Binding of viruses to cell surface molecules is an essential step in viral infection. In vitro studies suggested that the alpha v beta3 integrin receptor is the epithelial cell receptor for Hantaan virus (HTNV). Whether beta3 is in vivo the only or central cellular receptor for HTNV infection is not known. To investigate the role of beta3 integrin for cellular entry of HTNV, we established an HTNV infection model in newborn murine pups. Infected pups died at an average age of 14.2 +/- 1.1 days with high levels of viral antigen detected in their brain, lung, and kidney. Pre-injection of blocking monoclonal antibodies (mAb) specific for either beta3 or av prolonged survival significantly to a maximal average survival of 19.7 +/- 1.5 days (P<0.01) and 18.4 +/- 0.9 days (P<0.01), respectively. XT-199, a chemical blocker of the alpha v beta3 receptor also prolonged survival to 19.5 +/- 1.3 days (P<0.01). In contrast to these receptor blockades, anti-HTNV antibody was not only able to prolong survival, but 20% of infected pups achieved long-term survival. An anti-murine beta1 antibody comparatively prolonged survival (19.0 +/- 1.2 days), suggesting that HTNV infection is partly mediated through integrin beta1 receptors as well as through beta3 receptors in vivo. Our data demonstrate that the beta3 receptor is important for HTNV infection in vivo, but also suggest that HTNV may utilize additional receptors beyond beta3 for cellular entry within an organism.
Animals ; Animals, Newborn ; Antibodies, Monoclonal/therapeutic use ; Antigens, CD29/metabolism ; Hantaan virus/*metabolism/pathogenicity ; Hemorrhagic Fever with Renal Syndrome/mortality/*virology ; Imidazoles/pharmacology ; Integrin alphaV/metabolism ; Integrin alphaVbeta3/antagonists & inhibitors ; Integrin beta3/*metabolism ; Mice ; Receptors, Virus/*metabolism ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.

Intradermal gene administration was found to induce a more profound immune response than direct intramusclular gene injection. We performed intradermal vaccination of B10.PL mice with DNA encoding for the V 8.2 region of the T-cell receptors (TCR). Three weeks later, these mice were immunized with rat myelin basic protein (MBP). Daily mean clinical scores and mortality rate were lower in this group compared with controls. The proliferative responses of lymph node cells to rat MBP were slightly less in the vaccination groups than in the control groups (p<0.05). However, we detected no differences between the two groups with regard to the production of MBP-specific IgG, IgG1, & IgG2a antibodies. The levels of cytokine mRNA expression in the vaccination groups were observed higher than in the control groups without antigen-specific stimulation, but all of cytokine expressions between the vaccination and control groups after antigen-specific stimulation were identical. These results demonstrate that intradermal DNA vaccines encoding for TCR might prove to be useful in the control of autoimmune disease.
Animals ; Autoantibodies/blood ; Base Sequence ; Cytokines/genetics ; DNA, Complementary/genetics ; Encephalomyelitis, Autoimmune, Experimental/etiology/immunology/*prevention and control ; Female ; Gene Expression ; *Genes, T-Cell Receptor beta ; In Vitro ; Injections, Intradermal ; Lymphocyte Activation ; Mice ; Myelin Basic Proteins/immunology ; RNA, Messenger/genetics/metabolism ; Rats ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Vaccines, DNA/*administration and dosage/genetics

Pathogenesis of the abdominal aortic aneurysm has been attributed to neovascularization of the aortic wall. However, it is not clear whether angiogenesis persists in the aneurysm. In sections of aneurysms, we determined the immunohistochemical distributions of the alpha v beta 3 integrin, tenascin and endothelial nitric oxide synthase (eNOS), which are markers respectively, of angiogenesis, matrix remodeling and vasoregulatory function. In addition, we used reverse transcription followed by in situ PCR, to determine the distribution of alpha v mRNA. All aneurysm specimens exhibited extensive increases of wall vascularization as compared with the control aortic wall, and showed the presence of perivascular inflammatory exudates containing macrophages and lymphocytes. The neovascularization consisted of thick-walled vessels in the media and adventitia, and capillaries in the subintima. The majority of vessels stained positively for the alpha v beta 3 antigen and eNOS. Tenascin was deposited as bands that circumscribed thick-walled vessels. The distribution of av mRNA was extensive and was positive even in those vessels that failed to stain for the alpha v beta 3 protein. No staining was evident in control aortas for the alpha v beta 3 antigen, tenascin or alpha v mRNA. The upregulation of av mRNA and the alpha v beta 3 integrin in blood vessels surrounded by a matrix expressing tenascin, indicates that angiogenesis is an ongoing process in the mature aortic aneurysm.
Adult ; Aorta, Abdominal/immunology/pathology ; Aortic Aneurysm, Abdominal/*pathology ; Biological Markers/analysis/metabolism ; Female ; Humans ; Integrin alphaVbeta3/analysis/genetics/metabolism ; Male ; Neovascularization, Pathologic/genetics/*metabolism ; Nitric-Oxide Synthase/analysis/metabolism ; RNA, Messenger/analysis/metabolism ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, P.H.S. ; Tenascin/analysis/metabolism