Keratinocyte CDw60 expression is modulated by both a Th-1 type cytokine IFN-gamma and Th-2 cytokines IL-4 and IL-13: relevance to psoriasis

The enchanting canvas of CAR technology: Unveiling its wonders in non-neoplastic diseases

Chimeric antigen receptor (CAR) T cells have made a groundbreaking advancement in personalized immunotherapy and achieved widespread success in hematological malignancies. As CAR technology continues to evolve, numerous studies have unveiled its potential far beyond the realm of oncology. This review focuses on the current applications of CAR-based cellular platforms in non-neoplastic indications, such as autoimmune, infectious, fibrotic, and cellular senescence-associated diseases. Furthermore, we delve into the utilization of CARs in non-T cell populations such as natural killer (NK) cells and macrophages, highlighting their therapeutic potential in non-neoplastic conditions and offering the potential for targeted, personalized therapies to improve patient outcomes and enhanced quality of life.

Keratinocytes Present Staphylococcus aureus Enterotoxins and Promote Malignant and Nonmalignant T Cell Proliferation in Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphoma is characterized by malignant T cells proliferating in a unique tumor microenvironment dominated by keratinocytes (KCs). Skin colonization and infection by Staphylococcus aureus are a common cause of morbidity and are suspected of fueling disease activity. In this study, we show that expression of HLA-DRs, high-affinity receptors for staphylococcal enterotoxins (SEs), by KCs correlates with IFN-γ expression in the tumor microenvironment. Importantly, IFN-γ induces HLA-DR, SE binding, and SE presentation by KCs to malignant T cells from patients with Sézary syndrome and malignant and nonmalignant T-cell lines derived from patients with Sézary syndrome and mycosis fungoides. Likewise, preincubation of KCs with supernatant from patient-derived SE-producing S aureus triggers proliferation in malignant T cells and cytokine release (including IL-2), when cultured with nonmalignant T cells. This is inhibited by pretreatment with engineered bacteriophage S aureus-specific endolysins. Furthermore, alteration in the HLA-DR-binding sites of SE type A and small interfering RNA-mediated knockdown of Jak3 and IL-2Rγ block induction of malignant T-cell proliferation. In conclusion, we show that upon exposure to patient-derived S aureus and SE, KCs stimulate IL-2Rγ/Jak3-dependent proliferation of malignant and nonmalignant T cells in an environment with nonmalignant T cells. These findings suggest that KCs in the tumor microenvironment play a key role in S aureus-mediated disease activity in cutaneous T-cell lymphoma.

Abnormalities of Sphingolipids Metabolic Pathways in the Pathogenesis of Psoriasis

Psoriasis is immune-mediated skin disorder affecting thousands of people. Sphingolipids (SLs) are bioactive molecules present in the epidermis, involved in the following cellular processes: proliferation, differentiation, and apoptosis of keratinocytes. Alterations in SLs synthesis have been observed in psoriatic skin. To investigate if the imbalance in lipid skin metabolism could be related to psoriasis, we analyzed the gene expression in non-lesioned and lesioned skin of patients with psoriasis available in two datasets (GSE161683 and GSE136757) obtained from National Center for Biotechnology Information (NCBI). The differentially expressed genes (DEGs) were searched for using NCBI analysis, and Gene Ontology (GO) biological process analyses were performed using the Database of Annotation, Visualization, and Integrated Discovery (DAVID) platform. Venn diagrams were done with InteractiVenn tool and heatmaps were constructed using Morpheus software. We observed that the gene expression of cytoplasmic phospholipase A₂ (PLA2G4D), glycerophosphodiester phosphodiesterase domain containing 3 (GDP3), arachidonate 12-lipoxygenase R type (ALOX12B), phospholipase B-like 1 (PLBD1), sphingomyelin phosphodiesterase 3 (SMPD3), ganglioside GM2 activator (GM2A), and serine palmitoyltransferase long chain subunit 2 (SPTLC2) was up-regulated in lesioned skin psoriasis when compared with the non-lesioned skin. These genes are related to lipid metabolism and more specifically to sphingolipids. So, in the present study, the role of sphingolipids in psoriasis pathogenesis is summarized. These genes could be used as prognostic biomarkers of psoriasis and could be targets for the treatment of patients who suffer from the disease.

