Acute alcohol intoxication suppresses the pulmonary ELR-negative CXC chemokine response to lipopolysaccharide

Alcohol abuse impairs the pulmonary immune response to infection and increases the morbidity and mortality of bacterial pneumonia. Acute alcohol intoxication suppresses lung expression of CXC chemokines bearing the Glu-Leu-Arg motif (ELR+) following lipopolysaccharide (LPS) challenge, but its effect on the structurally related ELR- CXC chemokines, which attract T cells, is unknown. We therefore investigated the effect of acute alcohol intoxication on the pulmonary response to intratracheal (i.t.) LPS challenge for the ELR- CXC chemokines monokine induced by gamma (MIG or CXCL9), interferon-inducible protein 10 (IP-10 or CXCL10), and interferon-inducible T cell alpha chemoattractant (I-TAC or CXCL11). Male C57BL/6 or C3H/HeN mice were given an intraperitoneal injection of ethanol (3.0 g/kg) or phosphate buffered saline 30 min before i.t. LPS challenge. Chemokine mRNA transcripts were measured at 0, 2, 6, and 16 h. Acute alcohol intoxication inhibited the lung's expression of all three chemokine genes in response to LPS. Lung IFN-gamma mRNA was also inhibited by acute intoxication over the same time course. The in vitro effect of ethanol on chemokine secretion was further studied in the MH-S alveolar macrophage cell line. IP-10, MIG, and I-TAC in response to LPS were enhanced by exogenous interferon (IFN)-gamma, and these responses were blunted by exposure to ethanol. Alcohol exposure did not affect MH-S cell nuclear factor kappa beta p65 nuclear localization during challenge, despite dose-dependent inhibition of Erk 1/2 phosphorylation. In addition, phospho-signal transduction and activator of transcription 1 was not decreased in the presence of acute ethanol, thereby indicating that acute intoxication does not affect IFN-gamma signaling in MH-S cells. Recruitment of CD3+ T cells into the alveolar space 4 days after LPS challenge was moderately impaired by acute ethanol intoxication. These results implicate acute ethanol intoxication as a significant inhibitor of lymphocyte chemoattractant expression during pulmonary inflammation.

B7/CD28 costimulation is critical in susceptibility to Pseudomonas aeruginosa corneal infection: a comparative study using monoclonal antibody blockade and CD28-deficient mice

Evidence suggests that Pseudomonas aeruginosa stromal keratitis and corneal perforation (susceptibility) is a CD4(+) T cell-regulated inflammatory response following experimental P. aeruginosa infection. This study examined the role of Langerhans cells (LC) and the B7/CD28 costimulatory pathway in P. aeruginosa-infected cornea and the contribution of costimulatory signaling by this pathway to disease pathology. After bacterial challenge, the number of LC infiltrating the central cornea was compared in susceptible C57BL/6 (B6) vs resistant (cornea heals) BALB/c mice. LC were more numerous at 1 and 6 days postinfection (p.i.), but were similar at 4 days p.i., in susceptible vs resistant mice. Mature, B7 positive-stained LC in the cornea and pseudomonas Ag-associated LC in draining cervical lymph nodes also were increased significantly p.i. in susceptible mice. To test the relevance of these data, B6 mice were treated systemically and subconjunctivally with neutralizing B7 (B7-1/B7-2) mAbs. Treatment decreased corneal disease severity and reduced significantly the number of B7-positive cells as well as the recruitment and activation of CD4(+) T cells in the cornea. IFN-gamma mRNA levels also were decreased significantly in the cornea and in draining cervical lymph nodes of mAb-treated mice. When CD28(-/-) animals were tested, they exhibited a less severe disease response (no corneal perforation) than wild-type B6 mice and had a significantly lower delayed-type hypersensitivity response to heat-killed pseudomonas Ag. These results support a critical role for B7/CD28 costimulation in susceptibility to P. aeruginosa ocular infection.

