Time-resolved fate mapping identifies the intestinal upper crypt zone as an origin of Lgr5+ crypt base columnar cells.

In the prevailing model, Lgr5+ cells are the only intestinal stem cells (ISCs) that sustain homeostatic epithelial regeneration by upward migration of progeny through elusive upper crypt transit-amplifying (TA) intermediates. Here, we identify a proliferative upper crypt population marked by Fgfbp1, in the location of putative TA cells, that is transcriptionally distinct from Lgr5+ cells. Using a kinetic reporter for time-resolved fate mapping and Fgfbp1-CreERT2 lineage tracing, we establish that Fgfbp1+ cells are multi-potent and give rise to Lgr5+ cells, consistent with their ISC function. Fgfbp1+ cells also sustain epithelial regeneration following Lgr5+ cell depletion. We demonstrate that FGFBP1, produced by the upper crypt cells, is an essential factor for crypt proliferation and epithelial homeostasis. Our findings support a model in which tissue regeneration originates from upper crypt Fgfbp1+ cells that generate progeny propagating bi-directionally along the crypt-villus axis and serve as a source of Lgr5+ cells in the crypt base.

Isthmus progenitor cells contribute to homeostatic cellular turnover and support regeneration following intestinal injury.

The currently accepted intestinal epithelial cell organization model proposes that Lgr5+ crypt-base columnar (CBC) cells represent the sole intestinal stem cell (ISC) compartment. However, previous studies have indicated that Lgr5+ cells are dispensable for intestinal regeneration, leading to two major hypotheses: one favoring the presence of a quiescent reserve ISC and the other calling for differentiated cell plasticity. To investigate these possibilities, we studied crypt epithelial cells in an unbiased fashion via high-resolution single-cell profiling. These studies, combined with in vivo lineage tracing, show that Lgr5 is not a specific ISC marker and that stemness potential exists beyond the crypt base and resides in the isthmus region, where undifferentiated cells participate in intestinal homeostasis and regeneration following irradiation (IR) injury. Our results provide an alternative model of intestinal epithelial cell organization, suggesting that stemness potential is not restricted to CBC cells, and neither de-differentiation nor reserve ISC are drivers of intestinal regeneration.

Somatic and autonomic nerve density and distribution within the clitoris: an immunohistochemical study in adult female cadavers.

INTRODUCTION AND HYPOTHESIS: Knowledge of clitoral neuroanatomy is critical to vulvar surgery. We sought to characterize the density and distribution of autonomic and somatic nerves supplying the clitoris. METHODS: Pelvic tissue harvested from female cadavers was sectioned axially at three anatomic levels: the proximal aspect of the clitoral body (CB), the distal CB, and the glans. The CB, glans, and the surrounding connective tissue (dorsal, lateral, and ventral) were outlined microscopically. An area containing large nerve bundles dorsal to the CB, referred to as the dorsal nerve subregion, was analyzed separately. Double-immunofluorescent staining for beta III tubulin (ßIIIT), a global axonal marker, and myelin basic protein (MBP), a myelinated nerve marker, was performed. Threshold-based automatic image-segmentation distinguished stained areas. Autonomic and somatic density were calculated as percentage of tissue stained with ßIIIT alone, and ßIIIT and MBP respectively. Comparisons were made using nonparametric Friedman tests. RESULTS: Seven cadavers, aged 22-81, were examined. Somatic (mean 4.42%, SD ± 1.97) and autonomic (2.14% ± 2.42) nerve density was highest in the dorsal nerve subregion and dorsal region at the distal CB level. Compared with the CB, somatic density was higher in proximal (0.05% ± 0.03 vs 1.27% ± 0.69, p = 0.03) and distal (0.29% ± 0.25 vs 1.09% ± 0.41, p = 0.05) dorsal regions. Somatic density was greater in the glans than in the surrounding lateral (0.78% ± 0.47 vs 0.43% ± 0.23, p = 0.03) and ventral (0.78% ± 0.47 vs 0.52% ± 0.2, p = 0.03) regions. Autonomic density was greater than somatic in all areas, except for the dorsal nerve subregion. CONCLUSIONS: Somatic and autonomic nerve density were greatest in a well-defined region dorsal to the CB. Surgical preservation of this region is critical for maintaining nerve supply to the clitoris.

Robotic resection of presacral tumors.

