Sensing of HIV-1 by TLR8 activates human T cells and reverses latency

AbstractDuring HIV infection, cell-to-cell transmission results in endosomal uptake of the virus by target CD4+ T cells and potential exposure of the viral ssRNA genome to endosomal Toll-like receptors (TLRs). TLRs are instrumental in activating inflammatory responses in innate immune cells, but their function in adaptive immune cells is less well understood. Here we show that synthetic ligands of TLR8 boosted T cell receptor signaling, resulting in increased cytokine production and upregulation of surface activation markers. Adjuvant TLR8 stimulation, but not TLR7 or TLR9, further promoted T helper cell differentiation towards Th1 and Th17. In addition, we found that endosomal HIV induced cytokine secretion from CD4+ T cells in a TLR8-specific manner. TLR8 engagement also enhanced HIV-1 replication and potentiated the reversal of latency in patient-derived T cells. The adjuvant TLR8 activity in T cells can contribute to viral dissemination in the lymph node and low-grade inflammation in HIV patients. In addition, it can potentially be exploited for therapeutic targeting and vaccine development.

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CCL21 mediates CD4+ T-cell costimulation via a DOCK2/Rac-dependent pathway

Blood ◽

10.1182/blood-2009-01-200923 ◽

2009 ◽

Vol 114 (3) ◽

pp. 580-588 ◽

Cited By ~ 45

Author(s):

Kathrin Gollmer ◽

François Asperti-Boursin ◽

Yoshihiko Tanaka ◽

Klaus Okkenhaug ◽

Bart Vanhaesebroeck ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cd4 T Cells ◽

Cell Activation ◽

Early Time ◽

Cell Receptor ◽

Tcr Signaling ◽

Activation Markers

Abstract CD4+ T cells use the chemokine receptor CCR7 to home to and migrate within lymphoid tissue, where T-cell activation takes place. Using primary T-cell receptor (TCR)–transgenic (tg) CD4+ T cells, we explored the effect of CCR7 ligands, in particular CCL21, on T-cell activation. We found that the presence of CCL21 during early time points strongly increased in vitro T-cell proliferation after TCR stimulation, correlating with increased expression of early activation markers. CCL21 costimulation resulted in increased Ras- and Rac-GTP formation and enhanced phosphorylation of Akt, MEK, and ERK but not p38 or JNK. Kinase-dead PI3KδD910A/D910A or PI3Kγ-deficient TCR-tg CD4+ T cells showed similar responsiveness to CCL21 costimulation as control CD4+ T cells. Conversely, deficiency in the Rac guanine exchange factor DOCK2 significantly impaired CCL21-mediated costimulation in TCR-tg CD4+ T cells, concomitant with impaired Rac- but not Ras-GTP formation. Using lymph node slices for live monitoring of T-cell behavior and activation, we found that G protein-coupled receptor signaling was required for early CD69 expression but not for Ca2+ signaling. Our data suggest that the presence of CCL21 during early TCR signaling lowers the activation threshold through Ras- and Rac-dependent pathways leading to increased ERK phosphorylation.

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The Proteomic Landscape of Resting and Activated CD4+ T Cells Reveal Insights into Cell Differentiation and Function

International Journal of Molecular Sciences ◽

10.3390/ijms22010275 ◽

2020 ◽

Vol 22 (1) ◽

pp. 275

Author(s):

Yashwanth Subbannayya ◽

Markus Haug ◽

Sneha M. Pinto ◽

Varshasnata Mohanty ◽

Hany Zakaria Meås ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Immune Cells ◽

Cd4 T Cells ◽

Cell Activation ◽

Cd4 T Cell ◽

Proteomic Profiling ◽

Altered Expression ◽

Adaptive Immune Cells

CD4+ T cells (T helper cells) are cytokine-producing adaptive immune cells that activate or regulate the responses of various immune cells. The activation and functional status of CD4+ T cells is important for adequate responses to pathogen infections but has also been associated with auto-immune disorders and survival in several cancers. In the current study, we carried out a label-free high-resolution FTMS-based proteomic profiling of resting and T cell receptor-activated (72 h) primary human CD4+ T cells from peripheral blood of healthy donors as well as SUP-T1 cells. We identified 5237 proteins, of which significant alterations in the levels of 1119 proteins were observed between resting and activated CD4+ T cells. In addition to identifying several known T-cell activation-related processes altered expression of several stimulatory/inhibitory immune checkpoint markers between resting and activated CD4+ T cells were observed. Network analysis further revealed several known and novel regulatory hubs of CD4+ T cell activation, including IFNG, IRF1, FOXP3, AURKA, and RIOK2. Comparison of primary CD4+ T cell proteomic profiles with human lymphoblastic cell lines revealed a substantial overlap, while comparison with mouse CD+ T cell data suggested interspecies proteomic differences. The current dataset will serve as a valuable resource to the scientific community to compare and analyze the CD4+ proteome.

