CELLULAR
IMMUNOLOGY
46,
184-186 (1979)
MEETING Third International
REPORT
Symposium
on Transfer
Factor
The Third International Symposium on Transfer Factor was held October 12- 14, 1978 at the Wadley Institutes of Molecular Medicine, Dallas, Texas. Progress in several areas was reported. The animal models that were tentative a few years ago have been defined and extended by several groups of investigators. Additional promising systems were described in mice and cattle. Several laboratories reported evidence that in mice the transfers of cutaneous and footpad DTH reactions from immune murine, bovine, or human donors to naive recipients were antigen specific. However, some found that when large doses of the transfer factor were given, specificity was lost and nonspecific reactions were observed. Antigen-independent activities of crude leukocyte dialysates were also examined in several species. Human leukocyte dialysates were shown to cause conversion of rat thymocytes from the cortisone-sensitive to the cortisone-resistant state. Addition of these dialysates to PHA-stimulated thymocytes increased thymidine incorporation. Preparations of dialysate from human and bovine lymphoid tissues were given to mice and the spleens of the recipients were then examined for antigen-reactive cells in a cell proliferation assay. Enhanced responses to antigenic stimulation were seen in about 30% of the recipients while about 40% of animals had suppressed responses. No effect was seen in the remaining mice. Immunomodulating effects were also seen in guinea pigs that were given either tolerizing doses of ABA-tyrosine (ABA-T) alone, or similar doses of ABA-T with leukocyte dialysates. In contrast to the recipients of ABA-T who became tolerant, the recipients of ABA-T plus dialysate exhibited flare-type skin responses and subsequently could be sensitized with ABA-T in CFA. In mice, PHA-responsive, e-positive lymphoid cells which did not adhere to nylon wool columns proved to be a rich source of antigen-specific transfer factor activity. In contrast, no activity was found in the adherent cell populations, even though such preparations were contaminated with about 20% e-positive cells. Considerable evidence suggests that there is no genetic restriction governing the in vivo activities of transfer factor. Human preparations have activity in mice and cattle, and bovine and murine preparations are active in mice and men. The results of experiments (including recent in vivo studies) studying the effect of enzymatic degradation of transfer factor, purified by high-pressure reversephase liquid chromatography, are listed in Table 1. The in vivo antigen-specific activity was sensitive to Pronase, protease K, carboxypeptidase A, and phosphodiesterase I. It resisted digestion with alkaline phosphatase, phosphodiesterase II, leucine aminopeptidase, chymotrypsin, and ribonuclease A. Somewhat different susceptibility to enzyme treatment was found when the induction of immune 184 0008-8749/79/090184-03$02.00/O Copyright 0 1979 by Academic Press, Inc. All rights of reproduction in any form reserved.
185
MEETING REPORT TABLE 1 Properties of Dialyzable Transfer Factor Present Present Present 1.6
Inosine (probably as IMP) Sugar (ribose?) Peptide (Fluoropa reactive) PI
Sensitivity to enzymes
Enzyme
In vivo transfer of antigen-specific cutaneous DTH
Pronase Protease K Carboxypeptidase A Leucine aminopeptidase Trypsin Chymotrypsin Phosphodiesterase I Phosphodiesterase II Alkaline phosphatase Ribonuclease, T, Ribonuclease A Ribonuclease A, dimerized Ribonuclease 1 (pancreatic) Deoxyribonuclease
Sensitive Sensitive Sensitive Resistant Resistant Resistant Sensitive Resistant Resistant Resistant Resistant Sensitive Resistant
In vitro transfer of leukocyte migration inhibition
Resistant Resistant Resistant Sensitive Sensitive Sensitive Resistant Sensitive Resistant
responsiveness in lymphocytes was studied in vitro using a leukocyte migration inhibition assay. In this system, the biological activity was sensitive to Pronase, phosphodiesterase II, alkaline phosphatase, T, ribonuclease, and pancreatic ribonuclease, but resisted phosphodiesterase I. These results have led to a tentative structural model of transfer factor which contains inosine (probably as IMP), ribose, a phosphodiester bond, and a peptide. Presumably the property of antigen specificity is encoded in the peptide component. After administration of transfer factor-containing dialysates to dogs, guinea pigs, or humans, the plasma of the recipients contained a new component that cochromatographed with IMP and contained a peptide (Fluoropa reactive), a sugar, and a phosphate ester. It was also sensitive to Pronase and protease K. Some of the most impressive clinical effects of transfer factor were seen in patients with viral infections such as herpes zoster, recurrent herpes simplex, or measles pneumonia. Good results were observed in some patients with Behcet’s syndrome; but another group reported that only the neurological manifestations of the syndrome improved. No benefits were seen in patients with SSPE. Patients with chronic mucocutaneous candidiasis were treated with transfer factor from either candida-sensitive or candida-negative donors. Both groups did better than would be expected from amphotericin B alone, but long-term remissions occurred only in the patients who developed and maintained positive cutaneous DTH to candida. A report of a controlled clinical trial in chronic cutaneous leishmaniasis was
