CD24 V/V is an allele associated with the risk of developing multiple sclerosis in the Spanish population

Surprising magic of CD24 beyond cancer

CD24 has emerged as a molecule of significant interest beyond the oncological arena. Recent studies have unveiled its surprising and diverse roles in various biological processes and diseases. This review encapsulates the expanding spectrum of CD24 functions, delving into its involvement in immune regulation, cancer immune microenvironment, and its potential as a therapeutic target in autoimmune diseases and beyond. The 'magic' of CD24, once solely attributed to cancer, now inspires a new paradigm in understanding its multifunctionality in human health and disease, offering exciting prospects for medical advancements.

CD24 is a surrogate for 'immune-cold' phenotype in aggressive large B-cell lymphoma

The tumor microenvironment (TME) is a critical regulator of the development of malignant lymphoma. Therapeutics targeting the TME, especially immune checkpoint molecules, are changing the treatment strategy for lymphoma. However, the overall response to these therapeutics for diffuse large B‐cell lymphoma (DLBCL) is modest and new targets of immunotherapy are needed. To find critical immune checkpoint molecules for DLBCL, we explored the prognostic impact of immune checkpoint molecules and their ligands using publicly available datasets of gene expression profiles. In silico analysis of three independent datasets (GSE117556, GSE10846, and GSE181063) revealed that DLBCL expressing CD24 had a poor prognosis and had a high frequency of MYC aberrations. Moreover, gene set enrichment analysis showed that the ‘MYC‐targets‐hallmark’ (false discovery rate [FDR] = 0.024) and ‘inflammatory‐response‐hallmark’ (FDR = 0.001) were enriched in CD24‐high and CD24‐low DLBCL, respectively. In addition, the expression of cell‐specific markers of various immune cells was higher in CD24‐low DLBCL than in CD24‐high DLBCL. CIBERSORT analysis of the datasets showed fewer macrophages in CD24‐high DLBCL than in CD24‐low DLBCL. Additionally, immunohistochemical analysis of 335 cases of DLBCL showed that few TME cells were found in CD24‐high DLBCL, although statistical differences were not observed. These data indicate that CD24 expression suppresses immune cell components of the TME in DLBCL, suggesting that CD24 may be a target for cancer immunotherapy in aggressive large B‐cell lymphoma.

Evaluation of two functional CD24 polymorphisms in primary sclerosing cholangitis

Background: Primary sclerosing cholangitis (PSC) is a progressive liver disease and characterized by chronic inflammation, sclerosis and strictures of bile ducts. Several genetic risk factors might contribute to pathogenesis. Functional single nucleotide polymorphisms (SNPs) in the CD24 gene have been associated with the development of autoimmune and autoinflammatory diseases and might contribute to the susceptibility for inflammatory bowel disease (IBD).Aim: This retrospective study aimed to evaluate the impact of two functional CD24 SNPs on clinical features and disease progression in patients with PSC.Methods: A C to T coding polymorphism (rs8734) and a TG deletion in the 3´- untranslated region (rs3838646) were genotyped. The study cohort comprises of 359 PSC patients for rs3838646 genotype and 335 PSC patients for rs8734 genotype. Clinical and laboratory parameters were collected by chart review.Results: For the rs8734 genotype, 175 patients (52.2%) were found to be homozygous wildtype ('Ala/Ala'), 127 (37.9%) patients were heterozygous ('Ala/Val') and 33 patients (9.9%) were homozygous mutant ('Val/Val'). The rs8734genotype was associated with a decreased risk for dominant strictures at first diagnosis of PSC (p = .04). For the rs3838646 genotype, 322 patients (89.7%) were found to be homozygous wildtype ('TG/TG'); 37 showed the 'TG/del' genotype (10.3%). The 'TG/del'genotype was associated with alower risk of IBD (p = .01).There was no influence of both CD24 SNPs with clinical end points or transplantation-free survival in our PSC cohort.Conclusion: Our results suggest a mild association of the rs8734 CD24 genotype with dominant strictures at first diagnosis of PSC. The rs3838646 CD24 genotype is associated with a lower rate of IBD. Both SNPs seem to modulate the clinical phenotype without major pathogenetic importance for disease progression in PSC.

Association between CD24 Ala/Val polymorphism and multiple sclerosis risk: A meta analysis

BACKGROUND

The aim of this study was to explore the association between CD24 Ala/Val polymorphism and susceptibility of multiple sclerosis (MS).

