High frequency of circulating follicular helper T cells is correlated with B cell subtypes in patients with ankylosing spondylitis
- Authors:
- Published online on: March 22, 2018 https://doi.org/10.3892/etm.2018.5991
- Pages: 4578-4586
Abstract
Introduction
Ankylosing spondylitis (AS) is a chronic, progressive autoimmune disease that, theoretically, affects the axial and sacroiliac joints. More importantly, the majority of patients with AS eventually develop spine malformations, leading to functional incapacity (1). Although, the pathogenesis of AS remains unknown, an increasing amount of research has been performed to elucidate it.
Previous studies have reported elevated percentages of peripheral blood T helper (Th)1, Th17 and Th22 cells, and decreased percentages of regulatory T cells in patients with AS (2–4). However, to the best of our knowledge, there have been only two studies regarding a novel, distinct subgroup of cluster of differentiation (CD)4+ T cells, known as follicular helper T cells (Tfh), in patients with AS (5,6). A number of previous studies have demonstrated that aberrant expression of circulating (c)Tfhs may mediate the development of autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis and Sjogren's syndrome (7–10). Tfhs are known as specialized providers of help to B cells and persistently express C-X-C chemokine receptor type 5 (CXCR5), which drives Tfh migration into B cell follicles in response to the specific ligand CXCL13, which is expressed by follicular dendritic cells (11). Morita et al (12) have identified CD4+CXCR5+ T cells as cTfhs as they share similar functional properties with Tfh cells. Furthermore, Tfh cells express programmed death 1 (PD-1), inducible T cell costimulator (ICOS), CD40 ligand (CD40L) and interleukin (IL)-21, which not only serve as excellent markers for the identification of Tfh cells, but can also interact with B cell surface ligands to promote the formation of germinal centers (GC), the differentiation of B cells and antibody production (13,14).
In addition, other previous studies have reported increased percentages of B cells and high levels of autoantibodies in patients with AS (15,16). However, very few studies have focused on the phenotypic and functional status of B cells in different disease activities of AS. Several reports have demonstrated that the abnormal distribution of B cell subtypes may participate in the pathogenesis of autoimmune diseases, such as RA, SLE and IgA nephropathy (17–19). A previous study of primary Sjogren's syndrome (8) has reported that abnormal increases of CD4+CXCR5+ Tfh cells and B cell subsets in the salivary gland were significantly correlated with serum antinuclear antibody titers. A further study (20) revealed higher percentages of activated B and Tfh cells in patients with RA as well as regulation of B cell activation via active Tfh cells in the process of RA.
As such, the aim of the present study was to investigate changes in the distribution of B cell subtypes and whether Tfh is associated with the distribution of B cell subtypes in patients with AS. The frequency of cTfhs and different stages of differentiated B cells were investigated in 65 patients with AS as well as in 20 gender and age-matched healthy participants. The present findings suggest that certain subtypes of cTfh cells and B cells may participate in the pathogenesis of AS due to their distinct functions, and the percentages of cTfhs and B cell subtypes may be useful as a valuable measure for evaluating disease activity in patients with AS.
Materials and methods
Patients and controls
A total of 65 patients with AS were recruited sequentially at the outpatient clinic of Guizhou Medical University Hospital (Guiyang, China) from September 2014 to October 2015. All patients fulfilled the 1984 modified New York criteria (21), which is the criterion for diagnosing AS. A further 20 healthy age- and sex-matched individuals with no history of inflammatory or autoimmune diseases were recruited during the same period as healthy controls (HC). Patients with AS were excluded if they had any other chronic inflammatory and autoimmune disorders such as diabetes, multiple sclerosis or inflammatory bowel disease, or if they were currently receiving treatment with non-steroidal anti-inflammatory drugs, steroids, or other immunosuppressants. The disease activity of individual patients was measured using the Bath AS Disease Activity Index (BASDAI) (22). The scores for each criterion ranged from 0–10, with high activity defined as a BASDAI score ≥4 and low activity defined as a BASDAI score <4. All patients provided written informed consent prior to their inclusion in the present study and the experimental protocol was approved by the institutional ethics committee of Guizhou Medical University Hospital. The characteristics of the study subjects are summarized in Table I.
