Pharmacologic Inhibition of COX-1 and COX-2 in Influenza A Viral Infection in Mice

Background

We previously demonstrated that cyclooxygenase (COX)-1 deficiency results in greater morbidity and inflammation, whereas COX-2 deficiency leads to reduced morbidity, inflammation and mortality in influenza infected mice.

Methodology/Principal Findings

We investigated the effects of COX-1 and COX-2 inhibitors in influenza A viral infection. Mice were given a COX-1 inhibitor (SC-560), a COX-2 inhibitor (celecoxib) or no inhibitor beginning 2 weeks prior to influenza A viral infection (200 PFU) and throughout the course of the experiment. Body weight and temperature were measured daily as indicators of morbidity. Animals were sacrificed on days 1 and 4 post-infection and bronchoalveolar lavage (BAL) fluid was collected or daily mortality was recorded up to 2 weeks post-infection. Treatment with SC-560 significantly increased mortality and was associated with profound hypothermia and greater weight loss compared to celecoxib or control groups. On day 4 of infection, BAL fluid cells were modestly elevated in celecoxib treated mice compared to SC-560 or control groups. Viral titres were similar between treatment groups. Levels of TNF-α and G-CSF were significantly attenuated in the SC-560 and celecoxib groups versus control and IL-6 levels were significantly lower in BAL fluid of celecoxib treated mice versus control and versus the SC-560 group. The chemokine KC was significantly lower in SC-560 group versus control.

Conclusions/Significance

Treatment with a COX-1 inhibitor during influenza A viral infection is detrimental to the host whereas inhibition of COX-2 does not significantly modulate disease severity. COX-1 plays a critical role in controlling the thermoregulatory response to influenza A viral infection in mice.     

A comprehensive resequence analysis of the KLK15–KLK3–KLK2 locus on chromosome 19q13.33

Single nucleotide polymorphisms (SNPs) in the KLK3 gene on chromosome 19q13.33 are associated with serum prostate-specific antigen (PSA) levels. Recent genome wide association studies of prostate cancer have yielded conflicting results for association of the same SNPs with prostate cancer risk. Since the KLK3 gene encodes the PSA protein that forms the basis for a widely used screening test for prostate cancer, it is critical to fully characterize genetic variation in this region and assess its relationship with the risk of prostate cancer. We have conducted a next-generation sequence analysis in 78 individuals of European ancestry to characterize common (minor allele frequency, MAF >1%) genetic variation in a 56 kb region on chromosome 19q13.33 centered on the KLK3 gene (chr19:56,019,829–56,076,043 bps). We identified 555 polymorphic loci in the process including 116 novel SNPs and 182 novel insertion/deletion polymorphisms (indels). Based on tagging analysis, 144 loci are necessary to tag the region at an r ² threshold of 0.8 and MAF of 1% or higher, while 86 loci are required to tag the region at an r ² threshold of 0.8 and MAF >5%. Our sequence data augments coverage by 35 and 78% as compared to variants in dbSNP and HapMap, respectively. We observed six non-synonymous amino acid or frame shift changes in the KLK3 gene and three changes in each of the neighboring genes, KLK15 and KLK2. Our study has generated a detailed map of common genetic variation in the genomic region surrounding the KLK3 gene, which should be useful for fine-mapping the association signal as well as determining the contribution of this locus to prostate cancer risk and/or regulation of PSA expression.     

Association of Multiple Sclerosis Susceptibility Variants and Early Attack Location in the CNS

Objective

The anatomic location of subsequent relapses in early multiple sclerosis (MS) appears to be predicted by the first attack location. We sought to determine if genetic polymorphisms associated with MS susceptibility are associated with attack location.

Methods

17 genome-wide association study-identified MS susceptibility polymorphisms were genotyped in 503 white, non-Hispanic patients seen within a year of MS onset. Their association with the CNS location of the first two MS attacks was assessed in multivariate repeated measures analyses (generalized estimating equations with robust standard errors).

Results

The IL12A polymorphism was independently associated with increased odds of attacks involving the spinal cord (OR = 1.52, 95% CI 1.11, 2.07, p = 0.009), as was the IRF8 polymorphism (OR = 2.40, 95% CI [1.04, 5.50], p = 0.040). The IL7R polymorphism was associated with reduced odds of attacks involving the brainstem/cerebellum (OR = 0.46, 95% CI 0.22, 0.97, p = 0.041), as were the TNFRSF1A and IL12A polymorphisms. The CD6 polymorphism conferred reduced odds of optic neuritis as an attack location (OR = 0.69, 95% CI [0.49, 0.97], p = 0.034). Several other genes showed trends for association with attack location.

Conclusions

Some of the MS susceptibility genes may be associated with MS attack location. The IL12A polymorphism is of particular interest given that interferon beta therapy appears to influence IL12 levels. These findings may lead to improved understanding of MS pathogenesis and treatment.     

Stimulating the Need to Know…

Nations, James D. Tropical Rainforest: Endangered Environment . New York: Franklin Watts, 1988. 143 pp. $12.90 hardcover. Reviewed by Jorge Zamacona Evenes.

Sharp, D.W.A., ed. The Penguin Dictionary of Chemistry , 2d ed. New York: Penguin, 1990. 434 pp. $9.95 paperback. Reviewed by Wayne Hanley.

