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Background The immunological determinants of delayed viral clearance and intrahost viral evolution that drive the development of new pathogenic virus strains in immunocompromised individuals are unknown. Therefore, we longitudinally studied severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–specific immune responses in relation to viral clearance and evolution in immunocompromised individuals. Methods Among Omicron-infected immunocompromised individuals, we determined SARS-CoV-2–specific T- and B-cell responses, anti-spike immunoglobulin G (IgG) and IgG3 titers, neutralization titers, and monoclonal antibody (mAb) resistance–associated mutations. The 28-day post-enrollment nasopharyngeal specimen defined early (reverse-transcription polymerase chain reaction [RT-PCR] negative ≤28 days) or late (RT-PCR positive >28 days) viral clearance. Results Of 30 patients included (median age, 61.9 [interquartile range, 47.4–72.3] years; 50% females), 20 (66.7%) received mAb therapy. Thirteen (43.3%) demonstrated early and 17 (56.7%) late viral clearance. Patients with early viral clearance and patients without resistance-associated mutations had significantly higher baseline interferon-γ release, and patients with early viral clearance had a higher frequency of SARS-CoV-2–specific B cells at baseline. In non-mAb-treated patients, day 7 IgG and neutralization titers were significantly higher in those with early versus late viral clearance. Conclusions An early robust adaptive immune response is vital for efficient viral clearance and associated with less emergence of mAb resistance–associated mutations in Omicron-infected immunocompromised patients. This emphasizes the importance of early SARS-CoV-2–specific T- and B-cell responses and thereby provides a rationale for development of novel therapeutic approaches. [ABSTRACT FROM AUTHOR]

Background Chronic immune activation is one of the hallmarks of human immunodeficiency virus (HIV) pathogenesis. Persistent upregulation of interferons (IFNs) and interferon-stimulated genes (ISGs) has previously been associated with chronic immune activation and HIV progression. Here a longitudinal analysis of the IFN and ISG response during HIV infection was performed to gain insights into the ongoing immune activation during HIV infection. Methods IFN and ISG levels were determined using quantitative polymerase chain reaction in peripheral blood mononuclear cells of people with HIV at pre-seroconversion, during acute and chronic HIV infection, and during suppressive antiretroviral therapy (ART). Results HIV infection induced the expression of a set of 4 ISGs—RSAD2, ISG15, IFI44L, and IFI27—which remained upregulated during chronic infection. This set of ISGs showed no clear correlations with T-cell activation as determined by co-expression of CD38 and HLA-DR. However, a strong correlation with monocyte activation marker soluble CD163 in serum was found. Furthermore, the expression of this ISG cluster was predictive of viral load before ART initiation and, on ART, expression levels normalized to pre-seroconversion levels. Conclusions The results presented here suggests that ISG expression is linked to monocyte activation, possibly driven by viral replication. [ABSTRACT FROM AUTHOR]

Background We recently reported that the levels of activation, exhaustion, and terminal differentiation within the peripheral T-cell compartment were increased in men who have sex with men (MSM) compared with blood bank donors. During activation and differentiation, T cells undergo metabolic changes to maintain their energy demand. Methods The effect of cytomeglovirus (CMV) infection and risk behavior on the immune phenotype of peripheral T cells and the immune bioenergy metabolism profile in human immunodeficiency virus-negative MSM (with high or low sexual risk behavior) and blood bank donors was evaluated. Results Men who have sex with men exhibited increased levels of T-cell activation and terminal differentiation and an impairment of the bioenergy metabolism (mitochondrial respiration and glycolysis) compared with blood bank donors. Cytomeglovirus infection was associated with increased terminal differentiation of CD4+ (B = 3.41; 95% confidence interval [CI], 1.98–4.85; P  < .0001) and CD8+ T cells (CD57+: B = 1.21, 95% CI = 0.41–2.02, P  = .004; CD27−CD28−: B = 2.20, 95% CI = 1.21–3.18, P  < .0001; and CD57+ of CD28−: B = 1.02, 95% CI = 0.38–1.66, P  = .002) and increased glycolysis (B = 0.97; 95% CI, 0.27–1.67; P  = .007). Risk behavior was associated with increase activation of CD4+ T cells (B = 0.22; 95% CI, 0.07–0.37; P  = .005), increased terminal differentiation of CD4+ (B = 0.82; 95% CI, 0.44–1.20; P  < .0001) and CD8+ T cells (B = 1.55; 95% CI, 0.58–2.51; P  = .002), and decreased glycolysis (glycolysis: B = −0.40, 95% CI = −0.68 to 0.12, P  = .006; and glycolytic capacity: B = −0.54, 95% CI = −0.91 to 0.16, P  = .005). Conclusions Men who have sex with men show an increased prevalence of bloodborne and sexually transmitted infection, indicating that immunological changes in the T-cell population and the bioenergy metabolism observed in MSM can most likely be attributed to chronic antigen exposure. [ABSTRACT FROM AUTHOR]