Marine Lectins DlFBL and HddSBL Fused with Soluble Coxsackie-Adenovirus Receptor Facilitate Adenovirus Infection in Cancer Cells BUT Have Different Effects on Cell Survival

Invertebrate C1q Domain-Containing Proteins: Molecular Structure, Functional Properties and Biomedical Potential

C1q domain-containing proteins (C1qDC proteins) unexpectedly turned out to be widespread molecules among a variety of invertebrates, despite their lack of an integral complement system. Despite the wide distribution in the genomes of various invertebrates, data on the structure and properties of the isolated and characterized C1qDC proteins, which belong to the C1q/TNF superfamily, are sporadic, although they hold great practical potential for the creation of new biotechnologies. This review not only summarizes the current data on the properties of already-isolated or bioengineered C1qDC proteins but also projects further strategies for their study and biomedical application. It has been shown that further broad study of the carbohydrate specificity of the proteins can provide great opportunities, since for many of them only interactions with pathogen-associated molecular patterns (PAMPs) was evaluated and their antimicrobial, antiviral, and fungicidal activities were studied. However, data on the properties of C1qDC proteins, which researchers originally discovered as lectins and therefore studied their fine carbohydrate specificity and antitumor activity, intriguingly show the great potential of this family of proteins for the creation of targeted drug delivery systems, vaccines, and clinical assays for the differential diagnosis of cancer. The ability of invertebrate C1qDC proteins to recognize patterns of aberrant glycosylation of human cell surfaces and interact with mammalian immunoglobulins indicates the great biomedical potential of these molecules.

Changes of Host Immunity Mediated by IFN-γ+ CD8+ T Cells in Children with Adenovirus Pneumonia in Different Severity of Illness

The host immunity of patients with adenovirus pneumonia in different severity of illness is unclear. This study compared the routine laboratory tests and the host immunity of human adenovirus (HAdV) patients with different severity of illness. A co-cultured cell model in vitro was established to verify the T cell response in vitro. Among 140 patients with confirmed HAdV of varying severity, the number of lymphocytes in the severe patients was significantly reduced to 1.91 × 10⁹/L compared with the healthy control (3.92 × 10⁹/L) and the mild patients (4.27 × 10⁹/L). The levels of IL-6, IL-10, and IFN-γ in patients with adenovirus pneumonia were significantly elevated with the severity of the disease. Compared with the healthy control (20.82%) and the stable patients (33.96%), the percentage of CD8⁺ T cells that produced IFN-γ increased to 56.27% in the progressing patients. Adenovirus infection increased the percentage of CD8⁺ T and CD4⁺ T cells that produce IFN-γ in the co-culture system. The hyperfunction of IFN-γ⁺ CD8⁺ T cells might be related to the severity of adenovirus infection. The in vitro co-culture cell model could also provide a usable cellular model for subsequent experiments.

A Novel C1q Domain-Containing Protein Isolated from the Mollusk Modiolus kurilensis Recognizing Glycans Enriched with Acidic Galactans and Mannans

C1q domain-containing (C1qDC) proteins are a group of biopolymers involved in immune response as pattern recognition receptors (PRRs) in a lectin-like manner. A new protein MkC1qDC from the hemolymph plasma of Modiolus kurilensis bivalve mollusk widespread in the Northwest Pacific was purified. The isolation procedure included ammonium sulfate precipitation followed by affinity chromatography on pectin-Sepharose. The full-length MkC1qDC sequence was assembled using de novo mass-spectrometry peptide sequencing complemented with N-terminal Edman's degradation, and included 176 amino acid residues with molecular mass of 19 kDa displaying high homology to bivalve C1qDC proteins. MkC1qDC demonstrated antibacterial properties against Gram-negative and Gram-positive strains. MkC1qDC binds to a number of saccharides in Ca2+-dependent manner which characterized by structural meta-similarity in acidic group enrichment of galactose and mannose derivatives incorporated in diversified molecular species of glycans. Alginate, κ-carrageenan, fucoidan, and pectin were found to be highly effective inhibitors of MkC1qDC activity. Yeast mannan, lipopolysaccharide (LPS), peptidoglycan (PGN) and mucin showed an inhibitory effect at concentrations three orders of magnitude greater than for the most effective saccharides. MkC1qDC localized to the mussel hemal system and interstitial compartment. Intriguingly, MkC1qDC was found to suppress proliferation of human adenocarcinoma HeLa cells in a dose-dependent manner, indicating to the biomedical potential of MkC1qDC protein.

