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At least 19 recordsLinked to original sources
PubMed2026

Immune subtyping of colorectal adenoma identifies a subtype with activated adaptive immunity ahead of progressing to cancer.

BACKGROUND: Colorectal adenomas (CRA) represent precursor lesions with varying risks of malignant transformation. However, molecular subtyping, particularly immune-related classification, remains underexplored in adenomas. This study aims to characterize the immune landscape of CRA through immune subtyping and evaluate its association with cancer progression, gene expression signatures, and functional pathways. METHODS: We conducted a retrospective analysis of transcriptomic data from multiple cohorts of CRA samples. Immune subtypes were identified using non-negative matrix factorization (NMF) based on immune-related genes. Diverse deconvolution algorithms were used to estimate immune cell infiltration. The immune status alteration in premalignant lesion was further consolidated by single-cell transcriptome data. Differential gene expression analysis was performed between subtypes, followed by functional enrichment analyses (Gene Ontology [GO] and Kyoto Encyclopedia of Genes and Genomes [KEGG]). RESULTS: Two distinct immune subtypes were identified: an immune-enriched subtype characterized by high lymphocyte infiltration and elevated expression of immune-related genes, and an immune-deficient subtype with suppressed immune activity. Differential expression analysis revealed significant upregulation of immune response genes (e.g., CD4, CD86, HLA-DRA) in the immune-enriched subtype. GO and KEGG analyses highlighted enrichments in leukocyte transendothelial migration, chemokine signaling, and antigen processing and presentation pathways. Single-cell result revealed an early occurrence of TIGIT activation and exhausted CD8 T cell features in adenoma when compared to normal tissue. CONCLUSION: This study delineates distinct immune subtypes within CRAs. The immune-enriched subtype demonstrates activated adaptive immunity and may reflect a higher potential for immune surveillance, while the immune-deficient subtype exhibits stromal features suggestive of progressive transformation. These findings provide insights into early immune microenvironment alterations and may inform strategies for risk stratification and immunoprevention in colorectal carcinogenesis.

Colorectal adenoma↗
PubMed1992

Functional analysis of interferon-alpha subtypes using monoclonal antibodies to interferon-alpha 4a--subtype reactivity, neutralisation of biological activities and epitope analysis.

A panel of monoclonal antibodies (mAb) to a major human interferon-alpha (IFN-alpha) subtype, -alpha 4a, have been produced, characterised and used for studies of structure/function relationships of IFN-alpha subtypes. The mAb were tested for effects on receptor binding of IFN-alpha 4a, reactivity with other major subtypes -alpha 1, -alpha 2b and -alpha 14 by competitive ELISA and western immunoblotting, and for neutralisation of antiviral and antiproliferative activities of the four subtypes. The mAb could be grouped according to reactivity with IFN-alpha subtypes, group I (designated I-4-A) reacted with -alpha 4a and -alpha 2b, group II (I-4-C and I-4-F) reacted with -alpha 4a and -alpha 1, group III (I-4-D), I-4-G and I-4-H) reacted with -alpha 4a only, whereas group IV (I-4-I) reacted with -alpha 4a, -alpha 1 and -alpha 2b. No mAb reacted with IFN-alpha 14. Sequence comparisons of reactive and non-reactive IFN-alpha subtypes, and reactivity patterns with IFN-alpha fragments obtained by Lys-C digestion indicated that the epitopes were located in the N-terminal region (group I), in two regions of the middle of the molecule (group III and IV) and in the C-terminal region (group II). Binding of mAb to any of these four distinct epitopes neutralised the biological activities of IFN-alpha 4a, and in all cases, except I-4-A, inhibited receptor binding. Only the group III mAb bind to an epitope proposed to be in the vicinity of residues 30-40 which are implicated, from in vitro mutagenesis studies, in receptor binding. Binding of mAb to the other 3 epitopes neutralises biological activities by indirect mechanisms. These results emphasise the antigenic diversity between highly homologous IFN-alpha subtypes, which may have a wider functional significance. Individual mAb will have practical applications in the purification and detection of several IFN-alpha subtypes and so facilitate their further characterisation. By virtue of their different mechanisms of neutralisation, this panel of mAb will be useful in further studies of receptor interaction and signal transduction by IFN-alpha, and illustrate principles which are relevant to immunochemical studies of the receptor interactions of other cytokines.

