Background: Despite the continuous shedding of HIV infected blood into the oral cavity and the detectable presence of the AIDS virus at a high frequency, human saliva is reported to inhibit oral transmission of HIV through kissing, dental treatment, biting, and aerosolization. The purpose of this study was to purify salivary MUC5B and MUC7 mucins from crude saliva and determine their anti-HIV-1 activities.

It has been reported that breast-feeding is responsible for approximately 40% of the HIV transmissions from HIV-positive mothers to children. Human breast milk, however, is known to contain numerous biologically active components which protect breast-fed infants against bacteria, viruses, and toxins. The purpose of this study was to purify and characterize breast milk mucin and to determine its anti-HIV-1 activity in an HIV inhibition assay. Sepharose CL-4B column chromatography and caesium chloride isopycnic density gradient purification were used to isolate and purify the mucin. Following Western blotting and amino acid analysis, an HIV-1 inhibition assay was carried out to determine the anti-HIV-1 activity of crude breast milk and purified milk mucin (MUC1) by incubating them with HIV-1 prior to infection of the human T lymphoblastoid cell line (CEM SS cells). SDS-PAGE analysis of the mucin, together with its amino acid composition and Western blotting, suggested that this purified mucin from human breast milk was MUC1. The HIV inhibition assay revealed that while the purified milk mucin (MUC1) inhibited the HIV-1 activity by approximately 97%, there was no inhibition of the HIV-1 activity by crude breast milk. Although the reason for this is not clear, it is likely that because the MUC1 in crude milk is enclosed by fat globules, there may not be any physical contact between the mucin and the virus in the crude breast milk. Thus, there is a need to free the mucin from the fat globules for it to be effective against the virus.

A 58-year-old man with a 1 year history of progressive abdominal distension underwent a laparotomy for pseudomyxoma peritonei. The mucin was identified and characterized in the present study. Approximately 6 L of crude mucus in the sol (highly viscous) and gel (semisolid) phases was obtained from the patient's peritoneal cavity. The sol material was briefly homogenized followed by slow stirring at dilutions of up to 1:10 with 6 mol/L guanidinium chloride and proteolytic inhibitors for periods of up to 48 h. Preparative and analytical gel filtration on Sepharose 2B showed some PAS-positive material eluting in the void volume accompanied by equal or larger amounts of protein in the void and included volumes of the columns. Sodium dodecylsulfate-polyacrylamide gel electrophoresis of purified mucin on a 4-20% gradient gel showed PAS-positive material on the top of the running gel and a distinct smaller-sized species of mucin of higher electrophoretic mobility with background material in between the large and small mucin. Western blot (confirmed by immunohistochemical analysis) after agarose gel electrophoresis showed the presence of MUC2, MUC5AC and MUC5B in the mucus. There was no MUC1, MUC1core or MUC6 in the tissue. Histopathological examination confirmed a mucinous appendicular adenocarcinoma. Histology showed the mucin to be predominantly of the sulfated and non-sulfated acidic type. Serine, threonine and proline comprised 21.6% of the total amino acid composition of the sample. The viscous nature of the material is due to the presence of three gel-forming mucins and possibly to its high content of protein.

Background: The female reproductive tract is amongst the main routes for Human Immunodeficiency Virus (HIV) transmission. Cervical mucus however is known to protect the female reproductive tract from bacterial invasion and fluid loss and regulates and facilitates sperm transport to the upper reproductive tract. The purpose of this study was to purify and characterize pregnancy plug mucins and determine their anti-HIV-1 activity in an HIV inhibition assay.

