To better understand the systemic response to naturally acquired acute respiratory viral infections, we prospectively enrolled 1610 healthy adults in 2009 and 2010. Of these, 142 subjects were followed for detailed evaluation of acute viral respiratory illness. We examined peripheral blood gene expression at 7 timepoints: enrollment, 5 illness visits and the end of each year of the study. 133 completed all study visits and yielded technically adequate peripheral blood microarray gene expression data. Seventy-three (55%) had an influenza virus infection, 64 influenza A and 9 influenza B. The remaining subjects had a rhinovirus infection (N = 32), other viral infections (N = 4), or no viral agent identified (N = 24). The results, which were replicated between two seasons, showed a dramatic upregulation of interferon pathway and innate immunity genes. This persisted for 2-4 days. The data show a recovery phase at days 4 and 6 with differentially expressed transcripts implicated in cell proliferation and repair. By day 21 the gene expression pattern was indistinguishable from baseline (enrollment). Influenza virus infection induced a higher magnitude and longer duration of the shared expression signature of illness compared to the other viral infections. Using lineage and activation state-specific transcripts to produce cell composition scores, patterns of B and T lymphocyte depressions accompanied by a major activation of NK cells were detected in the acute phase of illness. The data also demonstrate multiple dynamic gene modules that are reorganized and strengthened following infection. Finally, we examined pre- and post-infection anti-influenza antibody titers defining novel gene expression correlates.
Exhausted T cell (Tex) is a specific state of T cell dysfunction, in which these T cells gradually lose their effector function and change their phenotype during chronic antigen stimulation. The enrichment of exhausted CD8+ T cell (CD8+ Tex) in the tumor microenvironment is one of the important reasons leading to the poor efficacy of immunotherapy. Recent studies have reported many reasons leading to the CD8+ T cell exhaustion. In addition to cancer cells, myeloid cells can also contribute to T cell exhaustion via many ways. In this review, we discuss the history of the concept of exhaustion, CD8+ T cell dysfunction states, the heterogeneity, origin, and characteristics of CD8+ Tex. We then focus on the effects of myeloid cells on CD8+ Tex, including tumor-associated macrophages (TAMs), dendritic cells (DCs) and neutrophils. Finally, we systematically summarize current strategies and recent advancements in therapies reversing and CD8+ T cell exhaustion.
Respiratory syncytial virus (RSV) is a leading cause of pediatric lower respiratory tract infections and has a high impact on pediatric emergency department utilization. Variation in host response may influence the pathogenesis and disease severity. We evaluated global gene expression profiles to better understand the systemic host response to acute RSV bronchiolitis in infants and young children.Patients (age ≤ 24 months) who were clinically diagnosed with acute bronchiolitis and who had a positive rapid test for RSV assay were recruited from the Texas Children's Hospital emergency department. Global gene expression of peripheral whole blood cells were analyzed in 21 cases and 37 age-matched healthy controls. Transcripts exhibiting significant upregulation and downregulation as a result of RSV infection were identified and confirmed in a subset of samples using RNA sequencing. The potential pathways affected were analyzed.Blood was obtained from patients with acute RSV bronchiolitis (mean age 6 months). Of these, 43% were admitted to the hospital, 52% were given intravenous fluids and 24% received oxygen. Highly significant expression differences were detected in a discovery cohort of White infants (N = 33) and validated in an independent group of African-American infants (N = 19). Individuals with mild disease (N = 15) could not be distinguished from subjects with clinically moderate disease (N = 5). Pathway enrichment analyses of the differentially expressed genes demonstrated extensive activation of the innate immune response, particularly the interferon signaling network. There was a significant downregulation of transcripts corresponding to antigen presentation.