METHODS

A comprehensive literature search for relevant studies was performed on google scholar, PubMed, Web of science, Embase, the Chinese National Knowledge Infrastructure and the Chinese Biology Medicine. This meta-analysis was conducted using the STATA 11.0 software and the pooled odds ratio with 95% confidence interval was calculated.

RESULTS

Seven case-control studies were included in this meta-analysis. The results showed significant association between CD24 Ala/Val polymorphism and susceptibility to MS. Stratified analysis by areas also showed significant association in Asians. However, no association was found in Europeans.

CONCLUSION

This study suggested that the CD24 Val allele was associated with an increased risk of MS and larger-scale studies of populations are needed to explore the role of CD24 Ala/Val polymorphism during the pathogenesis of MS.

Combination of interleukin-10 gene promoter polymorphisms with HLA-DRB1*15 allele is associated with multiple sclerosis

BACKGROUND & OBJECTIVES

Multiple sclerosis (MS) is common in some ethnic groups. Interleukin-10 (IL-10) is a potent anti-inflammatory and immunosuppressive cytokine that may be an important regulator in MS disease pathogenesis. IL-10 promoter includes several single nucleotide polymorphisms and the level of IL-10 expression is related to these polymorphisms. Furthermore, loci within the histocompatibility regions are responsible for susceptibility to MS. The aim of this study was to investigate the association of IL-10 gene promoter polymorphisms and HLA-DRB1*15 allele frequencies with MS susceptibility in an Iranian population.

METHODS

In this study 336 MS patients and 454 healthy controls were included. Genomic DNA was purified from peripheral blood samples by a standard protocol. Genotyping was performed by the sequence-specific primer polymerase chain reaction method.

RESULTS

IL-10 -1082 G/G and IL-10 -819 C/C genotypes were more frequent in MS patients than healthy individuals. DRB1*15 allele showed a higher frequency among MS patients compared to controls.

INTERPRETATION & CONCLUSIONS

The IL-10 and HLA-DRB1*15 polymorphisms were associated with the susceptibility to MS in Iranian patients. Our results suggest that gene-gene interaction of IL-10 polymorphisms and HLA-DRB1*15 alleles may be important factors in the development of MS.

Extended B cell phenotype in patients with myalgic encephalomyelitis/chronic fatigue syndrome: a cross-sectional study

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a heterogeneous condition of unknown aetiology characterized by multiple symptoms including fatigue, post-exertional malaise and cognitive impairment, lasting for at least 6 months. Recently, two clinical trials of B cell depletion therapy with rituximab (anti-CD20) reported convincing improvement in symptoms. A possible but undefined role for B cells has therefore been proposed. Studies of the relative percentages of B cell subsets in patients with ME/CFS have not revealed any reproducible differences from healthy controls (HC). In order to explore whether more subtle alterations in B cell subsets related to B cell differentiation exist in ME/CFS patients we used flow cytometry to immunophenotype CD19⁺ B cells. The panel utilized immunoglobulin (Ig)D, CD27 and CD38 (classical B cell subsets) together with additional markers. A total of 38 patients fulfilling Canadian, Centre for Disease Control and Fukuda ME/CFS criteria and 32 age- and sex-matched HC were included. We found no difference in percentages of classical subsets between ME/CFS patients and HC. However, we observed an increase in frequency (P < 0·01) and expression (MFI; P = 0·03) of CD24 on total B cells, confined to IgD⁺ subsets. Within memory subsets, a higher frequency of CD21⁺ CD38⁻ B cells (> 20%) was associated with the presence of ME/CFS [odds ratio: 3·47 (1·15-10·46); P = 0·03] compared with HC, and there was a negative correlation with disease duration. In conclusion, we identified possible changes in B cell phenotype in patients with ME/CFS. These may reflect altered B cell function and, if confirmed in other patient cohorts, could provide a platform for studies based on clinical course or responsiveness to rituximab therapy.

