Growth characteristics and cytokine/chemokine induction profiles of dengue viruses in various cell lines.

The dengue disease varies clinically from mild fever to hemorrhagic fever up to potentially fatal shock syndrome. Such differences in manifestation of dengue virus (DENV) infection have been ascribed to intrinsic differences in DENVs. Four DENV serotypes or four dengue viruses (DENV-1 to DENV-4) have been clearly distinguished; however, only limited information is available on their biological characteristics in vitro. To shed more light on this subject, replication kinetics of all four DENVs in various cell lines and induction of 26 cytokines/chemokines were investigated. The results showed that, (i) all DENVs replicated relatively similarly in various cell lines, (ii) DENV-1 was most effective in this regard, (iii) A549 cells showed the highest virus replication rate compared to other cells, and (iv) all DENVs induced in A549 cells similar levels of several cytokines/chemokines, namely eotaxin, granulocyte colony stimulating factor (G-CSF), interferon alpha 2 (IFN-α2), interleukins 6, 8 15 (IL-6, IL-8, IL-15), and IP-10. In conclusion, this study revealed a similarity in growth characteristics and cytokine/chemokine induction profile for all four DENV serotypes in vitro.

The role of anti-dengue virus NS-1 and anti-protein disulfide isomerase antibodies on platelet aggregation in secondary dengue infection.

AIM: to observe the correlation between anti-NS-1 and anti PDI antibodies against platelets function disorder on secondary dengue infection. METHODS: 50 patients with secondary DV infection according to WHO criteria were observed by a cross sectional study. Patient's blood was collected on day 3, 5 and 7 after fever onset. Platelets aggregation test was done to prove the possibility of platelets dysfunction. Anti-NS-1 and anti-PDI antibodies were determined by solid phase ELISA. RESULTS: the inhibition of platelets aggregation was increased among day of observation. Means value of inhibition on day 3 is 46.6%, day 5 is 52.5% and day 7 is 56%. There is a significant difference (p<0.05) of inhibition of platelet aggregation value between days of observation. The antibodies against NS-1 DV and PDI were detected in all 50 sera with the positive rate of 90% develop NS-1 antibodies and 72% of PDI antibodies, on day 3 of symptoms. The highest OD of NS-1 antibodies is detected on the day 3 and decreased on day 7. The OD of PDI antibodies was increased on day 3 and still increasing on day 7. There is a significant correlation between anti NS-1 and PDI antibodies (r=0.386-0.490), while the differences of OD between observation days are not significant (p>0.05). CONCLUSION: the kinetics profile of NS1 and PDI antibodies responses, which were detected by the third day of symptoms. Dengue patients' sera inhibited platelets aggregation. NS-1 antibodies and PDI antibodies might have a role on the platelets aggregation dysfunction; however, there is no correlation between them. It is possible that other mechanism involve in the inhibition of platelets aggregation.

Distribution of the murine plasma cell antigen PC-1 in non-lymphoid tissues.

PC-1 is an alloantigen of murine plasma cells. Its close association with secretory function in lymphoid cells previously raised the question of whether PC-1 was part of the secretory apparatus. In addition to its expression on lymphocytes, PC-1 had been known to be present in liver, brain, and kidney, although the data were derived almost entirely from bulk absorption studies of polyclonal alloantisera, and virtually nothing was known about the nature of the cells expressing PC-1 in these organs. If PC-1 was functionally involved in the secretory process. it might be expected to be present at secretory sites within these and other organs. We now report the results of an immunohistochemical survey of the distribution of PC-1 in a variety of non-lymphoid organs, using a mAb. The PC-1 Ag was found in a small number of highly discrete locations that were mostly, but not exclusively, associated with epithelia. Sites of strong expression included the distal convoluted tubule of the kidney, ducts of the salivary glands, epididymis, proximal part of the vas deferens, and chondrocytes. The PC-1 glycoprotein was also found in the capillaries of the brain, but did not appear to be present in capillaries elsewhere, a pattern that is strikingly similar to that of the receptor for the iron transport protein, transferrin. Negative sites included the thyroid, pancreas, choroid plexus, smooth and striated muscle, stomach, small and large intestine, gall bladder, renal glomeruli, testis, and seminal vesicles. These results are not consistent with a generalized role for PC-1 in secretion, but are compatible with a role in a specialized subset of macromolecular transport events.