Amino Acid Sequence↗
PubMed1992

Hepatitis B surface antigen particles of subtypes adw and adr, and compound subtype (adwr) in symptom-free carriers in Japan.

Of sera from 1,878 Japanese blood donors who carried hepatitis B surface antigen (HBsAg), 420 were subtyped as adw (22.4%) and 1,443 as adr (76.8%); only 15 (0.8%) contained HBsAg of subtype ayw or ayr. Sera with HBsAg/adr had higher HBsAg titres than those with HBsAg/adw (geometric mean of haemagglutination titre: 10.1 +/- 2.4 vs. 9.7 +/- 2.4, p less than 0.01), and a higher prevalence of hepatitis B e antigen (24% vs. 13%, p less than 0.001). Carriers of HBsAg/adr progressively predominated over those of HBsAg/adw with increasing age. Of sera from 1,863 carriers of HBsAg/adw or HBsAg/adr, 182 (9.8%) contained HBsAg particles with both subtypic determinants in the w/r allele. The presence of w and r determinants on the same particles was ascertained by sandwiching them between monoclonal antibody with the specificity for w and that with the specificity for r. HBsAg particles of compound subtype (adwr) were found more often in sera with hepatitis B e antigen than those without it (145/403 [36.0%] vs. 37/1,460 [2.5%], p less than 0.001). Sera with HBsAg/adwr particles had HBsAg titres higher than those without them (12.4 +/- 1.9 vs. 9.7 +/- 2.3, p less than 0.001). HBsAg/adwr particles arise from phenotypic mixing of the S-gene product of wild-type virus and that of mutants with point mutations for subtypic changes. The results obtained indicated that HBV strains of subtype adr have a higher replicative activity than those of adw, and suggested that mutations in the S gene for subtypic changes would be associated with an active replication of hepatitis B virus.

Adult↗
PubMed1992

Structural subtypes of the dopamine D2 receptor are functionally distinct: expression of the cloned D2A and D2B subtypes in a heterologous cell line.

Dopamine, a major neurotransmitter in the mammalian nervous system, exerts its physiological effects through receptors of the G-protein-coupled receptor superfamily. Two major classes of dopamine receptor, D1 and D2, are distinguishable by both biochemical and pharmacological criteria. D1 receptors activate adenylyl cyclase, whereas the D2 class of receptors inhibits this second messenger system. Two subtypes of the human dopamine D2 receptor are generated by alternate splicing of the RNA transcript of a single gene. These two forms, termed D2A (long) and D2B (short), differ by the insertion of 29 amino acids within the putative third cytoplasmic loop, an intracellular domain thought to have a role in coupling this class of receptors to particular second messenger systems. We report here that the D2A and D2B structural subtypes are also functionally distinct. Expression of the two subtypes in a fibroblast cell line revealed that while occupation of both receptors leads to an increase in cytosolic free calcium concentration, they differ in their capacity to inhibit cAMP production. At physiological dopamine concentrations, the D2B-mediated inhibition of calcitonin gene-related peptide-stimulated cAMP accumulation is almost double the response mediated by the D2A subtype. Furthermore, the D2B subtype can maximally attenuate cAMP accumulation by up to 85%, whereas the D2A subtype is less effective, maximally inhibiting cAMP accumulation by only 64%. The D2A and D2B subtypes, thus, constitute functionally distinct forms of the dopamine receptor that can couple to multiple intracellular signalling pathways.

Animals↗
PubMed2026

Molecular subtyping of adrenocortical carcinoma reveals distinct subtypes with prognostic and therapeutic implications.