Polymorphisms of the CD24 Gene Are Associated with Risk of Multiple Sclerosis: A Meta-Analysis

CD24 is a cell-surface protein mainly expressed in cells of the immune and central nervous system (CNS), cells that play a critical role in the development of multiple sclerosis (MS). In the current study, we investigated four polymorphisms of the CD24 gene regarding their associations with MS. To this end, univariate and multivariate meta-analysis were applied along with modifications to include data from family-trios so as to increase the robustness of the meta-analysis. We found that the polymorphism 226 C>T (Ala57Val) of the CD24 gene is associated with MS according to the recessive mode of inheritance (odds ratio = 1.75; 95% CI: 1.09, 2.81). Moreover, the 1527–1528 TG>del polymorphism is inversely associated with MS according to the dominant mode of inheritance (odds ratio = 0.57; 95% CI 0.39, 0.83). Conversely, the 1056 A>G and 1626 A>G polymorphisms were not found to be associated with MS. We conclude that the CD24 226 C>T polymorphism increases the risk of MS, while the 1527–1528 TG>del polymorphism seems to have a protective role against MS, suggesting that these two polymorphisms can be used as predictive biomarkers for MS development.

Association between the CD24 Ala57Val polymorphism and risk for multiple sclerosis and systemic lupus erythematosus: a meta-analysis

The cluster of differentiation 24 (CD24) Ala57Val polymorphism has been implicated as a risk factor for multiple sclerosis (MS) and systemic lupus erythematosus (SLE); however, genetic studies have produced controversial results. A meta-analysis was performed on this topic. We used odds ratio (OR) and 95% confidence interval (95% CI) to investigate the strength of association. Eleven studies from nine publications consisting of 2466 cases and 2650 controls were included. The results suggested that the CD24 Val/Val genotypes were associated with an increased risk of MS in all study subjects and Caucasians (OR = 2.28, 95% CI: 1.68–3.10, P_z < 0.001 and OR = 2.30, 95% CI: 1.66–3.20, P_z < 0.001, respectively). Sensitivity analysis showed that no individual study was found to be significantly biasing the pooled results. Although meta-analysis also suggested an association between the CD24 Val/Val genotypes and SLE risk in Caucasians (OR = 1.71, 95% CI: 1.31–2.24, P_z < 0.001), sensitivity analysis demonstrated that the association was not statistically significant after removing a Spanish study. In conclusion, this meta-analysis suggests that the CD24 Ala57Val polymorphism is associated with an increased risk of MS in Caucasians. However, the available evidence is not sufficient to support an association between the CD24 Ala57Val polymorphism and SLE risk.

CD24 gene polymorphism--a novel prognostic factor in esophageal cancer

BACKGROUND

The CD24 gene has been correlated with poor prognosis of various malignancies. The significance of CD24 in esophageal cancer remains unknown. Our aim was to evaluate the association between CD24 genetic polymorphism and esophageal cancer.

MATERIALS AND METHODS

Between June 2011 and May 2012 patients with esophageal cancer and healthy controls were prospectively enrolled and clinicopathological data were collected. Genomic DNA was extracted and restriction fragment length polymorphism (RFLP) analysis was performed to determine CD24 polymorphism at the coding region of CD24, which results in a substitution of the amino acid Ala by Val. Statistical significance was determined by unpaired t-test, χ²-test, and Fisher's exact test.

RESULTS

A total of 102 patients were included, of whom 51 had esophageal cancer and the rest comprised a healthy control group. The incidence of the polymorphism variant (Val/Val) among the healthy subjects and the esophageal cancer cohort was 6% in both groups. The incidence of N3 (metastasis in 7 or more regional lymph nodes) was markedly higher in those esophageal cancer patients who carried the polymorphism variant compared with those who did not carry it (66% and 2%, respectively, p=0.007). No significant difference was found between the groups with regard to age, gender, histology type, tumor location, tumor stage, and other histological characteristics of the tumor.

CONCLUSIONS

This CD24 polymorphism may serve as a novel prognostic marker identifying esophageal cancer patients with poor prognosis. Further studies are warranted to evaluate CD24 function and to validate its predictive potential with regard to esophageal cancer.

CD24 polymorphisms cannot predict pathologic complete response to anthracycline- and taxane-based neoadjuvant chemotherapy in breast cancer

INTRODUCTION

To evaluate the correlations between CD24 polymorphisms and clinicopathologic variables of patients with breast cancer.

PATIENTS AND METHODS

Single-nucleotide polymorphisms (SNPs) of CD24 were genotyped by the Sequenom MassArray iPLEX Gold System in 170 patients with breast cancer, and a total of 120 patients with histologically confirmed T2-4N0-2 M0 breast cancer were recruited to therapy with docetaxel, doxorubicin, and cyclophosphamide (TAC) as neoadjuvant chemotherapy. Data were analyzed by the chi-square test and logistic regression analysis.