Flow cytometry analysis
Peripheral venous blood samples were collected following overnight fasting. Expression of human leukocyte antigen (HLA)-B27 in T cells of patients with AS was characterized via flow cytometry analysis. Fresh peripheral blood was incubated with mixed fluorescein-labeled antibodies [4.2 µg/ml fluorescein isothiocyanate (FITC)-anti-CD3 and 5.0 µg/ml phycoerythrin (PE)-anti-HLA-B27; cat. no. 340183; BD Biosciences, Franklin Lakes, NJ, USA] at room temperature for 15 min. Following lysis of erythrocytes with hemolysin (cat. no. 349202; BD Biosciences) at room temperature for 8 min and washing with PBS, white blood cells were subjected to BD FACS Canto IIflow cytometry analysis using FACSCanto Clinical software version 2.4 (BD Biosciences).
Peripheral venous blood in duplicate was incubated with 12 µg/ml allophycocyanin (APC)-cyanine (CY)7-anti-CD4 (cat no. 341115; BD Biosciences), peridinin-chlorophyll-protein complex (PERCP)-CY5.5-anti-CXCR5 (cat no. 562781; BD Pharmingen, San Diego, CA, USA), 0.5 mg/ml FITC-anti-PD-1 (FITC-anti-CD279; cat no. 561035; BD Pharmingen; BD Biosciences) and 0.2 mg/ml PE-anti-ICOS (PE-anti-CD278; cat no. 552146; BD Pharmingen; BD Biosciences) antibodies in the dark at room temperature for 15 min. Control cells were also from patients with AS and were incubated with 12 µg/ml APC-CY7-anti-CD4, 25 µg/ml PERCP-CY5.5-anti-immunoglobulin G (IgG)1 (cat no. 347202; BD Biosciences), 50 µg/ml FITC-anti-IgG (cat. no. 349041; BD Biosciences) and 50 µg/ml PE-anti-IgG1 (cat. no. 349043; BD Bioscience) in the dark at room temperature for 15 min, which is a negative control of flow analysis. Controls were isotyped, which helped eliminate non-specific fluorescent interference in flow analysis. In addition, peripheral blood in duplicate was stained with 0.05 mg/ml APC-anti-CD19 (cat. no. 340437; BD Biosciences), 8 µg/ml FITC-anti-CD27 (cat. no. 340424; BD Biosciences), 25 µg/ml PE-CY7-anti-CD38 (cat. no. 335790; BD Biosciences) or isotype-matched controls (BD Bioscience) at room temperature for 15 min. Following lysis of erythrocytes with hemolysin and washing with PBS, white blood cells were subjected to FACS Canto II flow cytometry analysis using a FACSDiva software version 6.1.3 (BD Biosciences).
Analysis of cytokine production
Peripheral blood in duplicate was stimulated with 50 ng/ml phorbol myristate acetate (PMA; Sigma-Aldrich; Merck KGaA, Darmstadt, Germany) and 1 µg/ml ionomycin (Sigma-Aldrich; Merck KGaA) with 10% fetal calf serum (Zhejiang Tianhang Biotechnology Co., Ltd., Zhejiang, China) in RPMI 1640 medium (Boster Biological Technology, Pleasanton, CA, USA) at 37°C in an incubator with 5% CO2 for 1.5 h and subsequently cultured for a further 4.5 h in the presence of GlogiStop (cat. no. 554724; BD Biosciences) at 37°C. As the expression of CD4 epitope would be decreased following the stimulation of PMA and ionomycin (23), CD3+CD8−T was used to represent CD3+CD4+ T cells. The stimulated cells were incubated with 100 µg/ml FITC-anti-CD3 (cat. no. 349201; BD Biosciences), 50 µg/ml PE-CY7-anti-CD8 (cat. no. 335822; BD Biosciences) and 3 µg/ml PE-anti-CD69 (cat. no. 341652; BD Pharmingen; BD Bioscineces) antibodies in the dark at room temperature for 15 min. Control cells were incubated with 100 µg/ml FITC-anti-CD3, 50 µg/ml PE-CY7-anti-CD8 and 50 µg/ml PE-anti-IgG1 (cat. no. 349043; BD Biosciences) antibodies in the dark at room temperature for 15 min. Following lysis of erythrocytes and washing with PBS, the expression of CD69 in CD3+CD8−(CD3+CD4+) T lymphocytes was analyzed using the BD FACS Canto II flow cytometer. When the proportion of CD3+CD8−CD69+ T cells in CD3+CD8− T lymphocytes was >90%, the subsequent experiments were performed.
