Rhinovirus-mediated changes in airway smooth muscle responsiveness: induced autocrine role of interleukin-1beta

An important interplay exists between specific viral respiratory pathogens, most commonly rhinovirus (RV), and altered airway responsiveness in the development and exacerbations of asthma. Given that RV infection reportedly induces the release of various cytokines in different cell types and that the reported effects of RV on airway smooth muscle (ASM) responsiveness are highly comparable to those obtained in ASM exposed to the proinflammatory cytokine interleukin (IL)-1beta, this study examined whether RV (serotype 16)-mediated pertubations in ASM responsiveness are mechanistically coupled to altered induced expression and action of IL-1beta in RV-exposed isolated rabbit and human ASM tissue and cultured cells. Relative to control tissues, ASM inoculated with RV exhibited significantly increased maximal isometric contractility to ACh (P < 0.01) and attenuated relaxation to isoproterenol (P < 0. 005). In extended studies, we found that 1) the RV-induced changes in ASM responsiveness were ablated by pretreating the tissues with the IL-1 recombinant human receptor antagonist; 2) in contrast to their respective controls, RV-inoculated ASM tissue and cultured cells exhibited progressively induced expression of IL-1beta mRNA and elaboration of IL-1beta protein at 6 and 24 h after viral exposure; and 3) the latter effect of RV was inhibited in the presence of a monoclonal antibody to intercellular adhesion molecule-1, the endogenous receptor for most RV. Collectively, these observations provide new evidence demonstrating that "pro-asthmatic-like" pertubations in agonist responsiveness elicited in RV-exposed ASM are largely attributed to the induced autologous expression and autocrine action of IL-1beta in the virus-infected ASM.

Stabilities of free and complexed human immunodeficiency virus p24 antigens during short- and long-term storage

By the standard p24 assay there was a 25 to 27% decrease in free p24 antigen in serum after storage at 4 degrees C over 14 days but no loss at -70 degrees C. There was no loss at either temperature by the immune complex dissociation (ICD) procedure. Furthermore, there was no significant loss of detectable p24 in serum by either the ICD or the standard p24 assay after 700 days of storage at -70 degrees C.

Relationship of cytomegalovirus to salivary gland dysfunction in HIV-infected patients

In a previous retrospective study of HIV-infected patients we detected a relationship between xerostomia and the presence of cytomegalovirus in saliva. This prospective study compares 13 patients with HIV and a complaint of xerostomia and low salivary flow rates with a control group of 7 patients with HIV without xerostomia and normal salivary flow rates. Both groups were evaluated for the presence of cytomegalovirus in saliva, peripheral blood mononuclear cells, and labial minor salivary glands. Viral cultures, polymerase chain reaction, and histopathologic examination were used to detect cytomegalovirus. Xerostomia and low salivary flow rates were associated with the presence of CMV in saliva. The virus was detected in 10 of 13 xerostomia patients and 2 of 7 controls (p = 0.05, Fisher's exact test). Cytomegalovirus was detected in the saliva of patients who did not also have it in their blood suggesting a local source of virus replication such as the salivary glands. The minor salivary glands were not a major site of cytomegalovirus. Culture was more sensitive then polymerase chain reaction in detecting salivary cytomegalovirus as a result of the presence of inhibitors to the reaction in saliva. These results suggest a link between cytomegalovirus in saliva and salivary gland dysfunction in HIV-infected patients.

Parasite-directed endocytosis

Following the attachment of gonococci to human fallopian tube mucosa in organ culture, the gonococci are endocytosed by specialized low columnar epithelial cells, are transported to the base of the epithelial cells, and are subsequently exocytosed into the subepithelial tissues. This transepithelial transport process by which "invasion" of the host occurs appears to be dependent on microbial factors is designated parasite-directed endocytosis to distinguish it from host-directed endocytosis by cells such as macrophages that eventually degrade the parasites. "Invasion" of the host by a number of human pathogens--bacteria (e.g., Neisseria meningitidis, Haemophilus influenzae, and Listeria monocytogenes), viruses, or protozoa--appears to be accomplished by parasite-directed endocytosis.