In vitro co-culture of human intestinal organoids and lamina propria-derived CD4+ T cells

Background:Neutrophils have been described as potent antigen-presenting cells able to activate T cells by MHC/TCR interaction and costimulatory molecules in tumor immunity. However, little is known about the direct interaction between neutrophils and CD4 T cells with respect to systemic lupus erythematosus (SLE). We have previously shown that OX40L expressed by monocytes from SLE patients promote the differentiation of naïve and memory cells into IL21 secreting T cells that are able to help B cells1,2.Objectives:In this study, we investigate OX40L expression on neutrophils from SLE patients and contribution of these OX40L+neutrophils in SLE pathogenesis to modulation of the B cell helper role of CD4 T cells.Methods:Surface expression of co-stimulatory molecules (OX40L, ICOSL, GITRL, 4-1BBL) on neutrophils from SLE patients and healthy donors (HD) was measured by flow cytometry (FC). Neutrophils from HD were stimulated with TLR7 or TLR8 agonists and IFNα after 5 hours of culture, OX40L expression was measured by FC and Western Blotting. CD4 T cells were cultured with the stimulated neutrophils for 3 days. At the end of the co-culture, percentages of IL21-expressing T follicular (Tfh) and peripheral helper (Tph) cells measured by FC. These generated T cells were also cultured in the presence of memory B cells. After 5 days of co-culture, plasmablast generation and Ig levels were assessed by FC and ELISA, respectively. Inhibition of OX40-OX40L interaction in vitro was achieved using ISB 830, a novel anti-OX40 mAb currently used in clinical trials.Results:Among the co-stimulatory molecules tested, percentages of OX40L+neutrophils in SLE (n=54) were increased compared to HD (n=25)(mean + SD: HD = 1,34%±1.62 vs SLE = 4,53%±8.1; p=0.29). OX40L expression positively correlated with SLE disease activity score (SLEDAI) (p = 0,04; r = 0,31) and with anti-DNA antibodies (p= 0,04, r = 0,33). Of note, the percentage of OX40L+neutrophils was higher in anti-sm-RNP+patients (n=16, mean= 9%±9.8), compared to anti-sm-RNP-patients (n=27, mean = 1,4%±2.5; p = 0,02). The percentage of OX40L+neutrophils was higher in patients with class III or IV lupus nephritis, and inflammatory infiltrate within the kidney biopsy disclosed OX40L+neutrophils, in close contact with T cells. Neutrophils from HD express OX40L with TLR8 agonist, or IFNα priming followed by TLR7 agonist. When memory CD4 T cells were cultured in the presence of TLR8-stimulated neutrophils, the proportion of IL21-expressing Tfh (CXCR5+PD1+) and Tph (CXCR5-PD1hi) were increased, compared to culture with unstimulated neutrophils. This process was dependent on OX40-OX40L interactions, since in vitro treatment with the anti-OX40 blocking antibody ISB 830, inhibited the differentiation of memory T cells into Tfh and Tph. Both generated Tfh and Tph were able to promote the differentiation of memory B cells into Ig-secreting plasmablasts.Conclusion:Our results disclose an unprecedented phenomenon where cross-talk between TLR7/8-activated neutrophils and CD4 lymphocytes operates through OX40L-OX40 costimulation, and neutrophils promote the differentiation of pro-inflammatory Tfh and Tph, as well as IL21 production. Therefore, OX40L/OX40 should be considered as a potentially therapeutic axis in SLE patients.References:[1]Jacquemin et al. Immunity 2015;[2]Jacquemin et al. JCI Insight 2018Disclosure of Interests:Angela Pappalardo Grant/research support from: Ichnos Sciences, Elodie Wojciechowski: None declared, Itsaso Odriozola: None declared, Isabelle Douchet: None declared, Nathalie Merillon: None declared, Andrea Boizard-Moracchini: None declared, Pierre Duffau: None declared, Estibaliz Lazaro: None declared, Marie-Agnes Doucey Employee of: Ichnos Sciences, Lamine Mbow Employee of: Ichnos Sciences, Christophe Richez Consultant of: Abbvie, Amgen, Mylan, Pfizer, Sandoz and UCB., Patrick Blanco Grant/research support from: Ichnos Sciences