186
MEETING REPORT
especially impressive. Recipients of transfer factor from leishmania-sensitive donors showed healing in 10 of 12 instances, in contrast to only 3 of 13 recipients of transfer factor prepared from nonsensitive donors. There were no responders in the placebo group. Other discussions dealt with very practical problems such as standardization of methods and terminologies used in various laboratories. A “unit” of transfer factor was defined as the material obtained from lOa lymphocytes pending development of more precise chemical or immunological assays. There was considerable disagreement, however, as to the clinical usefulness of such a unit, because of the uncertainty concerning what biological effects of leukocyte dialysates should be ascribed to transfer factor. Should this be limited to antigenspecific transfer of cell-mediated immunity in vivo or in vitro, or should it include such general adjuvant effects as enhancement of T-cell rosette formation? No agreement was reached in this area, but since the term transfer factor is being used in both senses by various groups it is important for the design and analysis of clinical studies that the distinction be clear. Clinical trials of transfer factor will only be interpretable and reproducible when the doses of transfer factor can be specified by biological or chemical assay. The Proceedings of the Symposium are published in a volume entitled “Immune Regulators in Transfer Factor: III International Symposium on Transfer Factor” (A. Khan, C. Kirkpatrick, and N. Hill, Eds.). Academic Press, New York, 1979. CHARLES H. KIRKPATRICK AMANULLAHKHAN' NORWOOD 0. HILL' Laboratory of Clinical Investigation National Institute of Allergy and Infectious Diseases National Institutes of Health Bethesda, Maryland 20014 1 Wadley Institutes of Molecular Medicine Dallas, Texas 75235
IMMUNOLOGY
46,
184-186 (1979)
MEETING Third International
REPORT
Symposium
on Transfer
Factor
The Third International Symposium on Transfer Factor was held October 12- 14, 1978 at the Wadley Institutes of Molecular Medicine, Dallas, Texas. Progress in several areas was reported. The animal models that were tentative a few years ago have been defined and extended by several groups of investigators. Additional promising systems were described in mice and cattle. Several laboratories reported evidence that in mice the transfers of cutaneous and footpad DTH reactions from immune murine, bovine, or human donors to naive recipients were antigen specific. However, some found that when large doses of the transfer factor were given, specificity was lost and nonspecific reactions were observed. Antigen-independent activities of crude leukocyte dialysates were also examined in several species. Human leukocyte dialysates were shown to cause conversion of rat thymocytes from the cortisone-sensitive to the cortisone-resistant state. Addition of these dialysates to PHA-stimulated thymocytes increased thymidine incorporation. Preparations of dialysate from human and bovine lymphoid tissues were given to mice and the spleens of the recipients were then examined for antigen-reactive cells in a cell proliferation assay. Enhanced responses to antigenic stimulation were seen in about 30% of the recipients while about 40% of animals had suppressed responses. No effect was seen in the remaining mice. Immunomodulating effects were also seen in guinea pigs that were given either tolerizing doses of ABA-tyrosine (ABA-T) alone, or similar doses of ABA-T with leukocyte dialysates. In contrast to the recipients of ABA-T who became tolerant, the recipients of ABA-T plus dialysate exhibited flare-type skin responses and subsequently could be sensitized with ABA-T in CFA. In mice, PHA-responsive, e-positive lymphoid cells which did not adhere to nylon wool columns proved to be a rich source of antigen-specific transfer factor activity. In contrast, no activity was found in the adherent cell populations, even though such preparations were contaminated with about 20% e-positive cells. Considerable evidence suggests that there is no genetic restriction governing the in vivo activities of transfer factor. Human preparations have activity in mice and cattle, and bovine and murine preparations are active in mice and men. The results of experiments (including recent in vivo studies) studying the effect of enzymatic degradation of transfer factor, purified by high-pressure reversephase liquid chromatography, are listed in Table 1. The in vivo antigen-specific activity was sensitive to Pronase, protease K, carboxypeptidase A, and phosphodiesterase I. It resisted digestion with alkaline phosphatase, phosphodiesterase II, leucine aminopeptidase, chymotrypsin, and ribonuclease A. Somewhat different susceptibility to enzyme treatment was found when the induction of immune 184 0008-8749/79/090184-03$02.00/O Copyright 0 1979 by Academic Press, Inc. All rights of reproduction in any form reserved.