RESULTS

There were no significant correlations between CD24 polymorphisms and any of the clinicopathologic variables, and no significant associations were found between either of the polymorphisms and CD24 protein expression. The clinical response rate and the pathologic complete response (pCR) rate were 68.8% and 27.1% in patients with the CD24 rs3838646 CA/CA genotype, and 87.5% and 20.8% in CD24 CA/Del and Del/Del genotype. There were no statistically significant differences between the CA/CA group and the Del allele group. The clinical response rate was 85.4% in patients with the CD24 rs52812045 C/C genotype and 63.9% in patients with the CD24 C/T and T/T genotype. There was a statistically significant difference between the C/C group and the T allele group (odds ratio = 0.28; 95% confidence interval, 0.11-0.73, P = .01). The pCR rate was 29.2% in patients with the CD24 rs52812045 C/C genotype and 23.6% in patients with the CD24 C/T and T/T genotype. There were no statistically significant differences between the C/C group and the T allele group. In a multivariate analysis, there was no correlation between CD24 rs3838646 or rs52812045 genotype and pCR.

CONCLUSION

CD24 rs3838646 and rs52812045 polymorphism could not predict the pathologic complete response to anthracycline- and taxane-based neoadjuvant chemotherapy in breast cancer. Additional larger studies are required to confirm this finding.

Selectins and their ligands as potential immunotherapeutic targets in neurological diseases

Selectins are a family of adhesion receptors that bind to highly glycosylated molecules expressed on the surface of leukocytes and endothelial cells. The interactions between selectins and their ligands control tethering and rolling of leukocytes on the vascular wall during the process of leukocyte migration into the tissues under physiological and pathological conditions. In recent years, it has been shown that leukocyte recruitment in the CNS plays a pivotal role in diseases such as multiple sclerosis, ischemic stroke, epilepsy and traumatic brain injury. In this review, we discuss the role of selectins in leukocyte–endothelial interactions in the pathogenesis of neurological diseases, highlighting new findings suggesting that selectins and their ligands may represent novel potential therapeutic targets for the treatment of CNS diseases.

The genetics of multiple sclerosis: review of current and emerging candidates

Multiple sclerosis (MS) is a complex disease in which environmental, genetic, and epigenetic factors determine the risk of developing the disease. The human leukocyte antigen region is the strongest susceptibility locus linked to MS, but it does not explain the whole heritability of the disease. To find other non-human leukocyte antigen loci associated with the disease, high-throughput genotyping, sequencing, and gene-expression studies have been performed, producing a valuable quantity of information. An overview of the genomic and expression studies is provided in this review, as well as microRNA-expression studies, highlighting the importance of combining all the layers of information in order to elucidate the causes or pathological mechanisms occurring in the disease. Genetics in MS is a promising field that is presumably going to be very productive in the next decade understanding the cross talk between all the factors contributing to the development of MS.

CD24 polymorphisms in breast cancer: impact on prognosis and risk

Overexpression of CD24 has a negative impact on breast cancer prognosis. We have recently reported that the CD24 codon 57 Val/Val genotype (rs52812045) is associated with pathologic complete response after neoadjuvant chemotherapy for primary breast cancer and correlates with intratumoral lymphocyte infiltrates. This study was performed to investigate the influence of CD24 polymorphisms on breast cancer prognosis and risk. A total of 2,514 patients and 4,858 controls recruited as part of the MARIE study, a population-based case-control study, were genotyped for two CD24 polymorphisms (rs52812045, rs3838646) using TaqMan custom genotyping assays. Associations with overall and breast cancer-specific survival were assessed using uni- and multivariable Cox regression models stratified by age at diagnosis and adjusted for prognostic factors. Conditional logistic regression analysis adjusted for major risk factors was used to estimate multivariable odds ratios for risk of putative allele carriers compared to wildtype carriers. CD24 Ala/Val was significantly associated with breast cancer prognosis [Val/Val hazard ratio (HR)(adjusted) = 1.52; 95 % confidence interval (CI): 1.00-2.30, p = 0.05 and HR(adjusted) = 1.83; 95 % CI: 1.10-3.05, p = 0.018 for all-cause and breast cancer-specific mortality, respectively). The association was significant only in patients with a BMI <25 and in those who received adjuvant chemotherapy. None of the CD24 alleles was associated with breast cancer risk. These results provide further evidence of the CD24 Val/Val genotype influencing outcome in primary breast cancer. Together with previous data of CD24 overexpression as a poor prognostic marker, the findings underline the biological importance of CD24 for breast cancer.

