HLA-I and HLA-II Peptidomes of SARS-CoV-2: A Review.

The adaptive (T-cell-mediated) immune response is a key player in determining the clinical outcome, in addition to neutralizing antibodies, after SARS-CoV-2 infection, as well as supporting the efficacy of vaccines. T cells recognize viral-derived peptides bound to major histocompatibility complexes (MHCs) so that they initiate cell-mediated immunity against SARS-CoV-2 infection or can support developing a high-affinity antibody response. SARS-CoV-2-derived peptides bound to MHCs are characterized via bioinformatics or mass spectrometry on the whole proteome scale, named immunopeptidomics. They can identify potential vaccine targets or therapeutic approaches for SARS-CoV-2 or else may reveal the heterogeneity of clinical outcomes. SARS-CoV-2 epitopes that are naturally processed and presented on the human leukocyte antigen class I (HLA-I) and class II (HLA-II) were identified for immunopeptidomics. Most of the identified SARS-CoV-2 epitopes were canonical and out-of-frame peptides derived from spike and nucleocapsid proteins, followed by membrane proteins, whereby many of which are not caught by existing vaccines and could elicit effective responses of T cells in vivo. This review addresses the detection of SARS-CoV-2 viral epitopes on HLA-I and HLA-II using bioinformatics prediction and mass spectrometry (HLA peptidomics). Profiling the HLA-I and HLA-II peptidomes of SARS-CoV-2 is also detailed.

Volatile Compounds, Fatty Acids Constituents, and Antimicrobial Activity of Cultured Spirulina (Arthrospira fusiformis) Isolated from Lake Mariout in Egypt.

In this study, Arthrospira fusiformis previously isolated from Lake Mariout (Alexandria, Egypt) was cultivated in the laboratory using a medium for pharmaceutical grade Arthrospira, named as Amara and Steinbüchel medium. Hot water extract of the Egyptian Spirulina was prepared by autoclaving dried biomass in distilled water at 121°C for 15 min. This algal water extract was analyzed by GC-MS to evaluate its volatile compounds and fatty acids composition. The antimicrobial activity of phycobiliprotein extract from Arthrospira fusiformis using phosphate buffer was evaluated against thirteen microbial strains (two Gram-positive bacteria, eight Gram-negative bacteria, one yeast, and two filamentous fungi). The major components of fatty acids in the hot extract of Egyptian A. fusiformis were hexadecanoic acid (palmitic acid, 55.19%) and octadecanoic acid (stearic acid, 27.14%). The main constituents of its volatile compounds were acetic acid (43.33%) and oxalic acid (47.98%). The most potent antimicrobial effect of phycobiliprotein extract was obtained against two Gram-negative bacteria Salmonella typhi and Proteus vulgaris, filamentous fungus Aspergillus niger, and the pathogenic yeast Candida albicans (all of which showed MIC values of 58.1 µg/ml). Escherichia coli and Salmonella typhimurium come second in their susceptibility to the phycobiliprotein extract from Arthrospira fusiformis and Serratia marcescens and Aspergillus flavus are the least in susceptibility, with MIC values of 116.2 and 232.5 µg/ml, respectively, while phycobiliprotein extract has no antibacterial effect on methicillin-resistant as well as susceptible Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Shigella sonnei. These findings confirmed the nutritional value of Egyptian A. fusiformis isolated from Lake Mariout and suggest the potential use of this strain as an ingredient in the cooking of some foods to increase the level of stearic acid and palmitic acid. Moreover, its effective antibacterial activities against some important and highly resistant to antibiotics bacterial pathogens in addition to its antifungal effects recommend the therapeutic use of its biomass.

Exploring the mechanisms by which camel lactoferrin can kill Salmonella enterica serovar typhimurium and Shigella sonnei.