185
MEETING REPORT TABLE 1 Properties of Dialyzable Transfer Factor Present Present Present 1.6
Inosine (probably as IMP) Sugar (ribose?) Peptide (Fluoropa reactive) PI
Sensitivity to enzymes
Enzyme
In vivo transfer of antigen-specific cutaneous DTH
Pronase Protease K Carboxypeptidase A Leucine aminopeptidase Trypsin Chymotrypsin Phosphodiesterase I Phosphodiesterase II Alkaline phosphatase Ribonuclease, T, Ribonuclease A Ribonuclease A, dimerized Ribonuclease 1 (pancreatic) Deoxyribonuclease
Sensitive Sensitive Sensitive Resistant Resistant Resistant Sensitive Resistant Resistant Resistant Resistant Sensitive Resistant
In vitro transfer of leukocyte migration inhibition
Resistant Resistant Resistant Sensitive Sensitive Sensitive Resistant Sensitive Resistant
responsiveness in lymphocytes was studied in vitro using a leukocyte migration inhibition assay. In this system, the biological activity was sensitive to Pronase, phosphodiesterase II, alkaline phosphatase, T, ribonuclease, and pancreatic ribonuclease, but resisted phosphodiesterase I. These results have led to a tentative structural model of transfer factor which contains inosine (probably as IMP), ribose, a phosphodiester bond, and a peptide. Presumably the property of antigen specificity is encoded in the peptide component. After administration of transfer factor-containing dialysates to dogs, guinea pigs, or humans, the plasma of the recipients contained a new component that cochromatographed with IMP and contained a peptide (Fluoropa reactive), a sugar, and a phosphate ester. It was also sensitive to Pronase and protease K. Some of the most impressive clinical effects of transfer factor were seen in patients with viral infections such as herpes zoster, recurrent herpes simplex, or measles pneumonia. Good results were observed in some patients with Behcet’s syndrome; but another group reported that only the neurological manifestations of the syndrome improved. No benefits were seen in patients with SSPE. Patients with chronic mucocutaneous candidiasis were treated with transfer factor from either candida-sensitive or candida-negative donors. Both groups did better than would be expected from amphotericin B alone, but long-term remissions occurred only in the patients who developed and maintained positive cutaneous DTH to candida. A report of a controlled clinical trial in chronic cutaneous leishmaniasis was
186
MEETING REPORT
especially impressive. Recipients of transfer factor from leishmania-sensitive donors showed healing in 10 of 12 instances, in contrast to only 3 of 13 recipients of transfer factor prepared from nonsensitive donors. There were no responders in the placebo group. Other discussions dealt with very practical problems such as standardization of methods and terminologies used in various laboratories. A “unit” of transfer factor was defined as the material obtained from lOa lymphocytes pending development of more precise chemical or immunological assays. There was considerable disagreement, however, as to the clinical usefulness of such a unit, because of the uncertainty concerning what biological effects of leukocyte dialysates should be ascribed to transfer factor. Should this be limited to antigenspecific transfer of cell-mediated immunity in vivo or in vitro, or should it include such general adjuvant effects as enhancement of T-cell rosette formation? No agreement was reached in this area, but since the term transfer factor is being used in both senses by various groups it is important for the design and analysis of clinical studies that the distinction be clear. Clinical trials of transfer factor will only be interpretable and reproducible when the doses of transfer factor can be specified by biological or chemical assay. The Proceedings of the Symposium are published in a volume entitled “Immune Regulators in Transfer Factor: III International Symposium on Transfer Factor” (A. Khan, C. Kirkpatrick, and N. Hill, Eds.). Academic Press, New York, 1979. CHARLES H. KIRKPATRICK AMANULLAHKHAN' NORWOOD 0. HILL' Laboratory of Clinical Investigation National Institute of Allergy and Infectious Diseases National Institutes of Health Bethesda, Maryland 20014 1 Wadley Institutes of Molecular Medicine Dallas, Texas 75235
