Elevated Blood Mitochondrial DNA in Early Life Among Uninfected Children Exposed to Human Immunodeficiency Virus and Combination Antiretroviral Therapy in utero.

BACKGROUND: Combination antiretroviral therapy (cART) during pregnancy prevents vertical transmission, but many antiretrovirals cross the placenta and several can affect mitochondria. Exposure to maternal human immunodeficiency virus (HIV) and/or cART could have long-term effects on children who are HIV exposed and uninfected (CHEU). Our objective was to compare blood mitochondrial DNA (mtDNA) content in CHEU and children who are HIV unexposed and uninfected (CHUU), at birth and in early life. METHODS: Whole-blood mtDNA content at birth and in early life (age 0-3 years) was compared cross-sectionally between CHEU and CHUU. Longitudinal changes in mtDNA content among CHEU was also evaluated. RESULTS: At birth, CHEU status and younger gestational age were associated with higher mtDNA content. These remained independently associated with mtDNA content in multivariable analyses, whether considering all infants, or only those born at term. Longitudinally, CHEU mtDNA levels remained unchanged during the first 6 months of life, and gradually declined thereafter. A separate age- and sex-matched cross-sectional analysis (in 214 CHEU and 214 CHUU) illustrates that the difference in mtDNA between the groups remains detectable throughout the first 3 years of life. CONCLUSION: The persistently elevated blood mtDNA content observed among CHEU represents a long-term effect, possibly resulting from in utero stresses related to maternal HIV and/or cART. The clinical impact of altered mtDNA levels is unclear.

Evaluation of glucocorticoid-induced TNF receptor (GITR) expression in breast cancer and across multiple tumor types.

Glucocorticoid-induced TNF receptor (GITR) is an emerging immunotherapy target that is expressed at high levels on regulatory T cells. Agonistic anti-GITR antibodies have anti-tumor activity in cancer mouse models, and recent phase 1 trials have demonstrated their safe pharmacological profile. However, there is limited knowledge on the relationship between GITR expression and the tumor microenvironment. GITR protein expression was assayed by immunohistochemistry on 3992 breast cancer surgical excision specimens assembled into tissue microarrays and scored visually by a pathologist for GITR expression on tumor-infiltrating lymphocytes and on carcinoma cells. GITR expression by the malignant cells was further surveyed in gastrointestinal stromal tumor (N = 713), lung carcinoma (N = 705), pancreatic cancer (N = 486), ovarian cancer (N = 445), bladder cancer (N = 88), prostate cancer (N = 88), testicular cancer (N = 76), melanoma (N = 75), renal cell carcinoma (N = 68),  epithelioid sarcoma (N = 53), and neuroendocrine tumors (N = 41). In breast cancer, GITR expression on tumor-infiltrating lymphocytes (12.4%) correlated with other immune response biomarkers (PD-L1+ on tumor cells, and PD-1+, LAG-3+, TIM-3+ lymphocytes; p < 0.001), and T-cell markers (CD8+, FOXP3+; p < 0.001). GITR+ carcinoma cells were observed in 6.0% of breast cancer cases and correlated with worse relapse-free survival (p = 0.015). Among the additional tumor types examined, cancers with GITR+ malignant cells included bladder cancer (5.7%), primary (but not metastatic) melanoma (4.5%), and ovarian cancer (3.2%); no expression was identified among examined sarcomas. To our knowledge, this is the first immunohistochemistry study to report the frequency and pattern of GITR expression in a large breast cancer cohort, or to report membranous GITR expression on malignant cells. The co-infiltration of GITR with other immune biomarkers and T-cell markers supports a potential role for anti-GITR agents in combination immunotherapies. In addition, GITR expression on carcinoma cells could imply the existence of a novel cancer immune evasion strategy worthy of further investigation.

Indoleamine Dioxygenase Inhibitors: Clinical Rationale and Current Development.

