CD1b-autoreactive T cells recognize phospholipid antigens and contribute to antitumor immunity against a CD1b+ T cell lymphoma

To explore the prognostic characteristics of colon cancer based on tertiary lymphoid structure-related genes and reveal the characteristics of tumor microenvironment and drug prediction

In order to construct a prognostic evaluation model of TLS features in COAD and better realize personalized precision medicine in COAD. Colon adenocarcinoma (COAD) is a common malignant tumor of the digestive system. At present, there is no effective prognostic marker to predict the prognosis of patients. Tertiary lymphoid structure (TLS) affects cancer progression by regulating immune microenvironment. Mining COAD biomarkers based on TLS-related genes helps to improve the prognosis of patients. In order to construct a prognostic evaluation model of TLS features in COAD and better realize personalized precision medicine in COAD. The mRNA expression data and clinical information of COAD and adjacent tissues were downloaded from the Cancer Genome Atlas database. The differentially expressed TLS-related genes of COAD relative to adjacent tissues were obtained by differential analysis. TLS gene co-expression analysis was used to mine genes highly related to TLS, and the intersection of the two was used to obtain candidate genes. Univariate, LASSO, and multivariate Cox regression analysis were performed on candidate genes to screen prognostic markers to construct a risk assessment model. The differences of immune characteristics were evaluated by ESTIMATE, ssGSEA and CIBERSORT in high and low risk groups of prognostic model. The difference of genomic mutation between groups was evaluated by tumor mutation burden score. Screening small molecule drugs through the GDSC library. Finally, a nomogram was drawn to evaluate the clinical value of the prognostic model. Seven TLS-related genes ADAM8, SLC6A1, PAXX, RIMKLB, PTH1R, CD1B, and MMP10 were screened to construct a prognostic model. Survival analysis showed that patients in the high-risk group had significantly lower overall survival rates. Immune microenvironment analysis showed that patients in the high-risk group had higher immune indicators, indicating higher immunity. The genomic mutation patterns of the high-risk and low-risk groups were significantly different, especially the KRAS mutation frequency was significantly higher in the high-risk group. Drug sensitivity analysis showed that the low-risk group was more sensitive to Erlotinib, Savolitinib and VE _ 822, which may be used as a potential drug for COAD treatment. Finally, the nomogram constructed by pathological features combined with RiskScore can accurately evaluate the prognosis of COAD patients. This study constructed and verified a TLS model that can predict COAD. More importantly, it provides a reference standard for guiding the prognosis and immunotherapy of COAD patients.

αβ T-cell receptor recognition of self-phosphatidylinositol presented by CD1b

CD1 glycoproteins present lipid-based antigens to T-cell receptors (TCRs). A role for CD1b in T-cell-mediated autoreactivity was proposed when it was established that CD1b can present self-phospholipids with short alkyl chains (∼C34) to T cells; however, the structural characteristics of this presentation and recognition are unclear. Here, we report the 1.9 Å resolution binary crystal structure of CD1b presenting a self-phosphatidylinositol-C34:1 and an endogenous scaffold lipid. Moreover, we also determined the 2.4 Å structure of CD1b-phosphatidylinositol complexed to an autoreactive αβ TCR, BC8B. We show that the TCR docks above CD1b and directly contacts the presented antigen, selecting for both the phosphoinositol headgroup and glycerol neck region via antigen remodeling within CD1b and allowing lateral escape of the inositol moiety through a channel formed by the TCR α-chain. Furthermore, through alanine scanning mutagenesis and surface plasmon resonance, we identified key CD1b residues mediating this interaction, with Glu-80 abolishing TCR binding. We in addition define a role for both CD1b α1 and CD1b α2 molecular domains in modulating this interaction. These findings suggest that the BC8B TCR contacts both the presented phospholipid and the endogenous scaffold lipid via a dual mechanism of corecognition. Taken together, these data expand our understanding into the molecular mechanisms of CD1b-mediated T-cell autoreactivity.