The stimulated cells (200 µl) in duplicate were incubated with 100 µg/ml FITC-anti-CD3, 50 µg/ml PE-CY7-anti-CD8 and PERCP-CY5.5-anti-CXCR5 antibodies at room temperature for 15 min. The cells were subsequently fixed with 50 µl BD FACS permeabilizing solution A (cat. no. 347692; BD Biosciences) at room temperature for 5 min according to the manufacturer's protocol, and then permeabilized with BD FACS permeabilizing solution B (cat. no. 347692; BD Biosciences) and incubated with PE-anti-IL-21 antibody (cat. no. 562042; BD Pharmingen; BD Biosciences) or PE-anti-IgG1 antibody at room temperature for 20 min, followed by BD FACS Canto II flow cytometry analysis of IL-21 expression.
Statistical analysis
Statistic analyses were performed using SPSS (version 20.0; IBM Corp., Armonk, NY, USA). Normally distributed data are expressed as the mean ± standard deviation, whereas skewed data are presented as the median. Kolmogorov-Smirnov test was used to assess the distribution of the data. In addition, Levene's test was used to evaluate the homogeneity of variances. The significance of the difference between multiple groups was performed using one-way analysis of variance with a post-hoc Student-Newman-Keuls test and the significance of difference between two groups was evaluated with two-tailed Student's t-test. Spearman correlation coefficient or Pearson correlation coefficient with two-tailed P-values were determined in the analysis of correlations. Two-sided P<0.05 was considered to indicate a statistically significant difference.
Results
Increased percentages of CD4+CXCR5+ cTfh cells in patients with AS
To investigate the potential role of Tfh cells and their surface molecules in the development of AS, the frequency of peripheral blood CD4+ T and CD4+CXCR5+ cTfh cells were characterized with flow cytometry analysis (Fig. 1A). It was demonstrated that there was a decreased frequency of CD4+ T cells in patients with AS compared with HC (P<0.01; Fig. 1B). conversely, it was demonstrated that the percentages of CD4+CXCR5+ cTfh cells, CD4+CXCR5+PD-1+ and CD4+CXCR5+ICOS+ T cells were significantly increased in patients with AS compared with HC (P<0.01 for all; Fig. 1C-E). Furthermore, the percentage of CD4+CXCR5+ cTfh was significantly elevated in the high activity AS group (BASDAI score ≥4; n=41) compared with that in the low activity AS group (BASDAI score <4; n=24; P=0.001) and in HC (n=20; P<0.001; Fig. 1C). However, there was no significant difference observed in the frequency of peripheral blood CD4+ T cells, CD4+CXCR5+PD−1+ and CD4+CXCR5+ICOS+ T cells between the high and low activity AS groups (Fig. 1B, D and E).
Increased percentage of CD3+CD8−CXCR5+IL-21+ T cells in patients with AS
To determine whether the lymphocytes were activated, the expression of CD69 in stimulated T lymphocytes was measured using flow cytometry, as presented in Fig. 2A. As such, these experiments were performed only when the percentage of the CD3+CD8−CD69+ T cells in CD3+CD8− T cells was ≥90%.
The intracellular production of IL-21 by CD3+CD8−(CD3+CD4+) T cells was initially assessed using flow cytometry (Fig. 2A), which revealed that CD3+CD8−T cells producing IL-21 were significantly increased in peripheral blood of patients with AS compared with that in HC (P<0.001; Fig. 2B). As IL-21 is secreted by CD4+ T cells, including Tfh cells, Th17 cells and natural killer T cells (24), CXCR5 expression was used to dichotomize CD3+CD8−IL-21+ T cells into CD3+CD8−CXCR5+IL-21+ T and CD3+CD8−CXCR5−IL-21+ T portions (Fig. 2A). Compared with HC, the percentages of CD3+CD8−CXCR5+IL-21+ T and CD3+CD8−CXCR5−IL-21+ T cells were significantly increased in patients with AS (P<0.001 for all; Fig. 2C and D). The percentage of CD3+CD8−CXCR5+IL-21+ T cells were significantly increased in the high activity AS group (n=33; some patients with AS failed the test and were not included in statistical analysis) compared with that in the low activity AS group (n=21) and in HC (P<0.001 for all; Fig. 2C), and a similar increase was also observed in the percentages of CD3+CD8−IL-21+ T and CD3+CD8−CXCR5−IL-21+ T cells (P<0.001 for all; Fig. 2B and D). This suggests that different cellular sources of IL-21 are associated with the development of AS in this cellular population.
