous. Furthermore, ecosystem perturbations could introduce allochthonous microbial groups and reshape riverine bacterial communities. Using full- and partial-length 16S ribosomal RNA gene sequences, we analyzed the composition of bacterial communities in the Tar River of North Carolina from November 2010 to November 2011, during which a natural perturbation occurred: the inundation of the lower reaches of an otherwise drought-stricken river associated with Hurricane Irene, which passed over eastern North Carolina in late August 2011. This event provided the opportunity to examine the microbiological, hydrological, and geochemical impacts of a disturbance, defined here as the large freshwater influx into the Tar River, superimposed on seasonal changes or other ecosystem variability independent of the hurricane. Our findings demonstrate that downstream communities are more taxonomically diverse and temporally variable than their upstream counterparts. More importantly, pre- vs. post-disturbance taxonomic comparison of the freshwater-dominant Betaproteobacteria class and the phylum Verrucomicrobia reveal a disturbance signature of previously undetected taxa of diverse origins. We use known traits of closely-related taxa to interpret the ecological function of disturbance-associated bacteria, and hypothesize that carbon cycling was enhanced post-disturbance in the Tar River, likely due to the flux of organic carbon into the system associated with the large freshwater pulse. Our analyses demonstrate the importance of geochemical and hydrological alterations in structuring bacterial communities, and illustrate the response of temperate riverine bacteria on fine taxonomic scales to a disturbance.

Developing Enterprise Skills in Undergraduate Medical Students: A Mixed-methods Evaluation.

INTRODUCTION: Support for the development of enterprise skills in medical education exists from the perspectives of educators, researchers, and healthcare leaders. However, literature is limited evaluating the understanding of medical students about these skills. This study aimed to determine whether medical students valued gaining enterprise skills within the course and those skills that they identified and recognized contributed to enterprise practice in subsequent training. METHODOLOGY: Quantitative and qualitative evaluations were undertaken for over three years. Students completed end-of-course evaluations (n = 895) in 2011 and 2012, responding to closed questions utilizing a Likert scale. Subsequent qualitative reflections were collected by interviews one year later with nine students and eight supervisors. RESULTS: Immediately after course completion, students gave positive feedback, identifying the development of independent learning, creativity, and reflection, as these enterprise skills were most valued. However, in subsequent reflection one year later, they were unable to transfer the acquired knowledge and identify the examples of enterprise around them in their later experiences and had mixed beliefs about its value in medicine. CONCLUSION: Enterprise skills need to be revisited explicitly throughout the medical curriculum, with authentic real-life examples, to sustain students' understanding about the role of enterprise in medicine.

Subtypes of non-suicidal self-injury based on childhood adversity.

The aim of this study was to examine the latent clusters in non-suicidal self-injury (NSSI) based on childhood adversity. Data were derived from Waves I (2001-2002) and II (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative sample of U.S. adults. Individuals engaging in NSSI (N = 672) comprised the analytic sample. Latent class statistical analysis was undertaken to elucidate the latent structure of NSSI based on child experiences of physical and sexual abuse, neglect, and family violence. Four-classes of respondents were identified vis-à-vis childhood adversities. A low abuse/neglect class (35.7% of respondents, 91.1% male) demonstrated less mental health and substance use comorbidity and antisocial behavior. A sexual abuse class (43.1% of respondents, 98.6% female) evinced somewhat lower levels of antisocial behavior than the other classes but similarly high levels of mental health disorder and a non-sexual abuse/neglect class (8.3% of respondents, 91.5% male) characterized by varied and intensive forms of antisocial and externalizing behaviors. Finally, a severe high abuse/neglect/family violence class (12.95% of respondents, 100% female) demonstrated high levels of clinical psychiatric and personality disorders. The current project is a nationally representative study of NSSI latent clusters and extends and validates the existence of NSSI subtypes revealed by prior research.