CD24 gene allele variation is not associated with oligoclonal IgG bands and IgG index of multiple sclerosis patients

OBJECTIVE

Multiple sclerosis (MS) shows evidence of many distinctive aspects of an autoimmune disorder, including a polygenic inheritance. A recent candidate gene for susceptibility to MS is CD24, which has also been shown to be associated with disease progression. This study was designed to examine whether there is a relationship between the CD24 genotype, oligoclonal band (OCB) status and IgG index in the cerebrospinal fluid (CSF) of MS patients.

METHODS

A total of 27 definite MS patients were enrolled in this cross-sectional study. Blood samples were collected from a peripheral vein, and CSF was obtained by lumbar puncture. The CD24 gene was sequenced in the blood specimen, and albumin and IgG concentrations were measured in both CSF and serum. We compared both IgG index and OCB status in patients with and without CD24V/V. The correlation between MS severity score (MSSS), OCB status, CD24 genotype and IgG index was studied.

RESULTS

Only 15 patients were OCB positive. Among patients with negative OCBs, only 2 patients had the V/V genotype. Furthermore, in those with the V/V genotype, IgG index was not significantly elevated (p = 0.322). Patients with the V/V genotype had a significantly higher MSSS (p = 0. 04), but neither the presence of OCBs nor the IgG index showed significant correlation with MSSS (p = 0.379 and 0.20, respectively).

CONCLUSION

We could not show any relationship between the CD24V/V genotype, OCB status and IgG index. This could be interpreted as indicating that the CD24V/V allele exerts its effects on the disease course independently of CSF IgG synthesis.

CD24 Ala57Val polymorphism predicts pathologic complete response to sequential anthracycline- and taxane-based neoadjuvant chemotherapy for primary breast cancer

Overexpression of CD24 is an independent prognostic factor for breast cancer. Recently, two polymorphisms in the CD24 gene were linked to disease risk and progression in autoimmune diseases. Here, we evaluated the clinical relevance of these polymorphisms with respect to their potential to predict a pathologic complete response (pCR) to neoadjuvant chemotherapy (NCT) for primary breast cancer (PBC), one of the strongest prognostic factors in this setting. A total of 257 patients were randomized to either doxorubicin/cyclophosphamide (AC) or doxorubicin/pemetrexed (AP), both followed by docetaxel (Doc) as NCT for T2-4 N0-2 M0 PBC as part of an international, multicenter, randomized phase II trial. CD24 polymorphisms were analyzed on germ line DNA and correlated with clinicopathologic variables and pCR. No significant associations were found between either of the polymorphisms and any of the clinicopathologic variables. In a multivariate analysis, CD24 Val/Val genotype was the only significant predictor of pCR (OR: 4.97; P = 0.003). The predictive potential was significant in both treatment arms and in the hormone receptor-positive subgroup. There was no correlation between CD24 3'UTR (TG/Del) genotype and pCR. We did not observe any association between CD24 genotype and CD24 protein expression or in vitro chemosensitivity, but there was a significant correlation between CD24 Val/Val and intratumoral lymphocyte aggregates. In conclusion, CD24 Ala/Val SNP is a strong and independent predictor of pCR after NCT for PBC and may affect immune functions rather than tumor characteristics. Further evaluation of the CD24 function and validation of its predictive potential are clearly warranted.

Investigation of CD24 and its expression in Iranian relapsing-remitting multiple sclerosis

CD24 is a glycosylphosphatidylinositol (GPI)-linked cell surface glycoprotein expressed in central nervous system cells. Recent investigations have suggested that CD24 participates in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). However, a limited number of studies have been published regarding the contribution of CD24 to the risk and severity of MS in humans. We investigated the contribution of a CD24 single nucleotide polymorphism (SNP) to MS disease risk and severity. We also studied mRNA expression of the CD24 gene in Iranian MS patients using quantitative real-time polymerase chain reaction (PCR). Our findings showed that the CD24(v/v) genotype was significantly more frequent in MS patients compared with controls (p(c) = .004). Moreover, a statistically significant difference in the Multiple Sclerosis Severity Score (MSSS) was found between MS patients carrying CD24(a/a) and CD24(v/v) genotypes (p = .008). The results also indicated that the expression of CD24 mRNA was 1.7 times more in MS patients compared with controls. In conclusion, our results suggest that the CD24(v/v) genotype influences both MS disease risk and severity in Iranian MS patients, and the high disease severity in CD24(v/v) patients may indicate that they require more aggressive treatment than do patients carrying CD24(a/a).

