1141154113Expression of natural cytotoxicity receptors in peripheral blood NK cell subsets of women with recurrent spontaneous abortions (RSA) or implantation failures

Aim:  To determine if IgA is required for protection against Chlamydia infection in the male reproductive tract (MRT).
Materials and Methods:  Male polyimmunoglobulin receptor knockout mice (PIgR^-/-) and wild-type C57BL/6 (WT) mice were immunised intranasally with chlamydial major outer membrane protein (MOMP) and cholera toxin (CT). MOMP-specific IgG and IgA in serum and prostatic fluids were measured by ELISA. Serum and PF were also assayed for inhibition of in vitro chlamydial infection. Immunized WT and PIgR^-/- mice were challenged by direct inoculation of C. muridarum into the meatus urethra. Four weeks post challenge Chlamydia levels in the penile urethra, epididymis and testis were determined by PCR.
Results:  Equivalent levels of IgG were found in the serum of both WT and PIgR^-/- mice however IgA in serum of PIgR^-/- mice was 19- to 20-fold higher than in WT animals consistent with the lack of the PIgR IgA transport molecule. IgA levels were significantly lower in PIgR^-/- PF compared to WT PF after both immunization and infection. Only PF from WT but not PIgR^-/- animals was able to inhibit in vitro chlamydial infection. Following challenge significantly higher levels of Chlamydia were recovered from the MRT of PIgR^-/- mice compared to WT animals.
Conclusions:  Male mice lacking a functional PIgR were unable to clear a genital tract Chlamydia infection despite high levels of serum IgA. These data show that mucosal IgA plays a major role in preventing chlamydial infection of the male genital tract and suggest that immunization strategies to protect males should target a strong mucosal IgA response.     

Bioavailability of Soil-Bound TCDD: Dermal Bioavailability in the Rat

Bioavailability of Soil-Bound TCDD: Dermal Bioavailability inthe Rat. SHU, H., TEITELBAUM, T., WEBB, A. S., MARPLE, L., BRUNCK,B. DEI ROSSI, D., MURRAY, J., AND PAUSTENBACH, D. (1988). Fundam.Appl. Toxicol. 10, 335-343. 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD), an unwanted by-product formed during the manufactureof hexachlorophene and phenoxyherbicides, has been found asan environmental contaminant in many U.S. and Western Europeansites. This study examines in the rat the degree of dermal absorptionof TCDD bound to soil. Such information would assist regulatoryagencies in evaluating the degree of exposure of humans whocome in contact with TCDD-contaminated soil. Several parameterswhich may influence dermal absorption were studied, includingTCDD dose, duration of contact, presence of crankcase oil asa co-contaminant, and environmentally contaminated vs laboratory-preparedsoil. The dermal penetration of TCDD following 4 hr of contactwith skin was approximately 60% of that following 24 hr of contact(P 0.05). Following 24 hr of contact with the skin, the degreeof dermal uptake of TCDD contaminated soil was approximately1% of the administered dose. Under the conditions of the presentstudy, the degree of uptake does not appear to be influencedto any significant extent by the concentration of TCDD on soil,the presence of crankcase oil as co-contaminants, or by environmentallyvs laboratory-contaminated soil. Although a number of parametersexamined in this study did not significantly influence the degreeof dermal absorption of TCDD in the rat following 24 hr of contactwith the contaminated soil, the unqualified use of the 1% valueto estimate human exposure would overestimate human exposure,since there is general agreement among researchers that ratskin tends to be more permeable than human skin to highly lipid-solublecompounds such as TCDD.     

In vitro parasite-monocyte interactions in human leishmaniasis: possible role of fibronectin in parasite attachment.

Leishmania spp. must attach to mononuclear phagocyte surfaces before entering this host cell. We investigated the potential role of fibronectin in facilitating parasite attachment. Human plasma fibronectin bound to axenically cultured promastigotes, and promastigotes and amastigotes preferentially bound to fibronectin-coated cover slips. Promastigotes grown in the absence of fibronectin were strikingly deficient in their ability to attach to human monocytes compared with promastigotes grown in the presence of fibronectin. Rabbit anti-human plasma fibronectin antiserum decreased promastigote and amastigote attachment to monocytes. Immunoglobulin G F(ab')2 and Fab fragments also reduced the ability of amastigotes to bind to monocytes. Antiserum pretreatment of amastigotes followed by washing resulted in reduced parasite binding, whereas antibody pretreatment of monocytes did not. Addition of exogenous fibronectin did not enhance parasite attachment to monocytes. These findings suggest that Leishmania spp. can bind fibronectin and may utilize this glycoprotein to facilitate attachment to the mononuclear phagocytes that they infect.     