Antigen Specificity Enhances Disease Control by Tregs in Vitiligo

Vitiligo is an autoimmune skin disease characterized by melanocyte destruction. Regulatory T cells (Tregs) are greatly reduced in vitiligo skin, and replenishing peripheral skin Tregs can provide protection against depigmentation. Ganglioside D3 (GD3) is overexpressed by perilesional epidermal cells, including melanocytes, which prompted us to generate GD3-reactive chimeric antigen receptor (CAR) Tregs to treat vitiligo. Mice received either untransduced Tregs or GD3-specific Tregs to test the hypothesis that antigen specificity contributes to reduced autoimmune reactivity in vitro and in vivo. CAR Tregs displayed increased IL-10 secretion in response to antigen, provided superior control of cytotoxicity towards melanocytes, and supported a significant delay in depigmentation compared to untransduced Tregs and vehicle control recipients in a TCR transgenic mouse model of spontaneous vitiligo. The latter findings were associated with a greater abundance of Tregs and melanocytes in treated mice versus both control groups. Our data support the concept that antigen-specific Tregs can be prepared, used, and stored for long-term control of progressive depigmentation.

Interferon γ is a strong, STAT1-dependent direct inducer of BCL6 expression in multiple myeloma cells

B-cell CLL/lymphoma 6 (BCL6) is a transcriptional master regulator that can repress more than 1200 potential target genes. It exerts oncogenic effects through the inhibition of differentiation, DNA damage sensing and apoptosis in several human hematopoietic malignancies, including multiple myeloma (MM). The multifunctional cytokine interferon γ (IFNγ) exerts pro-apoptotic and anti-proliferative effects on MM cells in vitro, at least partially through the inhibition of the effects of interleukin 6 (IL6), one of the most important growth factor of MM and a strong inducer of BCL6 expression. However, IFNγ was also reported to directly upregulate BCL6 in several cell types. These observations prompted us to analyze the effect of IFNγ on BCL6 expression in MM cells. We discovered that among several myeloma growth/survival factors tested (including IL6, oncostatin M, insulin-like growth factor 1, tumor necrosis factor α and IFNα) IFNγ was the strongest inducer of BCL6 mRNA and protein expression in MM cell lines. IFNγ induced upregulation of BCL6 was dependent on the classical STAT1 signaling pathway, and affected both major BCL6 variants. Interestingly, although IFNα induced stronger STAT1 phosphorylation than IFNγ, it only slightly upregulated BCL6 in MM lines. We proved that IFNα induced BCL6 upregulation was limited by the concomitant activation of STAT5 signaling. We assume that BCL6 upregulation may represent a potentially pro-tumorigenic effect of IFNγ signaling in MM cells.

Interferon γ is a STAT1-dependent direct inducer of BCL6 expression in imatinib-treated chronic myeloid leukemia cells

B-cell CLL/lymphoma 6 (BCL6) exerts oncogenic effects in several human hematopoietic malignancies including chronic myeloid leukemia (CML), where BCL6 expression was shown to be essential for CML stem cell survival and self-renewal during imatinib mesylate (IM) treatment. As several lines of evidence suggest that interferon γ (IFNγ) production in CML patients might have a central role in the response to tyrosine kinase inhibitor (TKI) therapy, we analyzed if IFNγ modulates BCL6 expression in CML cells. Although separate IFNγ or IM treatment only slightly upregulated BCL6 expression, combined treatment induced remarkable BCL6 upregulation in CML lines and primary human CD34+ CML stem cells. We proved that during combined treatment, inhibition of constitutive signal transducer and activator of transcription (STAT) 5 activation by IM allowed the specific enhancement of the STAT1 dependent, direct upregulation of BCL6 by IFNγ in CML cells. By using colony-forming assay, we found that IFNγ enhanced the ex vivo colony or cluster-forming capacity of human CML stem cells in the absence or presence of IM, respectively. Furthermore, inhibition of the transcriptional repressor function of BCL6 in the presence of IM and IFNγ almost completely blocked the cluster formation of human CML stem cells. On the other hand, by using small interfering RNA knockdown of BCL6, we demonstrated that in an IM-treated CML line the antiapoptotic effect of IFNγ was independent of BCL6 upregulation. We found that IFNγ also upregulated several antiapoptotic members of the BCL2 and BIRC gene families in CML cells, including the long isoform of MCL1, which proved to be essential for the antiapoptotic effect of IFNγ in an IM-treated CML line. Our results suggest that combination of TKIs with BCL6 and MCL1 inhibitors may potentially lead to the complete eradication of CML stem cells.

