scholarly journals Autoantibody-Mediated Erythrophagocytosis Increases Tuberculosis Susceptibility in HIV Patients

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Youchao Dai ◽  
Yi Cai ◽  
Xin Wang ◽  
Jialou Zhu ◽  
Xiaoqing Liu ◽  
...  
Keyword(s):  
T Cell ◽  
Hiv Infection ◽  
Bactericidal Activity ◽  
Cell Loss ◽  
Cd4 T Cell ◽  
Heme Oxygenase 1 ◽  
Hiv Patients ◽  
Content Type ◽  
Macrophage Function ◽  
Macrophage Dysfunction

ABSTRACT Macrophage dysfunction is associated with increased tuberculosis (TB) susceptibility in patients with human immunodeficiency virus (HIV) infection. However, the mechanisms underlying how HIV infection impairs macrophage function are unclear. Here, we found that levels of autoantibodies against red blood cells (RBCs) were significantly elevated in patients with HIV as determined by direct antiglobulin test (DAT). DAT positivity was significantly associated with TB incidence in both univariate and multivariate analyses (odds ratio [OR] = 11.96 [confidence interval {CI}, 4.68 to 30.93] and 12.65 [3.33 to 52.75], respectively). Ex vivo analysis showed that autoantibodies against RBCs enhanced erythrophagocytosis and thus significantly impaired macrophage bactericidal function against intracellular Mycobacterium tuberculosis. Mechanistically, autoantibody-mediated erythrophagocytosis increased heme oxygenase-1 (HO-1) expression, which inhibited M. tuberculosis-induced autophagy in macrophages. Silencing ATG5, a key component for autophagy, completely abrogated the effect of erythrophagocytosis on macrophage bactericidal activity against M. tuberculosis. In conclusion, we have demonstrated that HIV infection increases autoantibody-mediated erythrophagocytosis. This process impairs macrophage bactericidal activity against M. tuberculosis by inhibiting HO-1-associated autophagy. These findings reveal a novel mechanism as to how HIV infection increases TB susceptibility. IMPORTANCE HIV infection significantly increases TB susceptibility due to CD4 T-cell loss and macrophage dysfunction. Although it is relatively clear that CD4 T-cell loss represents a direct effect of HIV infection, the mechanism underlying how HIV infection dampens macrophage function is unknown. Here, we show that HIV infection enhances autoantibody-mediated erythrophagocytosis, which dampens macrophage bactericidal activity against TB by inhibiting HO-1-associated autophagy. Our findings reveal a novel mechanism explaining how HIV infection increases susceptibility to TB. We propose that DAT could be a potential measure to identify HIV patients who are at high TB risk and who would be suitable for anti-TB chemotherapy preventive treatment.

scholarly journals HIV-1 Env Glycoprotein Phenotype along with Immune Activation Determines CD4 T Cell Loss in HIV Patients

2016 ◽  
Vol 196 (4) ◽  
pp. 1768-1779 ◽  
Author(s):  
Anjali Joshi ◽  
Melina Sedano ◽  
Bethany Beauchamp ◽  
Erin B. Punke ◽  
Zuber D. Mulla ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Activation ◽  
Cell Loss ◽  
Cd4 T Cell ◽  
Hiv Patients ◽  
Hiv 1 ◽  
Env Glycoprotein

Loss of CD127 expression links immune activation and CD4+ T cell loss in HIV infection

2008 ◽  
Vol 16 (12) ◽  
pp. 567-573 ◽  
Author(s):  
Sandra A. Koesters Kiazyk ◽  
Keith R. Fowke
Keyword(s):  
T Cell ◽  
Hiv Infection ◽  
Immune Activation ◽  
Cell Loss ◽  
Cd4 T Cell ◽  
Cd127 Expression

scholarly journals HIV Infection Functionally Impairs Mycobacterium tuberculosis-Specific CD4 and CD8 T-Cell Responses

2018 ◽  
Vol 93 (5) ◽  
Author(s):  
Patrizia Amelio ◽  
Damien Portevin ◽  
Jerry Hella ◽  
Klaus Reither ◽  
Lujeko Kamwela ◽  
...  
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Hiv Infection ◽  
Cd4 T Cells ◽  
Latent Tuberculosis ◽  
Cd4 T Cell ◽  
Content Type ◽  
Cell Responses ◽  
Immunodeficiency Virus