P-selectin inhibition suppresses muscle regeneration following injury

This investigation sought to determine if P-selectin-mediated mechanisms contributed to macrophage localization in damaged muscle, an essential process for muscle regeneration. Mice were injected intravenously (i.v.) with soluble P-selectin glycoprotein ligand-1 (sPSGL-1) at 5, 50, or 200 microg/mouse or with 100 microl vehicle alone, and then, lengthening contractions were induced in hindlimb plantar-flexor muscles. The contractions caused fiber damage in soleus muscles, with maximal invasion by CD11b+ mononuclear cells at 24 h post-injury and substantial accumulation of CD11b+ mononuclear cells in the extracellular matrix up to 7 days post-injury. sPSGL-1 treatment caused a dose-dependent decrease in the number of regenerating fibers (P=0.021), as determined by developmental myosin heavy chain (dMHC) expression. This expression was reduced 93% at 7 days post-injury by the highest dose of sPSGL-1, which had no significant influence on intrafiber or extracellular accumulation of cells expressing CD11b, a general marker for phagocytic cells. Additional mice were injected i.v. with 20 microg anti-P-selectin or isotype-control immunoglobulin G and were then subjected to lengthening contractions as before. At 7 days post-injury, soleus muscles from anti-P-selectin-treated mice contained 48% fewer mononuclear cells that bound ER-BMDM1 (P=0.019), a marker for mature macrophages and dendritic cells, and 84% fewer fibers expressing dMHC (P = 0.006), compared with muscles from isotype-injected, control mice. The number of CD11b+ cells was not significantly different between groups. The results are consistent with the concept that P-selectin is involved in the recruitment, maturation, and/or activation of cells that are critical for muscle fiber regeneration.     

Intergenerational instability of the CAG repeat of the gene for Machado- Joseph disease (MJD1) is affected by the genotype of the normal chromosome: implications for the molecular mechanisms of the instability of the CAG repeat

Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder caused by unstable expansion of a CAG repeat in the MJD1 gene at 14q32.1. To identify elements affecting the intergenerational instability of the CAG repeat, we investigated whether the CGG/GGG polymorphism at the 3' end of the CAG repeat affects intergenerational instability of the CAG repeat. The [expanded (CAG)n-CGG]/[normal (CAG)n- GGG] haplotypes were found to result in significantly greater instability of the CAG repeat compared to the [expanded (CAG)n- CGG]/[normal (CAG)n-CGG] or [expanded (CAG)nGGG]/[normal (CAG)n-GGG] haplotypes. Multiple stepwise logistic regression analysis revealed that the relative risk for a large intergenerational change in the number of CAG repeat units (< -2 or > 2) is 7.7-fold (95% CI: 2.5-23.9) higher in the case of paternal transmission than in that of maternal transmission and 7.4-fold (95% CI: 2.4-23.3) higher in the case of transmission from a parent with the [expanded (CAG)n-CGG]/[normal (CAG)n-GGG] haplotypes than in that of transmission from a parent with the [expanded (CAG)n-CGG]/[normal (CAG)n-CGG] or [expanded (CAG)n- GGG]/[normal (CAG)n-GGG] haplotypes. The combination of paternal transmission and the [expanded (CAG)n-CGG]/[normal (CAG)n-GGG] haplotypes resulted in a 75.2-fold (95% CI: 9.0-625.0) increase in the relative risk compared with that of maternal transmission and the [expanded (CAG)n-CGG]/[normal (CAG)n-CGG] or [expanded (CAG)n- GGG]/[normal (CAG)n-GGG] haplotypes. The results suggest that an inter- allelic interaction is involved in the intergenerational instability of the expanded CAG repeat.      

Chromosomal aberrations and micronucleus frequency in nurses occupationally exposed to cytotoxic drugs

In this study, we evaluated the effect of low level occupationalexposure of nurses in a medical oncology unit in Cairo, Egypt,to anticancer drugs. Twenty nurses who constantly handled thesedrugs and 20 controls, matched according to age and sex, wereexamined. Metaphase chromosomes were studied. Percentages ofmetaphases with chromosomal aberrations were significantly higher(P < 0.001) in the exposed group (6.1 ± 2.7) versusthe controls (2.6 ± 1.6). The detected chromosomal aberrationswere in the form of chromatid gaps, chromatid breaks and acentricfragments. Micronucleated peripheral blood lymphocytes werealso analyzed in cytochalasin B treated binucleated lymphocytes.There was significant increase in cells with micronuclei (P< 0.001) in nurses (10.05 ± 4.71) in comparison tothe matched control (5.42 ± 2.22) (P < 0.001). Nursesexposed to the cytotoxic drugs for     