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mTOR pathway regulates the differentiation of peripheral blood Th2/Treg cell subsets in patients with pemphigus vulgaris

Acta Biochimica et Biophysica Sinica ◽

10.1093/abbs/gmab008 ◽

2021 ◽

Author(s):

Kuan Lai ◽

Wenjing Zhang ◽

Songshan Li ◽

Zhiwen Zhang ◽

Shuangde Xie ◽

...

Keyword(s):

T Cells ◽

Peripheral Blood ◽

Cd4 T Cells ◽

Pemphigus Vulgaris ◽

Treg Cells ◽

Mtor Pathway ◽

Cd4 T Cell ◽

Cell Ratio ◽

Loss Of Balance

Abstract Pemphigus vulgaris (PV) is a chronic and potentially life-threatening autoimmune blistering disease. Aberrant mTOR pathway activity is involved in many autoimmune diseases. This study investigated the correlation of mTOR pathway (PI3K/AKT/mTOR/p70S6K) activity with the loss of balance in T helper 2/regulatory T (Th2/Treg) cells in the peripheral blood of PV patients. CD4+ T cells were isolated from 15 PV patients and 15 healthy controls (HCs), the ratios of Th2/CD4+ T cells and Treg/CD4+ T cells, the activity of the mTOR pathway (PI3K/AKT/mTOR/p70S6K), the transcription factors and cytokines of Th2 and Treg cells were detected. Primary CD4+ T cells from PV patients were cultured under Th2- or Treg-polarizing conditions with or without rapamycin in vitro. We found that PV patients showed significantly elevated serum IL-4 when compared with HCs, and serum IL-4 level was positively correlated with the titer of anti-Dsg1/3 antibody and disease severity, while the serum TGF-β level was negatively correlated with the titer of anti-Dsg3 antibody and disease severity. Meanwhile, PV patients showed increased Th2/CD4+ T cell ratio; decreased Treg/CD4+ T cell ratio; elevated mRNA of PI3K, AKT, mTOR and protein of PI3K (P85), AKT, p-AKT (Ser473), mTOR, p-mTOR (Ser2448), p-p70S6K (Thr389), GATA3; reduced protein of forkhead box protein 3. Rapamycin inhibited Th2 cell differentiation and promoted Treg cell differentiation in vitro. These data suggest a close association between mTOR pathway activation and the loss of balance in Th2/Treg cells in peripheral blood of PV patients. Inhibiting mTORC1 can help restore the Th2/Treg balance.

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THU0046 A PIPELINE TO STUDY ANTIGEN-SPECIFIC CD4+ T CELLS IN RHEUMATOID ARTHRITIS

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2020-eular.1093 ◽

2020 ◽

Vol 79 (Suppl 1) ◽

pp. 235.1-236

Author(s):