Immortalization of a human prostate stromal cell line using a recombinant retroviral approach

PURPOSE

We established an immortalized human prostate stromal cell line with retained markers of cell differentiation and alpha1-adrenergic receptor expression.

MATERIALS AND METHODS

Primary human prostate stromal explants were infected with an amphotrophic retrovirus encoding the E6/E7 open reading frame of the human papillomavirus type 16. Immunohistochemistry was used to verify the expression of prostate stromal markers. alpha1-Adrenergic receptor expression was investigated using ribonuclease protection assays and radioligand binding. Cell proliferation was measured by the WST-1 assay and cell counting.

RESULTS

Clonal isolates of individual prostate stromal cells were isolated and passed in selection media. E6 and E7 expression was verified using reverse transcriptase polymerase chain reaction in the selected cell line. The new prostate stromal cell line PS30 was established which maintains the expression of alpha-smooth muscle actin and expresses 22 fmol./mg. of protein of alpha 1-adrenergic receptors, approximately equal to native human prostate alpha 1-adrenergic receptor expression. However, at a subtype level alpha 1a-adrenergic receptor expression is down-regulated and not detectable by ribonuclease protection assays or radioligand binding, while alpha 1b and alpha 1d-adrenergic receptor expression is enhanced. From a physiological prospective PS30 cells do not form tumors in nude mice and stimulation with phenylephrine does not increase cell proliferation.

CONCLUSIONS

We successfully established and characterized an in vitro human prostate stromal cell line. This cell line should facilitate studies designed to characterize the role of the adrenergic nervous system in the regulation of prostate growth.

In the immature mouse, Pseudomonas aeruginosa pili bind a 57-kd (alpha 2-6) sialylated corneal epithelial cell surface protein: a first step in infection

PURPOSE

To test the hypothesis that in the unscarified immature eye, Pseudomonas aeruginosa pili bind glycoprotein receptors, one or more of which are surface associated.

METHODS

Several methods--including radioiodination of bacterial pili and surface-associated corneal epithelial proteins (CEPs), solid-phase binding assays, carbohydrate detection, and immunoblotting techniques in which periodate oxidation and preincubation of blots with purified pili, neuraminidase, sialic acid, other sugars, and SNA and MAA lectins--were used to identify and characterize host proteins. Some of these proteins in the immature mouse corneal epithelium interacted with bacterial pili.

RESULTS

Seven proteins, with molecular weights from 14 to 66 kd were identified that strongly bound PAK/PR1 pili. To determine if any protein(s) was cell surface localized, corneal epithelial surface membrane proteins were radioiodinated and examined using a pilus overlay assay and lectin analysis. Only one protein of 57 kd was cell surface labeled and bound pili in an overlay assay. This protein was alpha (2-6) sialylated, as shown by SNA binding. Furthermore, SNA lectin was able to block pilus binding to CEPs. 125I labeling of pili and a solid-phase binding assay confirmed that pili bind to CEPs and, further, that binding could be competitively inhibited by excess unlabeled pili and that the receptors appeared saturable. GlycoTrack reagents were used to show that the epithelial proteins of the postnatal day 5 (P5) mouse cornea were glycosylated. Removal of carbohydrates by preincubation of blots with periodate, or combining pili with sialic acid, eliminated pili binding. Pretreatment of blots with either neuraminidase (N'ase) to decrease and/or remove sialic acid residues, or pretreatment with SNA lectin with specificity for alpha (2-6) linked sialic acid to galactose, also diminished pili binding to CEPs. Other sugars or MAA lectin, specific for sialic acid alpha (2-3) linked to galactose, had no inhibitory effect.

CONCLUSIONS

These data show that a 57-kd surface membrane protein bound pili in the immature cornea and that for both this protein and the other nonsurface proteins, sialic acid alpha (2-6) linked to galactose was important in receptor recognition by the pilus adhesion. The 57-kd protein is putatively important in the initial interaction of pili with the unwounded ocular epithelium and may be the initial pathogenic event in this model.