scholarly journals Regulatory T Cells in HIV Infection: Can Immunotherapy Regulate the Regulator?

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Mohammad-Ali Jenabian ◽  
Petronela Ancuta ◽  
Norbert Gilmore ◽  
Jean-Pierre Routy
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Hiv Infection ◽  
Immune Activation ◽  
Viral Infections ◽  
Dominant Role ◽  
Frequency Function ◽  
Lymphoid Tissues ◽  
And Control ◽  
Anti Hiv

Regulatory T cells (Tregs) have a dominant role in self-tolerance and control of autoimmune diseases. These cells also play a pivotal role in chronic viral infections and cancer by limiting immune activation and specific immune response. The role of Tregs in HIV pathogenesis remains poorly understood as their function, changes according to the phases of infection. Tregs can suppress anti-HIV specific responses and conversely can have a beneficial role by reducing the deleterious impact of immune activation. We review the frequency, function and homing potential of Tregs in the blood and lymphoid tissues as well as their interaction with dendritic cells in the context of HIV infection. We also examine the new insights generated by recombinant IL-2 and IL-7 clinical trials in HIV-infected adults, including the immunomodulatory effects of Tregs. Based on their detrimental role in limiting anti-HIV responses, we propose Tregs as potential targets for immunotherapeutic strategies aimed at decreasing Tregs frequency and/or immunosuppressive function. However, such approaches require a better understanding of the time upon infection when interfering with Treg function may not cause a deleterious state of hyperimmune activation.

Dysregulation of CD4+CD25+CD127lowFOXP3+ regulatory T cells in HIV-infected pregnant women

Blood ◽  
2011 ◽  
Vol 117 (6) ◽  
pp. 1861-1868 ◽  
Author(s):  
Lilian Kolte ◽  
Julie C. Gaardbo ◽  
Ingrid Karlsson ◽  
Anna Louise Sørensen ◽  
Lars P. Ryder ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Hiv Infection ◽  
Immune Activation ◽  
Lymphocyte Subsets ◽  
Peripheral Tolerance ◽  
Cd4 Counts ◽  
Thymic Output ◽  
Pregnancy And Postpartum ◽  
Hiv Negative

Abstract Pregnancy represents a major challenge to immunologic tolerance. How the fetal “semiallograft” evades maternal immune attack is unknown. Pregnancy success may involve alteration of both central (thymic) and peripheral tolerance mechanisms. HIV infection is characterized by CD4+ T-cell depletion, chronic immune activation, and altered lymphocyte subsets. We studied immunologic consequences of pregnancy in 20 HIV-infected women receiving highly active antiretroviral therapy (HAART), and for comparison in 16 HIV-negative women. Lymphocyte subsets, thymic output, and cytokine profiles were measured prospectively during pregnancy and postpartum. A significant expansion of CD4+CD25+CD127lowFoxP3+ regulatory T cells indicating alteration of peripheral tolerance was seen during second trimester, but only in HIV-negative women. HIV-infected women had lower CD4 counts, lower thymic output and Th-2 cytokines, and more immune activation at all time points compared with controls. Immune activation was decreased in HIV-infected patients during pregnancy. In contrast, CD4 counts were increased in both groups. In conclusion, the study does not indicate that pregnancy adversely affects the immunologic course of HIV infection. However, despite HAART during pregnancy, HIV-infected women display different immunologic profiles from HIV-negative women, which may have importance for the induction of fetal-maternal tolerance and in part explain the increased risk of abortion in HIV-infected women.

scholarly journals Depletion of Regulatory T Cells in HIV Infection Is Associated with Immune Activation

2005 ◽  
Vol 174 (7) ◽  
pp. 4407-4414 ◽  
Author(s):  
Mark P. Eggena ◽  
Banson Barugahare ◽  
Norman Jones ◽  
Martin Okello ◽  
Steven Mutalya ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Hiv Infection ◽  
Immune Activation

The split personality of regulatory T cells in HIV infection

Blood ◽  
2013 ◽  
Vol 121 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Mathieu F. Chevalier ◽  
Laurence Weiss
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Hiv Infection ◽  
T Cell Activation ◽  
Immune Activation ◽  
Cell Activation ◽  
Chronic Infections ◽  
Viral Control ◽  
Cell Dynamics ◽  
Split Personality