ABSTRACT Human immunodeficiency virus (HIV) infection is the major risk factor predisposing for Mycobacterium tuberculosis progression from latent tuberculosis infection (LTBI) to tuberculosis disease (TB). Since long-term-treated aviremic HIV-infected individuals remained at higher risk of developing TB than HIV-uninfected individuals, we hypothesized that progression from LTBI to pulmonary TB (PTB) might be due not only to CD4 T-cell depletion but also to M. tuberculosis-specific CD4 T-cell functional impairment. To test this hypothesis, M. tuberculosis-specific T-cell frequencies and cytokine profiles were investigated in untreated Tanzanian individuals suffering from LTBI (n = 20) or PTB (n = 67) and compared to those of untreated M. tuberculosis/HIV-coinfected individuals suffering from LTBI (n = 15) or PTB (n = 10). We showed that HIV infection significantly reduced the proportion of Th2 (interleukin 4 [IL-4]/IL-5/IL-13) producing M. tuberculosis-specific CD4 T cells and IL-2-producing M. tuberculosis-specific CD4 and CD8 T cells in individuals with LTBI or PTB (P < 0.05). Interestingly, the loss of IL-2 production was associated with a significant increase of PD-1 expression on M. tuberculosis-specific CD4 and CD8 T cells (P < 0.05), while the loss of Th2 cytokine production was associated with a significant reduction of Gata-3 expression in memory CD4 T cells (P < 0.05). Finally, we showed that the serum levels of IL-1α, IL-6, C-reactive protein (CRP), IL-23, and IP-10 were significantly reduced in M. tuberculosis/HIV-coinfected individuals with PTB compared to those in HIV-negative individuals with PTB (P < 0.05), suggesting that HIV infection significantly suppresses M. tuberculosis-induced systemic proinflammatory cytokine responses. Taken together, this study suggests that in addition to depleting M. tuberculosis-specific CD4 T cells, HIV infection significantly impairs functionally favorable M. tuberculosis-specific CD4 T-cell responses in Tanzanian individuals with LTBI or PTB. IMPORTANCE Mycobacterium tuberculosis and human immunodeficiency virus (HIV) infections are coendemic in several regions of the world, and M. tuberculosis/HIV-coinfected individuals are more susceptible to progression to tuberculosis disease. We therefore hypothesized that HIV infection would potentially impair M. tuberculosis-specific protective immunity in individuals suffering from latent tuberculosis infection (LTBI) or active pulmonary tuberculosis (PTB). In this study, we demonstrated that M. tuberculosis/HIV-coinfected individuals have fewer circulating M. tuberculosis-specific CD4 T cells and that those that remained were functionally impaired in both LTBI and PTB settings. In addition, we showed that HIV infection significantly interferes with M. tuberculosis-induced systemic proinflammatory cytokine/chemokine responses. Taken together, these data suggest that HIV infection impairs functionally favorable M. tuberculosis-specific immunity.

The Effect of Antiretroviral Therapy on IL-6, IL-1β, TNF-α, IFN-γ Levels and their Relationship with HIV-RNA and CD4+ T Cells in HIV Patients

2020 ◽  
Vol 18 (5) ◽  
pp. 354-361
Author(s):  
Gülay Okay ◽  
Meliha Meric Koc ◽  
Eray Metin Guler ◽  
Ayşegül Yabaci ◽  
Abdürrahim Kocyigit ◽  
...  
Keyword(s):  
T Cell ◽  
Hiv Infection ◽  
Cell Count ◽  
Cd4 T Cell ◽  
Positive Correlation ◽  
Hiv Rna ◽  
Tnf Α ◽  
Cytokine Levels ◽  
Ifn Γ ◽  
Cd4 T Cell Count