Adrenocortical carcinoma (ACC) is a rare but aggressive malignancy with poor survival and limited treatment options. To comprehensively characterize its molecular landscape and identify clinically relevant subtypes, we performed an integrated genomic analysis - including whole-exome sequencing, RNA sequencing, and copy number variation profiling - on 61 Chinese patients with ACC. We identified recurrent mutations in TP53 (25%), CTNNB1 (15%), ZNRF3 (10%), and MEN1 (8%). Unsupervised clustering of transcriptomic data revealed four distinct molecular subtypes: cortisol-driven (CD, 14%), immune-suppressed (IS, 40%), cell cycle-altered (CCA, 22%), and immunomodulatory (IM, 24%). The CD subtype exhibited steroidogenic pathway activation; the IS subtype showed T cell receptor downregulation and the worst disease-free survival; the CCA subtype was marked by chromosomal instability and cell cycle gene overexpression; and the IM subtype displayed enriched immune signaling and favorable outcomes. Copy number analysis further uncovered focal amplifications (e.g. TERT, CDK4) and HLA-II deletions. This study establishes a novel molecular classification of ACC, providing a framework for subtype-specific therapeutic strategies, such as CDK4/6 inhibition for CCA and immunotherapy for IM tumors, while highlighting the clinical challenges of immune-cold IS tumors.

Humans↗
PubMed1992

Pharmacological characteristics of alpha 2-adrenergic receptors: comparison of pharmacologically defined subtypes with subtypes identified by molecular cloning.

On the basis of extensive radioligand data and more limited functional data, three pharmacological subtypes of alpha 2-adrenergic receptors have been identified. More recently, three human genes or cDNAs for alpha 2-adrenergic receptors have been identified by molecular cloning. The relationship, however, among the pharmacologically defined subtypes and those identified by molecular cloning has not been clear. In order to resolve this issue, we have compared the pharmacological characteristics of the receptors identified by molecular cloning and expressed in COS-7 cells with the characteristics of the pharmacologically defined receptors in their respective prototypic tissue or cell line. The affinities (Ki values) of 12 subtype-selective alpha 2-adrenergic antagonists were determined for the alpha 2 receptor in the six preparations, by radioligand binding. Correlation analyses of the pKi values indicate that the alpha 2A subtype, as defined in the HT29 cell line, the alpha 2B receptor of the neonatal rat lung, and the alpha 2C subtype, as defined in an oppossum kidney cell line, correspond to the cloned human alpha 2-C10, alpha 2-C2, and alpha 2-C4 receptor subtypes, respectively.

Adrenergic alpha-Antagonists↗
PubMed1992

Pharmacologic characterization of cloned alpha 1-adrenoceptor subtypes: selective antagonists suggest the existence of a fourth subtype.

In membranes prepared from Cos-7 or HeLa cells expressing one of three individual cloned alpha 1-adrenoceptor subtypes, competition with 2-[(beta-(4-hydroxy-3-[125I]iodophenyl)ethylaminomethyl]-tetralone ([125I]HEAT) by the selective compounds [+]-niguldipine, 5-methyl-urapidil, and benoxathian reveals high affinity for the cloned alpha 1C-adrenoceptor subtype and low affinity for both the cloned alpha 1A-adrenoceptor and alpha 1B-adrenoceptor. Competition with [125I]HEAT by spiperone revealed high affinity for the cloned alpha 1C-adrenoceptor, intermediate affinity for the cloned alpha 1B-adrenoceptor, and low affinity for the cloned alpha 1A-adrenoceptor. Combining pharmacological properties previously described for alpha 1-adrenoceptor subtypes in rat membranes and here described from cloned receptors, these data suggest the existence of a fourth distinct alpha 1-adrenoceptor subtype.

Adrenergic alpha-Agonists↗
PubMed1992

Generation of a subtype-specific neutralization epitope in foot-and-mouth disease virus of a different subtype.

An epitope involved in neutralization of foot-and-mouth disease virus (FMDV) of subtype C3 was generated by a single amino acid replacement in VP1 of FMDV of subtype C1. The replacement [Ser (139)----Ile, in the immunodominant site A] was consistently found in those FMDV C1 Santa Pau-Sp/70 mutants resistant to neutralization by monoclonal antibody (MAb) SD6 (specific for most C1 viruses) that acquired the capacity to be neutralized by MAb 7AB5 (specific for C3 viruses).

Amino Acid Sequence↗
PubMed1992

Identification of endothelin receptor subtypes in human renal cortex and medulla using subtype-selective ligands.