Abstract Natural regulatory T cells (Tregs) participate in responses to various chronic infections including HIV. HIV infection is associated with a progressive CD4 lymphopenia and defective HIV-specific CD8 responses known to play a key role in the control of viral replication. Persistent immune activation is a hallmark of HIV infection and is involved in disease progression independent of viral load. The consequences of Treg expansion, observed in HIV infection, could be either beneficial, by suppressing generalized T-cell activation, or detrimental, by weakening HIV-specific responses and thus contributing to viral persistence. The resulting balance between Tregs contrasting outcomes might have critical implications in pathogenesis. Topics covered in this review include HIV-induced alterations of Tregs, Treg cell dynamics in blood and tissues, Treg-suppressive function, and the relationship between Tregs and immune activation. This review also provides a focus on the role of CD39+ Tregs and other regulatory cell subsets. All these issues will be explored in different situations including acute and chronic infection, antiretroviral treatment-mediated viral control, and spontaneous viral control. Results must be interpreted with regard to both the Treg definition used in context and to the setting of the disease in an attempt to draw clearer conclusions from the apparently conflicting results.

scholarly journals CD4+ CD25+ Regulatory T Cells Modulate the T-Cell and Antibody Responses in Helicobacter-Infected BALB/c Mice

2006 ◽  
Vol 74 (6) ◽  
pp. 3519-3529 ◽  
Author(s):  
Maria Kaparakis ◽  
Karen L. Laurie ◽  
Odilia Wijburg ◽  
John Pedersen ◽  
Martin Pearse ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Bacterial Colonization ◽  
Antibody Responses ◽  
T Helper 1 ◽  
Time Of Infection ◽  
Lymph Node Cells ◽  
Antibody Levels ◽  
And Control

ABSTRACT Gastric Helicobacter spp. induce chronic gastritis that may lead to ulceration and dysplasia. The host elicits a T helper 1 (Th1) response that is fundamental to the pathogenesis of these bacteria. We analyzed immune responses in Helicobacter-infected, normal mice depleted of CD4+ CD25+ T cells to investigate the in vivo role of regulatory T cells (Tregs) in the modulation of Helicobacter immunopathology. BALB/c and transgenic mice were depleted of CD4+ CD25+ T cells by administration of an anti-CD25 antibody either at the time of infection with Helicobacter or during chronic infection and gastritis. Depletion of CD25+ Tregs prior to and during infection of mice with Helicobacter spp. did not affect either bacterial colonization or severity of gastritis. Depletion of CD25+ Tregs was associated with increased Helicobacter-specific antibody levels and an altered isotype distribution. Paragastric lymph node cells from CD25+ Treg-depleted and control infected mice showed similar proliferation to Helicobacter antigens, but only cells from anti-CD25-treated animals secreted Th2 cytokines. CD25+ Tregs do not control the level of gastritis induced by gastric Helicobacter spp. in normal, thymus-intact BALB/c mice. However, CD25+ Tregs influence the cytokine and antibody responses induced by infection. Autoimmune gastritis is not induced in Helicobacter-infected mice depleted of CD25+ Tregs but is induced in CD25+ Treg-depleted mice, which have a higher frequency of autoreactive T cells.

scholarly journals Immune activation and regulatory T cells in Mycobacterium tuberculosis infected lymph nodes

2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Karima Sahmoudi ◽  
Hassan Abbassi ◽  
Nada Bouklata ◽  
Mohamed Nouredine El Alami ◽  
Abderrahmane Sadak ◽  
...  
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
Regulatory T Cells ◽  
Lymph Nodes ◽  
Immune Activation

scholarly journals CD4+CD8+T Cells Represent a Significant Portion of the Anti-HIV T Cell Response to Acute HIV Infection

2012 ◽  
Vol 188 (9) ◽  
pp. 4289-4296 ◽  
Author(s):  
Marc A. Frahm ◽  
Ralph A. Picking ◽  
JoAnn D. Kuruc ◽  
Kara S. McGee ◽  
Cynthia L. Gay ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Hiv Infection ◽  
Cd8 T Cells ◽  
Cell Response ◽  
T Cell Response ◽  
Acute Hiv Infection ◽  
Acute Hiv ◽  
Anti Hiv

scholarly journals CD38 Correlates with an Immunosuppressive Treg Phenotype in Lupus-Prone Mice

