Functioning metastases in liver from thyroid carcinoma: Case report

Radioiodine uptake in liver metastases was observed in two patients with follicular carcinoma of the thyroid

HIV gp120 Binds to Mannose Receptor on Vaginal Epithelial Cells and Induces Production of Matrix Metalloproteinases

BACKGROUND: During sexual transmission of HIV in women, the virus breaches the multi-layered CD4 negative stratified squamous epithelial barrier of the vagina, to infect the sub-epithelial CD4 positive immune cells. However the mechanisms by which HIV gains entry into the sub-epithelial zone is hitherto unknown. We have previously reported human mannose receptor (hMR) as a CD4 independent receptor playing a role in HIV transmission on human spermatozoa. The current study was undertaken to investigate the expression of hMR in vaginal epithelial cells, its HIV gp120 binding potential, affinity constants and the induction of matrix metalloproteinases (MMPs) downstream of HIV gp120 binding to hMR. PRINCIPAL FINDINGS: Human vaginal epithelial cells and the immortalized vaginal epithelial cell line Vk2/E6E7 were used in this study. hMR mRNA and protein were expressed in vaginal epithelial cells and cell line, with a molecular weight of 155 kDa. HIV gp120 bound to vaginal proteins with high affinity, (Kd = 1.2±0.2 nM for vaginal cells, 1.4±0.2 nM for cell line) and the hMR antagonist mannan dose dependently inhibited this binding. Both HIV gp120 binding and hMR exhibited identical patterns of localization in the epithelial cells by immunofluorescence. HIV gp120 bound to immunopurified hMR and affinity constants were 2.9±0.4 nM and 3.2±0.6 nM for vaginal cells and Vk2/E6E7 cell line respectively. HIV gp120 induced an increase in MMP-9 mRNA expression and activity by zymography, which could be inhibited by an anti-hMR antibody. CONCLUSION: hMR expressed by vaginal epithelial cells has high affinity for HIV gp120 and this binding induces production of MMPs. We propose that the induction of MMPs in response to HIV gp120 may lead to degradation of tight junction proteins and the extracellular matrix proteins in the vaginal epithelium and basement membrane, leading to weakening of the epithelial barrier; thereby facilitating transport of HIV across the vaginal epithelium

Low-molecular-weight inhibin from sheep, human, rat, and chicken testes

Low-molecular-weight peptides with inhibin activity have been isolated from sheep, human, rat, and chicken testes by simple gel filtration. These peptides, isolated from avian and mammalian species, suppressed the postcastration rise of serum FSH levels in adult male rats by 34 to 45% and appeared to be biologically and chromatographically similar

Localization of HIV gp120 binding and hMR in vaginal epithelial cells.

<p>Vaginal epithelial cells (a and e) and Vk2/E6E7 cells (b and f) incubated with FITC labeled HIV gp120 (green fluorescence) and counter stained with propidium iodide (red fluorescence). Vaginal epithelial cells (c and g) and Vk2/E6E7 cells (d and h) probed with hMR antibody (green fluorescence) and counter stained with propidium iodide (red fluorescence). <i>Inset</i> on (a) and (b) represents vaginal epithelial cells and Vk2/E6E7 cells respectively, incubated with excess unlabelled gp120. <i>Inset</i> on (c) and (d) represents negative control (-ve), for vaginal epithelial cells and Vk2/E6E7 cells respectively labeled with IgG antibody FITC labeled. Images (a and c) are at 400× magnification, (b and d) are at 630× magnification. (e–h): Images captured at 1260× magnification and further digitally magnified.</p

HIV gp120 binding to vaginal hMR and its affinity constants.

<p>(a) HIV gp120 binding and its inhibition to immunopurified hMR from human vaginal proteins and Vk2/E6E7 proteins. Results are mean ± SE, n = 3. *Statistically significant (p<0.05) when compared with controls. ^#Statistically significant (p<0.05) when compared with HIV gp120 treated cells. Saturation Isotherm of HIV gp120 binding to hMR immunopurified from (b) human vaginal proteins and (c) Vk2/E6E7 proteins at concentrations indicated on the X axis. Affinity constants, Kd = 2.9±0.4 nM and Kd = 3.2±0.6 nM for human vaginal proteins and Vk2/E6E7 proteins respectively. Results are a representative of three independent experiments.</p

Binding of HIV gp120 to vaginal proteins and its inhibition by mannan or the hMR blocking antibody.

<p>Saturation isotherm of HIV gp120 HRP conjugated binding at the indicated concentrations on the X axis to (a) vaginal protein lysates (Kd = 1.2±0.2 nM) and (b) vaginal epithelial cell line Vk2/E6E7 protein lysates (Kd = 1.4±0.2 nM). Results are representative of three experiments. Inhibition of HIV gp120 binding using mannan in (c) vaginal protein lysates or (d) Vk2/E6E7 protein lysates. Mannan or sucrose concentrations in ug/ml are plotted on a logarithimic scale. Experiments were repeated in triplicates. Binding of HIV gp120 to (e) vaginal protein lysates or (f) Vk2/E6E7 protein lysates in the presence of increasing concentrations of hMR blocking antibody or isotype matched IgG antibody. Results are mean ± SE, n = 3. ^*Statistically significant (p<0.05) when compared with cells treated with HIV gp120 in the absence of antibody.</p

Expression of hMR in vaginal cells.

<p>(a) Purity of vaginal epithelial cells: RT-PCR for lymphocyte marker CD3 (lane 2, 5 9), macrophage/monocyte marker CD14 (lanes 3, 6, 10) and dendritic cell marker CD11c (lanes 4, 7 and 11) using RNA isolated form PBMCs (lane 2, 3, 4), epithelial cells (lanes 5, 6, 7) and Vk2/E6E7 (lanes 9, 10, 11). Lanes 8 and 12 - positive control (18S rRNA) from vaginal epithelial cells and Vk2/E6E7 cells respectively. Lane 1 is 100 bp ladder. (b) RT-PCR for hMR mRNA: Lane 1: 100 bp DNA ladder. Lanes 2 and 6: Amplification of hMR in RNA derived from vaginal epithelial cells and Vk2/E6E7 cells respectively using hMR specific primers (201 bp product). Lanes 4 and 5: positive control (18S rRNA) from vaginal epithelial cells and Vk2/E6E7 cells respectively. Lane 3: negative control (no template). (c) Western blot for hMR protein: Lane 1: human vaginal protein lysate and lane 2: Vk2/E6E7 protein lysate were probed with goat polyclonal anti-hMR serum (1∶1000) and HRP conjugated donkey anti-goat secondary antibody (1∶5000), and detected by chemiluminescence. Lane 3: human vaginal protein lysate and lane 4: Vk2/E6E7 protein lysate were probed with normal goat serum (negative controls) and detected as in lanes 1 and 2.</p