Innate Immunity in Lobsters: Partial Purification and Characterization of a Panulirus cygnus Anti-A Lectin

A lectin detected in haemolymph from the Australian spiny lobster Panulirus cygnus agglutinated human ABO Group A cells to a higher titre than Group O or B. The lectin also agglutinated rat and sheep erythrocytes, with reactivity with rat erythrocytes strongly enhanced by treatment with the proteolytic enzyme papain, an observation consistent with reactivity via a glycolipid. The lectin, purified by affinity chromatography on fixed rat-erythrocyte stroma, was inhibited equally by N-acetylglucosamine and N-acetylgalactosamine. Comparison of data from gel filtration of haemolymph (behaving as a 1,800,000 Da macromolecule), and polyacrylamide gel electrophoresis of purified lectin (a single 67,000 Da band), suggested that in haemolymph the lecin was a multimer. The purified anti-A lectin autoprecipitated unless the storage solution contained chaotropic inhibitors (125 mmol/L sucrose: 500 mmol/L urea). The properties of this anti-A lectin and other similar lectins are consistent with a role in innate immunity in these invertebrates.

Peripheral compartment innate immune response to Haemophilus influenzae and Streptococcus pneumoniae in chronic obstructive pulmonary disease patients.

Alterations in innate immunity that predispose to chronic obstructive pulmonary disease (COPD) exacerbations are poorly understood. We examined innate immunity gene expression in peripheral blood polymorphonuclear leukocytes (PMN) and monocytes stimulated by Haemophilus influenzae and Streptococcus pneumoniae. Thirty COPD patients (15 rapid and 15 non-rapid lung function decliners) and 15 smokers without COPD were studied. Protein expression of IL-8, IL-6, TNF-α and IFN-γ (especially monocytes) increased with bacterial challenge. In monocytes stimulated with S. pneumoniae, TNF-α protein expression was higher in COPD (non-rapid decliners) than in smokers. In co-cultures of monocytes and PMN, mRNA expression of TGF-β1 and MYD88 was up-regulated, and CD14, TLR2 and IFN-γ down-regulated with H. influenzae challenge. TNF-α mRNA expression was increased with H. influenzae challenge in COPD. Cytokine responses were similar between rapid and non-rapid decliners. TNF-α expression was up-regulated in non-rapid decliners in response to H. influenzae (monocytes) and S. pneumoniae (co-culture of monocytes and PMN). Exposure to bacterial pathogens causes characteristic innate immune responses in peripheral blood monocytes and PMN in COPD. Bacterial exposure significantly alters the expression of TNF-α in COPD patients, although not consistently. There did not appear to be major differences in innate immune responses between rapid and non-rapid decliners.

Sex hormone regulation of innate immunity in the female reproductive tract : the role of epithelial cells in balancing reproductive potential with protection against sexually transmitted pathogens

The immune system in the female reproductive tract (FRT) does not mount an attack against HIV or other sexually transmitted infections (STI) with a single endogenously produced microbicide or with a single arm of the immune system. Instead, the body deploys dozens of innate antimicrobials to the secretions of the female reproductive tract. Working together, these antimicrobials along with mucosal antibodies attack many different viral, bacterial and fungal targets. Within the FRT, the unique challenges of protection against sexually transmitted pathogens coupled with the need to sustain the development of an allogeneic fetus have evolved in such a way that sex hormones precisely regulate immune function to accomplish both tasks. The studies presented in this review demonstrate that estradiol and progesterone secreted during the menstrual cycle act both directly and indirectly on epithelial cells and other immune cells in the reproductive tract to modify immune function in a way that is unique to specific sites throughout the FRT. As presented in this review, studies from our laboratory and others demonstrate that the innate immune response is under hormonal control, varies with the stage of the menstrual cycle, and as such is suppressed at mid-cycle to optimize conditions for successful fertilization and pregnancy. In doing so, a window of STI vulnerability is created during which potential pathogens including HIV enter the reproductive tract to infect host targets.

