Long-term humoral and cellular immunity after primary SARS-CoV-2 infection: a 20-month longitudinal study.

Background: SARS-CoV-2 remains a world-wide health issue. SARS-CoV-2-specific immunity is induced upon both infection and vaccination. However, defining the long-term immune trajectory, especially after infection, is limited.

Examination of autoantibodies to type I interferon in patients suffering from long COVID.

Long COVID (LC) is an emerging global health concern. The underlying mechanism and pathophysiology remain unclear. Presence of neutralizing autoantibodies against type 1 interferons (IFN) has been established as a predictor of critical COVID-19.

Single cell analysis reveals a subset of cytotoxic-like plasmacytoid dendritic cells in people with HIV-1.

Human plasmacytoid dendritic cells (pDCs) play a central role in initiating and activating host immune responses during infection. To understand how the transcriptome of pDCs is impacted by HIV-1 infection and exogenous stimulation, we isolated pDCs from healthy controls, people with HIV-1 (PWH) before and during toll-like receptor 9 (TLR9) agonist treatment and performed single-cell (sc)-RNA sequencing. Our cluster analysis revealed four pDC clusters: pDC1, pDC2, cytotoxic-like pDC and an exhausted pDC cluster.

High-dose coenzyme Q10 therapy versus placebo in patients with post COVID-19 condition: a randomized, phase 2, crossover trial.

Background: Post COVID-19 condition (PCC) is defined as symptoms lasting more than 12 weeks after developing COVID-19. Evidence of mitochondrial dysfunction has been reported in peripheral blood mononuclear cells obtained from patients with COVID-19. We hypothesized that PCC is caused by prolonged mitochondrial dysfunction.

CD169 (Siglec-1) as a Robust Human Cell Biomarker of Toll-Like Receptor 9 Agonist Immunotherapy.

Immunotherapy is a promising therapeutic area in cancer and chronic viral infections. An important component of immunotherapy in these contexts is the activation of innate immunity. Here we investigate the potential for CD169 (Siglec 1) expression on monocytes to serve as a robust biomarker for activation of innate immunity and, particular, as a proxy for IFN-α production.

The Impact of IFNλ4 on the Adaptive Immune Response to SARS-CoV-2 Infection.

Genetic polymorphisms at the loci are known to influence the clinical outcome of several different infectious diseases. Best described is the association between the genotype and hepatitis C virus clearance. However, an influence of the genotype on the adaptive immune system was suggested by several studies but never investigated in humans.

Persistent Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Immunocompromised Host Displaying Treatment Induced Viral Evolution.

We report a coronavirus disease 2019 case with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) persisting beyond 333 days in an immunocompromised patient with chronic lymphocytic leukemia, asymptomatically carrying infectious SARS-CoV-2 at day 197 postdiagnosis. In addition, viral sequencing indicates major changes in the spike protein over time, temporally associated with convalescent plasma treatment.

SARS-CoV-2 elicits robust adaptive immune responses regardless of disease severity.

Background: The SARS-CoV-2 pandemic currently prevails worldwide. To understand the immunological signature of SARS-CoV-2 infections and aid the search and evaluation of new treatment modalities and vaccines, comprehensive characterization of adaptive immune responses towards SARS-CoV-2 is needed.

Methods: We included 203 recovered SARS-CoV-2 infected patients in Denmark between April 3 and July 9 2020, at least 14 days after COVID-19 symptom recovery.

SARS-CoV-2 persistence is associated with antigen-specific CD8 T-cell responses.

Background: Upon SARS-CoV-2 infection, most individuals develop neutralizing antibodies and T-cell immunity. However, some individuals reportedly remain SARS-CoV-2 PCR positive by pharyngeal swabs weeks after recovery. Whether viral RNA in these persistent carriers is contagious and stimulates SARS-CoV-2-specific immune responses is unknown.

TLR9 agonist MGN1703 enhances B cell differentiation and function in lymph nodes.

Background: TLR9 agonists are being developed as immunotherapy against malignancies and infections. TLR9 is primarily expressed in B cells and plasmacytoid dendritic cells (pDCs). TLR9 signalling may be critically important for B cell activity in lymph nodes but little is known about the in vivo impact of TLR9 agonism on human lymph node B cells.

Effects of 24-week Toll-like receptor 9 agonist treatment in HIV type 1+ individuals.

Design: This was an exploratory, single-arm clinical trial that tested the immune enhancement effects of 24-weeks of Toll-like receptor 9 (TLR9) agonist (MGN1703; Lefitolimod; 60 mg × 2 weekly) therapy.

Methods: We enrolled HIV-1-infected individuals on suppressive combination antiretroviral therapy. Safety was assessed throughout the study.

Characterization of Intact Proviruses in Blood and Lymph Node from HIV-Infected Individuals Undergoing Analytical Treatment Interruption.

The role of lymphoid tissue as a potential source of HIV-1 rebound following interruption of antiretroviral therapy (ART) is uncertain. To address this issue, we compared the latent viruses obtained from CD4 T cells in peripheral blood and lymph nodes to viruses emerging during treatment interruption. Latent viruses were characterized by sequencing near-full-length (NFL) proviral DNA and from viral outgrowth assays (VOAs).