The HIV virus has the ability to incorporate into the DNA of human lymphocytes. As a retrovirus, it can further multiply in these cells and increase its number resulting in the destruction of the t-helper cell subtype of lymphocytes in the resulting viremia. (Ref. 1) At the same time, it apparently is not attacked by the normal scavenging white blood cells such as macrophages. The retrovirus is sexually transmitted by bodily fluids including breast milk and semen. (Ref. 2) The incubation period of the virus can be up to 6 months. The resulting infection over a five year interval causes an irreversible depression of cell-mediated immunity leading to death from opportunistic infection or rare malignancy.

The clearcut heterosexual transmission of AIDS by prostitutes and blood transfusion has increased. (Ref. 3) Many HIV antibody screening tests have been developed to prevent AIDS spread through the nations blood supply. All individuals infected by HIV show a reversal of the normal ratio of t-helper to t-suppressor cells. Once the CD4 helper cell level falls into the 200 to 500 c/ccm range, antiviral therapy has been recommended. LENTINAN and DDI together may have a synergistic effect to increase survival. (Ref. 4)

According to clinical studies, LENTINAN produces specific T-helper cell stimulation in healthy humans as well as animals. LENTINAN has also been found to stimulate lymphokine activated killer activity in combination with Interleukin-2. (Ref. 5) "The drug has a host-mediated activity, and an effector mechanism that involves killer T cells, activated macrophages, natural killer cell, and antibody dependent macrophage mediated cytotoxicity (ADMC)." (Ajinomoto insert).

In my own clinical studies, LENTINAN produces specific T-helper cell (CD4) stimulation in healthy humans . Recently LENTINAN , in combination with Interleukin-2 has been found to stimulate lymphokine activated killer cells. (Ref. 5) In a clinical 4 year study of 68 of private patients, 11 volunteered to ingest 0.2 mg of LENTINAN daily in the form of Shiitake mushroom powder; no side effects were reported by those using the powder in their daily diets as a food supplement. Determination of"active T-cell" levels, yielded on analysis, a statistically significant increase in their numbers. Immunodiagnostic Labs later proved"active cells" were the same as t-helper cells. The control group of 56 patients not using Shiitake extract had a lower percentage of active T-cells than the long term users of the powder. (Ref. 6) LENTINAN increased natural killer cells and macrophage activity. These early investigations of this biologic modifier stimulated the author to postulate a theoretical treatment for AIDS related complex or HIV infection of patients with greater than 500 t-helper cells per cubic millimeter of blood. (Ref. 7)

Infection of cells by HIV is a multistage process. A glycoprotein (gp120) on the surface of the virus binds to CD4 receptors on t-helper cells, which then internalize the virion. After entry into the cell, the virion RNA is converted by reverse transcriptase (also contained in the virion) to a double stranded DNA provirus that then becomes integrated into the host genome. Using the reverse transcriptase , the virus further reproduces in these cells and increases its number resulting in viremia. Reverse transcription is essential for the further replication of the virus and subsequent productions of virions and/or cytopathology. Since the virus can be transmitted in breast milk and semen, even cells not expressing CD4 may also be infectable.

During infection, HIV is not attacked by the normal scavenging macrophages eventually causing the destruction of the t-helper cells. All individuals infected by HIV show a reversal of the normal ratio of t-helper to t-suppressor cells. The incubation period of the virus can run from 2 to 6 months. The resulting infection over a 5-8 year interval causes an irreversible depression of cell-mediated immunity leading to death from opportunistic infections, e.g., fungi, TB or rare malignancies. The clear-cut hetero-sexual transmission of AIDS by prostitutes and blood transfusion has increased. (Ref. 8) AIDS is now the number one cause of death of young American women. HIV antibody screening tests have been developed to prevent AIDS spread through the nations of the world and their blood supply . Current testing only reveals the tip of the iceberg.

Extracts of Lentinus edodes were first found useful in inhibiting, Sarcoma 180, (a retrovirus, similar to HIV which uses reverse transcriptase for its tumor-promoting activity). (Ref. 9) As you know, the extracts were refined to produce LENTINAN, a B-1, 3 glucan, which is an antitumor polysaccharide produced by Ajinomoto, your parent company. The purified form which "prolongs life and reduces tumor size" is a white powder which desolves in distilled water for injection. LENTINAN's mode of action is "characterized not by direct cytotoxic effect, but by host-mediated activation of host defense factors. Clinical studies have shown that LENTINAN in combination with oral tegafur enhanced the reduction of tumor size, and prolongs life in patients with inoperable or recurrent gastric cancers."