BACKGROUND: Presacral tumors are a rare entity typically treated with an open surgical approach. A limited number of minimally invasive resections have been described. The aim of the study is to evaluate the safety and efficacy of roboticresection of presacral tumors. METHODS: This is a retrospective single system analysis, conducted at a quaternary referral academic healthcare system, and included all patients who underwent a robotic excision of a presacral tumor between 2015 and 2023. Outcomes of interest were operative time, estimated blood loss, complications, length of stay, margin status, and recurrence rates. RESULTS: Sixteen patients (11 females and 5 males) were included. The median age of the cohort was 51 years (range 25-69 years). The median operative time was 197 min (range 98-802 min). The median estimated blood loss was 40 ml, ranging from 0 to 1800 ml, with one patient experiencing conversion to open surgery after uncontrolled hemorrhage. Urinary retention was the only postoperative complication that occurred in three patients (19%) and was solved within 30 days in all cases. The median length of stay was one day (range 1-6 days). The median follow-up was 6.7 months (range 1-110 months). All tumors were excised with appropriate margins, but one benign and one malignant tumor recurred (12.5%). Ten tumors were classified as congenital (one was malignant), two were mesenchymal (both malignant), and five were miscellaneous (one malignant). CONCLUSIONS: Robotic resection of select presacral pathology is feasible and safe. Further studies must be conducted to determine complication rates, outcomes, and long-term safety profiles.

Reasons for Nonparticipation in the Special Supplemental Nutrition Program for Women, Infants, and Children.

This cross-sectional study evaluates reasons reported for not participating in or withdrawing participation from the Special Supplemental Nutrition Program for Women, Infants, and Children from 2019 to March 2020.

Predicting Progestin Therapy Response With PTEN, PAX2, and ß-Catenin in Patients With Endometrioid Precancer.

This study investigates the predictive value of biomarkers PTEN, PAX2, and ß-catenin for therapeutic outcomes in patients with atypical endometrial hyperplasia or endometrioid intraepithelial neoplasia undergoing progestin therapy. In a retrospective study of 128 patients, we analyzed a total of 351 endometrial biopsy samples and categorized outcomes into responders (absence of residual disease) and nonresponders (presence of residual disease). We found aberrant biomarker expression in pretreatment cases: 48% for PTEN, 65% for PAX2, and 36% for ß-catenin. Approximately 77.3% of patients responded to progestin treatment, with nonresponders showing significantly higher initial PTEN loss (75.86% vs 39.79%, P < 0.001). Nonresponders also demonstrated significant PTEN loss (53.33% vs 20.55%, P < 0.001), PAX2 loss (57.33% vs 41.22%, P < 0.05), and ß-catenin nuclear staining (53.45% vs 27.91%, P < 0.01) in follow-up samples. In addition, nonresponders exhibited lower recovery of intact PTEN and PAX2, along with higher ß-catenin aberrancy in cases initially showing normal ß-catenin levels. We conclude that persistent aberrant PTEN and PAX2 expression, coupled with emerging aberrant ß-catenin in follow-ups, indicates a greater likelihood of treatment failure. Conversely, the absence of these aberrations suggests successful progestin therapy. Our findings highlight the utility of this 3-marker panel in assessing residual disease status and predicting progestin treatment outcomes, thus offering critical insights for patient management.

Microbial-Dependent Recruitment of Immature Myeloid Cells Promotes Intestinal Regeneration.

BACKGROUND & AIMS: The intestinal epithelium functions both in nutrient absorption and as a barrier, separating the luminal contents from a network of vascular, fibroblastic, and immune cells underneath. After injury to the intestine, multiple cell populations cooperate to drive regeneration of the mucosal barrier, including lymphatic endothelial cells (LECs). A population of granulocytic immature myeloid cells (IMCs), marked by Hdc, participate in regeneration of multiple organs such as the colon and central nervous system, and their contribution to intestinal regeneration was investigated. METHODS: By using male and female histidine decarboxylase (Hdc) green fluorescent reporter (GFP) mice, we investigated the role of Hdc+ IMCs in intestinal regeneration after exposure to 12 Gy whole-body irradiation. The movement of IMCs was analyzed using flow cytometry and immunostaining. Ablation of Hdc+ cells using the HdcCreERT2 tamoxifen-inducible recombinase Cre system, conditional knockout of Prostaglandin-endoperoxidase synthase 2 (Ptgs2) in Hdc+ cells using HdcCre; Ptgs2 floxed mice, and visualization of LECs using Prox1tdTomato mice also was performed. The role of microbial signals was investigated by knocking down mice gut microbiomes using antibiotic cocktail gavages. RESULTS: We found that Hdc+ IMCs infiltrate the injured intestine after irradiation injury and promote epithelial regeneration in part by modulating LEC activity. Hdc+ IMCs express Ptgs2 (encoding cyclooxygenase-2/COX-2), and enables them to produce prostaglandin E2. Prostaglandin E2 acts on the prostaglandin E2 receptor 4 receptor (EP4) on LECs to promote lymphangiogenesis and induce the expression of proregenerative factors including R-spondin 3. Depletion of gut microbes leads to reduced intestinal regeneration by impaired recruitment of IMCs. CONCLUSIONS: Altogether, our results unveil a critical role for IMCs in intestinal repair by modulating LEC activity and implicate gut microbes as mediators of intestinal regeneration.

