cTfh Subsets Research Articles

CD4+ T Follicular Helper Cells in Human Tonsils and Blood Are Clonally Convergent but Divergent from Non-Tfh CD4+ Cells

T follicular helper (Tfh) cells are fundamental for B cell selection and antibody maturation in germinal centers. Circulating Tfh (cTfh) cells constitute a minor proportion of the CD4+ T cells in peripheral blood, but their clonotypic relationship to Tfh populations resident in lymph nodes and the extent to which they differ from non-Tfh CD4+ cells have been unclear. Using donor-matched blood and tonsil samples, we investigate T cell receptor (TCR) sharing between tonsillar Tfh cells and peripheral Tfh and non-Tfh cell populations. TCR transcript sequencing reveals considerable clonal overlap between peripheral and tonsillar Tfh cell subsets as well as a clear distinction between Tfh and non-Tfh cells. Furthermore, influenza-specific cTfh cell clones derived from blood can be found in the repertoire of tonsillar Tfh cells. Therefore, human blood samples can be used to gain insight into the specificity of Tfh responses occurring in lymphoid tissues, provided that cTfh subsets are studied.

CXCR5+PD1+ICOS+ Circulating T Follicular Helpers Are Associated With de novo Donor-Specific Antibodies After Renal Transplantation.

Donor-specific anti-HLA antibodies (DSAs) are a major risk factor associated with renal allograft outcomes. As a trigger of B cell antibody production, T follicular helper cells (Tfhs) promote DSA appearance. Herein, we evaluated whether circulating Tfhs (cTfhs) are associated with the genesis of antibody-mediated rejection. We measured cTfh levels on the day of transplantation and 1 year after transplantation in blood from a prospective cohort of 237 renal transplantation patients without DSA during the first year post-transplantation. Total cTfhs were characterized as CD4+CD45RA−CXCR5+, and the three following subsets of activated cTfh were analyzed: CXCR5+PD1+, CXCR5+PD1+ICOS+, an CXCR5+PD1+CXCR3−. Immunizing events (previous blood transfusion and/or pregnancy) and the presence of class II anti-HLA antibodies were associated with increased frequencies of activated CXCR5+PD1+, CXCR5+PD1+ICOS+, and CXCR5+PD1+CXCR3− cTfh subsets. In addition, ATG-depleting induction and calcineurin inhibitor treatments were associated with a relative increase of activated cTfh subsets frequencies at 1 year post-transplantation. In multivariate survival analysis, we reported that a decrease in activated CXCR5+PD1+ICOS+ at 1 year after transplantation in the blood of DSA-free patients was significantly associated with the risk of developing de novo DSA after the first year (p = 0.018, HR = 0.39), independently of HLA mismatches (p = 0.003, HR = 3.79). These results highlight the importance of monitoring activated Tfhs in patients early after transplantation and show that current treatments cannot provide early, efficient prevention of Tfh activation and migration. These findings indicate the need to develop innovative treatments to specifically target Tfhs to prevent DSA appearance in renal transplantation.

T follicular helper cells in human efferent lymph retain lymphoid characteristics.

T follicular helper cells (Tfh), a subset of CD4+ T cells, provide requisite help to B cells in the germinal centers (GC) of lymphoid tissue. GC Tfh are identified by high expression of the chemokine receptor CXCR5 and the inhibitory molecule PD-1. Although more accessible, blood contains lower frequencies of CXCR5+ and PD-1+ cells that have been termed circulating Tfh (cTfh). However, it remains unclear whether GC Tfh exit lymphoid tissues and populate this cTfh pool. To examine exiting cells, we assessed the phenotype of Tfh present within the major conduit of efferent lymph from lymphoid tissues into blood, the human thoracic duct. Unlike what was found in blood, we consistently identified a CXCR5-bright PD-1-bright (CXCR5BrPD-1Br) Tfh population in thoracic duct lymph (TDL). These CXCR5BrPD-1Br TDL Tfh shared phenotypic and transcriptional similarities with GC Tfh. Moreover, components of the epigenetic profile of GC Tfh could be detected in CXCR5BrPD-1Br TDL Tfh and the transcriptional imprint of this epigenetic signature was enriched in an activated cTfh subset known to contain vaccine-responding cells. Together with data showing shared TCR sequences between the CXCR5BrPD-1Br TDL Tfh and cTfh, these studies identify a population in TDL as a circulatory intermediate connecting the biology of Tfh in blood to Tfh in lymphoid tissue.

