Histopathology of murine toxoplasmosis under treatment with dialyzable leukocyte extract.

BACKGROUND: Dialyzable leukocyte extracts (DLEs) contain molecules smaller than 10 kDa with biological activity in receptor organisms. Primarily, they participate in the regulation of the Th1 immune response, which is essential for the control of several intracellular infections, such as toxoplasmosis. This disease is associated with congenital infection, encephalitis or systemic infections in immunocompromised individuals. The clinical course of this infection fundamentally depends on a well-regulated immune response and timely treatment with the appropriate drugs. OBJECTIVE: The aim of this study was to evaluate the effect of treatment with a leukocyte extract, derived from crocodile lymphoid tissue, on the histopathology and brain parasite load in NIH mice that had been infected with cysts of Toxoplasma gondii (ME-49 strain). METHODS: The treatment was applied during the acute and chronic stages of the infection. Histopathological changes were evaluated in the ileum, liver and spleen at one, four and eight weeks after infection and in the brain at week 8. The parasite load was evaluated by counting the cysts of T. gondii found in the brain. FINDINGS: Compared to the control mouse group, the mice infected with T. gondii and under treatment with DLE showed less tissue damage, mainly at the intestinal, splenic and hepatic levels. In addition, a greater percentage of survival was observed, and there was a considerable reduction in the parasite load in the brain. CONCLUSIONS: The results suggest that DLE derived from crocodile is a potential adjunctive therapy in the conventional treatment of toxoplasmosis.

Histopathology of murine toxoplasmosis under treatment with dialyzable leukocyte extract

BACKGROUND Dialyzable leukocyte extracts (DLEs) contain molecules smaller than 10 kDa with biological activity in receptor organisms. Primarily, they participate in the regulation of the Th1 immune response, which is essential for the control of several intracellular infections, such as toxoplasmosis. This disease is associated with congenital infection, encephalitis or systemic infections in immunocompromised individuals. The clinical course of this infection fundamentally depends on a well-regulated immune response and timely treatment with the appropriate drugs. OBJECTIVE The aim of this study was to evaluate the effect of treatment with a leukocyte extract, derived from crocodile lymphoid tissue, on the histopathology and brain parasite load in NIH mice that had been infected with cysts of Toxoplasma gondii (ME-49 strain). METHODS The treatment was applied during the acute and chronic stages of the infection. Histopathological changes were evaluated in the ileum, liver and spleen at one, four and eight weeks after infection and in the brain at week 8. The parasite load was evaluated by counting the cysts of T. gondii found in the brain. FINDINGS Compared to the control mouse group, the mice infected with T. gondii and under treatment with DLE showed less tissue damage, mainly at the intestinal, splenic and hepatic levels. In addition, a greater percentage of survival was observed, and there was a considerable reduction in the parasite load in the brain. CONCLUSIONS The results suggest that DLE derived from crocodile is a potential adjunctive therapy in the conventional treatment of toxoplasmosis.

[Transfer factors in medical therapy]. / Factores de transferencia en la terapéutica médica.

Transfer factor (TF) consists of messenger peptides produced by activated T lymphocytes as part of cellular immunity, and it acts in virgin lymphocytes through TF inducers, suppressors and specific antigens. TF is not immunogenic because it is not species-specific, since it contains a consensus sequence of amino acids LLYAQDL/VEDN. TF extracted from leukocytes can transfer immunity from a human to another species. TF extracts are complex, containing more than 200 molecules with molecular weights ranging from 1 to 20 kDa. The antigen specific transfer factors (STF) have molecular weights between 3,5 and 5 kDa. TF is easy to prepare and well tolerated. It does not contain HL-A antigens against potential receptors and it can used as adjuvant therapy in several diseases.

Preparation and properties of the specific anti-influenza virus transfer factor.

Specific anti-influenza virus and normal transfer factors prepared in an experimental animal model, the pig, have been tested for their components, characteristics, and activity of known specificity. Two transfer factors are small molecular mixture which consist entirely or partly of polypeptides and polynucleosides. Moreover, the biological activity of transfer factors could be approved by Rosettes test and specific skin test. The study would lay a foundation for the research and development of other specific transfer factor.

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.

Adult chronic granulomatosis disease-like neutrophil granulocyte disorder corrected by dialysable leukocyte extract.