Aberrant distribution of peripheral blood B cell subtypes in patients with AS
As presented in Fig. 3, the distribution of B cell subtypes was also measured using flow cytometry. The percentages of CD19+CD27high plasmablasts and CD19+CD38+ antibody-secreting B cells in patients with AS were significantly higher than those in HC (P<0.001 for all; Fig. 3C and F). There was no significant difference in the frequency of CD19+ B cells, CD19+CD27− naïve B cells and CD19+CD27+ memory B cells between patients with AS and HC (Fig. 3B, D and E). The percentages of CD19+CD38+ antibody-secreting B cells and CD19+CD27− naïve B cells were also significantly increased in the high activity AS group (n=24) compared with the low activity AS group (n=22) and HC groups (P<0.05; Fig. 3C and D). In contrast, the frequency of CD19+CD27+ memory B cells was significantly decreased in the high activity patients with AS, compared with the low activity AS group (P<0.05; Fig. 3E). Notably, the percentage of CD19+CD38+ antibody-secreting B cells was positively correlated with the BASDAI values in patients with AS (r=0.329, P=0.007; Fig. 3G). However, there was no significant correlation between the BASDAI values and the frequency of other B cell subtypes in patients with AS (data not shown).
Increase in peripheral blood cTfh cells was positively correlated with disease activities in patients with AS
The percentage of CD4+CXCR5+ cTfh and CD3+CD8−CXCR5+IL-21+ T cells was positively correlated with the values of BASDAI (r=0.334, P=0.006; r=0.594, P<0.001; Fig. 4A and B). A similar correlation was observed in the percentages of CD3+CD8−IL-21+ T and CD3+CD8−CXCR5−IL-21+ T cells with the BASDAI values (r=0.558, P<0.001; r=0.561, P<0.001; Fig. 4C and D). However, there was no significant correlation between percentages of other cTfh cell phenotypes (CD4+CXCR5+PD-1 and CD4+CXCR5+ICOS+ T cells) and the BASDAI values in patients with AS (data not shown).
Association between cTfh cells and B cells in patients with AS
The percentage of CD4+CXCR5+ cTfh cells was positively correlated with the frequency of CD19+CD38+ antibody-secreting B cells in patients with AS (r=0.38, P=0.002; Fig. 5A). Similarly, the percentage of CD3+CD8−CXCR5+IL-21+ T cells was also positively correlated with the frequency of CD19+CD27− naïve B cells (r=0.321, P=0.034; Fig. 5B). However, there was no significant association between the percentages of other phenotypes of cTfh cells and the subtypes of B cells evaluated in these patients (data not shown). These data suggest that different phenotypes of cTfh cells may have variable functions in regulating the differentiation of B cells during AS development.
Discussion
Tfh cells have been recognized in recent years as a crucial regulator of GC formation, B cell development and long-term humoral memory generation (25–27), and have a significant role in the pathogenesis of autoimmune diseases. Previous studies (5,6) have characterized the frequency of circulating Tfh cells in AS. However, the mechanisms by which cTfh cells and associated molecules regulate B cell differentiation in humans remain largely unknown. In the present study, it was observed that the frequency of peripheral blood CD4+CXCR5+ cTfh cells was significantly higher in patients with AS than in HC. Furthermore, the frequency of CD4+CXCR5+ cTfh cells was positively correlated with BASDAI values in patients with AS. These results improve upon those of previous studies by Xiao et al (5) and Wu et al (6), which did not reveal the correlation of CD4+CXCR5+ cTfh cells with BASDAI values in patients with AS.
ICOS and PD-1 are expressed by Tfh cells (28) and are closely associated with the function of Tfh cells (29–31). ICOS is known as a positive regulator of Tfh cells and previous studies using a mouse model of AS indicated that ICOS overexpression induces overproduction of CD4+CXCR5+ Tfh cells and exuberant GC responses, and promotes antibody production (32,33), whereas PD-1 is a potent negative regulator of humoral immune responses (31,34). The present study demonstrated increased percentages of CD4+CXCR5+PD-1+ T and CD4+CXCR5+ICOS+ T cells in patients with AS compared with those in HC. According to BASDAI values, which are important for the evaluation of AS disease activity, patients were categorized into high activity and low activity AS groups. It was observed that higher percentages of CD4+CXCR5+ICOS+ T cells were present in the high activity AS group compared with the low activity AS group. Conversely, lower percentages of CD4+CXCR5+PD-1+ T cells were detected in the high activity AS group compared with the low activity AS group. However, differences between these two comparisons were not significant. As expected, there was no correlation between BASDAI values and the percentages of CD4+CXCR5+ICOS+ T cells or CD4+CXCR5+PD-1+ T cells. These data suggest that high percentages of CD4+CXCR5+ cTfh cells and expression of ICOS and PD-1 may be associated with the pathogenesis of AS; however, further research is required to elucidate the precise function of ICOS and PD-1 in AS.