Analysis of the influence of two CD24 genetic variants in Crohn's disease and ulcerative colitis

The aim of this study was to evaluate the possible implication of CD24 gene in the genetic predisposition to inflammatory bowel disease (IBD). Our study population consisted of 1321 female Spanish individuals (369 Crohn's disease [CD] patients, 323 ulcerative colitis [UC] patients, and 629 healthy matched controls). Two putative functional polymorphisms, a C to T coding polymorphism (rs8734) and a TG deletion in the 3' untranslated region (rs3838646), were used as CD24 genetic markers and genotyped using a Taqman 5' allelic discrimination assay. The "del" allele of the dinucleotide deletion was associated with an increased risk of CD (odds ratio = 1.61, 95% confidence interval = 1.17-2.21, p(FDR) = 6.4E-03) but not with UC. Moreover, this allele was significant associated with the age of CD diagnosis between 17 and 40 years, the ileocolonic location, and the inflammatory behavior of CD. We observed no significant differences between the allelic or genotypic frequencies of the A57V polymorphism in our studied IBD cohort. Our results suggest that the rs3838646 CD24 polymorphism is part of the genetic background of CD.

CD24 as a genetic modifier of disease progression in multiple sclerosis in Argentinean patients

INTRODUCTION

Previous reports have shown that CD24 gene polymorphisms have an important role in the risk of development and progression of multiple sclerosis (MS).

OBJECTIVE

To investigate the association between P226 polymorphisms (T/C), P1056 (A/G), P1527 (TG/del) and P1626 (A/G) of the CD24 gene and MS, comparing allele and genotype frequencies of patients versus controls.

MATERIALS AND METHODS

We analyzed DNA samples from 102 MS patients and from 205 unrelated healthy individuals. DNA was extracted from peripheral blood and polymorphic regions were amplified by nested PCR. Genotyping was performed by restriction fragments length polymorphisms. Time from disease onset to reach EDSS 6 and time to conversion to secondary progressive phase (SP) were used as variables of survival as well as percentage of patients that reached those endpoints. We used the log Rank test for data comparison (significant p≤0.05).

RESULTS

We found no differences between cases and controls in frequency of polymorphisms at the CD24 gene. 44.6% of patients with the AA genotype (P1626) reached an EDSS 6 vs 16% of patients with other genotypes (p<0.001, HR 3.2, 95% CI 1.4 to 7.4). 45.8% of patients with the AA genotype reached SPMS vs 16.7% without this genotype (p<0.001, HR 3.4, 95% CI 1.5 to 7.8).

CONCLUSIONS

This study showed a strong association between the presence of AA genotype in the 1626 polymorphism of the CD24 gene and the risk of disease progression in MS patients.

CD24: from A to Z

As a testament to the importance of CD24, researchers with diverse interests, including adaptive immunity, inflammation, autoimmune diseases and cancer, have encountered CD24. CD24 is overexpressed in many cancers and appears oncogenic. In the adaptive immune response, CD24 is a redundant costimulatory molecule in costimulation-rich lymphoid organs but is essential in selected target organs tested, such as brain and skin. More recent studies suggest it may have a role in discriminating danger and pathogen-associated molecular patterns by dendritic cells. The biology of CD24 is intriguing but poorly understood. Here we summarize the major findings associated with CD24 to stimulate new ideas for further research that may reveal the underlying link among the diverse processes mediated by CD24.

