T-cell polarization differs in various stages of discoid lupus erythematosus skin

TY - JOUR

T1 - T-cell polarization differs in various stages of discoid lupus erythematosus skin

AU - Coias, J.

AU - Marzuka, A.

AU - Hosler, G. A.

AU - Chong, B. F.

N1 - Funding Information: J. Coias A. Marzuka G.A. Hosler B.F. Chong ben.chong@utsouthwestern.edu Department of Dermatology University of Texas Southwestern Medical Center Dallas TX U.S.A. ProPath Dallas TX U.S.A. National Center for Advancing Translational Sciences UL1TR001105 National Institute of Arthritis and Musculoskeletal and Skin Diseases K23AR061441 Funding sources: The research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under award number K23AR061441, and by the National Center for Advancing Translation Sciences of the National Institutes of Health under award number UL1TR001105. The content is solely the responsibility of the authors and does not necessarily represent the official views of The University of Texas Southwestern Medical Center at Dallas and its affiliated academic and healthcare centres, the National Center for Research Resources or the National Institutes of Health. Conflicts of interest: B.F.C. is an investigator for Daavlin Corporation, Biogen Incorporated and Pfizer Incorporated, and a consultant for Viela Bio. D ear Editor , The clinical presentation and pathology of discoid lupus erythematosus (DLE) vary by stage. Erythematous scaly papules and plaques characterize the early lesions. They progress to dyspigmented patches and plaques with central scarring and atrophy. Under histology, early lesions demonstrate a perivascular and perifollicular inflammatory infiltrate, liquefactive degeneration and keratinocyte apoptosis. Increased collagen deposition within the dermis and reduced inflammatory infiltrate are seen in later stages. The cellular and molecular underpinnings associated with the progression of the lesions from inflammatory to scarring stages in DLE are not well understood. We previously identified higher levels of CD8 + T cells in early‐stage DLE skin and elevated CD20 To explore the immune‐cell microenvironment further, we sought to compare the T helper (Th)1 and Th2 subpopulations in early‐, mid‐ and late‐stage DLE skin using immunohistochemistry. Th1 and Th2 cells have distinct effector functions where Th1 cells potentiate a cell‐mediated inflammatory response and Th2 cells promote a humoral and fibrotic response. We hypothesized that there would be a predominance of Th1 cells in early‐stage DLE skin, where recruitment and activation of macrophages and CD8 + B cells in later‐stage DLE skin. + T cells can occur. We postulated that late‐stage DLE skin would show Th2 cell predominance, leading to activation of fibrotic pathways and plasma cell differentiation. We collected lesional skin biopsies from the face (six), scalp (ten) and arms (five) of 21 participants with DLE. Patients on immunosuppressive medications (e.g. prednisone or methotrexate) or antimalarials were excluded. A dermatopathologist (G.A.H.) blinded to the clinical data examined haematoxylin and eosin slides of formalin‐fixed, paraffin‐embedded biopsy specimens, and divided them into three DLE stages: inflammatory (DLE‐I; n = 9), inflammatory with scarring (DLE‐I/S; n = 7) or scarring (DLE‐S; n = 5). DLE‐I lesions featured robust perifollicular, interface and/or perivascular inflammatory infiltrates with no increased dermal collagen deposition. DLE‐S lesions had sparse infiltrates and substantially increased collagen deposition. DLE‐I/S lesions had moderate inflammation and increased dermal collagen. specimens were stained with chromogen‐linked monoclonal antibodies against T‐bet (Abcam, Cambridge, U.K.) (Th1 cells), GATA‐3 (Biocare, Pacheco, CA, U.S.A.) (Th2 cells) and CD4 (Abcam) (T cells). Double‐ and single‐positive cells were manually counted by independent readers (B.F.C., G.A.H.) in representative high‐power fields in three microanatomical regions: dermoepidermal junction (interface), perifollicular and perivascular. Cell counts and percentage ratios of CD4 Following published immunohistochemistry protocols, +  T‐bet + (Th1) over CD4 +  GATA‐3 + (Th2) cells were calculated for each specimen in each region. Nonparametric comparisons were performed with Kruskal–Wallis tests and Dunn pairwise comparison tests using GraphPad Prism v. 8·1 (GraphPad Software, La Jolla, CA, U.S.A.). For all regions, the median percentage ratio of Th1 to Th2 cells was highest in DLE‐I skin [1·70, interquartile range (IQR) 1·04–1·97], compared with DLE‐I/S (0·57, IQR 0·44–0·89) and DLE‐S skin (0·27, IQR 0·17–0·92) ( a). Pairwise comparison revealed a significant difference between DLE‐I and DLE‐I/S skin ( P = 0·002, Fig.  