Subsequently, to better understand the role of Tfh in the pathogenesis of AS, the main effector cytokines of Tfh cells were investigated, including IL-21, which exists with IL-6, regulates the differentiation of Tfh cells and induces B cell proliferation and class switch recombination (24,35). Xiao et al (5) previously observed a higher frequency of peripheral blood IL-21 positive Tfh cells in patients with AS-a result which the present findings expand upon. The present study demonstrated that there were significantly higher percentages of CD3+CD8− IL-21+, CD3+CD8−CXCR5+IL-21+ and CD3+CD8−CXCR5−IL-21+ T cells in patients with AS compared with HC. Notably, the percentages of CD3+CD8− IL-21+, CD3+CD8−CXCR5+IL-21+ and CD3+CD8−CXCR5−IL-21+ T cells were positively correlated with BASDAI values in patients with AS. These findings suggest that regardless of cellular sources of IL-21, they may participate in the development of AS.
The activation and differentiation of B cells require help from Tfh cells. Different subtypes of B cell express unique profiles of immunomodulatory factors and thereby evolve distinct functions. CD19+CD27− B cells display no maturity and are defined as naïve B cells (36). Upon gain of expression of CD27 (CD19+CD27+ B cells), the cells become activated memory B cells (37). CD19+CD27high B cells are defined as plasmablasts, whereas upon the expression of CD38, the cells lead to the antibody-secreting phenotype (CD19+CD38+) (17,18). In the present study, it was demonstrated that the percentages of CD19+CD27high plasmablasts and CD19+CD38+ antibody-secreting B cells were increased in patients with AS, relative to HC, although there was no significant difference in the frequency of CD19+ B cells, CD19+CD27− naïve B cells, and CD19+CD27+ memory B cells between patients with AS and HC. These results suggest that, following antigen stimulation, the distribution of B cell subtypes was changed and the proportions of the plasmablasts and antibody-secreting B cells were highly increased compared with other B cell subtypes in patients with AS. This was likely due to a higher presence of plasmablasts and antibody-secreting B cells following the high differentiation of bone marrow stem cells in order to produce more antibodies against a foreign antigen. The present findings were partially consistent with a previous study by Lin et al (15), which demonstrated that, compared with controls, the percentages of CD19+ B cells and subsets (CD19+CD27−, CD19+CD27dim and CD19+CD27high) were not significantly different in patients with AS. These disparities may be due to a number of reasons, including varying genetic backgrounds, disease duration and cohort size.
The present study also demonstrated that, compared with the low activity AS group, the high activity AS group exhibited increased percentages of CD19+CD38+ antibody-secreting B cells and CD19+CD27− naïve B cells, but a decreased percentage of CD19+CD27+ memory B cells. These results indicate that there may be an association between B cell subtypes and BASDAI values. However, the present results have only revealed a significant positive correlation between the percentage of CD19+CD38+ antibody-secreting B cells and BASDAI values in patient with AS, which is in accordance with a previous study (38). This suggests that particular B cell subtypes may be associated with different stages of AS disease pathogenesis and the percentage of CD19+CD38+ antibody-secreting B cells may be a potential biomarker to evaluate the disease activity of AS.
It has been reported previously that Tfh cells are able to regulate B cell activation and promote B cell maturation in autoimmune disease (8,20). In the present study, it was observed that the percentage of CD4+CXCR5+ cTfh cells was positively correlated with the percentage of CD19+CD38+ antibody-secreting B cells in patients with AS. The percentage of CD3+CD8−CXCR5+IL-21+ T cells was also correlated positively with the frequency of CD19+CD27− naïve B cells in patients with AS. These findings may be a clinical display of a previous in vitro finding by Morita et al (12), which demonstrated that culturing naïve B cells with CXCR5+CD4+ T cells yielded higher numbers of CD38+CD19lo cells than with CXCR5−CD4+ T cells. This indicated that CXCR5+CD4+ T cells were more efficient at inducing naive B cells to differentiate into CD38+B cells. In addition, the study by Morita et al (12) also demonstrated that blood CXCR5+CD4+ T cells secreted IL-21 upon contact with naïve B cells. High percentages of CXCR5+CD4+ T cells secrete more IL-21 following interaction with naïve B cells in patients with AS, as the increased IL-21 promotes naïve B and memory B cells differentiation into antibody-secreting B cells (39). This may explain why antibody-secreting B cell levels markedly increased and more naive B cells were released by bone marrow. Furthermore, this may be the underlying reason for the significant positive correlations between cTfh and B subtypes. These findings support the hypothesis that Tfh cells may regulate the distribution of B cell subtypes via different functional molecules; however, further research is required to elucidate the precise molecular and immunological mechanism.
