ABSTRACT
BACKGROUND: The HIV-AIDS pandemic is prevalent in sub-Saharan Africa. Breastfeeding is a risk factor, with transmission from mother to child being as high as 40%. OBJECTIVES: To determine the antiviral activity of crude breast milk and its purified mucins MUC1 and MUC4 against HIV-1 in patients who were HIV positive compared to those who were not. METHODS: Twenty-one human milk samples were taken from both groups. Breast milk mucins were purified by density-gradient ultracentrifugation in caesium chloride and analyzed by SDS-PAGE, Western blotting and amino acid content. The inhibition of the virus by crude milk and purified mucin was assayed by an in vitro HIV-1 p24 assay. RESULTS: SDS-PAGE for purified mucin showed several high-molecular-weight bands for the HIV-negative group and prominently stained single bands on the stacking gel with faintly periodic acid Schiff-positive glycoprotein bands observed in some cases in the running gel for the HIV-positive mucins. Western blot analysis identified the mucins in both groups to be MUC1 and MUC4. Both mucins showed more intensity on Western blotting for the HIV-positive group. There was no difference in the content of serine, threonine and proline of purified mucins for both groups. HIV-1 was not inhibited by crude breast milk from normal (13/14 samples) and infected individuals (19/19 samples). Fifteen of 20 and 16/18 samples of purified mucin from the uninfected and HIV-positive groups, respectively, inhibited the virus. CONCLUSIONS: Crude breast milk does not inhibit HIV-1, whilst purified mucins do in an in vitro assay.
Subject(s)
Anti-HIV Agents/pharmacology , HIV-1/drug effects , Milk, Human/chemistry , Mucin-1/pharmacology , Mucin-4/pharmacology , Anti-HIV Agents/isolation & purification , Cells, Cultured , Female , HIV Core Protein p24/metabolism , HIV-1/growth & development , HIV-1/metabolism , Humans , Leukocytes, Mononuclear/virology , Mucin-1/isolation & purification , Mucin-4/isolation & purification , Virus Replication/drug effectsABSTRACT
We previously reported the presence of MUC2, MUC5AC and, for the first time, MUC5B in a 58-year-old male with pseudomyxoma peritonei (PMP). This is a report on the biochemical and immunohistochemical characterization of mucin in a 50-year-old female with the same rare illness. A right oophorectomy and appendicectomy and a resection of the involved omentum were performed. Approximately a litre of crude material in the sol and gel phases was obtained from the patient during laparotomy. This was briefly homogenized in 6 M guanidinium hydrochloride and proteolytic inhibitors and purified by density gradient centrifugation in caesium chloride. At laparotomy it was noted that the patient had appendiceal and ovarian masses as well as extensive mucinous deposits in the omentum and peritoneum. A mucinous adenocarcinoma of the appendix and ovary was confirmed on histology. The cells expressed both sulphated and non-sulphated acidic mucins. The presence of MUC2, MUC5AC, MUC5B and a-1-acid glycoprotein was shown by Western blotting and MUC4 by immunohistochemical staining. MUC1 and MUC6 were not detectable in the tissue. The study confirms that MUC2, MUC5AC and MUC5B are produced in the mucus of patients with PMP. The expression of MUC4 in this disease has not been previously reported.