R. Kumar ◽

N. Yoosuf ◽

C. Gerstner ◽

S. Turcinov ◽

K. Chemin ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

T Cells ◽

T Cell ◽

Cd4 T Cells ◽

Mononuclear Cells ◽

Tenascin C ◽

Tetramer Staining ◽

Tcr Repertoire ◽

Citrullinated Antigen

Background:Autoimmunity to citrullinated autoantigens forms a critical component of disease pathogenesis in rheumatoid arthritis (RA). Presence of anti-citrullinated protein antibodies (ACPAs) in patients has high diagnostic value. Recently, several citrullinated antigen specific CD4+T cells have been described. However, detailed studies of their T-cell receptor usage and in-vivo profile suffer from the disadvantage that these cells are present at very low frequencies. In this context, we here present a pipeline for TCR repertoire analysis of antigen-specific CD4+T cells from RA patients, including both citrulline and influenza (control) specificities using in-vitro peptide challenge induced-cell expansion.Objectives:To enable studies of the T cell repertoire of citrullinated antigen-specific CD4+T cells in rheumatoid arthritisMethods:Peripheral blood mononuclear cells (PBMCs) (n=7) and synovial fluid mononuclear cells (SFMCs) (n=5) from HLA-DR*0401-postive RA patients were cultured in the presence of citrullinated Tenascin C peptide cocktails or influenza peptides (positive control). Citrulline reactive cells were further supplemented with recombinant human IL-15 and IL-7 on day 2. All cultures were replenished with fresh medium on day 6 and rIL-2 was added every 2 days from then. Assessment of proportion of peptide-HLA-tetramer positive cells was performed using flow cytometry whereby individual antigen-specific CD4+T cells were sorted into 96-well plates containing cell lysis buffer, followed by PCR-based alpha/beta TCR sequencing. TCR sequencing data was demultiplexed and aligned for TCR gene usage using MiXCR. Some tetramer positive cells were sorted into complete medium containing human IL-2 and PHA for expansion of antigen-specific cells. Cells were supplemented with irradiated allogenic PBMCs (30 times number of antigen specific cells). Clones of antigen specific CD4+T cells were further subjected to tetramer staining to confirm expansion of cells.Results:As evidenced by increase in frequency of tetramer positive CD4+T cells, in vitro peptide stimulation resulted in expansion of both influenza specific (Fig. 1a) and citrullinated antigen specific (Fig. 1b) CD4+T cells. Polyclonal in-vitro expansion of tenascin C tetramer positive sorted cells followed by tetramer staining further confirmed antigen specificity and enrichment for antigen specific CD4+T cells after polyclonal stimulation (Fig.1c). TCR repertoire analysis in PB and SF dataset from the first patient showed clonal expansion of influenza specific cells in both sites. Synovial fluid had more diversity of expanding clones as compared to paired PB, with few expanded clones being shared among SF and PB. We observed a more diverse TCR repertoire in citrulline specific CD4+T cells. We also observed sharing of TCR alpha chains among different citrulline specific CD4+T cell clones.Fig. 1In-vitroexpansion of antigen specific CD4+T cells:Conclusion:This method provides a highly suitable approach for investigating TCR specificities of antigen specific CD4+T cells under conditions of low cell yields. Building on this dataset will allow us to assess specific features of TCR usage of autoreactive T cells in RA.PBMCs were cultured in presence of (a) influenza (HA, MP54) and (b) citrullinated tenascin peptides. The proportion of antigen specific CD4+T cells was assessed using HLA-class II tetramer staining. We observed an increase in frequency of (a) Infleunza specific cells (red dots in upper left and lower right quadrants) and (b) citrullinated tenascin C specific cells (red dots in lower right quadrant), at day 13 post culture as compared to day 3. (c) Sorting of citrullinated tenascin specific CD4+T cells, followed by PHA expansion resulted in visible increase in proportion of citrullinated tenascin specific CD4+T cells.Disclosure of Interests:Ravi kumar: None declared, Niyaz Yoosuf: None declared, Christina Gerstner: None declared, Sara Turcinov: None declared, Karine Chemin: None declared, Vivianne Malmström Grant/research support from: VM has had research grants from Janssen Pharmaceutica

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CD73+ CD127high Long-Term Memory CD4 T Cells Are Highly Proliferative in Response to Recall Antigens and Are Early Targets in HIV-1 Infection

International Journal of Molecular Sciences ◽

10.3390/ijms22020912 ◽

2021 ◽

Vol 22 (2) ◽

pp. 912

Author(s):

Nabila Seddiki ◽

John Zaunders ◽

Chan Phetsouphanh ◽

Vedran Brezar ◽

Yin Xu ◽

...