PURPOSE OF REVIEW: This review focuses on the recent clinical development of indolamine-2,3-dioxygenase-1 (IDO-1) inhibitors. RECENT FINDINGS: IDO-1 alters tryptophan metabolism in a manner enhancing T-regulatory cell activity, but pre-clinical data show that its role in tumorigenesis is context-dependent on host and tumor interaction, highlighting some challenges in understanding the molecular oncology of this enzymatic drug target. Because results from phase I/II trials of IDO-1 inhibitor monotherapy have been disappointing, current clinical trials employ IDO-1 inhibitors in combination strategies with other immunotherapy agents or with chemotherapy ± radiation. Combinations with anti-PD-1/PD-L1 antibodies are already showing promise, and related strategies are under active evaluation. While further research is needed to elucidate the precise role of IDO-1 in tumor development, its mechanisms of action appear sufficiently distinct from other immunotherapy targets to warrant inclusion in combination immunotherapy regimens, an approach where multiple clinical trials are currently underway.

Robust tobacco smoking self-report in two cohorts: pregnant women or men and women living with or without HIV.

Understanding the true burden of tobacco smoking on adverse pregnancy outcomes is critical in generating appropriate interventions to improve outcomes. Self-reporting of human behaviour that is associated with stigma is associated with underreporting in general and may bias the impact of smoking in studies; however, self-reporting is frequently the most practical method of gleaning this information. The objective of this study was to evaluate concordance between self-reported smoking and concentrations of plasma cotinine, a biomarker of smoking, among participants enrolled in two related HIV cohorts. A total of 100 pregnant women (76 living with HIV [LWH] and 24 negative controls) in their third trimester, and 100 men and non-pregnant women (43 LWH and 57 negative controls) were included. Among all participants, 43 pregnant women (49% LWH and 25% negative controls) and 50 men and non-pregnant women (58% LWH and 44% negative controls) were self-reported smokers. The odds of discordance between self-reported smoking and cotinine levels were not significantly different between self-reported smokers and non-smokers, nor between pregnant women and others, but were significantly increased, regardless of self-reported status, among people LWH compared to negative controls. The overall concordance between plasma cotinine and self-reported data among all participants was 94% with a sensitivity and specificity of 90% and 96%, respectively. Taken together, these data demonstrate that participant surveying in a non-judgemental context can lead to accurate and robust self-report smoking data among both persons LWH and not, including in the context of pregnancy.

Sarcomas: Immune biomarker expression and checkpoint inhibitor trials.

Sarcomas are a heterogenous group of mesenchymal cancers comprising over 100 subtypes. Current chemotherapy for all but a very few subtypes has limited efficacy, resulting in 5-year relative survival rates of 16% for metastatic patients. While sarcomas have often been regarded as an "immune cold" tumor category, recent biomarker studies have confirmed a great deal of immune heterogeneity across sarcoma subtypes. Reports from the first generation of clinical trials treating sarcomas with immunotherapy demonstrate a few positive responses, supporting efforts to stratify patients to optimize response rates. This review summarizes recent advances in knowledge around immune biomarker expression in sarcomas, the potential use of new technologies to complement these study results, and clinical trials particularly of immune checkpoint inhibitor therapy in sarcomas. Each of the immune biomarkers assessed was reviewed for subtype-specific expression patterns and correlation with prognosis. Overall, there is extensive heterogeneity of immune biomarker presence across sarcoma subtypes, and no consensus on the prognostic effect of these biomarkers. New technologies such as multiplex immunohistochemistry and high plex in situ profiling may offer more insights into the sarcoma microenvironment. To date, clinical trials using immune checkpoint inhibitor monotherapy have not shown compelling clinical benefits. Combination therapy with dual checkpoint inhibitors or in combinations with other agents has yielded more promising results in dedifferentiated liposarcoma, undifferentiated pleomorphic sarcoma, angiosarcoma and alveolar soft-part sarcoma. Better understanding of the sarcoma immune status through biomarkers may help decipher the reasons behind differential responses to immunotherapy.

Immune Checkpoint Profiles in Luminal B Breast Cancer (Alliance).