Somatic and autonomic nerve density of the urethra, periurethral tissue, and anterior vaginal wall: an immunohistochemical study in adult female cadavers.

INTRODUCTION AND HYPOTHESIS: Retropubic procedures may disrupt nerves supplying the pelvic viscera; however, knowledge of pelvic neuroanatomy is limited. We sought to characterize somatic and autonomic nerve density within the urethra, periurethral tissue, and anterior vagina. METHODS: Axial sections were obtained from pelvic tissue harvested from female cadavers ≤24 h from death at three anatomical levels: the midurethra, proximal urethra, and upper trigone. Periurethral/perivesical tissue was divided into medial and lateral sections, and the anterior vagina into middle, medial, and lateral sections. Double immunofluorescent staining for beta III tubulin (ßIIIT), a global axonal marker, and myelin basic protein (MBP), a myelinated nerve marker, was performed. Threshold-based automatic image segmentation distinguished stained areas. Autonomic and somatic density were calculated as percentage of tissue stained with ßIIIT alone, and with ßIIIT and MBP respectively. Statistical comparisons were made using nonparametric Friedman tests. RESULTS: Six cadavers, aged 22-73, were examined. Overall, autonomic nerve density was highest at the midurethral level in the lateral and middle anterior vagina. Somatic density was highest in the external urethral sphincter (midurethra mean 0.15%, SD ±0.11; proximal urethra 0.19%, SD ±0.19). Comparison of annotated sections revealed significant differences in autonomic density among the lateral, medial, and middle vagina at the midurethra level (0.71%, SD ±0.48 vs 0.60%, SD ±0.48 vs 0.70%, SD ±0.63, p=0.03). Autonomic density was greater than somatic density in all sections. CONCLUSIONS: Autonomic and somatic nerves are diffusely distributed throughout the periurethral tissue and anterior vagina, with few significant differences in nerve density among sections analyzed. Minimizing tissue disruption near urethral skeletal muscle critical for urinary continence may prevent adverse postoperative urinary symptoms.

Gluten induces rapid reprogramming of natural memory αß and γδ intraepithelial T cells to induce cytotoxicity in celiac disease.

Celiac disease (CD) is an autoimmune disease in which intestinal inflammation is induced by dietary gluten. The means through which gluten-specific CD4+ T cell activation culminates in intraepithelial T cell (T-IEL)-mediated intestinal damage remain unclear. Here, we performed multiplexed single-cell analysis of intestinal and gluten-induced peripheral blood T cells from patients in different CD states and healthy controls. Untreated, active, and potential CD were associated with an enrichment of activated intestinal T cell populations, including CD4+ follicular T helper (TFH) cells, regulatory T cells (Tregs), and natural CD8+ αß and γδ T-IELs. Natural CD8+ αß and γδ T-IELs expressing activating natural killer cell receptors (NKRs) exhibited a distinct TCR repertoire in CD and persisted in patients on a gluten-free diet without intestinal inflammation. Our data further show that NKR-expressing cytotoxic cells, which appear to mediate intestinal damage in CD, arise from a distinct NKR-expressing memory population of T-IELs. After gluten ingestion, both αß and γδ T cell clones from this memory population of T-IELs circulated systemically along with gluten-specific CD4+ T cells and assumed a cytotoxic and activating NKR-expressing phenotype. Collectively, these findings suggest that cytotoxic T cells in CD are rapidly mobilized in parallel with gluten-specific CD4+ T cells after gluten ingestion.

Immature myeloid cells are indispensable for intestinal regeneration post irradiation injury.