The mouse Mid1 gene: implications for the pathogenesis of Opitz syndrome and the evolution of the mammalian pseudoautosomal region

We have recently reported isolation of the gene responsible for X- linked Opitz G/BBB syndrome, a defect of midline development. MID1 is located on the distal short arm of the human X chromosome (Xp22. 3) and encodes a novel member of the B box family of zinc finger proteins. We have now cloned the murine homolog of MID1 and performed preliminary expression studies during development. Mid1 expression in undifferentiated cells in the central nervous, gastrointestinal and urogenital systems suggests that abnormal cell proliferation may underlie the defect in midline development characteristic of Opitz syndrome. We have also found that Mid1 is located within the mouse pseudoautosomal region (PAR) in Mus musculus , while it seems to be X- specific in Mus spretus. Therefore, Mid1 is likely to be a recent acquisition of the M. musculus PAR. Genetic and FISH analyses also demonstrated a high frequency of unequal crossovers in the murine PAR, creating spontaneous deletion/duplication events involving Mid1. These data provide evidence for the first time that genetic instability of the PAR may affect functionally important genes. In addition, we show that MID1 is the first example of a gene subject to X-inactivation in man while escaping it in mouse. These data contribute to a better understanding of the molecular content and evolution of the rodent PAR.      

Blockade of the GLT-1 Transporter in the Central Nucleus of the Amygdala Induces both Anxiety and Depressive-Like Symptoms

Depression has been associated with abnormalities in glutamatergic neurotransmission and decreased astrocyte number in limbic areas. We previously demonstrated that global and prefrontal cortical blockade of the astrocytic glutamate transporter (GLT-1) induces anhedonia and c-Fos expression in areas that regulate anxiety, including the central amygdala (CEA). Given the role of the amygdala in anxiety and the high degree of comorbidity between anxiety and depression, we hypothesized that GLT-1 blockade in the CEA would induce symptoms of anhedonia and anxiety in rats. We microinjected the GLT-1 inhibitor, dihydrokainic acid (DHK), into the CEA and examined effects on intracranial self-stimulation (ICSS) as an index of hedonic state, and on behavior in two anxiety paradigms, elevated plus maze (EPM) and fear conditioning. At lower doses, intra-CEA DHK produced modest increases in ICSS responding (T0). Higher doses resulted in complete cessation of responding for 15 min, suggesting an anhedonic or depressive-like effect. Intra-CEA DHK also increased anxiety-like behavior such that percent time in the open arms and total entries were decreased in the EPM and acquisition of freezing behavior to the tone was increased in a fear-conditioning paradigm. These effects did not appear to be explained by non-specific changes in activity, because effects on fear conditioning were assessed in a drug-free state, and a separate activity test showed no significant effects of intra-CEA DHK on locomotion. Taken together, these studies suggest that blockade of GLT-1 in the CEA is sufficient to induce both anhedonia and anxiety and therefore that a lack of glutamate uptake resulting from glial deficits may contribute to the comorbidity of depression and anxiety.     

IL-13 blockade reduces lung inflammation after Ascaris suum challenge in cynomolgus monkeys

BACKGROUND: Airway inflammation is a hallmark feature of asthma and a driver of airway hyperresponsiveness. IL-13 is a key inducer of airway inflammation in rodent models of respiratory disease, but a role for IL-13 has not been demonstrated in primates. OBJECTIVE: We sought to test the efficacy of a neutralizing antibody to human IL-13 in a cynomolgus monkey model of lung inflammation. METHODS: Using cynomolgus monkeys (Macaca fascicularis) that are sensitized to Ascaris suum through natural exposure, we developed a reproducible model of acute airway inflammation after segmental A suum antigen challenge. This model was used to test the in vivo efficacy of mAb13.2, a mouse mAb directed against human IL-13, and IMA-638, the humanized counterpart of mAb13.2. Bronchoalveolar lavage (BAL) cells and BAL fluid were collected before and after antigen challenge and assayed for cellular content by means of differential count. RESULTS: Total BAL cell count, eosinophil number, and neutrophil number were all reduced in animals treated with mAb13.2 or IMA-638 compared with values in control animals that were untreated, given saline, or treated with human IgG of irrelevant specificity. In addition, levels of eotaxin and RANTES in BAL fluid were reduced in anti-IL-13-treated animals compared with levels seen in control animals. CONCLUSION: These findings support a role for IL-13 in maintaining lung inflammation in response to allergen challenge in nonhuman primates. CLINICAL IMPLICATIONS: IL-13 neutralization with a specific antibody could be a useful therapeutic strategy for asthma.