Physicochemical Characteristics of Transferon™ Batches

Use of Extracellular Monomeric Ubiquitin as a Therapeutic Option for Major Depressive Disorder

Major depressive disorder (MDD) is a mood disorder that has become a global health emergency according to the World Health Organization (WHO). It affects 280 million people worldwide and is a leading cause of disability and financial loss. Patients with MDD present immunoendocrine alterations like cortisol resistance and inflammation, which are associated with alterations in neurotransmitter metabolism. There are currently numerous therapeutic options for patients with MDD; however, some studies suggest a high rate of therapeutic failure. There are multiple hypotheses explaining the pathophysiological mechanisms of MDD, in which several systems are involved, including the neuroendocrine and immune systems. In recent years, inflammation has become an important target for the development of new therapeutic options. Extracellular monomeric ubiquitin (emUb) is a molecule that has been shown to have immunomodulatory properties through several mechanisms including cholinergic modulation and the generation of regulatory T cells. In this perspective article, we highlight the influence of the inflammatory response in MDD. In addition, we review and discuss the evidence for the use of emUb contained in Transferon as a concomitant treatment with selective serotonin reuptake inhibitors (SSRIs).

Discovery of Transfer Factors in Plant-Derived Proteins and an In Vitro Assessment of Their Immunological Activities

Repeated exposure to pathogens leads to evolutionary selection of adaptive traits. Many species transfer immunological memory to their offspring to counteract future immune challenges. Transfer factors such as those found in the colostrum are among the many mechanisms where transfer of immunologic memory from one generation to the next can be achieved for an enhanced immune response. Here, a library of 100 plants with high protein contents was screened to find plant-based proteins that behave like a transfer factor moiety to boost human immunity. Aqueous extracts from candidate plants were tested in a human peripheral blood mononuclear cell (PBMC) cytotoxicity assay using human cancerous lymphoblast cells-with K562 cells as a target and natural killer cells as an effector. Plant extracts that caused PBMCs to exhibit enhanced killing beyond the capability of the colostrum-based transfer factor were considered hits. Primary screening yielded an 11% hit rate. The protein contents of these hits were tested via a Bradford assay and Coomassie-stained SDS-PAGE, where three extracts were confirmed to have high protein contents. Plants with high protein contents underwent C18 column fractionation using methanol gradients followed by membrane ultrafiltration to isolate protein fractions with molecular weights of <3 kDa, 3-30 kDa, and >30 kDa. It was found that the 3-30 kDa and >30 kDa fractions had high activity in the PBMC cytotoxicity assay. The 3-30 kDa ultrafiltrates from the top two hits, seeds from Raphanus sativus and Brassica juncea, were then selected for protein identification by mass spectrometry. The majority of the proteins in the fractions were found to be seed storage proteins, with a low abundance of proteins involved in plant defense and stress response. These findings suggest that Raphanus sativus or Brassica juncea extracts could be considered for further characterization and immune functional exploration with a possibility of supplemental use to bolster recipients' immune response.

Sequencing Analysis and Identification of the Primary Peptide Component of the Dialyzable Leukocyte Extract "Transferon Oral": The Starting Point to Understand Its Mechanism of Action