Human breast milk is known to contain numerous biologically active components which protect breast fed infants against microbes, viruses, and toxins. The purpose of this study was to purify and characterize the breast milk mucin and determine its anti-poxvirus activity. In this study human milk mucin, free of contaminant protein and of sufficient quantity for further analysis, was isolated and purified by Sepharose CL-4B gel filtration and cesiumchloride density-gradient centrifugation. Based on the criteria of size and appearance of the bands and their electrophoretic mobility on sodium dodecyl sulfate polyacrylamide-gel electrophoresis, Western blotting together with the amino acid analysis, it is very likely that the human breast milk mucin is MUC1. It was shown that this breast milk mucin inhibits poxvirus activity by 100% using an inhibition assay with a viral concentration of 2.4 million plaque-forming units/ml. As the milk mucin seems to aggregate poxviruses prior to their entry into host cells, it is possible that this mucin may also inhibit other enveloped viruses such as HIV from entry into host cells.

BackgroundWe have previously shown that MUC5B and MUC7 mucins from saliva of HIV negative individuals inhibit HIV-1 activity by 100% in an in vitro assay. The purpose of this subsequent study was to investigate whether MUC5B and MUC7 from saliva of HIV patients or with full blown AIDS had a similar inhibitory activity against the virus.MethodsSalivary MUC5B and MUC7 from HIV patients with different CD4 counts (< 200, 200-400 and > 400) were incubated with HIV-1 prior to infection of the human T lymphoblastoid cell line (CEM SS cells). Cells were then cultured and viral replication was measured by a qualitative p24 antigen assay. The size, charge and immunoreactivity of mucins from HIV negative and positive individuals was also analysed by SDS-PAGE, Western blot and ELISA respectively.ResultsIt was shown that irrespective of their CD4 counts both MUC5B and MUC7 from HIV patients, unlike the MUC5B and MUC7 from HIV negative individuals, did not inhibit HIV-1 activity. Size, charge and immunoreactivity differences between the mucins from HIV negative and positive individuals and among the mucins from HIV patients of different CD4 count was observed by SDS-PAGE, Western blot and ELISA.ConclusionsPurified salivary mucins from HIV positive patients do not inhibit the AIDS virus in an in vitro assay. Although the reason for the inability of mucins from infected individuals to inhibit the virus is not known, it is likely that there is an alteration of the glycosylation pattern, and therefore of charge of mucin, in HIV positive patients. The ability to inhibit the virus by aggregation by sugar chains is thus diminished.

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The metabolism of lidocaine to monoethylglycinexylidide has been found useful as an indicator of liver function in association with liver transplantation. It has been postulated that this is due to the common effect of hypoxic damage on liver function and lidocaine metabolism. The effects of hypoxia on the elimination of lidocaine and the formation of monoethylglycinexylidide and on indexes of liver function were investigated with the isolated perfused pig liver preparation. This study was performed at similar hepatic effluent lidocaine concentrations of approximately 5 micrograms.ml-1 in normoxic (n = 7) and hypoxic (n = 8) livers of similar mass harvested from male Landrace x Large White pigs and perfused at standard unit hepatic flow rates. Whole blood lidocaine extraction ratio was 0.63 +/- 0.02 in normoxic livers (30% O2 at oxygenator inflow). It was significantly less (0.23 +/- 0.03) in livers subjected to hypoxia (2% O2 at oxygenator inflow), as were hepatic clearance (57.1 +/- 2.1 vs. 20.3 +/- 3.1 ml.min-1.100 gm-1), intrinsic clearance (1,706 +/- 182 vs. 284 +/- 53 ml.min-1.100 gm-1) and monoethylglycinexylidide formation as indicated by monoethylglycinexylidide/lidocaine ratios in the hepatic venous effluent (0.379 +/- 0.061 vs. 0.073 +/- 0.014) (p < 0.01). Hepatic oxygen consumption, adenine nucleotide status and bile flow were significantly impaired by hypoxia. Whereas perfusate potassium concentration increased early, AST levels showed delayed increases and ALT levels showed no changes. These changes correlated strongly with hepatic lidocaine elimination (p < 0.01). We conclude that lidocaine metabolism may be an early indicator of severe hepatic hypoxia.