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Discrete immune response signature to SARS-CoV-2 mRNA vaccination versus infection

10.1101/2021.04.20.21255677 ◽

2021 ◽

Author(s):

Ellie N. Ivanova ◽

Joseph C. Devlin ◽

Terkild B. Buus ◽

Akiko Koide ◽

Amber Cornelius ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Immune Responses ◽

Immune Cells ◽

Transcriptional Profiling ◽

Cell Receptor ◽

Interferon Response ◽

Effector Cells ◽

Adaptive Immune ◽

Adaptive Immune Cells

AbstractBoth SARS-CoV-2 infection and vaccination elicit potent immune responses. A number of studies have described immune responses to SARS-CoV-2 infection. However, beyond antibody production, immune responses to COVID-19 vaccines remain largely uncharacterized. Here, we performed multimodal single-cell sequencing on peripheral blood of patients with acute COVID-19 and healthy volunteers before and after receiving the SARS-CoV-2 BNT162b2 mRNA vaccine to compare the immune responses elicited by the virus and by this vaccine. Phenotypic and transcriptional profiling of immune cells, coupled with reconstruction of the B and T cell antigen receptor rearrangement of individual lymphocytes, enabled us to characterize and compare the host responses to the virus and to defined viral antigens. While both infection and vaccination induced robust innate and adaptive immune responses, our analysis revealed significant qualitative differences between the two types of immune challenges. In COVID-19 patients, immune responses were characterized by a highly augmented interferon response which was largely absent in vaccine recipients. Increased interferon signaling likely contributed to the observed dramatic upregulation of cytotoxic genes in the peripheral T cells and innate-like lymphocytes in patients but not in immunized subjects. Analysis of B and T cell receptor repertoires revealed that while the majority of clonal B and T cells in COVID-19 patients were effector cells, in vaccine recipients clonally expanded cells were primarily circulating memory cells. Importantly, the divergence in immune subsets engaged, the transcriptional differences in key immune populations, and the differences in maturation of adaptive immune cells revealed by our analysis have far-ranging implications for immunity to this novel pathogen.

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Proliferation of HIV-infected renal epithelial cells following virus acquisition from infected macrophages

10.1101/2020.03.27.011916 ◽

2020 ◽

Author(s):

Kelly Hughes ◽

Guray Akturk ◽

Sacha Gnjatic ◽

Benjamin Chen ◽

Mary Klotman ◽

...

Keyword(s):

T Cells ◽

Cd4 T Cells ◽

Inflammatory Responses ◽

Live Imaging ◽

Cell Contact ◽

Renal Cells ◽

Virus Acquisition ◽

Primary Monocyte ◽

Design And Methods ◽

Hiv 1

ABSTRACTObjectivesHIV-1 can infect and persist in different organs and tissues, resulting in the generation of multiple viral compartments and reservoirs. Increasing evidence supports the kidney as such a reservoir. Previous work demonstrated that HIV-1 infected CD4+ T-cells transfer virus to renal tubule epithelial (RTE) cells through cell-to-cell contact. In addition to CD4+ T-cells, macrophages represent the other major target of HIV-1. Renal macrophages induce and regulate inflammatory responses and are critical to homeostatic regulation of the kidney environment. Combined with their ability to harbor virus, macrophages may also play an important role in the spread of HIV-1 infection in the kidney.Design and MethodsMultiparametric histochemistry analysis was performed on kidney biopsies from individuals with HIV-1 associated nephropathy (HIVAN). Primary monocyte-derived macrophages were infected with a (GFP)-expressing replication competent HIV-1. HIV-1 transfer from macrophages to RTE cells was carried out in a co-culture system and evaluated by fluorescence-microscopy and flow-cytometry. Live imaging was performed to assess the fate of HIV-1 infected RTE cells over time.ResultsWe show that macrophages are abundantly present in the renal inflammatory infiltrate of individuals with HIVAN. We observed contact-dependent HIV-1 transfer from infected macrophages to both primary and immortalized renal cells. Live imaging of HIV-1 infected RTE cells revealed four different fates: proliferation, hypertrophy, latency and cell death.ConclusionsOur study suggests that macrophages may play a role in the dissemination of HIV-1 in the kidney and that proliferation of infected renal cells may contribute to HIV-1 persistence in this compartment.

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The proteomic landscape of resting and activated CD4+ T cells reveal insights into cell differentiation and function

10.1101/2020.11.17.385096 ◽

2020 ◽

Author(s):

Yashwanth Subbannayya ◽

Markus Haug ◽

Sneha M. Pinto ◽

Varshasnata Mohanty ◽

Hany Zakaria Meås ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Immune Cells ◽

