Preliminary data on Pemphigus vulgaris treatment by a proteomics-defined peptide: a case report

State of the Art in the Diagnosis and Assessment of Oral Malignant and Potentially Malignant Disorders: Present Insights and Future Outlook-An Overview

Oral Potentially Malignant Disorder (OPMD) is a significant concern for clinicians due to the risk of malignant transformation. Oral Squamous Cell Carcinoma (OSCC) is a common type of cancer with a low survival rate, causing over 200,000 new cases globally each year. Despite advancements in diagnosis and treatment, the five-year survival rate for OSCC patients remains under 50%. Early diagnosis can greatly improve the chances of survival. Therefore, understanding the development and transformation of OSCC and developing new diagnostic methods is crucial. The field of oral medicine has been advanced by technological and molecular innovations, leading to the integration of new medical technologies into dental practice. This study aims to outline the potential role of non-invasive imaging techniques and molecular signatures for the early detection of Oral Malignant and Potentially Malignant Disorders.

YoutubeTM Content Analysis as a Means of Information in Oral Medicine: A Systematic Review of the Literature

Background: Oral medicine represents a complex branch of dentistry, involved in diagnosing and managing a wide range of disorders. Youtube^TM offers a huge source of information for users and patients affected by oral diseases. This systematic review aims to evaluate the reliability of Youtube^TM oral medicine-related content as a valid dissemination aid. Methods: The MeSH terms “Youtube^TM” and “oral” have been searched by three search engines (PubMed, ISI Web of Science, and the Cochrane Library), and a systematic review has been performed; the PRISMA checklist has been followed in the search operations. Results: Initial results were 210. Ten studies definitely met our selection criteria. Conclusions: Youtube^TM represents a dynamic device capable of easy and rapid dissemination of medical-scientific content. Nevertheless, the most of information collected in the literature shows a lack of adequate knowledge and the need to utilize a peer-reviewing tool in order to avoid the spreading of misleading and dangerous content.

The role of proteomics in defining autoimmunity

INTRODUCTION

Proteomics, i.e. the study of the set of proteins produced in a cell, tissue, organism, or biological entity, has made possible analyses and contextual comparisons of proteomes/proteins and biological functions among the most disparate entities, from viruses to the human being. In this way, proteomic scrutiny of tumor-associated proteins, autoantigens, and pathogen antigens offers the tools for fighting cancer, autoimmunity, and infections.

AREAS COVERED

Comparative proteomics and immunoproteomics, the new scientific disciplines generated by proteomics, are the main themes of the present review that describes how comparative analyses of pathogen and human proteomes led to re-modulate the molecular mimicry concept of the pre-proteomic era. I.e. before proteomics, molecular mimicry - the sharing of peptide sequences between two biological entities - was considered as intrinsically endowed with immunologic properties and was related to cross-reactivity. Proteomics allowed to redefine such an assumption using physicochemical parameters according to which frequency and hydrophobicity preferentially confer an immunologic potential to shared peptide sequences.

EXPERT OPINION

Proteomics is outlining peptide platforms to be used for the diagnostics and management of human diseases. A Molecular Medicine targeted to obtain healing without paying the price for adverse events is on the horizon. The next step is to take up the challenge and operate the paradigm shift that the current proteomic era requires.

Lack of Molecular Mimicry between Nonhuman Primates and Infectious Pathogens: The Possible Genetic Bases

Recently, it was found that proteomes from poliovirus, measles virus, dengue virus, and severe acute respiratory syndrome-related Coronavirus 2 (SARS-CoV-2) have high molecular mimicry at the heptapeptide level with the human proteome, while heptapeptide commonality is minimal or absent with proteomes from nonhuman primates, that is, gorilla, chimpanzee, and rhesus macaque. To acquire more data on the issue, analyses here have been expanded to Ebola virus, Francisella tularensis , human immunodeficiency virus-1 (HIV-1), Toxoplasma gondii , Variola virus, and Yersinia pestis . Results confirm that heptapeptide overlap is high between pathogens and Homo sapiens , but not between pathogens and primates. Data are discussed in light of the possible genetic bases that differently model primate phenomes, thus possibly underlying the zero/low level of molecular mimicry between infectious agents and primates. Notably, this study might help address preclinical vaccine tests that currently utilize primates as animal models, since autoimmune cross-reactions and the consequent adverse events cannot occur in absentia of shared sequences.