Associations of circulating CXCR3–PD-1+CD4+T cells with disease activity of systemic lupus erythematosus

Objectives: Which helper CD4+ T cell subset contributes to autoantibodies generation and severity of end-organ involvement in lupus patients remains to be explored. Our research aims to investigate the roles of circulating Tfh (cTfh) cell subsets and corresponding CXCR5– Th cells in lupus patients and their correlation with SLE disease activity index 2000 (SLEDAI).Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from blood of systemic lupus erythematosus (SLE) patients as well as healthy donors. The proportion of Th cell subsets classified from cell surface markers (CD45RO, CXCR5, CXCR3, CCR6, PD-1, ICOS, and CCR7) is detected by flow cytometry.Results: We found no difference in the frequency of CD45RO+CXCR5+CD4+ T cells between SLE patients and health controls. As previously reported, SLE patients showed an increase in the percentage of CXCR5+PD-1+, CXCR5+ICOS+PD-1+ and CXCR5+CCR7loPD-1hi cTfh subset, however, none of these populations had correlation with SLEDAI. Therefore, we further investigated the CXCR5– subsets, and surprisingly we found that the frequency of CXCR3–PD-1+ subset was correlated with SLEDAI, ds-DNA IgG, anti-nucleosome antibody, C3, and C4 independent of CXCR5. Consistently, CXCR3–PD-1+CD45RO+CD4+T cells expressed factors associated with B-cell-help for the autoantibody production.Conclusion: CXCR3–PD-1+CD4+T cells are a sensitive indicator to assess SLE disease activity and might contribute B cell help and the generation of autoantibodies in patients.

Relapsing-Remitting Multiple Sclerosis Is Characterized by a T Follicular Cell Pro-Inflammatory Shift, Reverted by Dimethyl Fumarate Treatment.

Multiple sclerosis (MS) is considered a T cell-mediated autoimmune disease, although several evidences also demonstrate a B cell involvement in its etiology. Follicular T helper (Tfh) cells, a CXCR5-expressing CD4+ T cell subpopulation, are essential in the regulation of B cell differentiation and maintenance of humoral immunity. Alterations in circulating (c)Tfh distribution and/or function have been associated with autoimmune diseases including MS. Dimethyl fumarate (DMF) is a recently approved first-line treatment for relapsing–remitting MS (RRMS) patients whose mechanism of action is not completely understood. The aim of our study was to compare cTfh subpopulations between RRMS patients and healthy subjects and evaluate the impact of DMF treatment on these subpopulations, relating them to changes in B cells and humoral response. We analyzed, by flow cytometry, the distribution of cTfh1 (CXCR3+CCR6−), cTfh2 (CXCR3−CCR6−), cTfh17 (CXCR3−CCR6+), and the recently described cTfh17.1 (CXCR3+CCR6+) subpopulations of CD4+ Tfh (CD45RA−CXCR5+) cells in a cohort of 29 untreated RRMS compared to healthy subjects. CD4+ non-follicular T helper (Th) cells (CD45RA−CXCR5−) were also studied. We also evaluated the effect of DMF treatment on these subpopulations after 6 and 12 months treatment. Untreated RRMS patients presented higher percentages of cTfh17.1 cells and lower percentages of cTfh2 cells consistent with a pro-inflammatory bias compared to healthy subjects. DMF treatment induced a progressive increase in cTfh2 cells, accompanied by a decrease in cTfh1 and the pathogenic cTfh17.1 cells. A similar decrease of non-follicular Th1 and Th17.1 cells in addition to an increase in the anti-inflammatory Th2 subpopulation were also detected upon DMF treatment, accompanied by an increase in naïve B cells and a decrease in switched memory B cells and serum levels of IgA, IgG2, and IgG3. Interestingly, this effect was not observed in three patients in whom DMF had to be discontinued due to an absence of clinical response. Our results demonstrate a possibly pathogenic cTfh pro-inflammatory profile in RRMS patients, defined by high cTfh17.1 and low cTfh2 subpopulations that is reverted by DMF treatment. Monitoring cTfh subsets during treatment may become a biological marker of DMF effectiveness.