Sphingolipids and Lymphomas: A Double-Edged Sword

Lymphomas are a highly heterogeneous group of hematological neoplasms. Given their ethiopathogenic complexity, their classification and management can become difficult tasks; therefore, new approaches are continuously being sought. Metabolic reprogramming at the lipid level is a hot topic in cancer research, and sphingolipidomics has gained particular focus in this area due to the bioactive nature of molecules such as sphingoid bases, sphingosine-1-phosphate, ceramides, sphingomyelin, cerebrosides, globosides, and gangliosides. Sphingolipid metabolism has become especially exciting because they are involved in virtually every cellular process through an extremely intricate metabolic web; in fact, no two sphingolipids share the same fate. Unsurprisingly, a disruption at this level is a recurrent mechanism in lymphomagenesis, dissemination, and chemoresistance, which means potential biomarkers and therapeutical targets might be hiding within these pathways. Many comprehensive reviews describing their role in cancer exist, but because most research has been conducted in solid malignancies, evidence in lymphomagenesis is somewhat limited. In this review, we summarize key aspects of sphingolipid biochemistry and discuss their known impact in cancer biology, with a particular focus on lymphomas and possible therapeutical strategies against them.

CD1B is a Potential Prognostic Biomarker Associated with Tumor Mutation Burden and Promotes Antitumor Immunity in Lung Adenocarcinoma

Purpose

Tumor mutation burden (TMB) and tumor-infiltrating lymphocytes (TILs) have been well recognized as molecular determinants of immunotherapy responsiveness. In this study, we aimed to construct a TMB prognostic model and explore biomarkers that have predictive potential for prognosis and therapeutic effect in lung adenocarcinoma (LUAD).

Patients and Methods

The TCGA, GEO and Immport databases were used to analyze the mutation profiles and immune infiltration of LUAD. TMB scores were calculated and differential analysis was conducted to identify TMB-related genes. Then, Cox regression model and survival analysis were applied to identify the prognostic genes and construct a TMB prognostic model. The expression and prognostic value of CD1B were further verified by immunohistochemistry (IHC) in 92 patient tissue samples. GSEA was performed to analyze the signaling pathways associated with CD1B expression.

Results

High-TMB samples exhibited higher infiltration of CD8+ T cells, CD4+ memory T cells, and M1 macrophages. A total of 397 TMB-related differentially expressed genes were identified, of which 47 were immune-related genes. Cox regression analyses determined 3 hub TMB-related immune genes (CD1B, SCGB3A1, and VEGFD) with prognostic effects, and a TMB prognostic model was constructed. The model demonstrated robust predictive ability in both the training (TCGA) and testing (GEO) datasets. Notably, CD1B was identified as an independent prognostic factor. IHC of clinical samples showed that low expression of CD1B was related to poor overall survival and advanced pathological stages. In addition, there was a strong positive correlation between CD1B and most immune checkpoint molecules, including PD-L1. CD1B expression was associated with immune cell infiltration and immune activation in LUAD.

Conclusion

Our study constructed a TMB prognostic model that effectively predicted the prognosis of LUAD patients. CD1B expression is correlated with better prognosis and promotes antitumor immunity in LUAD, which may serve as a potential prognostic biomarker and immune-related therapeutic target for LUAD.

Novel Molecular Insights into Human Lipid-Mediated T Cell Immunity

T cells represent a critical arm of our immune defense against pathogens. Over the past two decades, considerable inroads have been made in understanding the fundamental principles underpinning the molecular presentation of peptide-based antigens by the Major Histocompatibility Complex molecules (MHC-I and II), and their molecular recognition by specialized subsets of T cells. However, some T cells can recognize lipid-based antigens presented by MHC-I-like molecules that belong to the Cluster of Differentiation 1 (CD1) family. Here, we will review the advances that have been made in the last five years to understand the molecular mechanisms orchestrating the presentation of novel endogenous and exogenous lipid-based antigens by the CD1 glycoproteins and their recognition by specific populations of CD1-reactive T cells.