A 47 year old female presented with a septic clinical picture including fever, abscesses, late cachexia, and unmanageable by disease. Similar characteristics to chronic granulomatosis disease (CGD) seriously decreased intracellular killing activity and chemiluminescence, granulomas in the histology, and the role of genetic factors were found, suggesting that our case is CGD-like disorder, manifested in an adult. Dialysable leukocyte extract (DLE) therapy, complemented with fresh normal plasma, resulted in a striking clinical improvement and there was an increase in the in vitro PMNL intracellular killing activity, too. Although it is generally accepted that DLE derives from monocytes and lymphocytes, it is possible that DLE is a family of DNA-oligopeptide molecules, including factors derived from PMNLs which are capable of influencing PMNL function, transferring information from normal cells. Our results also suggest that it would be worth trying DLE in patients with classic CGD.

Effect of human leukocyte and other tissue dialysates on Listeria resistance and phagocytosis in mice.

The effect of dialyzable transfer factor (TFd) on Listeria resistance was measured by survival studies and by assessing phagocytic capacity of peritoneal macrophages. Unfractionated dialysates from human leukocytes (DLE), bovine liver, porcine spleen and kidney as well as saline were injected i.p. into NMRI mice 72 h before the i.p. injection of 1-3 x 10(6) Listeria organisms. The results show that DLE, porcine spleen and bovine liver dialysate increased the LD50 5-20 times. Porcine kidney dialysate had no effect on the survival of the mice. After the fractionation of porcine spleen dialysate on Sephadex G-10 column, a significant activity was found in two fractions, II and IX. When active fractions were given together (II + IX) i.p. three days prior to the infection with listeria organisms, the survival of mice increased significantly, whereas no effect was seen when the fractions were given i.v. and the bacteria i.p. Also the treatment with active fractions increased significantly the phagocytic capacity of peritoneal macrophages. Taken together, our results suggest that the Listeria protective substances seem to operate via monocyte activation.

Transfer of osteosarcoma-specific cell-mediated immunity in hamsters by rabbit dialyzable leukocyte extracts.

We have investigated the transfer of specific cell-mediated immunity (CMI) to osteosarcoma-associated antigens (OSAA) to hamsters with dialyzable leukocyte extracts (DLE) from OSAA-immunized rabbits. The transfer of specific CMI was determined by leukocyte adherence inhibition (LAI) assay and skin testing. DLE was prepared from rabbits immunized with OSAA, purified protein derivative (PPD), or fibrosarcoma cell plasma membrane preparation (FSM). Control DLE was prepared from rabbits injected with 0.85% NaCl. Significant leukocyte adherence inhibition was observed with leukocytes from hamsters that had received OSAA-specific, PPD-specific, and FSM-specific rabbit DLE, when OSAA, PPD, and FSM were used as antigens, respectively. Similarly, significant ear swelling after injection of OSAA, PPD, or FSM was observed only in hamsters that had received DLE from rabbits immunized with OSAA, PPD, or FSM, respectively. These results suggest that CMI specific for OSAA, PPD, or FSM can be transferred to normal hamsters by DLE from immunized rabbits.

[Human transfer factor. I. Production by the great pool technic and the biochemical and immunological characteristics of the preparation]. / Humaner Transfer-Faktor. I. Herstellung nach einem Grosspoolverfahren sowie biochemische und immunologische Charakterisierung des Präparates.

A great pool procedure for producing human transfer factor preparations from buffy-coats of stored whole blood which has not been used up till now is described. From an initial tool size of about 1,500 units of whole blood the procedure represented makes it possible to gain higher amounts of uniform and in their immunological efficacy in vitro standardizable preparations for controlled long-term therapy studies. By means of various immunological in vitro tests, stimulating as well as suppressing activities of the charges obtained could be identified. Starting from the differentiated immunological effects of various charges of the transfer factor on T-cell populations in vitro, the possibility of influencing T-cell subpopulations through well-conceived therapeutic measures by a transfer factor is discussed.

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.

[A new approach to immunotherapy: the transfer factor]. / Un nuovo approccio all'immunoterapia: il transfer factor.