Association between human leukocyte antigen-DRB1 and human leukocyte antigen-DQB1 alleles and pemphigus vulgaris in Indian patients: A case-control study

BACKGROUND

HLA-DRB1*04, -DRB1*08, -DRB1*14, -DQB1*03 and -DQB1*05 are reported to have significant association with pemphigus vulgaris; however, this is partially dependent on ethnicity. This study was done to determine the HLA-DR and -DQ types prevalent in Indian patients with pemphigus vulgaris.

METHODS

A prospective case-control study was done for a period of 9 months in Christian Medical College Vellore, India. HLA typing was done by PCR-SSOP method in 50 cases and 50 healthy controls. Allele frequencies in cases and controls were compared and odds ratios with 95% confidence interval were calculated.

RESULTS

The mean age of the patients (29 females, 21 males) and that of controls (36 males, 14 females) were 41.3 ± 13.65 and 35.42 ± 11.09 years, respectively. HLA-DRB1*14 was present in 47 patients and 18 controls (OR, 27.85; 95% CI, 7.57-102.42) and HLA-DQB1*05 was seen in 47 patients and 24 controls (OR, 16.97; 95% CI, 4.66-61.80). The haplotype DRB1*14, DQB1*05 was present in 44 patients and 14 controls (OR, 18.86; 95% CI, 6.58-54.05). DRB1*15 was present in 7 cases and 16 controls (OR, 0.35; 95% CI, 0.13-0.94) and DQB1*06 was present in 8 cases and 19 controls (OR, 0.31; 95% CI, 0.12-0.80). HLA-DQB1*03 was associated with significantly higher pemphigus disease area index scores.

LIMITATIONS

The main limitations were that the numbers studied were small as the study was conducted at a single center, and the haplotype analysis was limited only to the proband. PDAI scores could have been influenced by prior treatment.

CONCLUSION

There was a significant association between HLA-DRB1*14 and HLA-DQB1*05 and pemphigus vulgaris in our patients. A negative association was seen with DRB1*15 and DQB1*06.

From HSV infection to erythema multiforme through autoimmune crossreactivity

Scientific and clinical data indicate that human herpes simplex virus 1 (HSV1) and, at a lesser extent, human herpes simplex virus 2 (HSV2) are factor(s) implicated in the development of erythema multiforme (EM). With a focus on oral EM, the present structured review of proteomic and epitope databases searched for the molecular basis that might link HSV1 and HSV2 infections to EM. It was found that a high number of peptides are shared between the two HSVs and human proteins related to the oral mucosa. Moreover, a great number of the shared peptides are also present in epitopes that have been experimentally validated as immunopositive in the human host. The results suggest the involvement of HSV infections in the induction of oral EM via a mechanism of autoimmune cross-reactivity and, in particular, highlight a potential major role for 180kDa bullous pemphigoid antigen and HSV1 infection in the genesis of crossreactions potentially conducive to EM.

A potential peptide pathway from viruses to oral lichen planus

Oral lichen planus is an idiopathic inflammatory disease of oral mucous membranes, characterized by an autoimmune epidermis attack by T cells. It remains unknown, however, how such aggressive T cells are activated in vivo to cause epidermal damage. This study analyzes the relationship at the peptide level between viruses and oral lichen planus disease. Four potentially immunogenic peptides (SSSSSSS, QEQLEKA, LLLLLLA, and MLSGNAG) are found to be shared between HCV, EBV, HHV-7, HSV-1, and CMV and three human proteins (namely pinin, desmoglein-3, and plectin). The described peptide sharing might be of help in deciphering the still unexplained immunopathogenic pathway that leads to oral lichen planus.