Retargeting adenoviruses for therapeutic applications and vaccines

Adenoviruses (Ads) are robust vectors for therapeutic applications and vaccines, but their use can be limited by differences in their in vitro and in vivo pharmacologies. This review emphasizes that there is not just one Ad, but a whole virome of diverse viruses that can be used as therapeutics. It discusses that true vector targeting involves not only retargeting viruses, but importantly also detargeting the viruses from off-target cells.

Antitumor Potential of Marine and Freshwater Lectins

Often, even the most effective antineoplastic drugs currently used in clinic do not efficiently allow complete healing due to the related toxicity. The reason for the toxicity lies in the lack of selectivity for cancer cells of the vast majority of anticancer agents. Thus, the need for new potent anticancer compounds characterized by a better toxicological profile is compelling. Lectins belong to a particular class of non-immunogenic glycoproteins and have the characteristics to selectively bind specific sugar sequences on the surface of cells. This property is exploited to exclusively bind cancer cells and exert antitumor activity through the induction of different forms of regulated cell death and the inhibition of cancer cell proliferation. Thanks to the extraordinary biodiversity, marine environments represent a unique source of active natural compounds with anticancer potential. Several marine and freshwater organisms, ranging from the simplest alga to the most complex vertebrate, are amazingly enriched in these proteins. Remarkably, all studies gathered in this review show the impressive anticancer effect of each studied marine lectin combined with irrelevant toxicity in vitro and in vivo and pave the way to design clinical trials to assess the real antineoplastic potential of these promising proteins. It provides a concise and precise description of the experimental results, their interpretation as well as the experimental conclusions that can be drawn.

Oncolytic Vaccinia Virus Expressing Aphrocallistes vastus Lectin as a Cancer Therapeutic Agent

Lectins display a variety of biological functions including insecticidal, antimicrobial, as well as antitumor activities. In this report, a gene encoding Aphrocallistes vastus lectin (AVL), a C-type lectin, was inserted into an oncolytic vaccinia virus vector (oncoVV) to form a recombinant virus oncoVV-AVL, which showed significant in vitro antiproliferative activity in a variety of cancer cell lines. Further investigations revealed that oncoVV-AVL replicated faster than oncoVV significantly in cancer cells. Intracellular signaling elements including NF-κB2, NIK, as well as ERK were determined to be altered by oncoVV-AVL. Virus replication upregulated by AVL was completely dependent on ERK activity. Furthermore, in vivo studies showed that oncoVV-AVL elicited significant antitumor effect in colorectal cancer and liver cancer mouse models. Our study might provide insights into a novel way of the utilization of marine lectin AVL in oncolytic viral therapies.

Tachypleus tridentatus Lectin Enhances Oncolytic Vaccinia Virus Replication to Suppress In Vivo Hepatocellular Carcinoma Growth

Lectins play diverse roles in physiological processes as biological recognition molecules. In this report, a gene encoding Tachypleus tridentatus Lectin (TTL) was inserted into an oncolytic vaccinia virus (oncoVV) vector to form oncoVV-TTL, which showed significant antitumor activity in a hepatocellular carcinoma mouse model. Furthermore, TTL enhanced oncoVV replication through suppressing antiviral factors expression such as interferon-inducible protein 16 (IFI16), mitochondrial antiviral signaling protein (MAVS) and interferon-beta (IFN-β). Further investigations revealed that oncoVV-TTL replication was highly dependent on ERK activity. This study might provide insights into a novel way of the utilization of TTL in oncolytic viral therapies.