Progesterone activates multiple innate immune pathways inChlamydia trachomatis-Infected endocervical cells

Problem Susceptibility to Chlamydia trachomatis infection is increased by oral con- traceptives and modulated by sex hormones. We therefore sought to determine the effects of female sex hormones on the innate immune response to C. trachomatis infection. Method of study ECC-1 endometrial cells, pre-treated with oestradiol or progesterone, were infected with C. trachomatis and the host transcriptome analysed by Illumina Sentrix HumanRef-8 microarray. Primary endocervical epithe- lial cells, prepared at either the proliferative or secretory phase of the menstrual cycle, were infected with C. trachomatis and cytokine gene expression determined by quantitative RT-PCR analysis. Results Chlamydia trachomatis yield from progesterone-primed ECC-1 cells was significantly reduced compared with oestradiol-treated cells. Genes upregulated in progesterone-treated and Chlamydia-infected cells only included multiple CC and CXC chemokines, IL-17C, IL-29, IL-32, TNF-a, DEFB4B, LCN2, S100A7-9, ITGAM, NOD2, JAK1, IL-6ST, type I and II interferon receptors, numerous interferon-stimulated genes and STAT6. CXCL10, CXCL11, CX3CL1 and IL-17C, which were also upregu- lated in infected secretory-stage primary cells, and there was a trend towards higher levels of immune mediators in infected secretory-phase compared with proliferative-phase cells. Conclusion Progesterone treatment primes multiple innate immune pathways in hormone-responsive epithelial cells that could potentially increase resis- tance to chlamydial infection.

Pulmonary innate immunity in children with protracted bacterial bronchitis

Objective To determine bronchoalveolar lavage (BAL) levels of 3 innate immunity components (human alpha-defensin-2 [hBD2], mannose-binding lectin [MBL], and surfactant protein-A [SP-A], the relationship with airway neutrophilia and infection, and cytokine production of stimulated BAL cells in children with current protracted bacterial bronchitis (PBB), children with resolved PBB (PBB well), and controls. Study design BAL of 102 children (mean age 2.8 years) fulfilling predefined criteria of current PBB (n=61), PBB well (n=20), and controls (n=21) was cultured (quantitative bacteriology) and viruses examined by polymerase chain reaction. hBD2, MBL, and SP-A were measured, and cytokine production of lipopolysaccharide-stimulated BAL cells were determined. Results Median hBD2 and MBL levels were significantly higher in the current PBB group (hBD2 = 164.4, IQR 0-435.5pg/mL; MBL = 1.7, 0.4-4ng/mL) than in the PBB well group (hBD2 = 0, IQR 0-85.2; MBL = 0.6, IQR 0.03-2.9) and controls (hBD2 = 3.6, IQR 0-126; MBL = 0.4, IQR 0.02-79). hBD2 was significantly higher in children with airway infection (n = 54; median 76.9, IQR 0-397.3) compared with those without (n = 48; 0, IQR 0-236.3), P=0.04. SP-A levels and cytokine production of stimulated BAL cells were similar between groups. Conclusion In children's airways, hBD2, but not MBL and SP-A, relates to inflammation and infection. In children with PBB, mechanisms involving airway hBD2 and MBL are augmented. These pulmonary innate immunity components and the ability of BAL cells to respond to stimuli are unlikely to be deficient.

Uropathogenic Escherichia coli virulence and innate immune responses during urinary tract infection

Urinary tract infections (UTI) are among the most common infectious diseases of humans and are the most common nosocomial infections in the developed world. It is estimated that 40–50% of women and 5% of men will develop a UTI in their lifetime, and UTI accounts for more than 1 million hospitalizations and $1.6 billion in medical expenses each year in the USA. Uropathogenic Escherichia coli (UPEC) is the primary cause of UTI. This review presents an overview of recent discoveries related to the primary virulence factors of UPEC and major innate immune responses to infection of the lower urinary tract. New and emerging themes in UPEC research are discussed in the context of the interface between host and pathogen.