A pilot study on the characteristics of circulating T follicular helper cells in liver transplant recipients

Circulating CD4+CXCR5+ T follicular helper cells (cTfh) have been demonstrated to be involved in B cell-mediated systemic autoimmune diseases and alloreactive responses following kidney transplantation; however, whether cTfh cells are involved in alloreactive responses after liver transplantation (LT) remains unclear. Our present study aimed to investigate the characteristics of cTfh, as well as CXCR3+CCR6−Tfh1, CXCR3−CCR6−Tfh2, and CXCR3−CCR6+Tfh17 subsets in liver allograft recipients. A total of 30 liver transplant recipients were enrolled in this study. The frequencies of cTfh, Tfh1, Tfh2, and Tfh17 subsets, and interleukin (IL)-21-producing Tfh cells in the circulating blood were analyzed by flow cytometry. The capacity of cTfh cells to help B cells differentiate into plasmablasts was determined one day before and one month after LT. The results revealed that the frequency of cTfh cells remained unaltered before and after LT. However, the frequency of the cTfh subsets (e.g., Tfh1 and Tfh2 cells) and B cells were reduced one month after LT. Functionally, the capacity of Tfh cells to produce IL-21 was reduced one month after LT. In addition, cTfh cells exhibited the capacity to help B cells differentiate into plasmablasts in an IL-21-dependent manner in vitro, which was reduced after LT, despite the unaltered production of IgM and IgG by plasmablasts. Thus, our data suggest that cTfh cells may be involved in alloreactive responses following LT via helping B cells differentiate into plasmablasts and plasma cells.

Circulating Tfh1 (cTfh1) cell numbers and PD1 expression are elevated in low-grade B-cell non-Hodgkin's lymphoma and cTfh gene expression is perturbed in marginal zone lymphoma.

CD4+ T-cell subsets are found in the tumour microenvironment (TME) of low-grade B-cell non-Hodgkin’s lymphomas such as marginal zone lymphoma (MZL) or follicular lymphoma (FL). Both numbers and architecture of activating follicular helper T-cells (Tfh) and suppressive Treg in the TME of FL are associated with clinical outcomes. There has been almost no previous work on CD4+ T-cells in MZL. It is now recognised that circulating CD4+CXCR5+ T-cells are the memory compartment of Tfh cells. We determined differences in number of circulating Tfh (cTfh) cells and cTfh subsets between normal subjects and patients with FL or MZL. Lymphoma patients showed increased numbers of cTfh1 and reduced cTfh17 cells due to decreased expression of the subset-defining marker CCR6 in patients. PD1, a surface marker associated with Tfh cells, showed increased expression on cTfh subsets in patients. Focusing on MZL we determined expression of 96 T-cell associated genes by microfluidic qRT-PCR. Analysis of differentially expressed genes showed significant differences between normal subjects and patients both for bulk cTfh (CCL4) and the cTfh1 subset (JAK3). While our findings require confirmation in larger studies we suggest that analysis of number and gene expression of circulating T-cells might be a source of clinically useful information as is the case for T-cells within lymphoma lymph nodes.

Vaccination establishes clonal relatives of germinal center T cells in the blood of humans.

Germinal center T follicular helper cells (GCTfh) in lymphatic tissue are critical for B cell differentiation and protective antibody induction, but whether GCTfh establish clonal derivatives as circulating memory T cells is less understood. Here, we used markers expressed on GCTfh, CXCR5, PD1, and ICOS, to identify potential circulating CXCR5+CD4+ Tfh-like cells (cTfh) in humans, and investigated their functional phenotypes, diversity, and ontogeny in paired donor blood and tonsils, and in blood after vaccination. Based on T cell receptor repertoire analysis, we found that PD-1-expressing cTfh and tonsillar GCTfh cells were clonally related. Furthermore, an activated, antigen-specific PD1+ICOS+ cTfh subset clonally expanded after booster immunization whose frequencies correlated with vaccine-specific serum IgG; these phenotypically resembled GCTfh, and were clonally related to a resting PD1+ICOS- CD4+ memory T cell subset. Thus, we postulate that vaccination establishes clonal relatives of GCTfh within the circulating memory CD4+CXCR5+PD1+ T cell pool that expand upon reencounter of their cognate antigen.

