The Effects of Curcuma longa L., Purple Sweet Potato, and Mixtures of the Two on Immunomodulation in C57BL/6J Mice Infected with LP-BM5 Murine Leukemia Retrovirus.

The immune response is stimulated to protect the body from external antigens and is controlled by several types of immune cells. In the present study, the immunomodulatory effects of Curcuma longa L., purple sweet potato, and mixtures of the two (CPM) were investigated in C57BL/6 mice infected with LP-BM5 murine leukemia virus (MuLV). Mice were divided into seven groups as follows: normal control, infected control (LP-BM5 MuLV infection), positive control (LP-BM5 MuLV infection+dietary supplement of red ginseng 300 mg/kg body weight), the original powder of C. longa L. (C; LP-BM5 MuLV infection+dietary supplement of C 189 mg/kg body weight), the original powder of purple sweet potato (P; LP-BM5 MuLV infection+dietary supplement of P 1811 mg/kg body weight), CPM Low (CPL; LP-BM5 MuLV infection+CPM 2 g/kg body weight), and CPM High (CPH; LP-BM5 MuLV infection+CPM 5 g/kg body weight). Dietary supplementation lasted for 12 weeks. Dietary supplementation of CPM inhibited LP-BM5 MuLV-induced lymphadenopathy and splenomegaly and inhibited reduction of messenger RNA (mRNA) expression of major histocompatibility complex (MHC) I and II. Moreover, CPM reduced the decrease in T- and B cell proliferation, reduced the population of CD4(+)/CD8(+) T cells, and remedied the unbalanced production of T helper-1 (Th1)/T helper-2 (Th2) cytokines in LP-BM5 MuLV-infected mice. In addition, CPM inhibited reduction of phagocytosis in peritoneal macrophages and decreased serum levels of immunoglobulin A (IgA), immunoglobulin E (IgE), and immunoglobulin G (IgG). These results suggest that CPM had a positive effect on immunomodulation in C57BL/6 mice induced by LP-BM5 leukemia retrovirus infection.

Immunomodulatory and Antioxidant Effects of Purple Sweet Potato Extract in LP-BM5 Murine Leukemia Virus-Induced Murine Acquired Immune Deficiency Syndrome.

The immunomodulatory effects of a dietary supplement of purple sweet potato extract (PSPE) in LP-BM5 murine leukemia virus (MuLV)-induced immune-deficient mice were investigated. Mice were divided into six groups: normal control, infected control (LP-BM5 MuLV infection), positive control (LP-BM5 MuLV infection+dietary supplement of red ginseng 300 mg/kg), purple sweet potato water extract (PSPWE) (LP-BM5 MuLV infection+dietary supplement of PSPE 300 mg/kg), PSP10EE (LP-BM5 MuLV infection+dietary supplement of 10% ethanol PSPE 300 mg/kg), and PSP80EE (LP-BM5 MuLV infection+dietary supplement of 80% ethanol PSPE 300 mg/kg). Dietary supplementation began on the day of LP-BM5 MuLV infection and continued for 12 weeks. Dietary supplementation of PSPE inhibited LP-BM5 MuLV-induced splenomegaly and lymphadenopathy and attenuated the suppression of T- and B-cell proliferation and T helper 1/T helper 2 cytokine imbalance in LP-BM5 MuLV-infected mice. Dietary supplement of PSPE increased the activity of the antioxidant enzymes, superoxide dismutase and glutathione peroxidase. The data suggest that PSPE may ameliorate immune dysfunction due to LP-BM5 MuLV infection by modulating antioxidant defense systems.

Supplementation with Lactobacillus reuteri or L. acidophilus reduced intestinal shedding of cryptosporidium parvum oocysts in immunodeficient C57BL/6 mice.

The effect of L. acidophilus supplementation to reduce fecal shedding of Cryptosporidium parvum oocysts was compared to L. reuteri using C57BL/6 female mice immunosuppressed by murine leukemia virus (strain LP-BM5) inoculation. After 12 weeks post LP-BM5 inoculation, 15 immunosuppressed mice each were randomly assinged to one of the following treatment groups: historical control (group A), LP-BM5 control (group B), C. parvum (group C), L. reuteri plus C. parvum (group D) or L. acidophilus plus C. parvum (group E). Mice were pre-fed the L. reuteri or L. acidophilus bacteria strains daily for 13 days, challenged with C. parvum oocysts and thereafter fed the specified Lactobacillus regimens daily during the experimental period. Animals supplemented with L. reuteri shed fewer (p<0.05) oocysts on day-7 post C. parvum challenge compared to controls. Mice supplemented with L. acidophilus also shed fewer (p<0.05) oocysts on days 7 and 14 post-challenge compared to controls. Overall, Lactobacillus supplementation reduced C. parvum shedding in the feces but failed to suppress the production of T-helper type 2 cytokines [interleukin-4 (IL-4), IL-8)] which are associated with immunosuppression. Additionally, Lactobacillus supplementation did not restore T-helper type 1 cytokines (interleukin-2 (IL-2) and gamma interferon (IFN-gamma), which are required for recovery from parasitic infections. Altered T-helper types 1 and 2 cytokine production as a consequence of immunodysfunction permitted the development of persistent cryptosporidiosis while mice with intact immune system were refractory to infection with C. parvum. Reduction in shedding of oocysts observed in the Lactobacillus supplemented mice during deminished IL-2 and IFN-gamma production may be mediated by factors released into the intestinal lumen by the Lactobacillus and possibly other host cellular mechanisms. These observations suggest that L. reuteri or L. acidophilus can reduce C. parvum parasite burdens in the intestinal epithelium during cryptosporidiosis and may serve potential benefits as probiotics for host resistance to intestinal parasitic infections. L. acidophilus was more efficacious in reducing fecal shedding than L. reuteri and therefore may also have implication in the therapy of cryptosporidiosis during immunosuppressive states including human AIDS.