LENTINAN¨ use in the pre-AIDS stage needs to be investigated further. It has been more than five years since I wrote this original proposal and still there is no research effort to stimulate immune system function in AIDS patients. A study on LENTINAN's effect on CD4 stimulation in normal people should be performed for an extended time period of at least 6-12 months since the cumulative effect of its use must be tested. One arm of the study comparing LENTINAN in conjunction with DDI in immunocompromised HIV + patients has been completed by Virex and the results are inconclusive. An adequate dose of LENTINAN (1-10 mg. IV) was to be used weekly for a minimum of 26 weeks in this ongoing study. My proposal involves studying another aspect of LENTINAN effects in a group of 25 HIV+ patients with >500 CD4 cells for 26 weeks and a control group of healthy patients for the same time period. The other arms would involve the use of LENTINAN alone intramuscularly as compared to intravenously in at least 50 patients with 200- 500+ helper cells per cubic millimeter.

LENTINAN has already been shown effective in gastric carcinomas (Refs. 10,11) and a preclinical screen by NCI proved a reduction in lung metastases and prolonged survival time in mice. (Ref. 12) Again, minimal toxicity was noted. An oral trial has been ongoing with the mushroom powder Reshi-Shigen safely used as food supplement in both normal and terminal cancer patients for up to 10 years. The exact LENTINAN concentration is being analyzed in the lab. Serendipitiously, the actual growers and regular users of the powder had very high T-helper cell levels as compared to the general population. This phenomenon which I reported in my paper (Ref. 6) needs to be looked at in a more controlled study.

Theoretically, LENTINAN would be most useful in HIV+ individuals with a functioning cellular immune system. I refer you to the reference on "Antibodies to HTLV I and III in sera...." The Phase 1 study, already in progress in HIV+ individuals with less than 500 CD4 cells/cmm, shows some immune stimulation in combination with DDI. Although possibly insufficient immune potential remains in this group, a positive effect has been noted according to current research to date. This is very promising.

LENTINAN has been proven safe in mice when taken orally in saline. As little as a one milligram dose resulted in" significantly higher T-cell levels, helper cells levels , and helper-suppressor ratio, and significantly lower suppressor-cell levels than did the control group" after four weeks of twice weekly use. (Ref. 13)

The use of mushroom powders in HIV+ patients is being studied in England, Spain and Italy. MRL products are being tested in Chronic Fatigue Syndrome and Hepatitis C in Santa Cruz, California. Lab test to show CD4 stimulation are performed by ImmunoDiagnostic Labs in Oakland, California. For more information, contact Dr. Kryger.

References

1. US Council on Scientific Affairs. ( OCT. 1984) The Acquired Immunodeficiency Syndrome. JAMA 252:15 , 2037.

2. Redfield, R.R., (1985) Frequent transmission of HTLV-11 among spouses of patients with AIDS-related complex and AIDS. JAMA 253:11, 1571.

3. Miyakoshi, H.,Usuda, Y. et al. (1985) Antigens of HTLV-1 and/or 111 and their antibodies as clinical criteria for the efficacy of LENTINAN administration. Int. J. of Immunopharmacology 7:3, 332.

4. Katzenstein, D. , Merrigan , T. (1992) The effect of AZT and DDI in AIDS. (Personal communication).

5. Suzuki,M., Higuchi, S. , Taki, Y.,Miwa, K. ,Hamuro,J., (1990) Activity of LENTINAN and Interleukin 2. Int. J. of Immunopharm.12(6) 613-623.

6. Kryger,A.H.,(1983) The LENTINAN phenomenon . Unpublished -copy attached.

7. Dennert, P. et al. (1973) Antitumor polysaccharide LENTINAN-a T cell adjuvant. J. of National Cancer Institute.51, 1727.

8. Valle, S.L., et al. (1985) Diversity of clinical spectrum of HTLV-111 infection. Lancet, Feb 9,1985.

9. Chihara, G. , Hamuro, J., Maeda, Y.Y., Arai, Y & Fukuoka, F. (1987) Function and purification of the polysaccharides with marked antitumor activity, especially LENTINAN, from Lentinus edodes (Berk.) Cancer Res., 30,2776-2781.

10. Taguchi, T., Furue,H.,Kimura, T.,Kondo, T., Hattori, T., Itoh, T,. and Osawa,N. (1985) End-point results of phase 111 study of LENTINAN. Japan. J. Cancer Chemother. 12:366

11. Chihara, G. (1981) Randomized controlled trial of LENTINAN use in advanced human gastric malignancy. Gann 8:6.

12. Talmadge, J.E., (1986) Preclinical screen for biological response modifiers. Pers. Communication, NCI-Frederick Cancer Research Facility.

13. Hanaue,H., Tokuda,Y. , et al. (1989) Effects of oral LENTINAN on T-cell subsets in peripheral venous blood.11(5): 614.