"Transferon Oral" is a peptide-derived product with immunomodulatory properties obtained from the lysis and dialysis of human buffy coat. Its active pharmaceutical ingredient, generically known as Dialyzable Leucocyte Extract, is a mixture of peptide populations with reproducible proportions among batches. "Transferon Oral" modulates IFN-γ, TNF-α, and IL-6 and increases the survival rate in a herpes infection murine model when oropharyngeally (ORO) administered, which correlate with clinical observations where "Transferon Oral" is used as a therapeutic auxiliary in inflammatory diseases. Notwithstanding, how a peptide-derived product elicits systemic modulation of cytokines when ORO administered remains unclear. To shed light on the pharmacology of "Transferon Oral" its peptide components must be known. Ten "Transferon Oral" batches were sequenced by mass spectrometry and the intact peptides were identified. The most abundant peptides were the monomeric human Ubiquitin (Ub), a globular low-molecular mass protein, and an Ub variant which lacks the two-terminal Gly (Ub-GG). Recombinant Ub prevented murine death when ORO administered in a herpes infection murine model. Besides, the percentage of survival increased in groups treated with Transferon Oral+Ub and decreased in groups treated with Ub-depleted "Transferon Oral" respect to the group treated with "Transferon Oral" only. Our findings indicate that the biological properties of "Transferon Oral" are partially associated to the Ub content. They suggest that Ub may activate its extracellular receptor (CXCR-4) in the stomach eliciting systemic immunomodulatory effects via vagus nerve. This is the first report that identifies an active component of "Transferon Oral" with the potential for the development of oral peptide immunomodulators.

Transfer Factor: Myths and Facts

Transfer factor (TF), also called "Lawrence transfer factor", or dialyzable leukocyte extract (DLE), has been used since the mid-twentieth century to transfer specific skin hypersensitivity through the injection of leukocytes from immunized donors to animals and humans. The main mechanism of action of TF has been suggested at the level of cell-mediated immunity, as it induces the production of migration inhibitory factor (MIF) and interferon gamma (IFN-γ). Otherwise, TF can inhibit nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB), and decrease tumoral necrosis factor α (TNF-α) and IL-4 levels. Given these biological effects, TF has been prescribed for a wide variety of conditions including infections, allergies, autoimmunity, and cancer, with inconsistent results. The exact nature of TF, however, remains unknown, so it has been impossible to accurately define its pharmacokinetics or dosage. This is further complicated because researchers have used TF in a variety of ways across the different studies: antigen-specific or non-antigen-specific, orally or subcutaneously administered, human and non-human origin. In this review we summarize the most important data about what TF is, its mechanism of action, how it is produced, its biological effects, and the available clinical trials using it, in order to establish its role and potential clinical applications in modern medicine.

Development and validation of a mass spectrometric method to determine the identity of rituximab based on its microheterogeneity profile

Analytical methods have been considered the "eyes" for development, characterization and batch releasing of biotherapeutics over the past 40 years. One of the most powerful analytical platform for biotherapeutic analysis is mass spectrometry coupled to liquid chromatography (LC-MS). Due to its wide flexibility and instrumental configurations, LC-MS can determine different physicochemical attributes of proteins, e.g. molecular mass, primary sequence, and posttranslational modifications. Intact molecular mass analysis of therapeutic proteins is essential to confirm their identity. Analytical methods must be validated to support drug quality information during its approval process. Although there are international guidelines that provide general information on validation of analytical methods, practical examples about the design, selection of validation attributes and acceptance criteria of identity LC-MS methods are scarce. Here, according to the recommendations of Q2R1 ICH guideline, we showcase the validation of an LC-MS-TOF method to identity rituximab by determining its intact and deglycosylated molecular mass profiles. The proposed method specifically identified the m/z profile and deconvoluted mass profile of rituximab from deglycosylated rituximab and from excipient blank (specificity) with a maximum error of 76.63 ppm (accuracy) and a maximum Relative Standard Deviation (RSD) of 0.00315% (precision). Besides, the system suitability test, which was based on the expected mass value of the mass calibrator, confirmed the reliability of the analytical results. In summary, validation showed that the proposed method is suitable for identifying rituximab based on its glycosylated (intact) and deglycosylated mass profile.