Exploiting CD1-restricted T cells for clinical benefit

CD1-restricted T cells were first described over 30 years ago along with the cloning of the CD1 family. Around the same time, invariant Natural Killer cells (iNKT) were identified based on invariant TCR-alpha chains with additional expression of natural killer (NK) cell markers. About 5 years later, iNKT were shown to react with CD1d. Since then, iNKT have been shown to be a major population of CD1d-restricted T cells in humans and many animals. Like NK cells, iNKT are innate lymphocytes with rapid and wide-ranging effector potential. These activities include cytotoxicity and an unusually broad and high-level cytokine production. The development of highly-specific methods of isolating, stimulating, expanding or depleting these relatively rare cells and controlling their potent activities has stimulated considerable interest in therapeutic targeting of iNKT cells. Potential applications include cancers, inflammatory, infectious and autoimmune among other diseases. To date, most trials have targeted various cancers, there are 2 published trials in viral hepatitis and one in sickle cell lung disease. Uniform safety, evidence of immunologic activity and increasingly clinical efficacy have been seen. Approaches to targeting iNKT cells in clinical development include highly specific natural glycolipid ligands presented by CD1d and chemical analogues thereof and monoclonal antibody-based targeting of iNKT cells. In the case of iNKT cell-based therapies, novel approaches include arming them with Chimeric Antigen Receptors (CARs) and recombinant TCRs (rTCR), gene editing and allogeneic use. Controlling the iTCR:CD1d molecular interaction and consequences is a unique and promising therapeutic technology.

Comprehensive analysis of prognostic immune-related genes in the tumor microenvironment of colorectal cancer

In this study, we used the ESTIMATE algorithm to analyze clinical data and transcriptome profiles of 1635 colorectal cancer (CRC) samples from the Gene Expression Omnibus and The Cancer Genome Atlas databases and identify prognostic immune-related genes (IRGs). We identified 941 differentially expressed (4 downregulated and 937 upregulated) genes by comparing samples with high and low immune, stromal scores and tumor purity. LASSO Cox regression analyses showed that the risk score based on a ten-IRG signature was an independent prognostic factor in CRC. The nomogram with pathological stages (TNM) and the ten-IRG signature showed a C-index of 0.769 (95% CI, 0.717-0.821), and area under ROC curve values of 0.788, 0.782 and 0.789 for 1-, 3-, and 5-year OS, respectively. TIMER database analysis showed positive correlation between the ten prognostic IRGs and the levels of tumor-infiltrated immune cells, including CD4⁺ and CD8⁺ T cells, macrophages, neutrophils, and dendritic cells. These findings demonstrate that this novel ten-IRG signature correlates with the pathological stages and the levels of multiple tumor-infiltrated immune cell types. This makes the ten-IRG signature a potential prognostic factor for CRC patients.

Role of Group 1 CD1-Restricted T Cells in Host Defense and Inflammatory Diseases

Group 1 CD1-restricted T cells are members of the unconventional T cell family that recognize lipid antigens presented by CD1a, CD1b, and CD1c molecules. Although they developmentally mirror invariant natural killer T cells, they have diverse antigen specificity and functional capacity, with both anti-microbial and autoreactive targets. The role of group 1 CD1-restricted T cells has been best established in Mycobacterium tuberculosis (Mtb) infection in which a wide variety of lipid antigens have been identified and their ability to confer protection against Mtb infection in a CD1 transgenic mouse model has been shown. Group 1 CD1-restricted T cells have also been implicated in other infections, inflammatory conditions, and malignancies. In particular, autoreactive group 1 CD1-restricted T cells have been shown to play a role in several skin inflammatory conditions. The prevalence of group 1 CD1 autoreactive T cells in healthy individuals suggests the presence of regulatory mechanisms to suppress autoreactivity in homeostasis. The more recent use of group 1 CD1 tetramers and mouse models has allowed for better characterization of their phenotype, functional capacity, and underlying mechanisms of antigen-specific and autoreactive activation. These discoveries may pave the way for the development of novel vaccines and immunotherapies that target group 1 CD1-restricted T cells.