Background: Serum cytokine levels over the course of HIV infection usually increase with immunosuppression and decrease after antiretroviral treatment (ART). Objectives: The aim of the study is to compare cytokine levels between HIV-infected patients (HIP) and controls and investigate the relationship between CD4+T cell count, HIV-RNA levels, and cytokine levels. Methods: The study subjects comprised ART-naive HIP (n=30) with no comorbidities and age-and sex-matched healthy controls. We measured levels of IL-6, IL-1β, TNF-α, and IFN-γ in serum samples of HIP at the beginning and at month 6 of ART and in controls. Results: The mean age of the study subjects was 38.7 ±10.3 years, with men making up 86.7% of the study subjects (n=26). IL-6, IL-1β, and TNF-α levels were significantly higher in both ART-naive (p<0.001, p=0.002, p=0.001) and ART-experienced HIP (p<0.001) than controls. The IFN-γ level was lower in both ART-naive and ART-experienced HIP compared to controls (p=0.082 and p=0.002). There was a positive correlation between the CD4+T cell count and serum concentration of IFN- γ(r=0.320, p<0.05). While the serum IFN-γ concentration showed a negative correlation with the HIVRNA level(r=-0.412, p<0.001), the serum IL-1β, IL-6, and TNF-α concentrations showed a positive correlation with the HIV-RNA level (r=0.349, p<0.001; r:0.54, p<0.001; r:0.438, p<0.00). Conclusions: Although serum concentrations of IL-6, IL-1β and TNF-α showed a significant decrease after ART, they were still significantly higher than the controls. IFN-γ responded differently to ART compared to the other cytokines, indicating that it may play a distinct and important role in the pathogenesis of HIV infection.

CD4+ T cell count, HIV-1 viral loads and demographic variables of newly identified patients with HIV infection in Wuhan, China

2013 ◽  
Vol 85 (10) ◽  
pp. 1687-1691 ◽  
Author(s):  
Man-Qing Liu ◽  
Li Tang ◽  
Wen-Hua Kong ◽  
Ze-Rong Zhu ◽  
Jin-Song Peng ◽  
...  
Keyword(s):  
T Cell ◽  
Hiv Infection ◽  
Cell Count ◽  
Demographic Variables ◽  
Cd4 T Cell ◽  
Viral Loads ◽  
Hiv 1 ◽  
Cd4 T Cell Count

scholarly journals CD4 T Cell Antigens from Staphylococcus aureus Newman Strain Identified following Immunization with Heat-Killed Bacteria

2012 ◽  
Vol 19 (4) ◽  
pp. 477-489 ◽  
Author(s):  
Paulraj K. Lawrence ◽  
Bachra Rokbi ◽  
Nadège Arnaud-Barbe ◽  
Eric L. Sutten ◽  
Junzo Norimine ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
T Cell ◽  
Reverse Genetics ◽  
Vaccine Development ◽  
Protein A ◽  
Cd4 T Cell ◽  
Content Type ◽  
Intramammary Infections ◽  
T Cell Antigens ◽  
Ifn Γ

ABSTRACTStaphylococcus aureusis a commensal bacterium associated with the skin and mucosal surfaces of humans and animals that can also cause chronic infection. The emergence of antibiotic-resistant strains such as methicillin-resistantS. aureus(MRSA) and strains causing chronic intramammary infections (IMI) in cows results in severe human and livestock infections. Conventional approaches to vaccine development have yielded only a few noneffective vaccines against MRSA or IMI strains, so there is a need for improved vaccine development. CD4 T lymphocytes are required for promoting gamma interferon (IFN-γ) mediated immunoglobulin isotype switching in B lymphocytes to produce high-affinity IgG antibodies and IFN-γ-mediated phagocyte activation for an effective resolution of bacterial infection. However, the lack of known CD4 T cell antigens fromS. aureushas made it difficult to design effective vaccines. The goal of this study was to identifyS. aureusproteins recognized by immune CD4 T cells. Using a reverse genetics approach, 43 antigens were selected from theS. aureusNewman strain. These included lipoproteins, proteases, transcription regulators, an alkaline shock protein, conserved-domain proteins, hemolysins, fibrinogen-binding protein, staphylokinase, exotoxin, enterotoxin, sortase, and protein A. Screening of expressed proteins for recall T cell responses in outbred, immune calves identified 13 proteins that share over 80% sequence identity among MRSA or IMI strains. These may be useful for inclusion in a broadly protective multiantigen vaccine against MRSA or IMI.

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