2021 ◽  
Vol 22 (21) ◽  
pp. 11977
Author(s):  
Jocelyn C. Pérez-Lara ◽  
Enrique Espinosa ◽  
Leopoldo Santos-Argumedo ◽  
Héctor Romero-Ramírez ◽  
Gabriela López-Herrera ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Immune Activation ◽  
Lupus Erythematosus ◽  
Clinical Signs ◽  
Foxp3 Expression ◽  
Cell Receptor ◽  
Treg Cells ◽  
Transmembrane Glycoprotein ◽  
Ifn Γ

CD38 is a transmembrane glycoprotein expressed by T-cells. It has been reported that patients with systemic lupus erythematosus (SLE) showed increased CD38+CD25+ T-cells correlating with immune activation and clinical signs. Contrariwise, CD38 deficiency in murine models has shown enhanced autoimmunity development. Recent studies have suggested that CD38+ regulatory T-cells are more suppressive than CD38− regulatory T-cells. Thus, we have suggested that CD38 overexpression in SLE patients could play a role in regulating immune activation cells instead of enhancing it. This study found a correlation between CD38 with FoxP3 expression and immunosuppressive molecules (CD69, IL-10, CTLA-4, and PD-1) in T-cells from lupus-prone mice (B6.MRL-Faslpr/J). Additionally, B6.MRL-Faslpr/J mice showed a decreased proportion of CD38+ Treg cells regarding wild-type mice (WT). Furthermore, Regulatory T-Cells (Treg cells) from CD38-/- mice showed impairment in expressing immunosuppressive molecules and proliferation after stimulation through the T-cell receptor (TCR). Finally, we demonstrated an increased ratio of IFN-γ/IL-10 secretion in CD38-/- splenocytes stimulated with anti-CD3 compared with the WT. Altogether, our data suggest that CD38 represents an element in maintaining activated and proliferative Treg cells. Consequently, CD38 could have a crucial role in immune tolerance, preventing SLE development through Treg cells.

scholarly journals Betamethasone induces potent immunosuppression and reduces HIV infection in a PBMC in vitro model

2020 ◽  
Vol 69 (1) ◽  
pp. 28-40 ◽  
Author(s):  
Ross Cromarty ◽  
Alexander Sigal ◽  
Lenine Julie Liebenberg ◽  
Lyle Robert Mckinnon ◽  
Salim Safurdeen Abdool Karim ◽  
...  
Keyword(s):  
T Cells ◽  
Hiv Infection ◽  
Immune Activation ◽  
Cd4 T Cells ◽  
Drug Targets ◽  
Complex Nature ◽  
Peripheral Blood Mononuclear ◽  
Established Risk Factor ◽  
Anti Inflammatory

Genital inflammation is an established risk factor for increased HIV acquisition risk. Certain HIV-exposed seronegative populations, who are naturally resistant to HIV infection, have an immune quiescent phenotype defined by reduced immune activation and inflammatory cytokines at the genital tract. Therefore, the aim of this study was to create an immune quiescent environment using immunomodulatory drugs to mitigate HIV infection. Using an in vitro peripheral blood mononuclear cell (PBMC) model, we found that inflammation was induced using phytohemagglutinin and Toll-like receptor (TLR) agonists Pam3CSK4 (TLR1/2), lipopolysaccharide (LPS) (TLR4) and R848 (TLR7/8). After treatment with anti-inflammatory drugs, ibuprofen (IBF) and betamethasone (BMS), PBMCs were exposed to HIV NL4-3 AD8. Multiplexed ELISA was used to measure 28 cytokines to assess inflammation. Flow cytometry was used to measure immune activation (CD38, HLA-DR and CCR5) and HIV infection (p24 production) of CD4+ T cells. BMS potently suppressed inflammation (soluble cytokines, p<0.05) and immune activation (CD4+ T cells, p<0.05). BMS significantly reduced HIV infection of CD4+ T cells only in the LPS (0.98%) and unstimulated (1.7%) conditions (p<0.02). In contrast, IBF had minimal anti-inflammatory and immunosuppressive but no anti-HIV effects. BMS demonstrated potent anti-inflammatory effects, regardless of stimulation condition. Despite uniform immunosuppression, BMS differentially affected HIV infection according to the stimulation conditions, highlighting the complex nature of these interactions. Together, these data underscore the importance of interrogating inflammatory signaling pathways to identify novel drug targets to mitigate HIV infection.

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