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At least 19 recordsLinked to original sources
PubMed1993

Structural nature and functions of transfer factors.

Transfer factors are molecules that "educate" recipients to express cell-mediated immunity. This effect is antigen-specific. The most consistent effects of transfer factors on the immune system are expression of delayed-type hypersensitivity and production of lymphokines such as macrophage migration inhibitory factor (MIF), which is probably identical to gamma-interferon in response to exposure to antigen. Transfer factors bind to antigens in an immunologically specific manner. This discovery has enabled us to isolate individual transfer factors from mixtures that contain several transfer factors. This reactivity probably explains the specificity of individual transfer factors, and it has provided a method for purification of individual transfer factors to apparent homogeneity. The purified materials are immunologically active and antigen-specific. They have molecular weights of approximately 5,000 Da and appear to be composed entirely of amino acids. Transfer factors appear to offer a novel means of molecular immunotherapy for certain patients with defective cell-mediated immunity.

Animals↗
PubMed1992

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.

Animals↗
PubMed1979

Transfer of contact sensitivity to beryllium using dialyzable leukocyte extracts (transfer factor).

Transfer factor derived from lymphocytes of donors with strong cellular immunity against beryllium was intradermally or subcutaneously injected into unprimed or subclinically primed human recipients who were patch test-negative. These recipients were challenged with beryllium at weekly intervals thereafter. Subjects who had been subclinically primed and received transfer factor either intradermally or subcutaneously showed transient patch test reactivity to the challenge. Subjects who received transfer factor but were not primed and subjects who had been primed but did not receive transfer factor showed no such conversion. This is the first demonstration of transfer of contact sensitivity in man using transfer factor, and it suggests that subclinical priming is necessary for such transfers.

Beryllium↗
PubMed1996

Profiles of cytokine production in recipients of transfer factors.

Transfer factors (TF) are proteins that transfer the ability to express cell-mediated immunity from immune donors to non-immune recipients. The mechanisms of these effects have not been defined. The experiments described in this report were undertaken to test the hypothesis that a mechanism through which the beneficial effects of TF are expressed in clinical situation is through "education" of the immune system to produce certain cytokines in response to antigenic stimulation. BALB/c mice were sensitized to Herpes simplexvirus (HSV) either by sublethal systemic or cutaneous infections by administration of a HSV-specific TF. One week later their spleen cells were collected and single cell suspensions were stimulated in vitro with irradiated HSV or concanavalin. A Culture supernatants were collected and assayed for content of IL-2, IL-4, IL-10 and IFN-g. Spleen cells from infected mice responded to concanavalin A and to HSV by secreting large amounts of IL-2 and IFN-g, modest amounts of IL-10, and no IL-4. Transfer factor recipients produced similar cytokine profiles in response to concavalin A. These mice, however, responded to HSV by secreting IFN-g, but no IL-2. Thus, TF treatment selectively affects cytokine production in response to antigenic stimulation.

Animals↗
PubMed1973

Bacteriophage restriction in Salmonella typhimurium by R factors and transfer factors.

A total of 2716 R factors and transfer factors isolated from Escherichia coli and salmonellas of human and animal origin were studied for their phage-restrictive effects in Salmonella typhimurium phage type 36. All of 1402 wild fi(+) factors were non-restricting. The F factor of E. coli K12 was unique among the F-like factors tested in that it inhibited lysis of type 36 by one typing phage. In contrast, eleven distinct changes in the phage type of 36 were produced by fi(-) I-like factors. I-like plasmids can thus be subdivided by this method.I-like R factors and transfer factors from human and animal enterobacteria were categorized by their phage-restrictive effects in type 36. Factors resembling Delta in this respect predominated among fi(-) I-like factor from human E. coli and S. typhimurium and from porcine E. coli. Delta-like and ColI-like fi(-) factors were equally distributed in bovine S. typhimurium. ColI-like factors were commonest in bovine and avian E. coli.

Animals↗
PubMed1979

Normal values of transfer factor and transfer coefficients in healthy males and females.

A population study was performed to obtain local normal values of the transfer factor for a respiratory laboratory providing a routine hospital service. Statistical analysis of the results obtained showed similar results to those of previous investigators for the transfer factor and alveolar volume. The transfer factor was found to be dependent on height, age and sex, while the alveolar volume depended only upon height and sex. Unlike previous investigations, however, the present study showed that the transfer coefficient was the same for women as for men and was related solely to age.

Adolescent↗
PubMed1975

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.

Adolescent↗
PubMed2000

Transfer factors: identification of conserved sequences in transfer factor molecules.