The transfer factor is a tiny molecule capable of transferring the function of the T lymphocytes (immunological memory and retarded hypersensitivity) from a sensitized to a non-sensitized individual. The exact structure and action modalities of the molecule have not yet been precisely established. The difficulties involved in the study of the transfer factor are aggravated by the lack of any suitable experimental model. The attention of immunologists is attracted by this factor which opens up new prospects for the treatment of cancer, immunological deficiencies and certain infectious and autoimmune diseases. More profound research would appear useful to evaluate if and in what cases a potentiation of the immune mechanism can represent an alternative to immunosuppression.

Human transfer factors: structural properties suggested by HPRP chromatography and enzymatic sensitivities.

Leukocyte extracts containing human transfer factor (TF) were fractionated by exclusion chromatography, and the active fraction (Sephadex G25, Fraction IIIa) was subjected to high pressure, reverse phase (HPRP) chromatography and enzymatic degradation. TF activity was assessed by the systemic transfer of dermal skin test reactivity from KLH-immunized donors to naive recipients. Preparative HPRP chromatography resolved Fraction IIIa into multiple chromophoric regions, two of which demonstrated transfer of KLH reactivity. Alkaline phosphatase treatment of Fraction IIIa converted the major ultraviolet-absorbing component, 5'-inosine monophosphate, to inosine and resulted in TF activity being restricted to one region. This HPRP region (R1A) contained less than 1% of the UV254 active material in Fraction IIIa but greater than 90% of the reactivity. The sensitivity of TF to pronase, proteinase K, phosphodiesterase I, and phosphodiesterase II was evaluated by inhibition of systemic transfer of KLH reactivity. Pronase and proteinase K destroyed systemic transfer activity and the pronase destruction could be inhibited with traysylol. Phosphodiesterase I, a 3' exonuclease, destroyed activity, whereas phosphodiesterase II, a 5' exonuclease, did not. The data are consistent with a phosphodiester-containing polypeptide in the structure of human TF for KLH reactivity.

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.

The effect of transfer factor on cystic acne.

A chromatographically purified component of human dialysable transfer factor, previously described as causing a non-specific stimulation of cell-mediated immunity, was used as a therapeutic agent in three cases of stage IV cystic acne. The treatment caused a marked strengthening of skin test responses and had a promising effect on skin eruption in each case.

Characterization of human dialyzable transfer factor from normal and chronic lymphoid leukemia sources.

Dialysates of lymphomonocytes can be roughly quantified through the use of optical density and measurements of RNA and protein contents. Dialysates of normal lymphocytes (N-TFd) contain about 224 +/- 67 mug of RNA-like material per 10(8) cells, 75 to 90% of which is eluted in fractions II and III on Biogel P10 chromatography. In contrast, dialysates of lymphocytes from patients suffering chronic lymphoid leukemia (CLL-TFd) contain approximately 12 times less RNA-like material (about 27 +/- 11 mug per 10(8) lymphocytes) and have a different characteristic chromatographic pattern. Bioassays with crude dialysates confirm (a) that N-TFd increases 3H-thymidine incorporation by nonsenstitized lymphocytes "in vitro" in the presence of PPD, and (b) that inbred Lewis rats develop positive skin tests (systemic transfer) after receiving injections of N-TFd or of fractions II and III from Biogel fractionation of N-TFd. Neither test gives positive results when CLL-TFd is used.

[The preparation and characterization of transfer factor (author's transl)]. / Zur präparation und Charakterisierung von Transfer-Faktor

A transfer factor (TF) was prepared and characterized from the leucocytes of Mantoux-positiv donors using a variety of techniques. The results allowed the following conclusions: Whilst extraction by dialysis and phenol (without precipitation) led to nearly the same positiv immunological activities, when assayed in the MEM-test, phenol extracts subjected to RNA-precipitation lost considerable activity. The residual activity was associated with the lower molecular fractions, and RNA itself has shown no activity. Residues after leucocyte dialysation have also shown considerable TF-activity when extracted by phenol. It was found that phenol extraction followed by gel filtration allowed recovery of considerable quantities of active TF, confined to several specific filtration fractions. Combination of active and inactive gel filtration fractions suggested that there existed an inhibitory factor within the extracted leucocyte preparations. This modified preparation and purification procedure may allow the preparation of TF for therapeutic purposes.