Identification of flu-specific ICOS+CD38+ cTfh after influenza vaccination

Abstract The foundation of successful vaccines lies in the ability to prime the immune system to target a specific pathogen. The interaction between follicular helper T cells (Tfh) and B cells within germinal centers is necessary for the production of class-switched, affinity-matured antibodies. However, the size, diversity, and specificity of the T cell receptor (TCR) repertoire of the Tfh during an immune response remains unknown. We identified a subset of circulating Tfh (cTfh) coexpressing ICOS and CD38 that expresses markers of recent activation, such as the proliferation marker Ki67 and the transcription factor Helios. This activated cTfh subset increases following influenza vaccination. To begin to interrogate how the TCR repertoire changes in human cTfh cells responding to a vaccine, we performed T-cell receptor beta chain sequencing on cTfh from individuals before and after influenza vaccination. Although the ICOS−CD38− cTfh maintained a stable TCR repertoire pre- and 7 days post vaccination, the ICOS+CD38+ cTfh exhibited increased clonality indicative of antigen-driven activation and expansion. Using HLA class II HA306- and HA40-specific tetramer staining on peripheral blood from HLA-DR0401 individuals, we then further assessed the specificity of the responding cTfh at day 7 after vaccination. We found many tetramer-positive cells that expressed ICOS and CD38 in the cTfh subset, confirming that the ICOS+CD38+ response after vaccination contains influenza-specific cells. Ultimately, rational vaccine design will depend on better understanding of the clonotypic response elicited in response to various pathogens and their relevance to the overall immune response.

ICOS+CD38+ cTfh in peripheral blood and thoracic duct lymph.

Abstract T follicular helper cells provide essential B cell help within the germinal center (GC), and these cells have been shown to populate the follicular mantel once the GC reaction is complete. The significance and ontology of circulating Tfh (cTfh) is less clear. Studies in humans have suggested subsets of cTfh that correlate with humoral responses in chronic infection (HIV, malaria) and in response to acute challenge (influenza vaccination). We have previously described a subset of CXCR5+PD1+ cTfh that expresses both ICOS and CD38. This population was significantly increased 7 days after influenza vaccination as well as in patients infected with HIV. Single cell transcriptional analysis of the ICOS+CD38+ cTfh after influenza vaccination demonstrated more frequent expression of the GC Tfh transcripts CMAF, BCL6, and CD200 than was found in the ICOS−CD38− cTfh, and bulk transcriptional analysis indicated higher expression of IL-21. These data suggested that ICOS and CD38 mark the rare population of cTfh that are more recent émigrés from the lymph nodes. To evaluate this possibility, we analyzed Tfh in an immune compartment that is more proximal to the lymph nodes than peripheral blood: thoracic duct lymph (TDL). As expected, TDL Tfh had a higher frequency of ICOS+CD38+ cells than cTfh in matched peripheral blood. In addition, TDL had a population of CXCR5+PD1bright Tfh, previously only identified in lymphoid tissues. CXCR5+PD1bright Tfh in the TDL had a significantly increased frequency of ICOS+CD38+ cells. These data provide a critical missing link in the understanding of cTfh and suggest that the ICOS+CD38+ cTfh subset warrants further exploration as peripheral surrogates of the active immune responses within secondary lymphoid tissues.

Activated Circulating T Follicular Helper Cells with Increased Function during Chronic Graft Versus Host Disease after Allogeneic Stem Cell Transplantation