High affinity and high density endothelin (ET)-binding sites were identified in membranes prepared from human kidney cortex and medulla. Saturation binding experiments performed in membranes prepared from cortex and medulla using [125I]ET-1 and [125I]ET-3 revealed that the proportion of [125I]ET-3-binding sites was 30-35% less than that of [125I]ET-1-binding sites. The apparent dissociation constants and maximum binding for [125I]ET-1 and [125I]ET-3 to membranes from cortex were 91 +/- 5 pM and 165 +/- 10 fmol/mg protein, and 117 +/- 9 pM and 110 +/- 7 fmol/mg protein, respectively, whereas in medulla they were 139 +/- 10 pM and 360 +/- 11 fmol/mg protein, and 142 +/- 11 pM and 245 +/- 15 fmol/mg protein, respectively. In the presence of 10 nM sarafotoxin-6c, which is selective for ETB receptors, [125I]ET-1 binding was decreased by 65-70%, whereas [125I]ET-3 binding was totally abolished, suggesting that 65-70% of [125I]ET-1 binding and 100% of [125I]ET-3 binding was to ETB receptors. This was further confirmed by the use of a cyclic pentapeptide [cyclo(D-Trp,D-Asp,L-Pro, D-Val,L-Leu)] (BQ123), which is selective for ETA receptors. In the presence of 1 microM BQ123, [125I]ET-1 binding was decreased by 25-30%, whereas [125I]ET-3 binding was unaffected, confirming that 30-35% of ET receptors belong to the ETA subtypes, and that [125I]ET-1 bound to both ETA and ETB receptors with the same high affinity, but [125I]ET-3 bound only to ETB receptors with high affinity. These results suggest that human kidney cortex and medulla contain ETA and ETB receptors in a ratio of 30:70, and that sarafotoxin-6c and BQ123 are valuable tools in identifying the subtype of ET receptors in various tissues.

Cell Membrane↗
PubMed1992

Identification of endothelin receptor subtypes in rat kidney cortex using subtype-selective ligands.

125I-Endothelin (ET)-1 and 125I-ET-3 displayed specific, saturable, and high affinity binding to membranes prepared from rat kidney cortex. Saturation binding experiments using 125I-ET-1 and 125I-ET-3 revealed that 125I-ET-3 binding sites were 40-50% less abundant than 125I-ET-1 binding sites. The dissociation constants (Kd) and maximum binding (Bmax) for 125I-ET-1 and 125I-ET-3 with these membranes were 218 +/- 23 pM and 275 +/- 20 fmol/mg of protein and 207 +/- 19 pM and 113 +/- 17 fmol/mg of protein, respectively. In the presence of 10 nM sarafotoxin 6c, a selective agonist for ETb receptors, 125I-ET-1 binding was decreased by 45-50% and 125I-ET-3 binding was totally abolished, suggesting that approximately 40-50% of kidney cortex ET receptors are of the ETB subtype and that 125I-ET-1 binds to both ETA and ETB receptors with the same high affinity, whereas 125I-ET-3 binds to only ETB receptors with high affinity. In addition, in the presence of BQ123 [cyclo(D-Trp,D-Asp,L-Pro,D-Val,L-Leu)], a selective antagonist for ETA receptors, 125I-ET-1 binding was decreased by 50%, whereas 125I-ET-3 binding was unaffected. Our results strongly suggest that rat kidney cortex contains ETA and ETB receptors in a 50:50 ratio and that sarafotoxin 6c and BQ123 are valuable tools in identifying the subtypes of ET receptors in various tissues.

Amino Acid Sequence↗
PubMed1992

Further characterization of neuropeptide Y receptor subtypes using centrally truncated analogs of neuropeptide Y: evidence for subtype-differentiating effects on affinity and intrinsic efficacy.