Immunopathogenesis of psoriasis

This paper reviews the pathogenesis of psoriasis, in particular, the immunological cascade in psoriasis. Psoriasis is an immune-mediated skin disease where the T cell plays a pivotal role in the pathogenesis of the disease. The critical steps involved in the pathogenesis include Langerhans cell activation and maturation by antigens in the skin, activation of the T cell by mature Langerhans cells, differentiation and expansion of T cells within the lymph nodes, trafficking of activated T cells from the lymph node to the skin and the subsequent release of cytokines. These cytokines are responsible for epidermal and vascular hyperproliferation and pro-inflammatory effects. Each of these steps provides an opportunity for biological agents designed to block the psoriatic immunological cascade. This paper reviews the immunopathogenesis of psoriasis. Biologic agents in psoriasis, to be published separately, reviews the new biologic therapies that aim to selectively block the immunological steps implicated in the pathogenesis of psoriasis outlined in this paper.

Psoriasis: immunopathogenesis and evolving immunomodulators and systemic therapies; U.S. experiences

BACKGROUND

Psoriasis is a chronic inflammatory skin disorder that is presently without a permanent cure. Up to 40% of patients with psoriasis also develop psoriatic arthritis. The mainstay armamentarium to treat psoriasis systemically includes methotrexate, cyclosporin and oral retinoids, all with significant potential for toxicity and the need for close laboratory supervision. The although the exact mechanism of psoriasis is still unclear, the involvement of T-cell-mediated cytokine expression in the aetiology of psoriasis is becoming clearer. The goal of modern treatment is to target such immune responses that lead to the formation of psoriatic plaques and psoriatic arthritis using selective immunomodulating pharmacotherapy. The advantages of these biological agents are less toxic systemic side-effect profiles that will improve the quality of life in psoriatic patients.

OBJECTIVES

This review article describes current and emerging selective immunotherapies and systemic therapies for the treatment of psoriasis, and will briefly discuss disease immunopathogenesis.

METHODS

Literature review.

RESULTS AND CONCLUSIONS

Given the role of the inflammatory immune responses in the pathogenesis of psoriasis, the goal of modern medicine and pharmacotherapy lies in the design and use of specific targets in cell-mediated immune reactions and the modulation of the expression of various inflammatory cytokines. The clinical evidence of efficacy of some of these new biological immunomodulatory agents from several U.S.-based research studies and clinical experiences is convincing.

Up-regulation of interleukin-13 receptor alpha1 on human keratinocytes in the skin of psoriasis and atopic dermatitis

BACKGROUND

Interleukin (IL)-13 is a pleiotropic cytokine, which shares many biological functions with IL-4. The receptor subunits of IL-13 consist of IL-4Ralpha, IL-13Ralpha1 and IL-13Ralpha2. The regulatory mechanisms of the IL-13Ralpha expression in the keratinocytes of certain skin disease have not been known.

OBJECTIVE

To clear the roles of IL-13 and the regulatory mechanisms of its receptor in atopic dermatitis (AD) and psoriasis.

METHOD

The expression of IL-13Ralpha1 in the skin of AD and psoriasis was investigated by immunohistochemistry. The regulation of IL-13Ralpha mRNA in the skin and human primary keratinocyte (HPK) was investigated by quantitative PCR. The secretion of IL-6 and RANTES from HPK was measured by ELISA.

