Antigenic Activity of Three Chimeric Synthetic Peptides of the Transmembrane (Gp41) and the Envelope (Gp120) Glycoproteins of HIV‐1 Virus

Immunoinformatics Design and Assessment of a Multiepitope Antigen (OvMCBL02) for Onchocerciasis Diagnosis and Monitoring

Onchocerciasis is a Neglected Tropical Disease that has a significant socioeconomic impact, especially in Sub-Saharan Africa. Numerous reports indicate that the Expanded Special Project for the Elimination of Neglected Tropical Diseases needs novel diagnostic tools before achieving its goal of successful elimination of onchocerciasis in Africa. The current diagnostic tests are either invasive, insensitive, or not applicable in the field and about 25% of persons infected cannot mount immune responses against the single antigen used in the only approved Ov-16 serological test. In the quest to identify novel biomarkers that can be used to certify that a patient is free from the disease, evaluate the progress of elimination programmes, and conduct post elimination surveillances, mass spectrometric analysis of Onchocerca volvulus crude extract revealed that 1392 proteins are expressed in the adult and microfilariae stages of the parasite. Computational analysis predicted six of the proteins as O. volvulus potential diagnostic targets. Linear B-epitopes were predicted from the six proteins and used to construct a multiepitope antigen (OvMCBL02). Serological analysis revealed that the OvMCBL02 test significantly differentiated between serum samples of onchocerciasis patients from the Kombone Health Area in the South West Region of Cameroon (n = 63) and control serum samples from Rwanda (n = 29) and Europe (n = 26) as well as between serum samples from the onchocerciasis hyperendemic region of Kombone Health Area (n = 63) and the hypoendemic region of Bandjoun Health District (n = 54). Interestingly, the test did not cross-react with serum samples from patients suffering from related nematode infections, thereby suggesting that further characterization of the OvMCBL02 multiepitope antigen will render it an additional member of the diagnostic toolbox for the elimination of onchocerciasis.

In Silico Design and Validation of OvMANE1, a Chimeric Antigen for Human Onchocerciasis Diagnosis

The public health goal of onchocerciasis in Africa has advanced from control to elimination. In this light, accurate diagnosis is necessary to determine treatment endpoints and confirm elimination, as well as to conduct surveillance for the identification of any possible recrudescence of the disease. Currently, the monitoring of onchocerciasis elimination relies on the Ov-16 test. However, this test is unable to discriminate between past and active infections. Furthermore, about 15-25% of infected persons are reported to be negative for the Ov-16 test, giving a misleading sense of security to false-negative individuals who might continue to serve as reservoirs for infections. Therefore, we opted to design and validate a more sensitive and specific chimeric antigen (OvMANE1) for onchocerciasis diagnosis, using previously reported immunodominant peptides of O. volvulus, the parasite responsible for the disease. In silico analysis of OvMANE1 predicted it to be more antigenic than its individual peptides. We observed that OvMANE1 reacts specifically and differentially with sera from O. volvulus infected and non-infected individuals, as well as with sera from communities of different levels of endemicity. Moreover, we found that total IgG, unlike IgG4 subclass, positively responded to OvMANE1, strongly suggesting its complementarity to the Ov-16 diagnostic tool, which detects Ov-16 IgG4 antibodies. Overall, OvMANE1 exhibited the potential to be utilized in the development of specific diagnostic tools-based on both antibody capture and antigen capture reactions-which are indispensable to monitor the progress of onchocerciasis elimination programs.

Mechanistic Studies of Viral Entry: An Overview of Dendrimer-Based Microbicides As Entry Inhibitors Against Both HIV and HSV-2 Overlapped Infections

This review provides an overview of the development of different dendrimers, mainly polyanionic, against human immunodeficiency virus (HIV) and genital herpes (HSV-2) as topical microbicides targeting the viral entry process. Vaginal topical microbicides to prevent sexually transmitted infections such as HIV and HSV-2 are urgently needed. To inhibit HIV/HSV-2 entry processes, new preventive targets have been established to maximize the current therapies against wild-type and drug-resistant viruses. The entry of HIV/HSV-2 into target cells is a multistep process that triggers a cascade of molecular interactions between viral envelope proteins and cell surface receptors. Polyanionic dendrimers are highly branched nanocompounds with potent activity against HIV/HSV-2. Inhibitors of each entry step have been identified with regard to generations and surface groups, and possible roles for these agents in anti-HIV/HSV-2 therapies have also been discussed. Four potential binding sites for impeding HIV infection (HSPG, DC-SIGN, GSL, and CD4/gp120 inhibitors) and HSV-2 infection (HS, gB, gD, and gH/gL inhibitors) exist according to their mechanisms of action and structures. This review clarifies that inhibition of HIV/HSV-2 entry continues to be a promising target for drug development because nanotechnology can transform the field of HIV/HSV-2 prevention by improving the efficacy of the currently available antiviral treatments.

Antibodies to citrullinated human fibrinogen synthetic peptides in diagnosing rheumatoid arthritis

Since aggressive therapy given early in the rheumatoid arthritis (RA) disease course has the greatest therapeutic potential, early diagnostic tests with both high specificity and sensitivity are desirable. Rheumatoid sera were found to contain antibodies against citrullinated peptides, which are considered to be highly specific markers of RA. In the present work several analogues of the alpha- and beta-chains of fibrin peptides containing different degrees of citrullination have been synthesized and analyzed by ELISA using 111 sera from RA patients. In addition, we have also investigated the synergistic effects of different presentation formats of the synthetic constructs. We have designed chimeric and cyclic peptides that bear different peptide sequences within the same molecule. Our results indicate that the synthesis of peptides bearing fibrinogen and filaggrin domains could be a robust method for the design of useful diagnostic strategies in RA.

Antigenicity of chimeric and cyclic synthetic peptides based on nonstructural proteins of GBV-C/HGV

In this work, new putative epitopes located in nonstructural proteins of GBV-C/HGV were synthesized using solid-phase chemistry for their use in immunoassays. The antigens were obtained in linear, chimeric and cyclic forms with the main aim of improving the sensitivity of the enzyme immunoassays. Our results showed, on one hand, that the combination of different antigens seems to be necessary to ensure good sensitivity and more specificity and, on the other hand, that cyclic compounds show higher ability to recognize anti-GBV-C/HGV antibodies than its parent peptide. Furthermore, CD and FTIR have been used in conjunction to characterize the conformational changes therein with synthetic constructs that could explain their different antigenicity.