BACKGROUND: Unlike estrogen receptor (ER)-negative breast cancer, ER-positive breast cancer outcome is less influenced by lymphocyte content, indicating the presence of immune tolerance mechanisms that may be specific to this disease subset. METHODS: A supervised analysis of microarray data from the ACOSOG Z1031 (Alliance) neoadjuvant aromatase inhibitor (AI) trial identified upregulated genes in Luminal (Lum) B breast cancers that correlated with AI-resistant tumor proliferation (percentage of Ki67-positive cancer nuclei, Pearson r > 0.4) (33 cases Ki67 > 10% on AI) vs LumB breast cancers that were more AI sensitive (33 cases Ki67 < 10% on AI). Overrepresentation analysis was performed using WebGestalt. All statistical tests were two-sided. RESULTS: Thirty candidate genes positively correlated (r ≥ 0.4) with AI-resistant proliferation in LumB and were upregulated greater than twofold. Gene ontologies identified that the targetable immune checkpoint (IC) components IDO1, LAG3, and PD1 were overrepresented resistance candidates (P ≤ .001). High IDO1 mRNA was associated with poor prognosis in LumB disease (Molecular Taxonomy of Breast Cancer International Consortium, hazard ratio = 1.43, 95% confidence interval = 1.04 to 1.98, P = .03). IDO1 also statistically significantly correlated with STAT1 at protein level in LumB disease (Pearson r = 0.74). As a composite immune tolerance signature, expression of IFN-γ/STAT1 pathway components was associated with higher baseline Ki67, lower estrogen, and progesterone receptor mRNA levels and worse disease-specific survival (P = .002). In a tissue microarray analysis, IDO1 was observed in stromal cells and tumor-associated macrophages, with a higher incidence in LumB cases. Furthermore, IDO1 expression was associated with a macrophage mRNA signature (M1 by CIBERSORT Pearson r = 0.62 ) and by tissue microarray analysis. CONCLUSIONS: Targetable IC components are upregulated in the majority of endocrine therapy-resistant LumB cases. Our findings provide rationale for IC inhibition in poor-outcome ER-positive breast cancer.

Dynamics of leukocyte telomere length in pregnant women living with HIV, and HIV-negative pregnant women: A longitudinal observational study.

BACKGROUND: HIV-mediated inflammation and immune activation can accelerate telomere attrition. In addition, antiretrovirals can inhibit telomerase, possibly shortening telomeres. We examined the longitudinal dynamics of leukocyte telomere length (LTL) during pregnancy in a unique cohort of women living with HIV (WLWH) treated with combination antiretroviral therapy (cART), and HIV-negative control women. METHODS: Blood was collected at three visits during pregnancy, at 13-23, >23-30, and >30-40 weeks of gestation, and for WLWH only, at 6 weeks post-partum. LTL was measured by qPCR and both cross-sectional and longitudinal (MANOVA) models were used to examine possible predictors of LTL among participants who attended all three visits during pregnancy. RESULTS: Among WLWH (n = 64) and HIV-negative women (n = 41), within participant LTL were correlated throughout pregnancy (p<0.001). LTL was shorter among WLWH at first visit, but this difference waned by the second visit. WLWH who discontinued cART post-partum experienced a decrease in LTL. Longitudinally, LTL was similar in both groups and increased as gestation progressed, a change that was more pronounced among women under 35 years. Among WLWH, both smoking throughout pregnancy (p = 0.04) and receiving a ritonavir-boosted protease inhibitor-based regimen (p = 0.03) were independently associated with shorter LTL. CONCLUSIONS: LTL increases as pregnancy progresses; the reasons for this are unknown but may relate to changes in blood volume, hormones, and/or cell subset distribution. While our observations need confirmation in an independent cohort, our data suggest that although some cART regimens may influence LTL, being on cART appears overall protective and that stopping cART post-partum may negatively impact LTL. The effect of smoking on LTL is clearly negative, stressing the importance of smoking cessation.