CD24 Ala57Val gene polymorphism and the risk of systemic lupus erythematosus

It was recently shown that the CD24 Ala57Val (rs 52812045) polymorphism plays a significant role in susceptibility to systemic lupus erythematosus (SLE) in a Spanish population, which has not been confirmed in other ethnic groups. We investigated the distribution of the CD24 Ala57Val polymorphism in patients with SLE (n = 250) and controls (n = 350) in Poland. The odds ratio (OR) for patients with SLE with the Ala/Val genotype compared with Ala/Ala genotype was 1.490 [95% confidence interval (CI) = 1.052-2.111, P = 0.0275], and OR for the Val/Val genotype compared with Ala/Ala genotypes was 2.001 (95% CI = 1.154-3.467, P = 0.0154). Moreover, we observed a significant association between the CD24 Val allele and the presence of anti-Scl-70 antibody (Ab) OR = 2.155 (1.438-3.229, P = 0.0002). There was also an association of Val allele with the presence of anti-snRNP Ab OR = 1.984 (1.266-3.110, P = 0.0034) in patients with SLE. We also found that the CD24 Val/Val and Ala/Val genotypes contribute to immunologic manifestations OR = 2.244 (1.323-3.806, P = 0.0037). Our observations indicate that the CD24 Ala57Val polymorphism may predispose to SLE incidence and can be linked to immunologic manifestations and production of autoantibodies in this disease.

CD24 gene polymorphism is associated with the disease progression and susceptibility to multiple sclerosis in the Iranian population

The impact of a single nucleotide polymorphism (SNP) in the CD24 gene on the risk and progression of multiple sclerosis (MS) was investigated in the Iranian population. Our data revealed that the susceptibility and the progression of MS in individuals with the CD24V/V genotype were greater than in those with the CD24A/V and CD24A/A genotypes.

CD24-Siglec G/10 discriminates danger- from pathogen-associated molecular patterns

It is now well accepted that the innate immune system recognizes both damage (or danger)- and pathogen-associated molecular patterns (DAMP and PAMP, respectively) through pattern recognition receptors, such as Toll-like receptors (TLR) and/or Nod-like receptors (NLR). Less clear are whether and how the response to PAMP and DAMP are regulated differentially. The answers may reveal whether the primary goal of the immune system is to defend against infections or to alert the host of tissue injuries. We demonstrated recently that the host response to DAMP is controlled by a DAMP-CD24-Siglec axis. Here we propose a key role for the CD24-Siglec pathway in discriminating between DAMPs and PAMPs.

O-glycosylation pattern of CD24 from mouse brain

The cell adhesion molecule CD24 is a highly glycosylated glycoprotein that plays important roles in the central nervous system, the immune system and in tumor biology. Since CD24 comprises only a short protein core of approximately 30 amino acids and low conservation among species, it has been proposed that the functions of CD24 are mediated by its glycosylation pattern. Our present study provides evidence that interaction of CD24 with the cell adhesion molecule L1 is mediated by O-linked glycans carrying alpha2,3-linked sialic acid. Furthermore, de-N-glycosylated CD24 was shown to promote or inhibit neurite outgrowth of cerebellar neurons or dorsal root ganglion neurons, respectively, to the same extent as untreated CD24. Therefore, this study is focused on the structural elucidation of the chemically released, permethylated CD24 O-glycans by electrospray ionization ion trap mass spectrometry. Our analyses revealed the occurrence of a diverse mixture of mucin-type and O-mannosyl glycans carrying, in part, functionally relevant epitopes, such as 3-linked sialic acid, disialyl motifs, Le(X), sialyl-Le(X) or HNK-1 units. Hence, our data provide the basis for further studies on the contribution of carbohydrate determinants to CD24-mediated biological activities.

Association of a CD24 gene polymorphism with susceptibility to systemic lupus erythematosus

OBJECTIVE

To determine the potential role of the CD24 A57V gene polymorphism in systemic lupus erythematosus (SLE).

METHODS

We studied 3 cohorts of Caucasian patients and controls. The Spanish cohort included 696 SLE patients and 539 controls, the German cohort included 257 SLE patients and 317 controls, and the Swedish cohort included 310 SLE patients and 247 controls. The CD24 A57V polymorphism was genotyped by polymerase chain reaction, using a predeveloped TaqMan allele discrimination assay. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

In the Spanish cohort there was a statistically significant difference in the distribution of the CD24 V allele between SLE patients and controls (OR 3.6 [95% CI 2.13-6.16], P < 0.0001). In addition, frequency of the CD24 V/V genotype was increased in SLE patients compared with controls (OR 3.7 [95% CI 2.16-6.34], P < 0.00001). We sought to replicate this association with SLE in a German population and a Swedish population. A similar trend was found in the German group. The CD24 V/V genotype and the CD24 V allele were more frequent in SLE patients than in controls, although this difference was not statistically significant. No differences were observed in the Swedish group. A meta-analysis of the Spanish and German cohorts demonstrated that the CD24 V allele has a risk effect in SLE patients (pooled OR 1.25 [95% CI 1.08-1.46], P = 0.003). In addition, homozygosity for the CD24 V risk allele significantly increased the effect (pooled OR 2.19 [95% CI 1.50-3.22], P = 0.00007).