In conclusion, the present findings suggest that the percentages of cTfh cells and activated B cell subtypes are significantly increased and positively correlated with disease activity in patients with AS, and the percentage of cTfh cells is positively correlated with particular B cell subtypes. The limitations of the present study, which must be considered when interpreting these results, include the relatively small sample size and the lack of cell culture experiments on cTfh cells and B cells. Further studies are required to address the relationship between circulating Tfh cells and B cell subtypes in patients with AS.
Acknowledgements
The authors would like to thank Dr Fred Bogott at the Austin Medical Center (Austin, MN, USA) and Dr Joshua Liao at Hormel Institute of University of Minnesota (Austin, MN, USA) for their English language editing of this manuscript.
Funding
No funding was received.
Availability of data and materials
The analyzed data sets generated during the present study are available from the corresponding author on reasonable request.
Authors' contributions
LM and SQL designed and directed the research. SQL performed the experiments, analyzed and interpreted data, and drafted the manuscript. DSW collected the experimental data and SWS collected the clinical data. All authors read and approved the final for publication.
Ethics approval and consent to participate
All patients provided written informed consent prior to their inclusion in the present study and the experimental protocol was approved by the institutional ethics committee of Guizhou Medical University Hospital (Guiyang, China).
Consent for publication
All patients provided written informed consent prior to their inclusion in the present study.
Competing interests
The authors declare that they have no competing interests.
References
|
Westerveld LA, Verlaan JJ and Oner FC: Spinal fractures in patients with ankylosing spinal disorders: A systematic review of the literature on treatment, neurological status and complications. Eur Spine J. 18:145–156. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Wang C, Liao Q, Hu Y and Zhong D: T lymphocyte subset imbalance in patients contribute to ankylosing spondylitis. Exp Ther Med. 9:250–256. 2015. View Article : Google Scholar : PubMed/NCBI | |
|
Zhang L, Li YG, Li YH, Qi L, Liu XG, Yuan CZ, Hu NW, Ma DX, Li ZF, Yang Q, et al: Increased frequencies of Th22 cells as well as Th17 cells in the peripheral blood of patients with ankylosing spondylitis and rheumatoid arehritis. PLoS One. 7:e310002012. View Article : Google Scholar : PubMed/NCBI | |
|
Wu Y, Ren M, Yang R, Liang X, Ma Y, Tang Y, Huang L, Ye J, Chen K, Wang P and Shen H: Reduced immunomodulation potential of bone marrow-derived mesenchymal stem cells induced CCR4+CCR6+Th/Treg cell subset imbalance in ankylosing spondylitis. Arthritis Res Ther. 13:R292011. View Article : Google Scholar : PubMed/NCBI | |
|
Xiao F, Zhang HY, Liu YJ, Zhao D, Shan YX and Jiang YF: Higher frequency of peripheral blood interleukin 21 positive follicular helper T cells in patients with ankylosing spondylitis. J Rheumatol. 40:2029–2037. 2013. View Article : Google Scholar : PubMed/NCBI | |
|
Wu S, Yang T, Pan F, Xia G, Hu Y, Liu L, Fan D, Duan Z, Ding N, Xu S, et al: Increased frequency of circulating follicular helper T cells in patients with ankylosing spondylitis. Mod Rheumatol. 25:110–115. 2015. View Article : Google Scholar : PubMed/NCBI | |
|
Choi JY, Ho JH, Pasoto SG, Bunin V, Kim ST, Carrasco S, Borba EF, Gonçalves CR, Costa PR, Kallas EG, et al: Circulating follicular helper-like T cells in systemic lupus erythematosus: Association with disease activity. Arthritis Rheumtol. 67:988–999. 2015. View Article : Google Scholar | |
|
Jin L, Yu D, Li X, Yu N, Li X and Wang Y and Wang Y: CD4+CXCR5+ follicular helper T cells in salivary gland promote B cells maturation in patients with primary Sjogren's syndrome. Int J Clin Exp Pathol. 7:1988–1996. 2014.PubMed/NCBI | |