Animal models for human group 1 CD1 protein function

The CD1 antigen presenting system is evolutionary conserved and found in mammals, birds and reptiles. Humans express five isoforms, of which CD1a, CD1b and CD1c represent the group 1 CD1-molecules. They are recognized by T cells that express diverse αβ-T cell receptors. Investigation of the role of group 1 CD1 function has been hampered by the fact that CD1a, CD1b and CD1c are not expressed by mice. However, other animals, such as guinea pigs or cattle, serve as alternative models and have established basic aspects of CD1-dependent, antimicrobial immune functions. Group 1 CD1 transgenic mouse models became available about ten years ago. In a series of seminal studies these mouse models coined the mechanistical understanding of the role of the corresponding CD1 restricted T cell responses. This review gives a short overview of available animal studies and the lessons that have been and still can be learned.

Identification and validation of tumor microenvironment-related genes of prognostic value in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a major subtype of non-small cell lung cancer. Despite significant progress in its diagnosis and treatment, the mortality and morbidity rate of LUAD remains high worldwide. The aim of the present study was to perform a systematic investigation of the tumor microenvironment (TME) and identify TME-related genes of prognostic value in patients with LUAD. Firstly, the immune scores and stromal scores of patients with LUAD from The Cancer Genome Atlas were calculated using the Estimation of STromal and Immune cells in MAlignant Tumors using Expression data algorithm, and a total of 281 prognostic TME-related genes were identified. Subsequently, functional analysis and protein-protein interaction network analysis revealed that these genes were mainly related to immune response, inflammatory response and chemotaxis. Finally, two independent LUAD cohorts from the Gene Expression Omnibus database were used to validate these genes, and 4 genes (GTPase IMAP family member 1, T-cell surface glycoprotein CD1b, integrin alpha-L and leukocyte surface antigen CD53) were identified, and downregulation of these genes was indicated to be associated with poor overall survival rate in patients with LUAD. In conclusion, a comprehensive analysis of TME was performed and 4 prognostic TME-related genes in patients with LUAD were identified.

Construction of an Immunogenomic Risk Score for Prognostication in Colon Cancer

Immune-related genes (IRGs) play regulatory roles in the immune system and are involved in the initiation and progression of colon cancer. This study aimed to develop an immunogenomic risk score for predicting survival outcomes among colon cancer patients. We analyzed the expressions of IRGs in colon specimens and discovered 484 differentially expressed IRGs when we compared specimens from colon cancer and adjacent normal tissue. Univariate Cox regression analyses were performed to identify 26 IRGs that were associated with survival. A Cox proportional hazards model with a lasso penalty identified five optimal IRGs for constructing the immunogenomic risk score (CD1B, XCL1, PLCG2, NGF, and OXTR). The risk score had good performance in predicting overall survival among patients with colon cancer and was correlated with the amount of tumor-infiltrating immune cells. Our findings suggest that the immunogenomic risk score may be useful for prognostication in colon cancer cases. Furthermore, the five IRGs included in the risk score might be useful targets for investigating the initiation of colon cancer and designing personalized treatments.

Prognostic Value of CD1B in Localised Prostate Cancer

Cluster of differentiation (CD) antigens are cell surface markers used to differentiate haematopoietic cell types. These antigens are present in various malignancies and are reportedly linked to patient prognosis; however, they have not been implemented as prostate cancer progression markers. Here, we aimed to assess the impact of genetic variation in haematopoietic cell CD markers on clinical outcomes in patients with prostate cancer. An association study of 458 patients with prostate cancer was conducted to identify single-nucleotide polymorphisms in 11 candidate CD marker genes associated with biochemical recurrence (BCR) after radical prostatectomy. Identified predictors were further evaluated in an additional cohort of 185 patients. Joint population analyses showed that CD1B rs3181082 is associated with BCR (adjusted hazard ratio 1.42, 95% confidence interval 1.09-1.85, p = 0.010). In addition, rs3181082 overlapped with predicted transcriptional regulatory elements and affected CD1B expression. Furthermore, low CD1B expression correlated with poorer BCR-free survival. Our results indicated that CD1B rs3181082 confers prostate cancer progression and may help improve clinical prognostic stratification.