BACKGROUND: Transfer factors are small proteins that "transfer" the ability to express cell-mediated immunity from immune donors to non-immune recipients. We developed a process for purifying specific transfer factors to apparent homogeneity. This allowed us to separate individual transfer factors from mixtures containing several transfer factors and to demonstrate the antigen-specificity of transfer factors. Transfer factors have been shown to be an effective means for correction of deficient cellular immunity in patients with opportunistic infections, such as candidiasis or recurrent Herpes simplex and to provide prophylactic immunity against varicella-zoster in patients with acute leukemia. MATERIALS AND METHODS: Transfer factors of bovine and murine origin were purified by affinity chromatography and high performance liquid chromatography. Cyanogen bromide digests were sequenced. The properties of an apparently conserved sequence on expression of delayed-type hypersensitivity by transfer factor recipients were assessed. RESULTS: A novel amino acid sequence, LLYAQDL/VEDN, was identified in each of seven transfer factor preparations. These peptides would not transfer expression of delayed-type hypersensitivity to recipients, which indicates that they are not sufficient for expression of the specificity or immunological properties of native transfer factors. However, administration of the peptides to recipients of native transfer factors blocked expression of delayed-type hypersensitivity by the recipients. The peptides were not immunosuppressive. CONCLUSIONS: These findings suggest that the peptides may represent the portion of transfer factors that binds to the "target cells" for transfer factors. Identification of these cells will be helpful in defining the mechanisms of action of transfer factors.

Amino Acid Sequence↗
PubMed1985

Murine transfer factor. III. Specific interactions between transfer factor and antigen.

The interactions between dialyzable transfer factor and antigens have been studied. Incubation of transfer factor-containing dialysates from ferritin-sensitized mice or ferritin-coated plastic surfaces removed the antigen-sensitizing activity; incubations of the same preparations on cytochrome c-coated surfaces did not. Similar results were obtained when cytochrome c-transfer factor was studied. Incubation on cytochrome c-coated surfaces removed the activity, but incubation on ferritin-coated surfaces did not. Specific transfer factor activities could be recovered by elution with 8 M urea or acetonitrile. The finding of interactions between transfer factor and antigens provides evidence for a molecular basis of the specificity of the immunologic effects of transfer factor. This technique may also enable us to obtain amounts of specific material that are adequate for chemical analysis.

Animals↗
PubMed1985

Murine transfer factor. II. Transfer of delayed hypersensitivity to synthetic antigens.

Synthetic polyaminoacid antigens were used to examine the specificity of transfer of delayed-type hypersensitivity with spleen cell dialysates in mice. Dialysates from GAT10-sensitized donors sensitized recipients to GAT10, but not GLA5 or cytochrome c. Dialysates from GLA5-sensitized donors sensitized recipients to GLA5, but not GAT10 or cytochrome c. We interpret these findings as consistent with the concept that passive transfer of delayed hypersensitivity with dialyzable materials is an immunologically specific event.

Animals↗
PubMed1980

Transfer factor: failure to transfer reactivity in normal human subjects.

Transfer factor was prepared from highly selected normal donors. One lot was made from donors strongly reactive to coccidioidin and negative to Dharmendra antigen in in vivo and in vitro testing. The other lot was made from donors without reactivity to coccidioidin and strongly reactive to Dharmendra. Aliquots of each lot were injected into eight normal recipients. Eight additional normal recipients were given placebo injections. Before and after injection, skin test reactivity and in vitro testing were evaluated by an individual who did not know which preparation the patient received. Changes in immunologic reactivity in subjects receiving transfer factor could not be distinguished from those in subjects receiving placebo. I conclude that transfer factor does not cause enhancement of immunologic reactivity in normal subjects. A well designed, critical study is needed to determine whether or not it does, in fact, cause enhancement of immunologic reactivity in patients with impaired cellular immune reactivity.

Antigens↗
PubMed1977

[In-vitro studies with human transfer factor].

Human transfer factor was prepared from "buffy coat" of human donors by ultra filtration. These batches of transfer factor were tested for their ability to increase DNA-synthesis of antigen(mitogen) incubated lymphocytes. An increase of DNA-synthesis was measured by the ratio of appr. 2. Column chromatographic separation of transfer factor on sephadex G-10 or DEAE cellulose columns showed an elution pattern with many peaks. In the lymphoblastogenese assay some peaks were found to be stimulatory, others in contrast inhibitory. It seems likely from our results that transfer factor represents a mixture of different chemical compounds with activating or inhibitory action on lymphoblastogenesis.

Culture Techniques↗
PubMed1975

Dialyzable transfer factor.

Dialyzable transfer factor, obtained from human peripheral blood leukocytes and first described by Lawrence, is being used in attempts to rectify defects in the cellular immune systems of patients with basic immunodeficiencies, chronic infectious diseases, and neoplastic diseases. Current knowledge of the chemical character of, assays for, and functional activities of transfer factor are briefly reviewed. An experimental animal model for dialyzable transfer factor involving the rhesus monkey (Macaca mulatta) and infection with the trematode Schistosoma mansoni is discussed. The results of this study suggest that in this model transfer factor may act both specifically and nonspecifically.

Animals↗