What is transfer factor?

Ancient DNA and high-resolution chronometry reveal a long-term human role in the historical diversity and biogeography of the Bahamian hutia

Quaternary paleontological and archaeological evidence often is crucial for uncovering the historical mechanisms shaping modern diversity and distributions. We take an interdisciplinary approach using multiple lines of evidence to understand how past human activity has shaped long-term animal diversity in an island system. Islands afford unique opportunities for such studies given their robust fossil and archaeological records. Herein, we examine the only non-volant terrestrial mammal endemic to the Bahamian Archipelago, the hutia Geocapromys ingrahami. This capromyine rodent once inhabited many islands but is now restricted to several small cays. Radiocarbon dated fossils indicate that hutias were present on the Great Bahama Bank islands before humans arrived at AD ~800-1000; all dates from other islands post-date human arrival. Using ancient DNA from a subset of these fossils, along with modern representatives of Bahamian hutia and related taxa, we develop a fossil-calibrated phylogeny. We found little genetic divergence among individuals from within either the northern or southern Bahamas but discovered a relatively deep North-South divergence (~750 ka). This result, combined with radiocarbon dating and archaeological evidence, reveals a pre-human biogeographic divergence, and an unexpected human role in shaping Bahamian hutia diversity and biogeography across islands.

Physicochemical Characteristics of Transferon™ Batches

Transferon, a biotherapeutic agent that has been used for the past 2 decades for diseases with an inflammatory component, has been approved by regulatory authorities in Mexico (COFEPRIS) for the treatment of patients with herpes infection. The active pharmaceutical ingredient (API) of Transferon is based on polydispersion of peptides that have been extracted from lysed human leukocytes by a dialysis process and a subsequent ultrafiltration step to select molecules below 10 kDa. To physicochemically characterize the drug product, we developed chromatographic methods and an SDS-PAGE approach to analyze the composition and the overall variability of Transferon. Reversed-phase chromatographic profiles of peptide populations demonstrated batch-to-batch consistency from 10 representative batches that harbored 4 primary peaks with a relative standard deviation (RSD) of less than 7%. Aminogram profiles exhibited 17 proteinogenic amino acids and showed that glycine was the most abundant amino acid, with a relative content of approximately 18%. Further, based on their electrophoretic migration, the peptide populations exhibited a molecular mass of about 10 kDa. Finally, we determined the Transferon fingerprint using a mass spectrometry tool. Because each batch was produced from independent pooled buffy coat samples from healthy donors, supplied by a local blood bank, our results support the consistency of the production of Transferon and reveal its peptide identity with regard to its physicochemical attributes.

Activities and characteristics of transfer factors

This report summarizes three components of our transfer factor research program. Several clinical studies have used oral administration of transfer factor containing materials. Sceptics have rejected these findings by assuming that the acidic and enzymatic environment of the gastrointestinal tract would destroy the factors. To further examine this issue, we have conducted dose-response studies of the delayed-type hypersensitivity reaction in mice that were given transfer factor either by gavage or subcutaneously. There were no difference in the responses that were related to the route of administration. We conclude that oral route of administration is efficacious and should be used when possible. We have also studied the effects of transfer factors on immune responses by recipients. The details of this research are presented in the paper by Dr. Alvarez-Thull. Briefly, the study showed that recipients of a specific transfer factor responded to the antigen for which the factor was specific by secreting gamma-IFN, but no other cytokines. The structures of transfer factor molecules are unknown. We have developed a process for isolating transfer factors in pure form and we have obtained preliminary data concerning amino acid sequences. Our goal is to obtain the complete primary structure of several transfer factor molecules.

Purification of transfer factors

Transfer factor activities have been studied in both clinical and basic science settings for several decades. Until now, highly purified transfer factors that are suitable for molecular analysis have not been available. This has impeded progress towards understanding the molecular and cellular basis of the activities of these important inducers of cell-mediated immune responses. Murine transfer factors with specificities for chicken egg albumin or horse spleen ferritin were purified to virtual homogeneity using a combination of affinity chromatography and reversed-phase and polytypic high performance liquid chromatography (hplc). Transfer factors prepared by this methodology were recovered in high yield and in biologically-active, antigen-specific forms. The purified materials were further analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis, chromatographic methods and an in vivo assay for immunological activity. For the first time definitions for unit transfer factor activity and specific activity are introduced. The results of these experiments indicate that transfer factors are a family of highly polar, hydrophilic molecules of low molecular weight (approximately 5,000) which are produced in small quantities by lymphoid cells and which have potent biological activity. The availability of purified transfer factors should facilitate definitive studies into the nature and mechanisms of production and action of these molecules.