|
Ma J, Zhu C, Ma B, Tian J, Baidoo SE, Mao C, Wu W, Chen J, Tong J, Yang M, Jiao Z, et al: Increased frequency of circulating follicular helper T cells in patients with rheumatoid arthritis. Clin Dev Immunol. 2012:8274802012. View Article : Google Scholar : PubMed/NCBI | |
|
Fan X, Jin T, Zhao S, Liu C, Han J, Jiang X and Jiang Y: Circulating CCR7+ICOS+ memory T follicular helper cells in patients with multiple sclerosis. PLoS One. 10:e01345232015. View Article : Google Scholar : PubMed/NCBI | |
|
Hardtke S, Ohl L and Förster R: Balanced expression of CXCR5 and CCR7 on follicular T helper cells determines their transient positioning to lymph node follicles and is essential for efficient B-cell help. Blood. 106:1924–1931. 2005. View Article : Google Scholar : PubMed/NCBI | |
|
Morita R, Schmitt N, Bentebibel SE, Ranganathan R, Bourdery L, Zurawski G, Foucat E, Dullaers M, Oh S, Sabzghabaei N, et al: Human blood CXCR5(+)CD4(+) T cells are counterparts of T follicular cells and contain specific subsets that differentially support antibody secretion. Immunity. 34:108–121. 2011. View Article : Google Scholar : PubMed/NCBI | |
|
King C: New insights into the differentiation and function of T follicular helper cells. Nat Rev Immunol. 9:757–766. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Crotty S: T follicular helper cell differentiation, function, and roles in disease. Immunity. 41:529–542. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Lin Q, Gu JR, Li TW, Zhang FC, Lin ZM, Liao ZT, Wei QJ, Cao SY and Li L: Value of the peripheral blood B-cells subsets in patients with ankylosing spondylitis. Chin Med J (Engl). 122:1784–1789. 2009.PubMed/NCBI | |
|
Wright C, Sibani S, Trudgian D, Fischer R, Kessler B, LaBaer J and Bowness P: Detection of multiple autoantibodies in patients with ankylosing spondylitis using nucleic acid programmable protein arrays. Mol Cell Proteomics. 11:M9.003842012. View Article : Google Scholar : PubMed/NCBI | |
|
Marston B, Palanichamy A and Anolik JH: B cells in the pathogenesis and treatment of rheumatoid arthritis. Curr Opin Rheumatol. 22:307–315. 2010. View Article : Google Scholar : PubMed/NCBI | |
|
Stasi R: Rituximab in autoimmune hematologic diseases: Not just a matter of B cells. Semin Hematol. 47:170–179. 2010. View Article : Google Scholar : PubMed/NCBI | |
|
Wang YY, Zhang L, Zhao PW, Ma L, Li C, Zou HB and Jiang YF: Functional implications of regulatory B cells in human IgA nephropathy. Scand J Immunol. 79:51–60. 2014. View Article : Google Scholar : PubMed/NCBI | |
|
Wang J, Shan Y, Jiang Z, Feng J, Li C, Ma L and Jiang Y: High frequencies of activated B cells and T follicular helper cells are correlated with disease activity in patients with new-onset rheumatoid arthritis. Clin Exp Immunol. 174:212–220. 2013.PubMed/NCBI | |
|
Van der Linden S, Valkenburg HA and Cats A: Evaluation of diagnostic criteria for ankylosing spondylitis. A proposal for modification of the New York criteria. Arthritis Rheum. 27:361–368. 1984. View Article : Google Scholar : PubMed/NCBI | |
|
Cardiel MH, Londoño JD, Gutiérrez E, Pacheco-Tena C, Vázquez-Mellado J and Burgos-Vargas R: Translation, cross-cultural adaptation, and validation of the Bath Ankylosing Spondylitis Functional Index (BASFI), the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Dougados Functional Index (DFI) in a Spanish speaking population with spondyloarthropathies. Clin Exp Rheumatol. 21:451–458. 2003.PubMed/NCBI | |
|
Petersen CM, Christensen EI, Andresen BS and Møller BK: Internalization, lysosomal degradation and new synthesis of surface membrane CD4 in phorbol ester-activated T-lymphocytes and U-937 cells. Exp Cell Res. 201:160–173. 1992. View Article : Google Scholar : PubMed/NCBI | |
|