The intestinal epithelium functions both in nutrient absorption and as a barrier, separating the luminal contents from a network of vascular, fibroblastic, and immune cells underneath. Following injury to the intestine, multiple different cell populations cooperate to drive regeneration of the mucosa. Immature myeloid cells (IMCs), marked by histidine decarboxylase ( Hdc ), participate in regeneration of multiple organs such as the colon and central nervous system. Here, we found that IMCs infiltrate the injured intestine and promote epithelial regeneration and modulate LEC activity. IMCs produce prostaglandin E2 (PGE2), which promotes LEC lymphangiogenesis and upregulation of pro-regenerative factors including RSPO3. Moreover, we found that IMC recruitment into the intestine is driven by invading microbial signals. Accordingly, antibiotic eradication of the intestinal microbiome prior to WB-IR inhibits IMC recruitment, and consequently, intestinal recovery. We propose that IMCs play a critical role in intestinal repair and implicate gut microbes as mediators of intestinal regeneration.

Anatomic relationships of the clitoral body, bulbs of the vestibule, and urethra.

BACKGROUND: Although recent studies have enhanced our understanding of the anatomy of the clitoris and its somatic innervation, less emphasis has been placed on the anatomic relationships of the clitoris to its surrounding structures. OBJECTIVE: This study aimed to further characterize the gross and histologic relationships of the clitoris, vestibular bulbs, and urethra. STUDY DESIGN: Detailed dissections were performed in 30 unembalmed female cadavers. In 23 specimens, gross dissections were performed, and relationships of the clitoris, vestibular bulbs, and urethra were annotated. Histologic evaluation was performed in 7 specimens, in which tissues were harvested within 24 hours from death. Descriptive statistics were used for data analyses. RESULTS: The clitoral body consisted of 2 components, the proximal body and the distal body. The distal body was oriented ≤90° from the proximal body, forming an outer and inner angle at the inflection point. A "septumlike" arrangement of fibroconnective and vascular tissues was noted between the inner angle of the clitoral body and the urethra. Neurovascular bundles coursed laterally along the clitoral body and the surfaces of the crura and vestibular bulbs. The vestibular bulbs approached each other over the ventral surface of the urethra, at the commissure of the vestibular bulbs. Each bulb was separated by fibrous tissue and did not merge along the midline. The vestibular bulbs approximated the clitoral body, but the erectile tissue of the vestibular bulbs was separated from the corpora cavernosa of the clitoral body by the tunica albuginea. The erectile tissue of the vestibular bulbs abutted the ventrolateral walls of the urethra but was separated from the urethral mucosa by an indiscrete layer of erectilelike tissue with dense stroma. CONCLUSION: This study provided gross and histological confirmation of the relationships of the clitoris, vestibular bulbs, and urethra. Detailed knowledge of the anatomy of the clitoris is crucial for reducing surgical complications associated with periclitoral and distal urethral procedures, which may adversely affect sexual arousal and sexual function.

Trends in Food Consumption Among Children Aged 1-4 Years by Participation in the Special Supplemental Nutrition Program for Women, Infants, and Children, United States, 2005-2018.

BACKGROUND: In 2009, the US Department of Agriculture Food and Nutrition Service's Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) food packages were revised to include more whole fruits, vegetables, whole grains, and lower-fat milk. OBJECTIVE: The aim of this study was to describe trends over time in the consumption of fruits (total and whole), vegetables, whole grains, milk (whole, reduced fat, low-fat or nonfat (LFNF), and flavored), and added sugars, including breakfast cereals, by WIC participation status (current WIC recipient, WIC income-eligible nonrecipient, and WIC income-ineligible nonrecipient). METHODS: Dietary intakes on a given day for 1- to 4-y-old children (n = 5568) from the 2005-2018 National Health and Nutrition Examination Survey (NHANES) were analyzed to examine trends in the percentage of individuals consuming and amounts consumed over time using linear regression adjusted for age, sex, and race and Hispanic origin. RESULTS: From 2005 through 2018, the percentage of WIC recipients or WIC income-eligible nonrecipients consuming fruits and vegetables on a given day did not change, but the percentage of fruit consumed as whole fruit increased significantly among WIC recipients (36.4%-62.1%), but not among income-eligible nonrecipients. Among the WIC recipients, the percentage of consumption (5.5%-29.3%), the amount of LFNF milk servings consumed (0.1-0.4 cups), and the percentage of the total milk consumed as LFNF milk (4.8%-27%) significantly increased from 2005 to 2018. Conversely, the percentage of energy (12.3%-10.8%) and servings (11.4-10.6 teaspoons) from added sugars declined significantly. Among WIC-eligible nonrecipients, the servings of whole grains increased significantly, whereas servings and percentage of energy from added sugars declined significantly. CONCLUSIONS: From 2005 through 2018, changes in dietary patterns for WIC recipients did not always mirror those of US children of the same age. The percentage of fruit consumed as whole fruit, and the percentage and quantity of milk consumed as LFNF milk increased significantly among WIC recipients, but not among income-eligible nonrecipients. J Nutr 20XX;xx:xx-xx.