Keyword(s):

T Cells ◽

Peripheral Blood ◽

Cd4 T Cells ◽

Significant Proportion ◽

Long Term Memory ◽

Ki 67 ◽

Memory Cd4 T Cells ◽

Hiv 1

HIV-1 infection rapidly leads to a loss of the proliferative response of memory CD4+ T lymphocytes, when cultured with recall antigens. We report here that CD73 expression defines a subset of resting memory CD4+ T cells in peripheral blood, which highly express the α-chain of the IL-7 receptor (CD127), but not CD38 or Ki-67, yet are highly proliferative in response to mitogen and recall antigens, and to IL-7, in vitro. These cells also preferentially express CCR5 and produce IL-2. We reasoned that CD73+ memory CD4+ T cells decrease very early in HIV-1 infection. Indeed, CD73+ memory CD4+ T cells comprised a median of 7.5% (interquartile range: 4.5–10.4%) of CD4+ T cells in peripheral blood from healthy adults, but were decreased in primary HIV-1 infection to a median of 3.7% (IQR: 2.6–6.4%; p = 0.002); and in chronic HIV-1 infection to 1.9% (IQR: 1.1–3%; p < 0.0001), and were not restored by antiretroviral therapy. Moreover, we found that a significant proportion of CD73+ memory CD4+ T cells were skewed to a gut-homing phenotype, expressing integrins α4 and β7, CXCR3, CCR6, CD161 and CD26. Accordingly, 20% of CD4+ T cells present in gut biopsies were CD73+. In HIV+ subjects, purified CD73+ resting memory CD4+ T cells in PBMC were infected with HIV-1 DNA, determined by real-time PCR, to the same level as for purified CD73-negative CD4+ T cells, both in untreated and treated subjects. Therefore, the proliferative CD73+ subset of memory CD4+ T cells is disproportionately reduced in HIV-1 infection, but, unexpectedly, their IL-7 dependent long-term resting phenotype suggests that residual infected cells in this subset may contribute significantly to the very long-lived HIV proviral DNA reservoir in treated subjects.

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Cd40-Independent Pathways of T Cell Help for Priming of Cd8+ Cytotoxic T Lymphocytes

Journal of Experimental Medicine ◽

10.1084/jem.191.3.541 ◽

2000 ◽

Vol 191 (3) ◽

pp. 541-550 ◽

Cited By ~ 144

Author(s):

Zhengbin Lu ◽

Lingxian Yuan ◽

Xianzheng Zhou ◽

Eduardo Sotomayor ◽

Hyam I. Levitsky ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cd4 T Cells ◽

Cytotoxic T Lymphocyte ◽

Cell Communication ◽

Cd8 T Cell ◽

Cd4 Help ◽

T Cell Help

In many cases, induction of CD8+ CTL responses requires CD4+ T cell help. Recently, it has been shown that a dominant pathway of CD4+ help is via antigen-presenting cell (APC) activation through engagement of CD40 by CD40 ligand on CD4+ T cells. To further study this three cell interaction, we established an in vitro system using dendritic cells (DCs) as APCs and influenza hemagglutinin (HA) class I and II peptide–specific T cell antigen receptor transgenic T cells as cytotoxic T lymphocyte precursors and CD4+ T helper cells, respectively. We found that CD4+ T cells can provide potent help for DCs to activate CD8+ T cells when antigen is provided in the form of either cell lysate, recombinant protein, or synthetic peptides. Surprisingly, this help is completely independent of CD40. Moreover, CD40-independent CD4+ help can be documented in vivo. Finally, we show that CD40-independent T cell help is delivered through both sensitization of DCs and direct CD4+–CD8+ T cell communication via lymphokines. Therefore, we conclude that CD4+ help comprises at least three components: CD40-dependent DC sensitization, CD40-independent DC sensitization, and direct lymphokine-dependent CD4+–CD8+ T cell communication.

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