EBV-Associated Cancer and Autoimmunity: Searching for Therapies

Epstein-Barr virus (EBV) infects B-, T-, and NK cells and has been associated not only with a wide range of lymphoid malignancies but also with autoimmune diseases such as lupus erythematosus, rheumatoid arthritis and, in particular, multiple sclerosis. Hence, effective immunotherapeutic approaches to eradicate EBV infection might overthrow cancer and autoimmunity incidence. However, currently no effective anti-EBV immunotherapy is available. Here we use the concept that protein immunogenicity is allocated in rare peptide sequences and search the Epstein-Barr nuclear antigen 1 (EBNA1) sequence for peptides unique to the viral protein and absent in the human host. We report on a set of unique EBV EBNA1 peptides that might be used in designing peptide-based therapies able to specifically hitting the virus or neutralizing pathogenic autoantibodies.

Current methods of treatment of true acantholytic pemphigus

Major stages of the pathogenesis of true acantholytic pemphigus are interpreted in terms of autoimmune pathology; therefore, treatment of this group of diseases remains pathogenetic and is aimed at suppressing the synthesis of autoantibodies against keratinocyte proteins. Treatment with the use of systemic glucocorticosteroids is currently the main method of treatment for true acantholytic pemphigus. To reduce the course dose of glucocorticosteroids, decrease the risk of adverse effect development and achieve long-term remission, further studies of disease pathogenesis and development of new treatment methods for reducing the doses of glucocorticosteroids are of great importance.

Pemphigus: associations and management guidelines: facts and controversies

Pemphigus, a prototypical organ-specific human autoimmune disease, may be associated with other immunity-related disorders, viral infections, and different types of tumors. Coexistence with immune diseases is fairly frequent and, for some of them (eg, myasthenia gravis, Basedow's disease, rheumatoid arthritis, or lupus erythematosus), common pathogenic mechanisms can be considered. The association with viral infections (mainly herpesvirus infections) raises the question of whether the virus triggers the outbreak of the disease or simply complicates its clinical course. Neoplastic proliferations coexisting with pemphigus have a different histogenesis and the pathogenic link may vary according to the associated tumor (thymoma, lymphoma, carcinoma, or sarcoma). A subset of pemphigus-neoplasia association is represented by Anhalt's paraneoplastic pemphigus, with peculiar clinical, histologic, and immunologic features characterizing it. Coexistence of pemphigus with Kaposi's sarcoma, albeit not frequent, offers an intriguing speculative interest. The cornerstone of management in pemphigus is the combination of systemic corticosteroids and immunosuppressants. The conventional treatment used in most cases is based on oral administration of deflazacort and azathioprine. In selected cases, mycophenolate mofetil is preferred to azathioprine. Severe forms of pemphigus require intravenous pulse therapy with dexamethasone (or methylprednisolone) and cyclophosphamide. In the recent years, the use of high-dose intravenous immunoglobulin therapy has gained several consents. Rituximab, a monoclonal anti-CD 20 antibody, which affects both the humoral and cell-mediated responses, has proved to give a good clinical response, often paralleled by decrease of pathogenic autoantibodies. The combination with intravenous immunoglobulin offers the double advantage of better clinical results and a reduced incidence of infection. Interventional treatments, such as plasmapheresis and extracorporeal immunoadsorption, are aimed at patients with life-threatening forms of pemphigus and high levels of circulating autoantibodies, a circumstance where the medical therapy alone risks failing. Second-line treatments include gold salts (which we do not favor because of the acantholytic potential inherent in thiol structure) and the association of oral tetracyclines with nicotinamide, which is rather safe. Local treatments, supplementary to the systemic therapy, are aimed at preventing infections and stimulating reepithelialization of eroded areas. Innovative topical treatments are epidermal growth factor, nicotinamide gel, pimecrolimus, and a proteomics-derived desmoglein peptide. Pemphigus patients should be warned against over-indulging in unnecessary drug intake, prolonged exposure to ultraviolet rays, intense emotional stress, and too spiced or too hot foods. Cigarette smoking is not contraindicated in pemphigus patients because of the nicotine anti-acantholytic properties.