The In-Vitro Effect of Homeopathically Prepared Rubus idaeus and 680 nm Laser Irradiation on Cervical Cancer Cells.

BACKGROUND: Cervical cancer (CC) is the second leading cancer in women and is the most common in those aged 15 to 44 years. Medicinal plant extracts have been used as homeopathic preparations for health benefits. Rubus idaeus (RI) is used to treat disorders of the female genital tract and produces cytotoxic effects. However, the use of homeopathically prepared RI in combination with low level laser therapy has not previously been explored. AIM: The study aims to investigate the in-vitro effects of homeopathically prepared RI alone and in combination as a potential photosensitizer with Low-level laser irradiation (LLLI) at fluencies of 5, 10, and 15 J/cm2. METHODS: HeLa CC cells were treated with RI (D3, D6, and 30cH homeopathic preparations). Cells were then treated with RI IC50 and 680 nm laser diode at 5, 10, and 15 J/cm2 fluencies, and the results compared with untreated control cells. Trypan blue viability, lactate dehydrogenase (LDH) cytotoxicity, and adenosine triphosphate (ATP) proliferation assays were used to analyze the cellular dose-responses along with inverted microscopy, Hoechst staining and Annexin-V/PI staining. RESULTS: RI D3 alone demonstrated an ability to reduce cellular viability to 59% and also to reduce ATP levels. The subsequent combined treatment protocol of RI D3 with all fluencies of laser demonstrated an increase in cellular ATP and increased LDH levels compared with the control. CONCLUSION: The increased ATP and LDH levels observed in the combined treatment protocol of 680 nm laser and RI D3 at fluencies of 5, 10 and 15 J/cm2, show that the Warburg effect might have been induced in the CC cells - an increase in glucose uptake and the preferential production of lactate, even in the presence of oxygen. More research, including work on other cell lines, needs to be conducted to identify if RI and perhaps a different wavelength of laser irradiation could have potential in inducing cell death in cancer cells.

Improving Nutrition in the First 1000 Days in the United States: A Federal Perspective.

The first 1000 days begins with pregnancy and ends at the child's second birthday. Nutrition throughout the life course, and especially during the first 1000 days, supports maternal health and optimal growth and development for children. We give a high-level summary of the state of nutrition in the first 1000 days in the United States. We provide examples where continued efforts are needed. We then discuss select opportunities to strengthen federal research and surveillance, programs, and communication and dissemination efforts aimed at improving nutrition and positively, and equitably, influencing the health and well-being of mothers and children. (Am J Public Health. 2022;112(S8):S817-S825. https://doi.org/10.2105/AJPH.2022.307028).

R-SPONDIN2+ mesenchymal cells form the bud tip progenitor niche during human lung development.

The human respiratory epithelium is derived from a progenitor cell in the distal buds of the developing lung. These "bud tip progenitors" are regulated by reciprocal signaling with surrounding mesenchyme; however, mesenchymal heterogeneity and function in the developing human lung are poorly understood. We interrogated single-cell RNA sequencing data from multiple human lung specimens and identified a mesenchymal cell population present during development that is highly enriched for expression of the WNT agonist RSPO2, and we found that the adjacent bud tip progenitors are enriched for the RSPO2 receptor LGR5. Functional experiments using organoid models, explant cultures, and FACS-isolated RSPO2+ mesenchyme show that RSPO2 is a critical niche cue that potentiates WNT signaling in bud tip progenitors to support their maintenance and multipotency.

Anemia Among Pregnant Women Participating in the Special Supplemental Nutrition Program for Women, Infants, and Children - United States, 2008-2018.