T follicular helper cells (TFH) interact with B cells in the germinal center to support B cell proliferation, differentiation and immunoglobulin class switch. Previous studies have demonstrated that donor B cells contribute to the immune pathology of chronic GVHD (cGVHD) and studies in murine models of cGVHD have suggested that TFH play a central role in this process. Although TFH are located primarily within germinal centers of secondary lymphoid organs, TFH can also be found in the peripheral blood and are identified as a subset of memory CD4 T cells expressing CXCR5. Circulating TFH (cTFH) share functional and phenotypic characteristics of TFH including the ability to interact with B cells and provide helper signals. To examine the potential role of cTFH in the pathogenesis of cGVHD we monitored the reconstitution of cTFH (CD4+CD45RA-CXCR5+ T cells) in fresh blood samples obtained at different times after allogeneic HSCT. Recovery of cTFH mirrored the recovery of CD4 T cells and absolute numbers of cTFH gradually increased over time, reaching a plateau at 24 months post-HSCT in the range of normal values. Within the CD4 T cell population, the frequency of cTFH was low initially, but reached normal levels 6-9 months post-HSCT.Detailed phenotypic and functional analysis of cTFH was undertaken in a cohort of 66 adult patients (>9 months post-HSCT): 16 had no cGVHD, 12 had resolved cGVHD, and 38 had active cGVHD (mild = 15, moderate = 14, severe = 9). Results were compared to 22 healthy donors (HD). Overall, the frequency of cTFH was significantly reduced in HSCT patients compared to HD (median: 9.87 vs. 13.65 % of CD4+ T-cells, respectively, p =0.0003). cTFH frequency was lower in active cGVHD compared to no cGVHD patients (median: 9.44 vs. 11.65 % of CD4+ T-cells, p = 0.029); while cTFH in patients with resolved cGVHD was similar to patients without cGVHD (Figure 1). CXCL13 chemokine facilitates T-B interaction, thus promoting the GC reaction. CXCL13 levels were increased in active cGVHD compared to no cGVHD (137.7 pg/mL vs. 33.74 pg/mL, p < 10-4) suggesting that trafficking of cTFH to lymphoid organs was promoted in cGVHD. cTFH activation results in increased surface expression of ICOS and PD1 and increased proliferation. ICOShi PD1hi cTFH were increased in active cGVHD compared to no cGVHD (2.035 % vs 1.065 %, p = 0.016) in association with high proliferative activity (Ki67) (3.38 % vs. 2.31 % respectively, p = 0.0086). Functional cTFH subsets are also characterized by expression of CXCR3 and CCR6 as follows: Th1 (CXCR3+CCR6-), Th2 (CXCR3-CCR6-), Th17 (CXCR3-CCR6+). Within these subsets, Th2 and Th17 cTFH provide greater levels of B cell help measured by in vitro co-cultureassays (plasmablast generation and IgG production). Although not statistically significant, Th1 cTFH frequency was decreased during active cGVHD (33.95 vs 37.6 for no cGVHD) and Th2 and Th17 cTFH frequencies were increased in the moderate-severe cGVHD group (31.1 and 30.5, respectively) compared to no cGVHD (27.05 and 24.45, respectively). Within active cGVHD patients, the frequencies of Th1 and Th17 were associated with clinical grade of cGVHD (Th1: 40, 34, 19, p=0.008; Th17: 21, 26, 37, p=0.02; for mild, moderate, severe, respectively). We used the ratio (Th2+Th17)/Th1 cTFH to normalize B cell help capacity, and found a higher ratio in severe cGVHD compared to no cGVHD (3.59 vs 1.36, p = 0.0006). To measure cTFH functional activity, cTFH and naive B cells were purified from patient samples by cell sorting and co-cultured for 6 days. cTFH from patients with active cGVHD induced greater plasmablast generation (CD27hi CD38hi B cells) compared to cTFH from non-active cGVHD (Fig. 2). Increased functional activity of cTFH was confirmed when patient cTFH were purified and cocultured with naive B cells from a normal allogeneic donor (Fig. 2). In patients with cGVHD, there was also a significant correlation between the proliferative activity of cTFH and the generation of CD27hi CD38hi B cells (r = 0.48, p = 0.0029).These results indicate that active cGVHD is characterized by phenotypic and functional abnormalities of cTFH. In cGVHD, cTFH show high levels of activation, proliferation and switch toward Th2 and Th17 phenotype. These changes enhance cTFH function, promoting GC reactions and B cell differentiation. These data support the involvement of cTFH in the immune pathology of human cGVHD, suggesting the investigation of novel therapies targeting the GC reaction. [Display omitted] DisclosuresArmand:Merck: Consultancy, Research Funding; Infinity Pharmaceuticals: Consultancy; Bristol-Myers Squibb: Research Funding. Antin:Gentium S.p.A.: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.

Constitutively altered frequencies of circulating follicullar helper T cell counterparts and their subsets in rheumatoid arthritis.

IntroductionCirculating CD4 T cells expressing CXCR5, ICOS and/or PD-1 are counterparts of follicular helper T cells (Tfh). There are three subpopulations of circulating Tfh (cTfh): CXCR5 + CXCR3 + CCR6- (Tfh-Th1), CXCR5 + CXCR3-CCR6- (Tfh-Th2) and CXCR5 + CXCR3-CCR6+ (Tfh-Th17). Our objective was to study the B cell helping capacity of cTfh subsets, and examine their frequency in Rheumatoid Arthritis (RA) patients, together with the frequency of circulating plasmablasts (CD19 + CD20-CD38high).MethodsPeripheral blood was drawn from RA patients with active disease (RA-a, DAS28 >2.6) (n = 17), RA in remission (RA-r, DAS28 <2.6) (n = 17) and healthy controls (HC) (n = 34). cTfh and plasmablast frequencies were determined by flow cytometry. Cocultures of sorted CD4 + CXCR5+ T cell subpopulations were established with autologous CD19 + CD27- naïve B cells of HC, and concentrations of IgG, A and M were measured in supernatants.ResultsIsolated Tfh-Th2 and Tfh-Th17 but not Tfh-Th1 cells, induced naïve B cells to secrete IgG and IgA. The frequency of CXCR5+ cells gated for CD4+ T cells was not different among HC, RA-a and RA-r. In contrast, both RA-a and RA-r patients demonstrated an increased frequency of CD4 + CXCR5 + ICOS+ T cells and augmented (%Tfh-Th2 + %Tfh-Th17)/%Tfh-Th1 ratio as compared with HC. In addition, RA-a but not RA-r patients, showed an increased frequency of circulating plasmablasts.ConclusionBoth RA-a and RA-r patients demonstrate an increased frequency of cTfh and overrepresentation of cTfh subsets bearing a B cell helper phenotype, suggesting that altered germinal center dynamics play a role in RA pathogenesis. In contrast, only RA-a patients show an increased proportion of circulating plasmablasts.