Previous attempts to classify neuropeptide Y receptor subtypes suffered from relying only on carboxyl-terminal analogs and fragments of neuropeptide Y. We have tested the potency and affinity of chemically different compounds, i.e., centrally truncated analogs of neuropeptide Y, in three Y1-like (Ca2+ mobilization in HEL cells, blood pressure increases in pithed rats, and 125I-neuropeptide Y binding in SK-N-MC cells) and two Y2-like (125I-neuropeptide Y binding to rabbit kidney membranes and presynaptic inhibition in rat vas deferens) model systems of neuropeptide Y receptors. Our data confirm the concept of two major subclasses of neuropeptide Y receptors, with some centrally truncated neuropeptide Y analogs having high affinity for Y2-like and low affinity for Y1-like neuropeptide Y receptors. Some of the truncated neuropeptide Y analogs are antagonists at Y1-like receptors and (possibly partial) agonists at Y2-like receptors. Our data also indicate that amino acid residues distal from the amino- and carboxyl-terminal ends of the peptide may subtype-selectively affect affinity and intrinsic efficacy of peptide agonists at neuropeptide Y receptors.

Amino Acid Sequence↗
PubMed1992

Role of alpha 1A adrenoceptor subtype in production of the positive inotropic effect mediated via myocardial alpha 1 adrenoceptors in the rabbit papillary muscle: influence of selective alpha 1A subtype antagonists WB 4101 and 5-methylurapidil.

In order to elucidate the contribution of alpha 1A subtype to the positive inotropic effect mediated by myocardial alpha 1 adrenoceptors, the influence of the alpha 1A selective antagonists WB 4101 and 5-methylurapidil on the alpha 1-mediated positive inotropic effect (induced by phenylephrine in the presence of a beta adrenoceptor blocking agent bupranolol) was assessed in the isolated rabbit papillary muscle. WB 4101 (10(-9)-10(-7) mol/l) shifted the concentration-response curve of the alpha 1-mediated positive inotropic effect to the right in parallel, but the slope of Schild plot did not meet the competitive antagonism: WB 4101 shifted the curve by log one unit at 10(-9) mol/l, whereas it did not cause further shift at higher concentrations of 10(-8) and 10(-7) mol/l. WB 4101 did not affect the beta adrenoceptor-mediated positive inotropic effect. 5-Methylurapidil (10(-9) to 10(-7) mol/l) shifted the curve of alpha 1-mediated positive inotropic effect to the right and downwards in a concentration-dependent manner; the slope of Schild plot calculated at the level of 20% of the maximum response to phenylephrine was close to unity. 5-Methylurapidil at 3 x 10(-7) mol/l abolished the alpha 1-mediated positive inotropic effect. In addition, 5-methylurapidil inhibited the beta adrenoceptor-mediated positive inotropic effect in the same concentration range as it antagonized the alpha 1-mediated positive inotropic effect, indicating that 5-methylurapidil is not selective for myocardial alpha 1 adrenoceptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Antagonists↗
PubMed1975

A method fof production or antisera to hepatitis b antigen subtypes, and the distribution of subtypes d and y among norwegian hepatitis b patients.

A method for production of antisera to hepatitis B antigen (HBsAg) subtypes D and Y is described. The method is based on the coupling of HBsAg to a colloidal silica gel (Aerosil), and the selective adsorption of unwanted antibodies from antisera with this preparation. Some results obtained with Norwegian hepatitis patient sera are included.

Animals↗
PubMed2025

Alzheimer's subtypes A supervised, unsupervised, multimodal, multilayered embedded recursive (SUMMER) AI study.

Since Alzheimer's disease (AD) is a heterogeneous disease, different subtypes may have distinct biological, genetic, and clinical characteristics, requiring tailored interventions. While several proposed subtypes of AD exist, there is still no clear consensus on a definitive classification. By leveraging complementary AI approaches, including supervised and unsupervised learning, within a recursive pipeline (SUMMER) that integrates multimodal datasets encompassing MRI measurements, phenotypes, and genetic data, our goal was to generate robust scientific evidence for identifying AD subtypes. Data was downloaded from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database and included neuroimaging data (MRI), genetics (SNPs), clinical diagnosis, and demographics. 1133 European American participants' images, aged 55-95, were included in this study. The analysis was multi-fold, where the first step involved applying an unsupervised application to a subset of the MRI sample (AD + cognitively normal (CN) aged matched groups, 100 men aged 68-85 years, and 76 women aged 68-85 years). The MRI brain gray matter was segmented into 44 regions of interest (ROIs) according to a standard atlas, and 618 features were extracted, including ROI voxel intensity measurements such as minimum, maximum, and histogram variables. Results identified a cluster of subtype AD men and a cluster of subtype AD women that were distinct from the rest of their respective samples. In the next step, the integrity of the identified subtype AD clusters was investigated using the XGBoost supervised machine learning application with genetic features (SNPs, N=36,724) and labels: the identified subtype AD cluster vs. the rest of the sample, stratified by sex. A significant AD subtype men model (accuracy=0.85, F1=0.72, AUC=0.83) and a significant women AD subtype model (accuracy=0.81, F1=0.81, AUC=0.81) were built, confirming the homogeneity of the isolated AD subtype clusters. Discriminative biomarkers were extracted from the significant models, including selected ROIs and SNPs. Finally, the subtype models were tested on an unseen subset of ADNI data. The genetic-based models identified clusters of AD subtype participants consisting of 34% of the men AD group and 47% of the women AD group. Phenotypic analysis indicates that lower body weight was associated with the women's AD subtype. Complex diseases like AD demand a sophisticated, multimodal approach for precise diagnosis. Effectively identifying disease subtypes enhances the potential for personalized treatment, ultimately improving patient outcomes.