Transfer factor

The understanding of passive transfer of cell mediated-immune responses with transfer factor and other cell free materials has progressed to the point that investigators are seeking the chemical identity of the molecule(s) that are responsible for these effects and are working on their mechanisms of action. In addition, clinical trials are underway that should clarify the potential for use of transfer factor in treatment of infections, neoplastic and autoimmune diseases. This chapter will critically review the past and current data concerning the components of transfer factor and their effects on immunologic and inflammatory reactions. Some of the recently developed animal models will be described and evaluated, and the clinical studies that have provided conclusive data regarding efficacy will be reviewed.

Studies on the chemical nature of dialysable transfer factor. Comparison of human leukocyte dialysate and dialysates derived from human serum and from mammalian lymphoid and non-lymphoid organs

The chemical nature of human dialysable transfer factor (TFd), capable of augmenting delayed hypersensitivity (DH) in human recipients, and some mammalian organ dialysates, known to augment DH in antigen-primed guinea pigs, were compared using chromatography on Sephadex G-10 and G-25 columns and on thin-layer plates. The fractions of human leukocyte dialysate which eluted at or after the Vt of the Sephadex columns have previously been shown to contain the in vivo TFd-activity and therefore special attention was paid to corresponding dialysate fractions. All together 52 identified or unidentified components were found at or close to this elution region with thin-layer chromatography (TLC). The 14 identified substances were nucleobases, nucleosides, sugars and aromatic or heterocyclic amino acids. Unidentified components had similar staining characteristics as the identified ones on TLC. No evidence was found for the presence of peptides or nucleotides. There were no components specific for human leukocyte dialysate. Several of the identified and unidentified substances in fractions of humal dialysable leukocyte extract were common to all or nearly all dialysates. The possibility that some of the unidentified components might be responsible for the in vivo effect of human leukocyte dialysate in man or guinea pig is discussed.

Transfer factor and possible applications in gynecology

Dialyzable transfer factor (TFd) is reviewed against its historical background, preparation methods, physiochemical properties, possible mechanisms of action, pharmacology, and clinical studies, including several areas relating to gynecology. The possible role of TFd as an adjunct in the treatment of cancer is discussed. The discussion centers on gynecologic cancer in several patients who have received TFd. The difficulties and future possibilities for this modality of treatment are considered.

Immunotherapy of viral infections with transfer factor

It has been reported that dialysable leucocyte extract preparations, thought to contain transfer factor, may be used therapeutically for the treatment of a variety of immunodeficiency syndromes. Clinical and laboratory studies have suggested that such preparations, in addition to transferring specific cellular immunity may also contain non-specific adjuvant activities. Attempts at immunotherapy of viral infections are described against a background of current research on the biological and biochemical properties of leucocyte dialysates.

Transfer factor preparations: some physico-chemical and biological properties

Some biological and physico-chemical properties were tested in 50 lots of transfer factor (TF). Each lot contained the extracts of a pool of 20 buffy coats, each originating from a 400 ml blood donation of a healthy individual. The optical densities at 260 and 280 nm were within a narrow range in all TF lots. The ratio 260/280 was 2.56-3.02. One unit TF (defined as the extract of two buffy coats (corresponding to 1-2 X 10(9) leucocytes) contained 36.58 +/- 3.77 mg of peptides as measured by the Lowry method and 123.6 +/- 4.5 mg ribose as estimated by the orcinol method. Cytotoxicity of TF lots was tested by measurement of chromium release of PHA-stimulated lymphocytes. Cytotoxicity was above 10% in 20 of 27 TF lots tested, most of which were produced by an Amicon ultrafiltration cell. Pyrogenicity was present in 8 of 42 TF lots produced by Amicon filters, but only in 1 of 8 lots produced by Sartorius filters. Sephadex G-10 chromatograms of TF gave characteristic patterns yielding 8 peaks. Sephadex G-25 chromatograms reproducibly showed 5 peaks. The distribution of osmotic activity, peptides and ribose in respect of the chromatographic fractions is given.

Therapeutic use of transfer factor

Transfer Factor (TF) was produced by ultrafiltration of repeatedly frozen and thawed, pooled buffy coats of healthy blood donors. One unit of TF Zürich was defined as the cell extract originating from 1 - 2 x 10-9 leucocytes. In collaboration with physicians and immunologists, 409 units TF have been given to 45 patients. Besides local pain and occasional fever no side effects were observed. Immune conversions and beneficial clinical effects were seen in 11 and 10 patients, respectively, out of 12 patients with chronic candidiasis. Immune conversion was also observed in patients with multiple sclerosis, while the clinical effects cannot yet be judged. The series also included patients with subacute sclerosing panencephalitis, HBAg-positive disorders, various immunodeficiency diseases, malignant malanoma and miscellaneous tumours. Immune conversion occurred only occasionally and the clinical effect was either non-existent or not judgeable. In the discussion the results of other investigators using TF therapy are included.