Identification of 15 new psoriasis susceptibility loci highlights the role of innate immunity

To gain further insight into the genetic architecture of psoriasis, we conducted a meta-analysis of 3 genome-wide association studies (GWAS) and 2 independent data sets genotyped on the Immunochip, including 10,588 cases and 22,806 controls. We identified 15 new susceptibility loci, increasing to 36 the number associated with psoriasis in European individuals. We also identified, using conditional analyses, five independent signals within previously known loci. The newly identified loci shared with other autoimmune diseases include candidate genes with roles in regulating T-cell function (such as RUNX3, TAGAP and STAT3). Notably, they included candidate genes whose products are involved in innate host defense, including interferon-mediated antiviral responses (DDX58), macrophage activation (ZC3H12C) and nuclear factor (NF)-κB signaling (CARD14 and CARM1). These results portend a better understanding of shared and distinctive genetic determinants of immune-mediated inflammatory disorders and emphasize the importance of the skin in innate and acquired host defense. © 2012 Nature America, Inc. All rights reserved.

Breastmilk-saliva interactions boost innate immunity by regulating the oral microbiome in early infancy

Introduction Xanthine oxidase (XO) is distributed in mammals largely in the liver and small intestine, but also is highly active in milk where it generates hydrogen peroxide (H2O2). Adult human saliva is low in hypoxanthine and xanthine, the substrates of XO, and high in the lactoperoxidase substrate thiocyanate, but saliva of neonates has not been examined. Results Median concentrations of hypoxanthine and xanthine in neonatal saliva (27 and 19 μM respectively) were ten-fold higher than in adult saliva (2.1 and 1.7 μM). Fresh breastmilk contained 27.3±12.2 μM H2O2 but mixing baby saliva with breastmilk additionally generated >40 μM H2O2, sufficient to inhibit growth of the opportunistic pathogens Staphylococcus aureus and Salmonella spp. Oral peroxidase activity in neonatal saliva was variable but low (median 7 U/L, range 2–449) compared to adults (620 U/L, 48–1348), while peroxidase substrate thiocyanate in neonatal saliva was surprisingly high. Baby but not adult saliva also contained nucleosides and nucleobases that encouraged growth of the commensal bacteria Lactobacillus, but inhibited opportunistic pathogens; these nucleosides/bases may also promote growth of immature gut cells. Transition from neonatal to adult saliva pattern occurred during the weaning period. A survey of saliva from domesticated mammals revealed wide variation in nucleoside/base patterns. Discussion and Conclusion During breast-feeding, baby saliva reacts with breastmilk to produce reactive oxygen species, while simultaneously providing growth-promoting nucleotide precursors. Milk thus plays more than a simply nutritional role in mammals, interacting with infant saliva to produce a potent combination of stimulatory and inhibitory metabolites that regulate early oral–and hence gut–microbiota. Consequently, milk-saliva mixing appears to represent unique biochemical synergism which boosts early innate immunity.

Ovarian steroid hormones: effects on immune responses and Chlamydia trachomatis infections of the female genital tract

Female sex hormones are known to regulate the adaptive and innate immune functions of the female reproductive tract. This review aims to update our current knowledge of the effects of the sex hormones estradiol and progesterone in the female reproductive tract on innate immunity, antigen presentation, specific immune responses, antibody secretion, genital tract infections caused by Chlamydia trachomatis, and vaccine-induced immunity.

Increased tubulointerstitial recruitment of human CD141(hi) CLEC9A(+) and CD1c(+) myeloid dendritic cell subsets in renal fibrosis and chronic kidney disease

Dendritic cells (DCs) play critical roles in immune-mediated kidney diseases. Little is known, however, about DC subsets in human chronic kidney disease, with previous studies restricted to a limited set of pathologies and to using immunohistochemical methods. In this study, we developed novel protocols for extracting renal DC subsets from diseased human kidneys and identified, enumerated, and phenotyped them by multicolor flow cytometry. We detected significantly greater numbers of total DCs as well as CD141(hi) and CD1c(+) myeloid DC (mDCs) subsets in diseased biopsies with interstitial fibrosis than diseased biopsies without fibrosis or healthy kidney tissue. In contrast, plasmacytoid DC numbers were significantly higher in the fibrotic group compared with healthy tissue only. Numbers of all DC subsets correlated with loss of kidney function, recorded as estimated glomerular filtration rate. CD141(hi) DCs expressed C-type lectin domain family 9 member A (CLEC9A), whereas the majority of CD1c(+) DCs lacked the expression of CD1a and DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), suggesting these mDC subsets may be circulating CD141(hi) and CD1c(+) blood DCs infiltrating kidney tissue. Our analysis revealed CLEC9A(+) and CD1c(+) cells were restricted to the tubulointerstitium. Notably, DC expression of the costimulatory and maturation molecule CD86 was significantly increased in both diseased cohorts compared with healthy tissue. Transforming growth factor-β levels in dissociated tissue supernatants were significantly elevated in diseased biopsies with fibrosis compared with nonfibrotic biopsies, with mDCs identified as a major source of this profibrotic cytokine. Collectively, our data indicate that activated mDC subsets, likely recruited into the tubulointerstitium, are positioned to play a role in the development of fibrosis and, thus, progression to chronic kidney disease.