Journal Article↗
PubMed2026

Refining the Genetic Contribution to Type 2 Diabetes Subtypes.

BACKGROUND: Type 2 diabetes (T2D) is a complex and highly heterogeneous disease driven in part by genetic predisposition and can be stratified into clinical subgroups to aid disease management. We recently grouped T2D subjects in the Qatar Biobank (QBB) cohort into Severe Insulin-Deficient Diabetes (SIDD), Severe Insulin-Resistant Diabetes (SIRD), Mild Obesity-Related Diabetes (MOD) and Mild Age-Related Diabetes (MARD) subtypes. Herein, we focused on the genetic makeup of these subtypes. METHODS: We used the QBB cohort (n = 13,808), of whom 2687 were with T2D, and comprehensively assessed polygenic risk scores (PGS) across T2D subtypes, investigated genetic loci associated with each subtype by leveraging the most recent and largest GWAS for T2D, evaluated SNP associations across T2D genetic clusters, and identified protein interaction pathways associated with these distinct T2D subtypes. RESULTS: MOD showed consistently lower PGS compared with other T2D subtypes across all tested scores. SIDD showed more associations with SNPs mapping to residual glycemic cluster compared with other T2D subtypes. The incremental analysis of PGS004838 demonstrated a high ΔAUC of 0.101 for SIDD and a moderate ΔAUC of 0.068 for SIRD, but not for MOD and MARD. Protein interaction analyses identified candidate subtype-associated gene networks linked to pathways related to glucose homeostasis in SIDD, insulin signalling and hepatic metabolism in SIRD, body fat distribution in MOD and vascular-related processes in MARD. CONCLUSION: We found heterogeneous genetic architectures across clinically defined T2D subtypes in a Middle Eastern population. Our findings provide evidence supporting differential polygenic burden, subtype genetic associations and subtype-associated biological pathways across T2D subtypes. These observations support the utility of subtype-based genetic analyses for improving biological understanding of T2D heterogeneity.

Humans↗
PubMed1975

Modified counterelectrophoresis method for subtyping hepatitis B antigen.

A modified counterelectrophoresis (CEP) method was developed for determining the d and y subtypes of hepatitis B antigen (HBSAg). In this method, HBSAg of known subtype was diffused into the agarose gel before electrophoresis from the wells which were subsequently to receive the subtyping antiserum. This served to absorb the common anti-alpha antibody from the subtyping antiserum, which was heterologous with respect to the d or y component, during electrophoresis. The remaining d or y antibody then reacted type specifically with the antigen to be subtyped. The modified CEP method was much more sensitive than the immunodiffusion (ID) method for subtyping HBSAg. Sixty-two sera which could not be subtyped by ID were successfully subtyped by the CEP method. The geometric mean HBSAg complement fixation titer determined on 48 of these sera was significantly lower (P congruent to 0.016) than that of a group of sera which could be subtyped by ID. Sixteen other sera could not be subtyped by either the CEP or the ID procedure (geometric mean titer equal to 5.2). Therefore, more sensitive means of subtyping must be used for some HBSAg-positive sera.

Counterimmunoelectrophoresis↗