Cd4 T Cells ◽

Cell Activation ◽

Cd4 T Cell ◽

Label Free ◽

Proteomic Profiling ◽

Adaptive Immune Cells

AbstractCD4+ T cells (T helper cells) are cytokine-producing adaptive immune cells that activate or regulate the responses of various immune cells. The activation and functional status of CD4+ T cells is important for adequate responses to pathogen infections but has also been associated with auto-immune disorders and survival in several cancers. In the current study, we carried out a label-free high-resolution FTMS-based proteomic profiling of resting and T cell receptor-activated (72h) primary human CD4+ T cells from peripheral blood of healthy donors as well as SUP-T1 cells. We identified 5,237 proteins, of which significant alterations in the levels of 1,119 proteins were observed between resting and activated CD4+ T cells. We confirmed several known T-cell activation-related processes such as IL-2 response, metabolic and signaling changes, cell cycle induction, differentiation into effector cells among others. Several stimulatory/inhibitory immune checkpoint markers were altered considerably between resting and activated CD4+ T cells. Network analysis identified several known regulatory hubs of CD4+ T cell activation, including IFNG, IRF1, FOXP3, AURKA, and novel hubs such as RIOK2. Comparison of primary CD4+ T cell proteomic profiles with human lymphoblastic cell lines revealed a substantial overlap, while comparison with mouse CD+ T cell data suggested interspecies proteomic differences.

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Novel Nested Peptide Epitopes Recognized by CD4+ T Cells Induced by HIV-1 Conserved-Region Vaccines

Vaccines ◽

10.3390/vaccines8010028 ◽

2020 ◽

Vol 8 (1) ◽

pp. 28 ◽

Cited By ~ 2

Author(s):

Nicola Borthwick ◽

Sandra Silva-Arrieta ◽

Anuska Llano ◽

Masafumi Takiguchi ◽

Christian Brander ◽

...

Keyword(s):

T Cells ◽

Cd4 T Cells ◽

Vaccine Development ◽

National Laboratory ◽

Class Ii ◽

Interferon Γ ◽

Hla Class Ii ◽

Peptide Epitopes ◽

Hiv 1

CD4+ T-cell responses play an important role in the immune control of the human immunodeficiency virus type 1 (HIV-1) infection and as such should be efficiently induced by vaccination. It follows that definition of HIV-1-derived peptides recognized by CD4+ T cells in association with HLA class II molecules will guide vaccine development. Here, we have characterized the fine specificity of CD4+ T cells elicited in human recipients of a candidate vaccine delivering conserved regions of HIV-1 proteins designated HIVconsv. The majority of these 19 most immunogenic regions contained novel epitopes, that is, epitopes not listed in the Los Alamos National Laboratory HIV Sequence Database, which were able in vitro to stimulate vaccinees’ CD4+ T cells to proliferate and produce interferon-γ and tumor necrosis factor-α. Accumulation of HLA class II epitopes will eventually accelerate development of HIV-1 prophylactic and therapeutic vaccines.

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Inflammatory Cells in Patients with Endstage Knee Osteoarthritis: A Comparison between the Synovium and the Infrapatellar Fat Pad

The Journal of Rheumatology ◽

10.3899/jrheum.151068 ◽

2016 ◽

Vol 43 (4) ◽

pp. 771-778 ◽

Cited By ~ 51

Author(s):

Inge R. Klein-Wieringa ◽

Badelog J.E. de Lange-Brokaar ◽

Erlangga Yusuf ◽

Stefan N. Andersen ◽

Joanneke C. Kwekkeboom ◽

...

Keyword(s):

T Cells ◽

Proinflammatory Cytokines ◽

Immune Cells ◽

Cd4 T Cells ◽

Inflammatory Cells ◽

Infrapatellar Fat Pad ◽

Fat Pad ◽

Activation Markers ◽

Knee Oa ◽

Activated State

Objective.To get a better understanding of inflammatory pathways active in the osteoarthritic (OA) joint, we characterized and compared inflammatory cells in the synovium and the infrapatellar fat pad (IFP) of patients with knee OA.Methods.Infiltrating immune cells were characterized by flow cytometry in 76 patients with knee OA (mean age 63.3, 52% women, median body mass index 28.9) from whom synovial tissue (n = 40) and IFP (n = 68) samples were obtained. Pain was assessed by the visual analog scale (VAS; 0–100 mm). Spearman rank correlations and linear regression analyses adjusted for sex and age were performed.Results.Macrophages and T cells, followed by mast cells, were the most predominant immune cells in the synovium and IFP, and were equally abundant in these tissues. Macrophages and T cells secreted mostly proinflammatory cytokines even without additional stimulation, indicating their activated state. Accordingly, most CD4+ T cells had a memory phenotype and contained a significant population of cells expressing activation markers (CD25+, CD69+). Interestingly, the percent of CD69+ T cells was higher in synovial than IFP CD4+ T cells. Preliminary analyses indicated that the number of synovial CD4+ T cells were associated with VAS pain (β 0.51, 95% CI 0.09–1.02, p = 0.02).Conclusion.Our data suggest that the immune cell composition of the synovium and the IFP is similar, and includes activated cells that could contribute to inflammation through secretion of proinflammatory cytokines. Moreover, preliminary analyses indicate that synovial CD4+ T cells might associate with pain in patients with endstage OA of the knee.

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