Evolutionary Underpinnings of Innate-Like T Cell Interactions with Cancer

Cancers impose a significant health and economic burden. By harnessing the immune system, current immunotherapies have revolutionized the treatment against human cancers and potentially offer a long-term cure. Among others, innate-like T (iT) cells, including natural killer T cells, are promising candidates for immunotherapies. Unlike conventional T cells, iT cells regulate multiple immune processes and express an invariant T cell receptor that is shared among different individuals. However, the conditions that activate the pro- and antitumor functions of iT cells are partially understood. These gaps in knowledge hamper the use of iT cell in clinics. It might be beneficial to examine the roles of iT cells in an alternative animal model - the amphibian Xenopus whose immune system shares many similarities to that of mammals. Here, we review the iT cell biology in the context of mammalian cancers and discuss the challenges currently found in the field. Next, we introduce the advantages of Xenopus as a model to investigate the role of iT cells and interacting major histocompatibility complex (MHC) class I-like molecules in tumor immunity. In Xenopus, 2 specific iT cell subsets, Vα6 and Vα22 iT cells, recognize and fight tumor cells. Furthermore, our recent data reveal the complex functions of the Xenopus MHC class I-like (XNC) gene XNC10 in tumor immune responses. By utilizing reverse genetics, transgenesis, and MHC tetramers, we have a unique opportunity to uncover the relevance of XNC genes and iT cell in Xenopus tumor immunity.

Unconventional T Cell Targets for Cancer Immunotherapy

Most studies on the immunotherapeutic potential of T cells have focused on CD8 and CD4 T cells that recognize peptide antigens (Ag) presented by polymorphic major histocompatibility complex (MHC) class I and MHC class II molecules, respectively. However, unconventional T cells, which interact with MHC class Ib and MHC-I like molecules, are also implicated in tumor immunity, although their role therein is unclear. These include unconventional T cells targeting MHC class Ib molecules such as HLA-E and its murine ortholog Qa-1b, natural killer T (NKT) cells, mucosal associated invariant T (MAIT) cells, and γδ T cells. Here, we review the current understanding of the roles of these unconventional T cells in tumor immunity and discuss why further studies into the immunotherapeutic potential of these cells is warranted.

The intricacies of self-lipid antigen presentation by CD1b

The CD1 family of glycoproteins are MHC class I-like molecules that present a wide array of self and foreign lipid antigens to T-cell receptors (TCRs) on T-cells. Humans express three classes of CD1 molecules, denoted as Group 1 (CD1a, CD1b, and CD1c), Group 2 (CD1d), and Group 3 (CD1e). Of the CD1 family of molecules, CD1b exhibits the largest and most complex antigen binding groove; allowing it the capabilities to present a broad spectrum of lipid antigens. While its role in foreign-lipid presentation in the context of mycobacterial infection are well characterized, understanding the roles of CD1b in autoreactivity are recently being elucidated. While the mechanisms governing proliferation of CD1b-restricted autoreactive T cells, regulation of CD1 gene expression, and the processes controlling CD1+ antigen presenting cell maturation are widely undercharacterized, the exploration of self-lipid antigens in the context of disease have recently come into focus. Furthermore, the recently expanded pool of CD1b crystal structures allow the opportunity to further analyze the molecular mechanisms of T-cell recognition and self-lipid presentation; where the intricacies of the two-compartment system, that accommodate both the presented self-lipid antigen and scaffold lipids, are scrutinized. This review delves into the immunological and molecular mechanisms governing presentation and T-cell recognition of the broad self-lipid repertoire of CD1b; with evidence mounting pointing towards a role in diseases such as microbial infection, autoimmune diseases, and cancer.