RESULTS

The expression of IL-13Ralpha1 was more prominent on the suprabasal keratinocytes in the skin of AD and striking increase of staining was observed on all layers of keratinocyte in the skin of psoriasis. The mRNA of IL-13Ralpha1, but not of IL-13Ralpha2 was overexpressed in both skin of AD and psoriasis. In vitro experiment using HPK demonstrated that IFN-gamma, IL-13 but not IL-4 could up-regulate the mRNA expression of IL-13Ralpha1. In contrast, IL-13Ralpha2 mRNA expression was up-regulated by IFN-gamma plus IL-4. Furthermore, the stimulation of HPK with IFN-gamma plus IL-13 and/or IL-4 resulted in significant enhancement of IL-6 and RANTES secretion.

CONCLUSION

These findings indicate that IL-4 and IL-13 have different regulatory effects on the expression of IL-13Ralpha1 and alpha2, and the overexpression of IL-13Ralpha1 may play some roles in the pathogenesis of chronic stage of AD or psoriasis.

Histological changes in radial forearm skin flaps in the oral cavity

We reported previously that skin flaps transplanted to the oral cavity in reconstructive surgery for oral cancer frequently acquired the gross appearance of buccal mucosa. The changes were shown to be reactive in nature. The "changed" flaps generally had a heavier infiltration of leukocytes in the dermis and appeared to have thicker epithelium. The present study quantifies these parameters, as well as the numbers of intraepithelial leukocytes. The flaps that had acquired the gross appearance of oral mucosa had significantly thicker epithelium, larger numbers of dermal leukocytes, and more intraepidermal inflammatory cells per unit length than flaps that retained the gross appearance of thin skin. No correlation was found between these changes and radiotherapy.

Expansion of vitiligo lesions is associated with reduced epidermal CDw60 expression and increased expression of HLA-DR in perilesional skin

BACKGROUND

Detection of CDw60 in skin is representative of ganglioside D3 expression. This ganglioside is expressed primarily by melanocytes, and is of interest as a membrane antigen targeted by immunotherapy for melanoma patients. Expression of CDw60 by keratinocytes is defined by the presence of T-helper cell (Th)1 vs. Th2 cytokines, and can serve as a sentinel molecule to characterize an ongoing skin immune response.

OBJECTIVES

These immunobiological characteristics have provided the incentive to study the expression of CDw60 in the context of progressive vitiligo.

METHODS

Frozen sections were obtained from control skin and from vitiligo lesions and immunostained to show CDw60. Cells were cultured, their CDw60 expression studied and ribonuclease protection assays run to detect cytokine mRNA.

RESULTS

Resistance to cytokine-mediated regulation of CDw60 expression was demonstrated in vitro by melanocytes, which appeared capable of generating autocrine and paracrine regulatory molecules supporting CDw60 expression. Induction of CDw60 expression was inhibited by antibodies to interleukin (IL)-4, suggesting that this cytokine was responsible, at least in part, for melanocyte-induced CDw60 expression. Marginal skin from patients with progressive generalized vitiligo consistently showed a reduction in epidermal CDw60 expression alongside elevated human leucocyte associated antigen (HLA)-DR expression at the margin. It thus appears that inflammatory infiltrates present in marginal skin generate type 1 rather than type 2 cytokines, supportive of a cell-mediated autoimmune response.

CONCLUSIONS

These results support an active role of melanocytes within the skin immune system, and associate their loss in generalized vitiligo with a cell-mediated immune response mediated by type 1 cytokines.

The immunology of psoriasis and biologic immunotherapy

In this review, we will discuss the immunological basis for psoriasis with special emphasis on the role of effector T cells. With the understanding of this immunologic process, we will present a model for the development of targeted immune response modifiers, termed biologic immunotherapies, and their potential role for the benefit of patients with psoriasis.