There is a continuously increasing pressure associated with the appearance of Salmonella enterica Serovar typhimurium (S. typhimurium) and Shigella sonnei (S. sonnei) that have developed pathogenic multiple antibiotic resistance and the cost of cure and control of these enterobacteriaceae infections increases annually. The current report for first time demonstrated the distinguished antimicrobial action of camel lactoferrin (cLf) obtained from the milk of different clans of camel in Saudi Arabia against S. typhimurium and S. sonnei. These cLf subtypes showed comparable antimicrobial potential when tested against the two bacterial strains but were superior to either bovine (bLf) or human lactoferrin (hLf). The synergism between lactoferrins and antibiotics concerning their antibacterial efficacies against the two bacterial strains was evident. Exploring mechanisms by which camel lactoferrin can kill S. typhimurium and S. sonnei revealed that cLf affects bacterial protein profile. Besides, it interacts with bacterial lipopolysaccharides (LPS) and numerous membrane proteins of S. typhimurium and S. sonnei, with each bacterial strain possessing distinctive binding membrane proteins for lactoferrin. Furthermore, as evidenced by electron microscopy analysis, cLf induces extracellular and intracellular morphological changes in the test bacterial strains when used alone or in combination treatment with antibiotics. Lactoferrin and antibiotics combination strongly disrupts the integrity of the bacterial cells and their membranes. Therefore, cLf can kill S. typhimurium and S. sonnei by four different mechanisms, such as iron chelation, affecting some bacterial proteins, binding to bacterial LPS and membrane proteins, and impairing the integrity of the bacterial cells and their membranes.

Molecular underpinnings of corneal angiogenesis: advances over the past decade.

The cornea is maintained in an avascular state by maintaining an environment whereby anti-angiogenic factors take the upper hand over factors promoting angiogenesis. Many of the common pathologies affecting the cornea involve the disruption of such equilibrium and the shift towards new vessel formation, leading to corneal opacity and eventually-vision loss. Therefore it is of paramount importance that the molecular underpinnings of corneal neovascularization (CNV) be clearly understood, in order to develop better targeted treatments. This article is a review of the literature on the recent discoveries regarding pro-angiogenic factors of the cornea (such as vascular endothelial growth factors, fibroblast growth factor and matrix metalloproteinases) and anti-angiogenic factors of the cornea (such as endostatins and neostatins). Further, we review the molecular underpinnings of lymphangiogenesis, a process now known to be almost separate from (yet related to) hemangiogenesis.

Clinical correlates of common corneal neovascular diseases: a literature review.

A large subset of corneal pathologies involves the formation of new blood and lymph vessels (neovascularization), leading to compromised visual acuity. This article aims to review the clinical causes and presentations of corneal neovascularization (CNV) by examining the mechanisms behind common CNV-related corneal pathologies, with a particular focus on herpes simplex stromal keratitis, contact lenses-induced keratitis and CNV secondary to keratoplasty. Moreover, we reviewed CNV in the context of different types of corneal transplantation and keratoprosthesis, and summarized the most relevant treatments available so far.

Ovine anti-rabies antibody production and evaluation.

In view of the disadvantages of human and equine rabies immunoglobulin still there is urgent needs for safe and cost-control anti-rabies immunoglobulins especially for person who have been severely exposed (categories III) to the virus. Our attempt to produce a less immunogenic and cheaper anti-rabies immunoglobulin affordable for those people living in developing countries, has been harnessed the ovine as a bioreactor instead the horse. The animals have been intramuscular immunized, and the plasma processed with 5% caprylic acid to yield IgG with purity of 95%. Moreover, antibody apparently indicated that the titer and neutralizing indexes were harmonized, especially at higher antibody dilution. The results showed that three immunized sheep were produced about 7000 IU of purified anti-rabies antibody. Sheep's IgG has low immunogenic effect than human and horse antibodies when injected into the mouse. Pure concentrated ovine antibody may serve as a possible alternative to currently available anti-rabies human or equine immunoglobulin.