Homology, similarity, and identity in peptide epitope immunodefinition

The tendency to use the terms homology, similarity, and identity interchangeably persists in comparative biology. When translated to immunology, overlapping the concepts of homology, similarity, and identity complicates the exact definition of the self-nonself dichotomy and, in particular, affects immunopeptidomics, an emerging field aimed at cataloging and distinguishing immunoreactive peptide epitopes from silent nonreactive amino acid sequences. The definition of similar/dissimilar peptides in immunology is discussed with special attention to the analysis of immunological (dis)similarity between two or more protein sequences that equates to measuring sequence similarity with the use of a proper measurement unit such as a length determinant.

The self/nonself issue: A confrontation between proteomes

Defining self and nonself is the most compelling challenge in science today, at the basis of the numerous questions that remain unanswered in the immunology-pathology-therapy debate. The generation of the antibody repertoire, the complicated scenario offered by tolerance and autoimmunity, natural auto-antibodies and their relationship to autoimmune diseases, and positive and negative selection are only a few examples of the unresolved immunological questions. In this context, we proposed that sequence similarity to the host proteome modulates antigen peptide recognition and immunogenicity. Using the available proteome assemblies of viruses, bacteria and higher vertebrates, and applying the low-similarity criterion, we are systematically defining the proteomic similarity of B-cell epitopes already validated experimentally. Here, we report further data documenting that a low similarity to the host proteome is the common property that defines the immunological "nonself" nature of antigenic sequences in cancer, autoimmunity, infectious diseases and allergy.

Pemphigus: a treatment update

Pemphigus is an uncommon but potentially life-threatening chronic autoimmune bullous disorder. Antibodies are directed against antigens (desmoglein 1 and 3) in the desmosomes linking keratinocytes and against acetylcholine receptors. Conventional treatment with high-dose corticosteroids, sometimes with adjuvant immunosuppressive agents, may be associated with very serious adverse effects. There is an urgent need to establish the evidence for the safest and most effective form of treatment. A literature review has revealed 11 controlled (9 randomized) trials of treatment for pemphigus. The numbers of participants in the individual trials are small and the data cannot be pooled as they evaluate different forms of treatment. The results of these trials suggest that very high doses of corticosteroids, either as pulse therapy or in daily dosage, are not superior to moderate daily doses. Based on evidence from the available trials, addition of an immunosuppressive agent generally does not appear to offer substantial benefit in terms of clinical response. However, a recent study demonstrated a significant reduction in corticosteroid requirements among patients receiving immunosuppressive agents. Newer therapies, such as biologic agents (in particular rituximab), calcineurin inhibitors, or immunoadsorption appear promising but there are inadequate controlled trials to establish their role clearly. Initial open-label studies suggest that specific peptide immunotherapy may offer a safe and novel approach to the treatment of pemphigus in the future. At present, treatment of an individual patient with pemphigus requires clinical judgment and should not be based purely on guidelines or on the inadequate available evidence alone. There is an urgent need for large randomized, controlled, multicenter trials of treatment in patients with pemphigus.

Sub-epitopic dissection of HCV E1315-328HRMAWDMMMNWSPT sequence by similarity analysis

Our labs are focused on identifying amino acid sequences having the ability to react specifically with the functional binding site of a complementary antibody. Our epitopic definition is based on the analysis of the similarity level of antigenic amino acid sequences to the host proteome. Here, the similarity profile to the human proteome of an HCV E1 immunodominant epitope, i.e. the HCV E1(315-328)HRMAWDMMMNWSPT sequence, led to i) characterizing the immunoreactive HCV E1 315-328 region as a sequence endowed with a low level of similarity to human proteins; ii) defining 2 contiguous immunodominant linear determinants respectively located at the NH(2) and COOH terminus of the conserved viral antigenic sequence. This study supports the hypothesis that low sequence similarity to the host's proteome modulates the pool of epitopic amino acid sequences in a viral antigen, and appears of potential value in defining immunogenic viral peptide sequences to be used in immunotherapeutic approaches for HCV treatment.