CONCLUSION

These findings suggest that the CD24 A57V polymorphism plays a role in susceptibility to SLE in a Spanish population.

Recent advances in genetic analysis of multiple sclerosis: genetic associations and therapeutic implications

Epidemiological studies have confirmed that genetic factors are a key component in the pathogenesis of multiple sclerosis (MS) and that those determining MS susceptibility have been extensively studied. Many papers have been published regarding the heritable differences useful in genetic studies; these include variations in DNA, such as single-nucleotide polymorphisms, microsatellites and insertion/deletion polymorphisms. However, to date, among other regions, HLA is the only region confirmed to possess genes that determine MS susceptibility. In this article, we review the progress during the last 5 years in the studies on the susceptibility genes and the pharmacogenetics of MS. Newer techniques and methods of analysis will hopefully result in better screening of individuals who are at highest risk and novel treatments.

CD24: a genetic checkpoint in T cell homeostasis and autoimmune diseases

CD24 is widely used as a marker for differentiation of multiple lineages of cells and can provide costimulation for T cells, especially in non-lymphoid target organs. Recent studies demonstrate that CD24 controls an important genetic checkpoint for homeostasis and autoimmune diseases in both mice and humans. Understanding the molecular and cellular basis of CD24 function could provide important insights into T cell biology and autoimmunity.

A dinucleotide deletion in CD24 confers protection against autoimmune diseases

It is generally believed that susceptibility to both organ-specific and systemic autoimmune diseases is under polygenic control. Although multiple genes have been implicated in each type of autoimmune disease, few are known to have a significant impact on both. Here, we investigated the significance of polymorphisms in the human gene CD24 and the susceptibility to multiple sclerosis (MS) and systemic lupus erythematosus (SLE). We used cases/control studies to determine the association between CD24 polymorphism and the risk of MS and SLE. In addition, we also considered transmission disequilibrium tests using family data from two cohorts consisting of a total of 150 pedigrees of MS families and 187 pedigrees of SLE families. Our analyses revealed that a dinucleotide deletion at position 1527∼1528 (P1527^del) from the CD24 mRNA translation start site is associated with a significantly reduced risk (odds ratio = 0.54 with 95% confidence interval = 0.34–0.82) and delayed progression (p = 0.0188) of MS. Among the SLE cohort, we found a similar reduction of risk with the same polymorphism (odds ratio = 0.38, confidence interval = 0.22–0.62). More importantly, using 150 pedigrees of MS families from two independent cohorts and the TRANSMIT software, we found that the P1527^del allele was preferentially transmitted to unaffected individuals (p = 0.002). Likewise, an analysis of 187 SLE families revealed the dinucleotide-deleted allele was preferentially transmitted to unaffected individuals (p = 0.002). The mRNA levels for the dinucleotide-deletion allele were 2.5-fold less than that of the wild-type allele. The dinucleotide deletion significantly reduced the stability of CD24 mRNA. Our results demonstrate that a destabilizing dinucleotide deletion in the 3′ UTR of CD24 mRNA conveys significant protection against both MS and SLE.

When an individual's immune system attacks self tissues or organs, he/she develops autoimmune diseases. Although it is well established that multiple genes control susceptibility to autoimmune diseases, most of the genes remain unidentified. In addition, although different autoimmune diseases have a common immunological basis, a very small number of genes have been identified that affect multiple autoimmune diseases. Here we show that a variation in CD24 is a likely genetic factor for the risk and progression of two types of autoimmune diseases, including multiple sclerosis (MS), an organ-specific autoimmune disease affecting the central nervous system, and systemic lupus erythematosus, a systemic autoimmune disease. Our data indicated that if an individual's CD24 gene has a specific two-nucleotide deletion in the noncoding region of CD24 mRNA, his/her risk of developing MS or SLE is reduced by 2- to 3-fold. As a group, MS patients with the two-nucleotide deletion will likely have a slower disease progression. Biochemical analysis indicated that the deletion leads to rapid decay of CD24 mRNA, which should result in reduced synthesis of the CD24 protein. Our data may be useful for the treatment and diagnosis of autoimmune diseases.