P = 0·03), and DLE‐I and DLE‐S skin ( P = 0·02). Within the perivascular region, the median percentage ratios of Th1 to Th2 cells for DLE‐I, DLE‐I/S and DLE‐S skin in the perivascular areas were 1·22 (IQR 0·96–2·97), 0·47 (IQR 0·32–0·99) and 0·45 (IQR 0·32–0·58), respectively ( b). Pairwise comparisons found a significant difference between DLE‐I and DLE‐S skin ( P = 0·01, Fig.  P = 0·03). In the interface region, the median percentage Th1 to Th2 ratios trended higher in DLE‐I skin (2·40, IQR 1·16–3·41) vs. DLE‐I/S (0·88, IQR 0·57–1·17) and DLE‐S (0·29, IQR 0·0–0·99) ( (c–f). P = 0·06). Low cell counts and missing follicles in the perifollicular region of DLE‐S skin precluded further subanalyses. Examples of immunostainings in DLE‐I and DLE‐I/S skin are shown in Figure  The percentage ratios of T helper (Th)1 to Th2 cells are different among the three stages of discoid lupus erythematosus ( DLE ) skin. (a) The three combined microanatomical regions demonstrated significantly higher percentage ratios of Th1 to Th2 cells in DLE ‐I (inflammatory) skin vs. DLE ‐I/S (inflammatory with scarring) and DLE ‐S (scarring) skin ( P = 0·002). * P < 0·05. Each data point represents the mean percentage ratio of Th1 to Th2 cells for all three regions for each biopsy specimen. The error bars represent the median and interquartile range. (b) In the perivascular region, there were significantly higher percentage ratios of Th1 to Th2 cells in DLE ‐I skin vs. DLE ‐I/S and DLE ‐S skin ( P = 0·014). (c–f) Representative double‐immunostaining photos of perivascular DLE ‐I (c, d) and DLE ‐I/S (e, f) skin. DLE ‐I and DLE ‐I/S skin were stained with CD 4 (purple) and T‐bet (brown; c, e) or GATA ‐3 (brown; d, f). The green and red arrows highlight examples of CD 4 +  T‐bet + Th1 cells and CD 4 +   GATA ‐3 + Th2 cells, respectively. Original magnification × 600. Our data support a predominance of Th1 cells in early DLE lesions. Th1 cells secrete proinflammatory cytokines including interleukin (IL)‐2 and interferon (IFN)‐γ. IL‐2 promotes proliferation of CD8 which are elevated in early DLE. IFN‐γ can activate macrophages and other immunocytes. We found elevations in Th2 cells in late DLE skin. Th2 cells promote fibrosis through upregulation of transforming growth factor (TGF)‐β and secretion of IL‐13, which signals fibroblast proliferation and collagen production. Additionally, Th2 cells inhibit proinflammatory M1 macrophages, suppress the secretion of proinflammatory cytokines and upregulate production of anti‐inflammatory mediators (IL‐4, IL‐10 and TGF‐β). Finally, through IL‐4 and IL‐13, Th2 cells promote B‐cell proliferation and plasma cell differentiation, which were previously observed in the latter stages of DLE. + T cells, Limitations of this study include the small sample size and CD4 + cells being expressed in other cells such as macrophages. Nonetheless, we have identified differences in T‐cell subsets that may drive histological and clinical changes in DLE. Further elucidation of immune changes in different stages of DLE skin will potentially lead to development of therapies that reduce the chronic skin sequelae of scarring and dyspigmentation in DLE.

PY - 2020/5/1

Y1 - 2020/5/1

UR - http://www.scopus.com/inward/record.url?scp=85076746548&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85076746548&partnerID=8YFLogxK

U2 - 10.1111/bjd.18704

DO - 10.1111/bjd.18704

M3 - Letter

C2 - 31721152

AN - SCOPUS:85076746548

SN - 0007-0963

VL - 182

SP - 1291

EP - 1293

JO - British Journal of Dermatology

JF - British Journal of Dermatology

IS - 5

ER -