Viral Load, Clinical Disease Severity and Cellular Immune Responses in Primary Varicella Zoster Virus Infection in Sri Lanka

BACKGROUND: In Sri Lanka, varicella zoster virus (VZV) is typically acquired during adulthood with significant associated disease morbidity and mortality. T cells are believed to be important in the control of VZV replication and in the prevention of reactivation. The relationship between viral load, disease severity and cellular immune responses in primary VZV infection has not been well studied. METHODOLOGY: We used IFNgamma ELISpot assays and MHC class II tetramers based on VZV gE and IE63 epitopes, together with quantitative real time PCR assays to compare the frequency and phenotype of specific T cells with virological and clinical outcomes in 34 adult Sri Lankan individuals with primary VZV infection. PRINCIPAL FINDINGS: Viral loads were found to be significantly higher in patients with moderate to severe infection compared to those with mild infection (p<0.001) and were significantly higher in those over 25 years of age (P<0.01). A significant inverse correlation was seen between the viral loads and the ex vivo IFNgamma ELISpot responses of patients (P<0.001, r = -0.85). VZV-specific CD4+ T cells expressed markers of intermediate differentiation and activation. CONCLUSIONS: Overall, these data show that increased clinical severity in Sri Lankan adults with primary VZV infection associates with higher viral load and reduced viral specific T cell responses

CD4:CD8 ratio: A valuable diagnostic parameter for pulmonary sarcoidosis

Sarcoidosis is a multi-organ disease and is characterized by sarcoidal noncaseating granuloma comprised of T-helper/inducer (CD4+) lymphocytes and scant cytotoxic (CD8+) T-lymphocytes. CD4+:CD8+ T-cell elevated ratio is a characteristic diagnostic parameter for sarcoidosis. This is the first report from Iran evaluating the CD4:CD8 ratio capability in differentiating pulmonary sarcoidosis from other interstitial lung diseases (ILDs) on a large cohort. Fifty pulmonary sarcoidosis patients and 50 non-sarcoidosis interstitial lung diseases (nsILDs) patients were included in the current study. Bronchoalveolar lavage (BAL) was performed using flexible fiberoptic bronchoscopy and flow cytometer. Non-sarcoidosis group was established by 50 components that were classified into eight subgroups. Fifty-two percent of sarcoidosis patients and 62% of non-sarcoidosis interstitial lung disease patients had normal spirometric results. The CD4/CD8 ratio was significantly higher in sarcoidosis than in non-sarcoidosis interstitial lung diseases (p 3.5 in 33.3%, 2.5-3.5 in 7.1%, 1.5-2.5 in 20.2% and < 1.5 in 39.4% of the entire study population. The best cut off point was 1.1 with the sensitivity of 92% and specificity of 80% for distinguishing sarcoidosis from other interstitial lung diseases. Performing bronchoalveolar lavage as the safe and rapid first step confirms the diagnosis of sarcoidosis in 92% of cases (current study sensitivity). Hence, performing an invasive procedure was required in a few patients only. Bronchoalveolar lavage flow cytometry in the assessment of clinical and radiological findings supplies an appropriate diagnostic adjunct for discriminating sarcoidosis from non-sarcoidosis interstitial lung diseases

Activation of Protein Kinase C Delta following Cerebral Ischemia Leads to Release of Cytochrome C from the Mitochondria via Bad Pathway

BACKGROUND: The release of cytochrome c from the mitochondria following cerebral ischemia is a key event leading to cell death. The goal of the present study was to determine the mechanisms involved in post-ischemic activation of protein kinase c delta (δPKC) that lead to cytochrome c release. METHODS/FINDINGS: We used a rat model of cardiac arrest as an in vivo model, and an in vitro analog, oxygen glucose deprivation (OGD) in rat hippocampal synaptosomes. Cardiac arrest triggered translocation of δPKC to the mitochondrial fraction at 1 h reperfusion. In synaptosomes, the peptide inhibitor of δPKC blocked OGD-induced translocation to the mitochondria. We tested two potential pathways by which δPKC activation could lead to cytochrome c release: phosphorylation of phospholipid scramblase-3 (PLSCR3) and/or protein phosphatase 2A (PP2A). Cardiac arrest increased levels of phosphorlyated PLSCR3; however, inhibition of δPKC translocation failed to affect the OGD-induced increase in PLSCR3 in synaptosomal mitochondria suggesting the post-ischemic phosphorylation of PLSCR3 is not mediated by δPKC. Inhibition of either δPKC or PP2A decreased cytochrome c release from synaptosomal mitochondria. Cardiac arrest results in the dephosphorylation of Bad and Bax, both downstream targets of PP2A promoting apoptosis. Inhibition of δPKC or PP2A prevented OGD-induced Bad, but not Bax, dephosphorylation. To complement these studies, we used proteomics to identify novel mitochondrial substrates of δPKC. CONCLUSIONS: We conclude that δPKC initiates cytochrome c release via phosphorylation of PP2A and subsequent dephosphorylation of Bad and identified δPKC, PP2A and additional mitochondrial proteins as potential therapeutic targets for ischemic neuroprotection