Decreased frequencies of circulating follicular helper T cell counterparts and plasmablasts in ankylosing spondylitis patients Naïve for TNF blockers.

Follicular helper T cells (Tfh), localized in lymphoid organs, promote B cell differentiation and function. Circulating CD4 T cells expressing CXCR5, ICOS and/or PD-1 are counterparts of Tfh. Three subpopulations of circulating CD4+CXCR5+ cells have been described: CXCR3+CCR6- (Tfh-Th1), CXCR3-CCR6+ (Tfh-Th17), and CXCR3-CCR6- (Tfh-Th2). Only Tfh-Th17 and Tfh-Th2 function as B cell helpers. Our objective was to study the frequencies of circulating Tfh (cTfh), cTfh subsets and plasmablasts (CD19+CD20-CD27+CD38high cells), and the function of cTfh cells, in patients with Ankylosing Spondylitis (AS). To this end, peripheral blood was drawn from healthy controls (HC) (n = 50), AS patients naïve for TNF blockers (AS/nb) (n = 25) and AS patients treated with TNF blockers (AS/b) (n = 25). The frequencies of cTfh and plasmablasts were determined by flow cytometry. Cocultures of magnetically sorted CD4+CXCR5+ T cells with autologous CD19+CD27- naïve B cells were established from 3 AS/nb patients and 3 HC, and concentrations of IgG, A and M were measured in supernatants. We obseved that AS/nb but not AS/b patients, demonstrated decreased frequencies of circulating CD4+CXCR5+ICOS+PD-1+ cells and plasmablasts, together with a decreased (Tfh-Th17+Tfh-Th2)/Tfh-Th1 ratio. The amounts of IgG and IgA produced in cocultures of CD4+CXCR5+ T cells with CD19+CD27- B cells of AS/nb patients were significantly lower than observed in cocultures established from HC. In summary, AS/nb but not AS/b patients, demonstrate a decreased frequency of cTfh and plasmablasts, and an underrepresentation of cTfh subsets bearing a B helper phenotype. In addition, peripheral blood CD4+CXCR5+ T cells of AS/nb patients showed a decreased capacity to help B cells ex vivo.

Circulating follicular helper T cells in Crohn's disease (CD) and CD-associated colorectal cancer.

Follicular helper T cells (Tfh) represent a distinct subset of CD4+ T cells specialized in providing help to B lymphocytes. Studies have indicated that Tfh in circulating blood can act as a prognostic marker for diseases. In the current study, we investigated the percentages of circulating Tfh (CTfh) in Crohn's disease (CD) and CD-associated colorectal cancer (CRC). CTfh and it subtypes were determined by measuring CD3, CD4, CXCR5, CXCR3, and CCR6 using flow cytometry in 32 healthy controls and 78 CD patients, which included 16 CD-associated CRC. Data showed that proportion of CTfh in CD4+ T cells was significantly increased in CD patients (9.8 %) than in controls (5.1 %) (p < 0.01). Further analysis revealed that the upregulation of CTfh was contributed by CTfh-Th1 subtype and CTfh-Th17 subtype. Investigating the behavior of the patients demonstrated that prevalence of CTfh was significantly elevated in penetrating CD (20.9 %) than inflammatory CD (8.2 %) or stricturing CD (7.5 %). In addition, we analyzed CTfh in CD-associated CRC, and identified that patients with CRC had 1.59-fold higher percentage of CTfh than patients without CRC (p < 0.01). Furthermore, the distribution of CTfh subsets was significantly altered in patients with the cancer. This study suggests the involvement of CTfh in CD and CD-associated CRC, in which the effect of CTfh is partially different between these two diseases.

Emerging from the shadows: Follicular helper T cells in autoimmunity

Emerging from the shadows: Follicular helper T cells in autoimmunity