The potential role for infections in the pathogenesis of autoimmune Addison's disease.

Autoimmune Addison's disease (AAD), or primary adrenocortical insufficiency, is a classical organ-specific autoimmune disease with 160 years of history. AAD is remarkably homogeneous with one major dominant self-antigen, the cytochrome P450 21-hydroxylase enzyme, which is targeted by both autoantibodies and autoreactive T cells. Like most autoimmune diseases, AAD is thought to be caused by an unfortunate combination of genetic and environmental factors. While the number of genetic associations with AAD is increasing, almost nothing is known about environmental factors. A major environmental factor commonly proposed for autoimmune diseases, based partly on experimental and clinical data and partly on shared pathways between anti-viral immunity and autoimmunity, is viral infections. However, there are few reports associating viral infections to AAD, and it has proved difficult to establish which immunological processes that could link any viral infection with the initiation or progression of AAD. In this review, we will summarize the current knowledge on the underlying mechanisms of AAD and take a closer look on the potential involvement of viruses.

Increased infiltration and tolerised antigen-specific CD8+ TEM cells in tumor but not peripheral blood have no impact on survival of HCMV+ glioblastoma patients.

Human cytomegalovirus (HCMV) antigens in glioblastoma (GBM) present opportunities for personalised immunotherapy. However, their presence in GBM tissue is still under debate, and evidence of their impact on functional immune responses and prognosis is sparse. Here, we investigated the presence of pp65 (UL83) and immediate early 1 (IE-1) HCMV antigens in a cohort of Norwegian GBM patients (n = 177), using qPCR, immunohistochemistry, and serology. HCMV status was then used to investigate whether viral antigens influenced immune cell phenotype, infiltration, activation and patient survival. Pp65 and IE-1 were detected by qPCR in 23% and 43% of GBM patients, respectively. Furthermore, there was increased seropositivity in GBM patients relative to donors (79% vs. 48%, respectively; Logistic regression, OR = 4.05, 95%CI [1.807-9.114], P = 0.001, also when adjusted for age (OR = 2.84, 95%CI [1.110-7.275], P = 0.029). Tissue IE-1-positivity correlated with increased CD3+CD8+ T-cell infiltration (P < 0.0001), where CD8+ effector memory T (TEM) cells accounted for the majority of CD8+T cells compared with peripheral blood of HCMV+ patients (P < 0.0001), and HCMV+ (P < 0.001) and HCMV- (P < 0.001) donors. HLA-A2/B8-restricted HCMV-specific CD8+ T cells were more frequent in blood and tumor of HCMV+ GBM patients compared with seronegative patients, and donors irrespective of their serostatus. In biopsies, the HCMV-specific CD8+ TEM cells highly expressed CTLA-4 and PD-1 immune checkpoint protein markers compared with populations in peripheral blood (P < 0.001 and P < 0.0001), which expressed 3-fold greater levels of CD28 (P < 0.001 and P < 0.0001). These peripheral blood T cells correspondingly secreted higher levels of IFNγ in response to pp65 and IE-1 peptide stimulation (P < 0.001). Thus, despite apparent increased immunogenicity of HCMV compared with tumor antigens, the T cells were tolerised, and HCMV status did not impact patient survival (Log Rank3.53 HR = 0.85 95%CI [0.564-1.290], P = 0.45). Enhancing immune functionality in the tumor microenvironment thus may improve patient outcome.

The effect of types I and III interferons on adrenocortical cells and its possible implications for autoimmune Addison's disease.

Autoimmune Addison's disease (AAD) is caused by selective destruction of the hormone-producing cells of the adrenal cortex. As yet, little is known about the potential role played by environmental factors in this process. Type I and/or type III interferons (IFNs) are signature responses to virus infections, and have also been implicated in the pathogenesis of autoimmune endocrine disorders such as type 1 diabetes and autoimmune thyroiditis. Transient development of AAD and exacerbation of established or subclinical disease, as well as the induction of autoantibodies associated with AAD, have been reported following therapeutic administration of type I IFNs. We therefore hypothesize that exposure to such IFNs could render the adrenal cortex susceptible to autoimmune attack in genetically predisposed individuals. In this study, we investigated possible immunopathological effects of type I and type III IFNs on adrenocortical cells in relation to AAD. Both types I and III IFNs exerted significant cytotoxicity on NCI-H295R adrenocortical carcinoma cells and potentiated IFN-γ- and polyinosine-polycytidylic acid [poly (I : C)]-induced chemokine secretion. Furthermore, we observed increased expression of human leucocyte antigen (HLA) class I molecules and up-regulation of 21-hydroxylase, the primary antigenic target in AAD. We propose that these combined effects could serve to initiate or aggravate an ongoing autoimmune response against the adrenal cortex in AAD.