Spolski R and Leonard WJ: Interleukin-21: Basic biology and implications for cancer and autoimmunity. Annu Rev Immunol. 26:57–79. 2008. View Article : Google Scholar : PubMed/NCBI | |
|
McHeyzer-Williams LJ, Pelletier N, Mark L, Fazilleau N and McHeyzer-Williams MG: Follicular helper T cells as cognate regulators of B cell immunity. Curr Opin Immunol. 21:266–273. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Linterman MA and Vinuesa CG: T follicular helper cells during immunity and tolerance. Prog Mol Biol Transl Sci. 92:207–248. 2010. View Article : Google Scholar : PubMed/NCBI | |
|
Crotty S: Follicular helper CD4 T cells (TFH). Annu Rev Immunol. 29:621–663. 2011. View Article : Google Scholar : PubMed/NCBI | |
|
Kerfoot SM, Yaari G, Patel JR, Johnson KL, Gonzalez DG, Kleinstein SH and Haberman AM: Germinal center B cell and T follicular helper cell development initiates in the interfollicular zone. Immunity. 34:947–960. 2011. View Article : Google Scholar : PubMed/NCBI | |
|
Bossaller L, Burger J, Draeger R, Grimbacher B, Knoth R, Plebani A, Durandy A, Baumann U, Schlesier M, Welcher AA, et al: ICOS deficiency is associated with a severe reduction of CXCR5+CD4 germinal center Th cells. J Immunol. 177:4927–4932. 2006. View Article : Google Scholar : PubMed/NCBI | |
|
Tafuri A, Shahinian A, Bladt F, Yoshinaga SK, Jordana M, Wakeham A, Boucher LM, Bouchard D, Chan VS, Duncan G, et al: ICOS is essential for effective T-helper-cell responses. Nature. 409:105–109. 2001. View Article : Google Scholar : PubMed/NCBI | |
|
Good-Jacobson KL, Szumilas CG, Chen L, Sharpe AH, Tomayko MM and Shlomchik MJ: PD-1 regulates germinalcenter B cell survival and the formation and affinity of longlived plasma cells. Nat Immunol. 11:535–542. 2010. View Article : Google Scholar : PubMed/NCBI | |
|
Fazilleau N, Mark L, McHeyzer-Williams LJ and McHeyzer-Williams MG: Follicular helper T cells: Lineage and location. Immunity. 30:324–35. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Yu D, Rao S, Tsai LM, Lee SK, He Y, Sutcliffe EL, Srivastava M, Linterman M, Zheng L, Simpson N, et al: The transcriptional repressor Bcl-6 directs T follicular helper cell lineage commitment. Immunity. 31:457–468. 2009. View Article : Google Scholar : PubMed/NCBI | |
|
Xu H, Wang X, Lackner AA and Veazey RS: PD-1(HIGH) follicular CD4 T helper cell subsets residing in lymph node germinal centers correlate with B cell maturation and IgG production in rhesus macaques. Front Immunol. 5:852014. View Article : Google Scholar : PubMed/NCBI | |
|
Eto D, Lao C, DiToro D, Barnett B, Escobar TC, Kageyama R, Yusuf I and Crotty S: IL-21 and IL-6 are critical for different aspects of B cell immunity and redundantly induce optimal follicular helper CD4 T cell (Tfh) differentiation. PloS One. 6:e177392011. View Article : Google Scholar : PubMed/NCBI | |
|
Potter KN, Mockridge CI, Rahman A, Buchan S, Hamblin T, Davidson B, Isenberg DA and Stevenson FK: Disturbances in peripheral blood B cell subpopulations in autoimmune patients. Lupus. 11:872–877. 2002. View Article : Google Scholar : PubMed/NCBI | |
|
Agematsu K, Nagumo H, Yang FC, Nakazawa T, Fukushima K, Ito S, Sugita K, Mori T, Kobata T, Morimoto C and Komiyama A: B cell subpopulations separated by CD27 and crucial collaboration of CD27+ B cells and helper T cells in immunoglobulin production. Eur J Immunol. 27:2073–2079. 1997. View Article : Google Scholar : PubMed/NCBI | |
|
Niu XY, Zhang HY, Liu YJ, Zhao D, Shan YX and Jiang YF: Peripheral B-cell activation and exhaustion markers in patients with ankylosing spondylitis. Life Sci. 93:687–692. 2013. View Article : Google Scholar : PubMed/NCBI | |
|
Ettinger R, Sims GP, Fairhurst AM, Robbins R, da Silva YS, Spolski R, Leonard WJ and Lipsky PE: IL-21 induces differentiation of human naive and memory B cells into antibody-secreting plasma cells. J Immunol. 175:7867–7879. 2005. View Article : Google Scholar : PubMed/NCBI |
