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Abstract Background Despite the successful eradication of smallpox by the WHO-led vaccination programme, pox virus infections remain a considerable health threat. The possible use of smallpox as a bioterrorism agent as well as the continuous occurrence of zoonotic pox virus infections document the relevance to deepen the understanding for virus host interactions. Since the permissiveness of pox infections is independent of hosts surface receptors, but correlates with the ability of the virus to infiltrate the antiviral host response, it directly depends on the hosts proteome set. In this report the proteome of HEK293 cells infected with Vaccinia Virus strain IHD-W was analyzed by 2-dimensional gel electrophoresis and MALDI-PSD-TOF MS in a bottom-up approach. Results The cellular and viral proteomes of VACV IHD-W infected HEK293 cells, UV-inactivated VACV IHD-W-treated as well as non-infected cells were compared. Derivatization of peptides with 4-sulfophenyl isothiocyanate (SPITC) carried out on ZipTipμ-C18 columns enabled protein identification via the peptides' primary sequence, providing improved s/n ratios as well as signal intensities of the PSD spectra. The expression of more than 24 human proteins was modulated by the viral infection. Effects of UV-inactivated and infectious viruses on the hosts' proteome concerning energy metabolism and proteins associated with gene expression and protein-biosynthesis were quite similar. These effects might therefore be attributed to virus entry and virion proteins. However, the modulation of proteins involved in apoptosis was clearly correlated to infectious viruses. Conclusions The proteome analysis of infected cells provides insight into apoptosis modulation, regulation of cellular gene expression and the regulation of energy metabolism. The confidence of protein identifications was clearly improved by the peptides' derivatization with SPITC on a solid phase support. Some of the identified proteins have not been described in the context of poxvirus infections before and need to be further characterised to identify their meaning for apoptosis modulation and pathogenesis.

A reliable and early diagnosis of viral infections and rejection episodes is a major goal of immunologic monitoring in transplantation. Soluble markers like the cytokines, neopterin or serum amyloid A are frequently recommended as diagnostic parameters. However they are not often used routinely in transplant medicine. The study investigates the diagnostic value of plasma (P), serum (S), and urine (U) levels of neopterin (S-/U-NEOP), serum amyloid A (SAA), tumor necrosis factor-α, (P-/U-TNF-α), soluble interleukin-2 receptor (P-/U -sIL-2R), and interleukin-6 (U -IL-6) in transplant monitoring and describes an approach for their use in the clinical routine decision making. In 29 renal transplant patients blood and urine samples were collected daily during the posttransplant course on ward. The cytokines were measured by ELISAs, neopterin by RIA, and SAA by immunonephelometry. Descriptive statistics, sensitivity and specificity, day of first significant parameter increase/decrease, receiver operating characteristic curves, and post-test probabilities were calculated for each parameter. 12 acute rejection episodes were diagnosed. As rejection markers, S-NEOP and P-TNF-α had the highest sensitivity, U-IL-6 the highest specificity. 8 viral infections occurred. U-NEOP showed values higher than 1000 μmol/moICrea. It did not exceed this threshold in case of rejection episodes. SAA and U-IL-6 showed peak. levels during rejections but not during episodes of viral infections. Using the calculated likelihood ratio formulas the probability for the occurrence of an acute rejection could be estimated for the individual, daily parameter measurement. Adding the physician IS rating for rejection posttest probabilities were computed. Immunologic monitoring is possible in transplant medicine. Using daily measurements of serum amyloid A and neopterin facilitates the differential diagnosis of acute rejection episodes and viral infections. The likelihood ratio approach permits an application of the parameter monitoring in the clinical routine.

Glycosylation is one of the most common forms of post-translational modification of eukaryotic proteins. Glycosylated proteins (glycoproteins) make up the majority of human proteins. The polysaccharide side chains (glycans) play [...]