Suppressor of cytokine signaling 1/JAB and suppressor of cytokine signaling 3/cytokine-inducible SH2 containing protein 3 negatively regulate the signal transducers and activators of transcription signaling pathway in normal human epidermal keratinocytes

The suppressor of cytokine signaling/cytokine-inducible SH2 containing proteins are cytokine inducible and are negative regulators of the signal transducers and activators of the transcription signaling pathway. We investigated the mechanism regulating signal transducers and activators of transcription and the suppressor of cytokine signaling/cytokine-inducible SH2 containing protein family in keratinocytes, one of the major target cells for cytokines. Suppressor of cytokine signaling 1 mRNA was upregulated 3 h post-interferon gamma, and a 8.1-fold increase in the suppressor of cytokine signaling 1 mRNA occurred 48 h post-interferon gamma. The suppressor of cytokine signaling 3 mRNA was also upregulated from 1 h post-interferon gamma, and a 6.7-fold increase in the suppressor of cytokine signaling 3/cytokine-inducible SH2 containing protein 3 mRNA occurred between 6 and 12 h post-interferon gamma. Interleukin-6 exposure for 1 h enhanced the expression of the suppressor of cytokine signaling 3/cytokine-inducible SH2 containing protein 3 mRNA, but the suppressor of cytokine signaling 1/JAB mRNA was not induced by interleukin-6. Interleukin-4 upregulated the suppressor of cytokine signaling 1/JAB and cytokine-inducible SH2 containing protein 1 mRNA, with 3.4-fold and 5.1-fold increases in mRNA observed at 1 h post-interleukin-4, respectively. In contrast, epidermal growth factor, which phosphorylates signal transducers and activators of transcription 3, did not influence the level of the suppressor of cytokine signaling/cytokine-inducible SH2 containing protein family mRNA expression. Transfection of an adenovirus vector expressing the suppressor of cytokine signaling 1/JAB completely inhibited interferon gamma-dependent signal transducers and activators of transcription 1 phosphorylation and interleukin-4-dependent signal transducers and activators of transcription 6 phosphorylation. Transfection of adenovirus vector expressing the suppressor of cytokine signaling 1/JAB did not inhibit interleukin-6-dependent signal transducers and activators of transcription 3 phosphorylation-several reports show that the suppressor of cytokine signaling 1/JAB is a potent inhibitor of signal transducers and activators of transcription 3 signaling in the myeloid leukemia M1 cell. Transfection of the adenovirus vector expressing suppressor of cytokine signaling 3/cytokine-inducible SH2 containing protein 3 completely inhibited interleukin-6-dependent signal transducers and activators of transcription 3 phosphorylation and partially inhibited interferon gamma-dependent signal transducers and activators of transcription 1 phosphorylation. Transfection of the adenovirus vector expressing suppressor of cytokine signaling 3/cytokine-inducible SH2 containing protein 3, however, did not inhibit interleukin-4-dependent signal transducers and activators of transcription 6 phosphorylation. Transfection of the adenovirus vector expressing cytokine-inducible SH2 containing protein 1 had no effect on signal transducers and activators of transcription 1, 3, and 6 signaling in normal keratinocytes. Therefore, the relationship between signal transducers and activators of transcription and suppressor of cytokine signaling is unique in the keratinocytes, and the suppressor of cytokine signaling regulates cytokine signals in these cells.

Genes modulated by expression of GD3 synthase in Chinese hamster ovary cells. Evidence that the Tis21 gene is involved in the induction of GD3 9-O-acetylation

