Mucus and Mucins: do they have a role in the inhibition of the human immunodeficiency virus?

Abstract

BackgroundMucins are large O-linked glycosylated proteins which give mucus their gel-forming properties. There are indications that mucus and mucins in saliva, breast milk and in the cervical plug inhibit the human immunodeficiency virus (HIV-1) in an in vitro assay.Main body of abstractCrude mucus gels form continuous layers on the epithelial surfaces of the major internal tracts of the body and protect these epithelial surfaces against aggressive luminal factors such as hydrochloric acid and pepsin proteolysis in the stomach lumen, the movement of hard faecal pellets in the colon at high pressure, the effects of shear against the vaginal epithelium during intercourse and the presence of foreign substances in the respiratory airways. Tumour-associated epitopes on mucins make them suitable as immune-targets on malignant epithelial cells, rendering mucins important as diagnostic and prognostic markers for various diseases, even influencing the design of mucin-based vaccines.Sub-Saharan Africa has the highest prevalence of HIV-AIDS in the world. The main points of viral transmission are via the vaginal epithelium during sexual intercourse and mother-to-child transmission during breast-feeding. There have been many studies showing that several body fluids have components that prevent the transmission of HIV-1 from infected to non-infected persons through various forms of contact.Crude saliva and its purified mucins, MUC5B and MUC7, and the purified mucins from breast milk, MUC1 and MUC4 and pregnancy plug cervical mucus (MUC2, MUC5AC, MUC5B and MUC6), inhibit HIV-1 in an in vitro assay. There are conflicting reports of whether crude breast-milk inhibits HIV-1 in an in vitro assay. However studies with a humanised BLT mouse show that breast-milk does inhibit HIV and that breast-feeding is still advisable even amongst HIV-positive women in under-resourced areas, preferably in conjunction with anti-retroviral treatment.ConclusionThese findings raise questions of how such a naturally occurring biological substance such as mucus, with remarkable protective properties of epithelial surfaces against aggressive luminal factors in delicate locations, could be used as a tool in the fight against HIV-AIDS, which has reached epidemic proportions in sub-Saharan Africa.

Morphogenetic (Mucin Expression) as Well as Potential Anti-Corona Viral Activity of the Marine Secondary Metabolite Polyphosphate on A549 Cells

“…An antiviral effect of polyP has also been observed against the human immunodeficiency virus 1 (HIV-1 [ 76 ]). In addition, an inhibitory effect of mucins has been proposed for this virus [ 77 ]. It is likely that the dual activities of polyP against viral infections on the level of virus host cell interaction and innate immunity is not limited to SARS-CoV-2 but also plays a general role in the natural antiviral defense of cells/tissues.…”

The Antiviral Properties of Human Milk: A Multitude of Defence Tools from Mother Nature

“…Among the various mucin subtypes, Type 1 and Type 4 (MUC1 and MUC4) are found in breast milk. These subtypes have demonstrated antiviral activity against HIV, influenza virus and other viruses in vitro [ 41 ]. Like the heparan-sulfate molecules described above, their action is based on many sialylated residues that are very similar to those of the cell membrane and that bind to the virus and trap it, preventing it from reaching the cell surface.…”

In the Age of Viral Pandemic, Can Ingredients Inspired by Human Milk and Infant Nutrition Be Repurposed to Support the Immune System?

“…Whereas an older report demonstrated no correlation with rotavirus infection [ 131 ], new in vitro evidence suggests mucin proteins provide protection against viral diseases, including HIV and rotavirus [ 135 , 136 ]. The mechanisms by which inhibition is provided is likely through glycosylation of sialic acid residues [ 137 , 138 ], which has been demonstrated both in vitro and in vivo to inhibit rotavirus binding [ 139 ].…”