Potential advantages of CD1-restricted T cell immunotherapy in cancer

Adoptive cell therapy (ACT) using tumor-specific "conventional" MHC-restricted T cells obtained from tumor-infiltrating lymphocytes, or derived ex vivo by either antigen-specific expansion or genetic engineering of polyclonal T cell populations, shows great promise for cancer treatment. However, the wide applicability of this therapy finds limits in the high polymorphism of MHC molecules that restricts the use in the autologous context. CD1 antigen presenting molecules are nonpolymorphic and specialized for lipid antigen presentation to T cells. They are often expressed on malignant cells and, therefore, may represent an attractive target for ACT. We provide a brief overview of the CD1-resticted T cell response in tumor immunity and we discuss the pros and cons of ACT approaches based on unconventional CD1-restricted T cells.

Linking CD1-Restricted T Cells With Autoimmunity and Dyslipidemia: Lipid Levels Matter

Dyslipidemia, or altered blood lipid content, is a risk factor for developing cardiovascular disease. Furthermore, several autoimmune diseases, including systemic lupus erythematosus, psoriasis, diabetes, and rheumatoid arthritis, are correlated highly with dyslipidemia. One common thread between both autoimmune diseases and altered lipid levels is the presence of inflammation, suggesting that the immune system might act as the link between these related pathologies. Deciphering the role of innate and adaptive immune responses in autoimmune diseases and, more recently, obesity-related inflammation, have been active areas of research. The broad picture suggests that antigen-presenting molecules, which present self-peptides to autoreactive T cells, can result in either aggravation or amelioration of inflammation. However, very little is known about the role of self-lipid reactive T cells in dyslipidemia-associated autoimmune events. Given that a range of autoimmune diseases are linked to aberrant lipid profiles and a majority of lipid-specific T cells are reactive to self-antigens, it is important to examine the role of these T cells in dyslipidemia-related autoimmune ailments and determine if dysregulation of these T cells can be drivers of autoimmune conditions. CD1 molecules present lipids to T cells and are divided into two groups based on sequence homology. To date, most of the information available on lipid-reactive T cells comes from the study of group 2 CD1d-restricted natural killer T (NKT) cells while T cells reactive to group 1 CD1 molecules remain understudied, despite their higher abundance in humans compared to NKT cells. This review evaluates the mechanisms by which CD1-reactive, self-lipid specific T cells contribute to dyslipidemia-associated autoimmune disease progression or amelioration by examining available literature on NKT cells and highlighting recent progress made on the study of group 1 CD1-restricted T cells.

The versatility of the CD1 lipid antigen presentation pathway

The family of non-classical major histocompatibility complex (MHC) class-I like CD1 molecules has an emerging role in human disease. Group 1 CD1 includes CD1a, CD1b and CD1c, which function to display lipids on the cell surface of antigen-presenting cells for direct recognition by T-cells. The recent advent of CD1 tetramers and the identification of novel lipid ligands has contributed towards the increasing number of CD1-restricted T-cell clones captured. These advances have helped to identify novel donor unrestricted and semi-invariant T-cell populations in humans and new mechanisms of T-cell recognition. However, although there is an opportunity to design broadly acting lipids and harness the therapeutic potential of conserved T-cells, knowledge of their role in health and disease is lacking. We briefly summarize the current evidence implicating group 1 CD1 molecules in infection, cancer and autoimmunity and show that although CD1 are not as diverse as MHC, recent discoveries highlight their versatility as they exhibit intricate mechanisms of antigen presentation.

CD1-Restricted T Cells During Persistent Virus Infections: "Sympathy for the Devil"

Some of the clinically most important viruses persist in the human host after acute infection. In this situation, the host immune system and the viral pathogen attempt to establish an equilibrium. At best, overt disease is avoided. This attempt may fail, however, resulting in eventual loss of viral control or inadequate immune regulation. Consequently, direct virus-induced tissue damage or immunopathology may occur. The cluster of differentiation 1 (CD1) family of non-classical major histocompatibility complex class I molecules are known to present hydrophobic, primarily lipid antigens. There is ample evidence that both CD1-dependent and CD1-independent mechanisms activate CD1-restricted T cells during persistent virus infections. Sophisticated viral mechanisms subvert these immune responses and help the pathogens to avoid clearance from the host organism. CD1-restricted T cells are not only crucial for the antiviral host defense but may also contribute to tissue damage. This review highlights the two edged role of CD1-restricted T cells in persistent virus infections and summarizes the viral immune evasion mechanisms that target these fascinating immune cells.