Among pregnant women, anemia, a condition of low hemoglobin concentration, can increase risk for maternal and fetal morbidity and mortality, including premature delivery, and other adverse outcomes (1). Iron deficiency is a common cause of anemia, and during pregnancy, iron requirements increase (2). Surveillance of anemia during pregnancy in the United States is limited. The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) Participant and Program Characteristics (PC) data provide an opportunity to establish national and WIC state agency-level* anemia surveillance for WIC participants. National and state agency anemia prevalences among pregnant WIC participants at enrollment were examined using 2008-2018 WIC-PC data. Across all 90 WIC agencies (50 states, the District of Columbia [DC], five territories, and 34 Indian Tribal Organizations), anemia prevalence among pregnant WIC participants at enrollment increased significantly, from 10.1% in 2008 to 11.4% in 2018 (13% increase). Anemia prevalence increased significantly in 36 (64%) of the 56 agencies in states, DC, and territories, and decreased significantly in 11 (20%). Prevalence of anemia overall and by pregnancy trimester were higher among non-Hispanic Black or African American (Black) women than among other racial or ethnic groups. Anemia prevalence was higher among women assessed during the third trimester of pregnancy than among those assessed during first or second trimesters. Routine anemia surveillance using WIC enrollment anemia data can identify groups at higher risk for iron deficiency. Findings from this report indicate that anemia continues to be a problem among low-income women and reinforces the importance of efforts that ensure these women have access to healthier, iron-rich foods before and during pregnancy. This includes ensuring that eligible women are enrolled in WIC early during pregnancy.

Low grade endometrial endometrioid adenocarcinoma: A review and update with emphasis on morphologic variants, mimics, immunohistochemical and molecular features.

Endometrioid adenocarcinoma (ECa) may feature a number of morphologic variations that can pose diagnostic challenge. The purpose of this review and update is to examine the spectrum of morphologic variants and mimics of low-grade (FIGO grades 1 and 2) ECa, with a focus on histologic, immunohistochemical, and molecular features that may inform diagnosis and treatment. In addition to ECa of usual type, variants with unique cytologic and/or architectural features presented include the following: 1) ECa with mucinous differentiation of conventional (Müllerian) type; 2) ECa with squamous differentiation; 3) ECa with morular metaplasia; 4) ECa with patterns resembling cervical transformation zone tissue and/or microglandular hyperplasia; 5) ECa with cytoplasmic clearing; 6) ECa with papillation, including villoglandular variant of ECa, ECa with small nonvillous papillae, and ECa with a "low-grade serous"-like component or surface changes mimicking ovarian serous borderline tumor; 7) corded and hyalinized variant of ECa; 8) ECa with spindled epithelial cells; 9) ECa with sex cord-like pattern; and 10) ECa with other unusual cytologic and associated features. For each variant, relevant differential diagnoses and diagnostic strategies are discussed. The most clinically significant distinctions come into play in the differential diagnosis between low-grade ECa and one of its high-grade mimics. In this setting, the most fundamental tool in the pathologist's diagnostic arsenal is recognition of the low-grade cytologic features typical of low-grade ECa. Circumspect evaluation of cytologic features, complemented by an awareness of the morphologic spectrum, an appropriate battery of immunohistochemical stains when needed, and mindfulness of the clinical scenario, should guide the pathologist to the correct histotype in even challenging cases.

Multiplexed single-cell analysis reveals prognostic and nonprognostic T cell types in human colorectal cancer.

Clinical outcomes in colorectal cancer (CRC) correlate with T cell infiltrates, but the specific contributions of heterogenous T cell types remain unclear. To investigate the diverse function of T cells in CRC, we profiled 37,931 T cells from tumors and adjacent normal colon of 16 patients with CRC with respect to transcriptome, TCR sequence, and cell surface markers. Our analysis identified phenotypically and functionally distinguishable effector T cell types. We employed single-cell gene signatures from these T cell subsets to query the TCGA database to assess their prognostic significance. We found 2 distinct cytotoxic T cell types. GZMK+KLRG1+ cytotoxic T cells were enriched in CRC patients with good outcomes. GNLY+CD103+ cytotoxic T cells with a dysfunctional phenotype were not associated with good outcomes, despite coexpression of CD39 and CD103, markers that denote tumor reactivity. We found 2 distinct Treg subtypes associated with opposite outcomes. While total Tregs were associated with good outcomes, CD38+ Tregs were associated with bad outcomes independently of stage and possessed a highly suppressive phenotype, suggesting that they inhibit antitumor immunity in CRC. These findings highlight the potential utility of these subpopulations in predicting outcomes and support the potential for novel therapies directed at CD38+ Tregs or CD8+CD103+ T cells.