9-O-Acetylation is a common sialic acid modification, expressed in a developmentally regulated and tissue/cell type-specific manner. The relevant 9-O-acetyltransferase(s) have not been isolated or cloned; nor have mechanisms for their regulation been elucidated. We previously showed that transfection of the GD3 synthase (ST8Sia-I) gene into Chinese hamster ovary (CHO)-K1 cells gave expression of not only the disialoganglioside GD3 but also 9-O-acetyl-GD3. We now use differential display PCR between wild type CHO-K1 cells and clones stably expressing GD3 synthase (CHO-GD3 cells) to detect any increased expression of other genes and explore the possible induction of a 9-O-acetyltransferase. The four CHO mRNAs showing major up-regulation were homologous to VCAM-1, Tis21, the KC-protein-like protein, and a functionally unknown type II transmembrane protein. A moderate increase in expression of the FxC1 and SPR-1 genes was also seen. Interestingly, these are different from genes observed by others to be up-regulated after transfection of GD3 synthase into a neuroblastoma cell line. We also isolated a CHO-GD3 mutant lacking 9-O-acetyl-GD3 following chemical mutagenesis (CHO-GD3-OAc(-)). Analysis of the above differential display PCR-derived genes in these cells showed that expression of Tis21 was selectively reduced. Transfection of a mouse Tis21 cDNA into the CHO-GD3-OAc(-) mutant cells restored 9-O-acetyl-GD3 expression. Since the only major gangliosides expressed by CHO-GD3 cells are GD3 and 9-O-acetyl-GD3 (in addition to GM3, the predominant ganglioside type in wild-type CHO-K1 cells), we conclude that GD3 enhances its own 9-O-acetylation via induction of Tis21. This is the first known nuclear inducible factor for 9-O-acetylation and also the first proof that 9-O-acetylation can be directly regulated by GD3 synthase. Finally, transfection of CHO-GD3-OAc(-) mutant cells with ST6Gal-I induced 9-O-acetylation specifically on sialylated N-glycans, in a manner similar to wild-type cells. This indicates separate machineries for 9-O-acetylation on alpha2-8-linked sialic acids of gangliosides and on alpha2-6-linked sialic acids on N-glycans.

Interleukin-13 receptor in psoriatic keratinocytes: overexpression of the mRNA and underexpression of the protein

Although several cytokines and their receptors have been involved in the development of psoriasis, the etiology is still unknown. In this study we looked for genes possibly involved in the disease by the reverse transcription-polymerase chain reaction differential display technique in lesional and nonlesional skin biopsies from psoriatic patients. We found the mRNA of the alpha1 chain of the interleukin-13 receptor expressed differentially in psoriatic biopsies. By reverse transcription-polymerase chain reaction, we confirmed an overexpression of the alpha1 chain of the IL-13 receptor and alpha chain of the interleukin-4 receptor mRNA in lesional skin psoriatic biopsies, when compared with skin biopsies from healthy subjects (p<0.01). The nonlesional skin obtained from a region close to a lesional zone in psoriatic patients presented also an overexpression of these mRNA in 50% of the samples. Interleukin-13 and interleukin-4 were not detected either as mRNA or as the proteins in any of the biopsies from psoriatic patients or healthy subjects. A monoclonal antibody to the alpha1 chain of the interleukin-13 receptor detected the receptor in the epidermal keratinocytes of psoriatic patients and of healthy subjects; however, the positive antibody reaction was stronger in skin tissue from healthy subjects than in psoriatic lesional skin tissue (p<0.01), although the mRNA was overexpressed. As interleukin-13 is a pleiotropic immunoregulatory cytokine with a variety of effects on different cell types, including monocytes, B lymphocytes, mast cells, and keratinocytes, we suggest, based on our results, that the interleukin-13 receptor possibly plays an important part in the early inflammatory process of psoriasis; however, its function is lost in the psoriatic keratinocytes.

Gangliosides with O-acetylated sialic acids in tumors of neuroectodermal origin

Gangliosides, carrying an O-acetylated sialic acid in their carbohydrate moiety, are often found in growing and developing tissues, especially of neuro-ectodermal origin. The most prominent one is 9-O-Ac-GD3, which is considered as an oncofetal marker in animal and human tumors like neuronal tumors, melanoma, basalioma or breast cancer, as well as in psoriatic lesions. Also other gangliosides like GD2 or GT3 were found to be O-acetylated in their terminal sialic acid. In this review we are summarising the occurrence of such gangliosides in normal and transformed tissues and delineate a more general theory that O-acetylated sialic acids in gangliosides are a universal marker for growing cells and tissues.

Disease mechanisms in psoriasis and psoriatic arthritis

Any hypothesis that tries to explain disease mechanisms in psoriasis and psoriatic arthritis (PsA) must take into account the containment of the inflammatory process to three specific sites: the skin, synovium, and enthesis. This article reviews the recent literature that advances our understanding of disease mechanisms at these specific sites. Additional progress will be achieved by research that focuses on common pathogenic pathways at these sites, in particular when searching for foreign candidates or auto-antigens triggering the T-cell-mediated immune response.