The role of inflammation in cutaneous repair

Inflammation is a fundamental component of the normal adult wound healing response occurring even in the absence of infection. It performs many beneficial roles such as the clearing of damaged cells and extracellular matrix (ECM), the removal of pathogens that might other wise multiply and spread, and the secretion of mediators that regulate other aspects of wound healing such as proliferation, re-epithelialisation and wound remodelling. Yet, excess and/or prolonged inflammation is detrimental to wound healing and leads to increased fibrosis and scarring, which can be disfiguring and, in cases such as contractures, can lead to disability. Furthermore, excessive inflammation is a major contributing factor to the persistence of chronic non-healing wounds, which are “stuck” in the inflammatory phase of healing and fail to reepithelialise. Current research suggest that the type of immune cells, their timing and the level of inflammation in a wound could have dramatic effect on whether a wound heals in a timely fashion and the final quality of the repaired tissue. Studies suggest that altering the level of inflammation might be beneficial in terms of reducing scarring and improving the rate of healing in chronic wounds. This review looks at the role of the major immune cells in normal and impaired wound healing and strategies that might be used to reduce inflammation in wounds.

Urinary tract infection of mice to model human disease: Practicalities, implications and limitations

Urinary tract infections (UTIs) are among the most common bacterial infections in humans. Murine models of human UTI are vital experimental tools that have helped to elucidate UTI pathogenesis and advance knowledge of potential treatment and infection prevention strategies. Fundamentally, several variables are inherent in different murine models, and understanding the limitations of these variables provides an opportunity to understand how models may be best applied to research aimed at mimicking human disease. In this review, we discuss variables inherent in murine UTI model studies and how these affect model usage, data analysis and data interpretation. We examine recent studies that have elucidated UTI host–pathogen interactions from the perspective of gene expression, and review new studies of biofilm and UTI preventative approaches. We also consider potential standards for variables inherent in murine UTI models and discuss how these might expand the utility of models for mimicking human disease and uncovering new aspects of pathogenesis

Uropathogenic Escherichia Coli engages CD14-dependent signaling to enable bladder-macrophage-dependent control of acute urinary tract infection

Background CD14, a coreceptor for several pattern recognition receptors and a widely used monocyte/macrophage marker, plays a key role in host responses to gram-negative bacteria. Despite the central role of CD14 in the inflammatory response to lipopolysaccharide and other microbial products and in the dissemination of bacteria in some infections, the signaling networks controlled by CD14 during urinary tract infection (UTI) are unknown. Methods We used uropathogenic Escherichia coli (UPEC) infection of wild-type (WT) C57BL/6 and Cd14−/− mice and RNA sequencing to define the CD14-dependent transcriptional signature and the role of CD14 in host defense against UTI in the bladder. Results UPEC induced the upregulation of Cd14 and the monocyte/macrophage-related genes Emr1/F4/80 and Csf1r/c-fms, which was associated with lower UPEC burdens in WT mice, compared with Cd14−/− mice. Exacerbation of infection in Cd14−/− mice was associated with the absence of a 491-gene transcriptional signature in the bladder that encompassed multiple host networks not previously associated with this receptor. CD14-dependent pathways included immune cell trafficking, differential cytokine production in macrophages, and interleukin 17 signaling. Depletion of monocytes/macrophages in the bladder by administration of liposomal clodronate led to higher UPEC burdens. Conclusions This study identifies new host protective and signaling roles for CD14 in the bladder during UPEC UTI.