Hale, W.G., and J.P. Margham. The HarperCollins Dictionary of Biology. New York: Harper Collins, 1991. 569 pp. $12.95 paperback; $25.00 hardcover. Reviewed by Wayne Hanley.

Sparks, John, and Tony Soper. Penguins. New York: Fact On File, 1987. 246 pp. $1995 hardcover. Reviewed by Wayne Hanley.

Mountfort, Guy. Rare Birds of the World . A Collins/ICBP Handbook. New York: Penguin (The Stephen Greene Press), 1988. 256 pp. $2995 hardcover. Reviewed by John W. McLure.

Woodcock, Martin. Collins Handguide to the Birds of the Indian Subcontinent . New York: Penguin (The Stephen Greene Press), 1989. 176 pp. $11.95 paperback. Reviewed by James Scheib.

Harris, Michael. The Collins Field Guide to the Birds of Galapagos . New York: Penguin (The Stephen Greene Press), 1989. 160 pp. $1995 hardcover. Reviewed by Jim Fuller.

Brudenell-Bruce, P. G. C. The Collins Guide to the Birds of New Providence and the Babama Islands. New York: Penguin (The Stephen Greene Press), 1989. 142 pp. $14.95 paperback. Reviewed by Carol A. Thompson.     

Germline mutations of regulator of telomere elongation helicase 1, RTEL1, in Dyskeratosis congenita

Dyskeratosis congenita (DC) is an inherited bone marrow failure and cancer predisposition syndrome caused by aberrant telomere biology. The classic triad of dysplastic nails, abnormal skin pigmentation, and oral leukoplakia is diagnostic of DC, but substantial clinical heterogeneity exists; the clinically severe variant Hoyeraal Hreidarsson syndrome (HH) also includes cerebellar hypoplasia, severe immunodeficiency, enteropathy, and intrauterine growth retardation. Germline mutations in telomere biology genes account for approximately one-half of known DC families. Using exome sequencing, we identified mutations in RTEL1, a helicase with critical telomeric functions, in two families with HH. In the first family, two siblings with HH and very short telomeres inherited a premature stop codon from their mother who has short telomeres. The proband from the second family has HH and inherited a premature stop codon in RTEL1 from his father and a missense mutation from his mother, who also has short telomeres. In addition, inheritance of only the missense mutation led to very short telomeres in the proband’s brother. Targeted sequencing identified a different RTEL1 missense mutation in one additional DC proband who has bone marrow failure and short telomeres. Both missense mutations affect the helicase domain of RTEL1, and three in silico prediction algorithms suggest that they are likely deleterious. The nonsense mutations both cause truncation of the RTEL1 protein, resulting in loss of the PIP box; this may abrogate an important protein–protein interaction. These findings implicate a new telomere biology gene, RTEL1, in the etiology of DC.     

Anti-MS4a4B treatment abrogates MS4a4B-mediated protection in T cells and ameliorates experimental autoimmune encephalomyelitis

Recent data show that anti-CD20 therapy is effective for some autoimmune diseases, including multiple sclerosis (MS). However, the efficacy of anti-CD20 therapy for MS is largely limited because anti-CD20 antibodies target only B cells. In previous studies, we have investigated the function of MS4a4B, a novel CD20 homologue, in T cell proliferation. Here, we found that MS4a4B regulates not only T cell proliferation but also T cell apoptosis. Knockdown of MS4a4B by MS4a4B-siRNA or MS4a4B-shRNA-expressing vector promoted apoptosis in primary T cells and T32 cell line. In contrast, vector-driven over-expression of MS4a4B reduced apoptosis in EL-4 cells. Machinery analysis showed that MS4a4B-mediated T cell survival was associated with decreased activity of caspases 3, 8 and 9. Interestingly, binding of anti-MS4a4B antibodies to T cells induced activated T cells to undergo apoptosis. To test whether anti-MS4a4B antibody interferes with MS4a4B-mediated protection of T cells, we injected anti-MS4a4B antibodies into mice with experimental autoimmune encephalomyelitis (EAE). The results show that anti-MS4a4B treatment ameliorated the severity of EAE, accompanied by decreased Th1 and Th17 cell responses and reduced levels of pro-inflammatory cytokines in the central nervous system, suggesting that MS4a4B may serve as a target of antibody-based therapy for T cell-mediated diseases.     

C4-alkylthiols with activity against Moraxella catarrhalis and Mycobacterium tuberculosis

Antimicrobial resistance represents a global threat to healthcare. The ability to adequately treat infectious diseases is increasingly under siege due to the emergence of drug-resistant microorganisms. New approaches to drug development are especially needed to target organisms that exhibit broad antibiotic resistance due to expression of β-lactamases which is the most common mechanism by which bacteria become resistant to β-lactam antibiotics. We designed and synthesized 20 novel monocyclic β-lactams with alkyl- and aryl-thio moieties at C4, and subsequently tested these for antibacterial activity. These compounds demonstrated intrinsic activity against serine β-lactamase producing Mycobacterium tuberculosis wild type strain (Mtb) and multiple (n=6) β-lactamase producing Moraxella catarrhalis clinical isolates.