Molecular features of lipid-based antigen presentation by group 1 CD1 molecules

Lipids are now widely considered to play a variety of important roles in T-cell mediated immunity, including serving as antigens. Lipid-based antigens are presented by a specialised group of glycoproteins termed CD1. In humans, three classes of CD1 molecules exist: group 1 (CD1a, CD1b, CD1c), group 2 (CD1d), and group 3 (CD1e). While CD1d-mediated T-cell immunity has been extensively investigated, we have only recently gained insights into the structure and function of group 1 CD1 molecules. Structural studies have revealed how lipid-based antigens are presented by group 1 CD1 molecules, as well as shedding light on the molecular requirements for T-cell recognition. Here, we provide an overview of our current understanding of lipid presentation by group 1 CD1 molecules in humans and their recognition by T-cells, as well as examining the potential differences in lipid presentation that may occur across different species.

Harnessing the CD1 restricted T cell response for leukemia adoptive immunotherapy

Disease recurrence following chemotherapy and allogeneic hematopoietic cell transplantation is the major unmet clinical need of acute leukemia. Adoptive cell therapy (ACT) with allogeneic T lymphocytes can control recurrences at the cost of inducing detrimental GVHD. Targeting T cell recognition on leukemia cells is therefore needed to overcome the problem and ensure safe and durable disease remission. In this review, we discuss adoptive cells therapy based on CD1-restricted T cells specific for tumor associated self-lipid antigens. CD1 molecules are identical in every individual and expressed essentially on mature hematopoietic cells and leukemia blasts, but not by parenchymatous cells, while lipid antigens are enriched in malignant cells and unlike to mutate upon immune-mediated selective pressure. Redirecting T cells against self-lipids presented by CD1 molecules can thus provide an appealing cell therapy strategy for acute leukemia that is patient-unrestricted and can minimize risks for GVHD, implying potential prognostic improvement for this cancer.

CD1b-autoreactive T cells contribute to hyperlipidemia-induced skin inflammation in mice

A large proportion of human T cells are autoreactive to group 1 CD1 proteins, which include CD1a, CD1b, and CD1c. However, the physiological role of the CD1 proteins remains poorly defined. Here, we have generated a double-transgenic mouse model that expresses human CD1b and CD1c molecules (hCD1Tg) as well as a CD1b-autoreactive TCR (HJ1Tg) in the ApoE-deficient background (hCD1Tg HJ1Tg Apoe-/- mice) to determine the role of CD1-autoreactive T cells in hyperlipidemia-associated inflammatory diseases. We found that hCD1Tg HJ1Tg Apoe-/- mice spontaneously developed psoriasiform skin inflammation characterized by T cell and neutrophil infiltration and a Th17-biased cytokine response. Anti-IL-17A treatment ameliorated skin inflammation in vivo. Additionally, phospholipids and cholesterol preferentially accumulated in diseased skin and these autoantigens directly activated CD1b-autoreactive HJ1 T cells. Furthermore, hyperlipidemic serum enhanced IL-6 secretion by CD1b+ DCs and increased IL-17A production by HJ1 T cells. In psoriatic patients, the frequency of CD1b-autoreactive T cells was increased compared with that in healthy controls. Thus, this study has demonstrated the pathogenic role of CD1b-autoreactive T cells under hyperlipidemic conditions in a mouse model of spontaneous skin inflammation. As a large proportion of psoriatic patients are dyslipidemic, this finding is of clinical significance and indicates that self-lipid-reactive T cells might serve as a possible link between hyperlipidemia and psoriasis.