Dialyzable Leukocyte Extract (Transferon™) Administration in Sepsis: Experience from a Single Referral Pediatric Intensive Care Unit

Immunomodulatory agents have been proposed as therapeutic candidates to improve outcomes in sepsis. Transferon™, a dialyzable leukocyte extract (DLE), has been supported in Mexico as an immunomodulatory adjuvant in anti-infectious therapy. Here we present a retrospective study describing the experience of a referral pediatric intensive care unit (PICU) with Transferon™ in sepsis. We studied clinical and laboratory data from 123 patients with sepsis (15 in the DLE group and 108 in the control group) that were admitted to PICU during the period between January 2010 and December 2016. Transferon™ DLE use was associated with lower C reactive protein (CRP), increase in total lymphocyte counts (TLC), and decrease in total neutrophil count (TNC) 72 hours after Transferon™ DLE administration. The control group did not present any significant difference in CRP values and had lower TLC after 72 hours of admission. There was no difference in PICU length of stay between control and Transferon™ DLE group. Transferon™ DLE administration was associated with a higher survival rate at the end of PICU stay. This study shows a possible immunomodulatory effect of Transferon™ on pediatric sepsis patients.

Development of Functional Antibodies Directed to Human Dialyzable Leukocyte Extract (Transferon®)

Transferon® is an immunomodulator made of a complex mixture of peptides from human dialyzable leucocyte extracts (hDLEs). Development of surrogate antibodies directed to hDLE is an indispensable tool for studies during process control and preclinical trials. These antibodies are fundamental for different analytical approaches, such as identity test and drug quantitation, as well as to characterize its pharmacokinetic and mechanisms of action. A previous murine study showed the inability of the peptides of Transferon® to induce antibody production by themselves; therefore, in this work, two approaches were tested to increase its immunogenicity: chemical conjugation of the peptides of Transferon® to carrier proteins and the use of a rabbit model. Bioconjugates were generated with Keyhole Limpet Hemocyanin (KLH) or Bovine Serum Albumin (BSA) through maleimide-activated carrier proteins. BALB/c mice and New Zealand rabbits were immunized with Transferon® conjugated to KLH or nonconjugated Transferon®. Animals that were immunized with conjugated Transferon® showed significant production of antibodies as evinced by the recognition of Transferon®-BSA conjugate in ELISA assays. Moreover, rabbits showed higher antibody titers when compared with mice. Neither mouse nor rabbits developed antibodies when immunized with nonconjugated Transferon®. Interestingly, rabbit antibodies were able to partially block IL-2 production in Jurkat cells after costimulation with Transferon®. In conclusion, it is feasible to elicit specific and functional antibodies anti-hDLE with different potential uses during the life cycle of the product.

Transferon™, a peptide mixture with immunomodulatory properties is not immunogenic when administered with various adjuvants

Transferon, a human dialyzable leukocyte extract (hDLE), is a biotherapeutic that comprises a complex mixture of low-molecular-weight peptides (< 10 kDa) and is used to treat diseases with an inflammatory component. Some biotherapeutics, including those composed of peptides, can induce anti-drug antibodies (ADA) that block or diminish their therapeutic effect. Nevertheless, few studies have evaluated peptide-derived drug immunogenicity. In this study, the immunogenicity of Transferon was examined in a murine model during an immunization scheme using the following adjuvants: Al(OH)₃, incomplete Freund's adjuvant (IFA), or Titermax Gold. The inoculation scheme entailed three routes of administration (intraperitoneal, Day 1; subcutaneous, Day 7; and intramuscular, Day 14) using 200 μg Transferon/inoculation. Serum samples were collected on Day 21. Total IgG levels were quantitated by affinity chromatography, and specific antibodies against components of Transferon were analyzed by dot-blot and ELISA. Ovalbumin (OVA, 44 kDa) and peptides from hydrolyzed collagen (PFHC, < 17 kDa) were used as positive and negative controls, respectively, in the same inoculation scheme and analyses for Transferon. OVA, PFHC, and Transferon increased total IgG concentrations in mice. However, only IgG antibodies against OVA were detected. Based on the results, it is concluded that Transferon does not induce generation of specific antibodies against its components in this model, regardless of adjuvant and route of administration. These results support the safety of Transferon by confirming its inability to induce ADA in this animal model.