Immune dysfunction during alcohol consumption and murine AIDS: the protective role of dehydroepiandrosterone sulfate.

Acquired immune deficiency syndrome (AIDS) is a clinical disorder caused by the human immunodeficiency virus (HIV) after development of severe immunosuppressive changes. Chronic ethanol (EtOH) consumption accentuates the severity of murine AIDS (MAIDS). Because hormone production is often suppressed by chronic EtOH intake, as well as retrovirus infection, we investigated whether hormone supplementation during chronic EtOH consumption contributes to slowing immune dysfunction caused by LP-BM5 infection and/or EtOH use. Because dehydroepiandrosterone sulfate (DHEAS) was previously shown to have immune-enhancing properties during MAIDS, we determined whether DHEAS reduced cytokine dysregulation otherwise exacerbated by chronic EtOH intake during MAIDS. Adult female C57BL/6 mice were infected with LP-BM5 murine retrovirus. Some were fed 40% EtOH in drinking water and agar gel for 16 weeks postinfection. EtOH consumption further inhibited T- and B-cell proliferation beyond suppression due to retrovirus infection. Interleukin (IL)-2 release produced by concanavalin A-stimulated splenocytes was reduced by EtOH use by infected and uninfected mice. DHEAS overcame much of the effects induced by retrovirus infection and/or EtOH use. IL-4 secretion and IL-6 secretion were enhanced. Hepatic vitamin E levels were decreased by murine retrovirus infection, as well as by EtOH use in both uninfected and infected mice. In addition, DHEAS (0.01%) supplementation during MAIDS prevented the further dysregulation of cytokines and hepatic lipid peroxidation due to EtOH intake, partially restored T- and B-cell proliferation, and maintained hepatic vitamin E levels to near normal levels.

Prevention of immune dysfunction and vitamin E loss by dehydroepiandrosterone and melatonin supplementation during murine retrovirus infection.

Female C57BL/6 mice infected with the LP-BM5 leukaemia retrovirus developed murine acquired immune-deficiency syndrome (AIDS). Dehydroepiandrosterone (DHEA) and melatonin (MLT) modify immune dysfunction and prevent lipid peroxidation. We investigated whether DHEA and MLT could prevent immune dysfunction, excessive lipid peroxidation, and tissue vitamin E loss induced by retrovirus infection. Retrovirus infection inhibited the release of T helper 1 (Th1) cytokines, stimulated secretion of Th2 cytokines, increased hepatic lipid peroxidation, and induced vitamin E deficiency. Treatment with DHEA or MLT alone, as well as together, largely prevented the reduction of B- and T-cell proliferation as well as of Th1 cytokine secretion caused by retrovirus infection. Supplementation also suppressed the elevated production of Th2 cytokines stimulated by retrovirus infection. DHEA and MLT simultaneously reduced hepatic lipid peroxidation and prevented vitamin E loss. The use of DHEA plus MLT was more effective in preventing retrovirus-induced immune dysfunction than either DHEA or MLT alone. These results suggest that supplementation with DHEA and MLT may prevent cytokine dysregulation, lipid oxidation and tissue vitamin E loss induced by retrovirus infection. Similarly, hormone supplementation also modified immune function and increased tissue vitamin E levels in uninfected mice.

Cytokine dysregulation and increased oxidation is prevented by dehydroepiandrosterone in mice infected with murine leukemia retrovirus.

The effects of murine leukemia retrovirus infection on production of cytokines was investigated in mice fed different doses of dehydroepiandrosterone (DHEA). Young C57BL/6 female mice were injected with LP-BM5 murine retrovirus or were kept as uninfected controls. Two weeks later, each group was divided into subgroups: fed unsupplemented AIN 93 diet as the control, or diets supplemented with 0.02% DHEA (0.9 mg/mouse/day) or 0.06% DHEA (2.7 mg/mouse/day). The uninfected mice supplemented with 0.06% DHEA showed a significant (P < 0.05) increase in interleukin-2 (IL-2) and gamma-interferon (IFN-gamma) production, and hepatic vitamin E levels. Retroviral infection induced severe oxidative stress that was reduced by DHEAS supplementation in retrovirally infected mice. DHEA supplementation prevented the retrovirus-induced loss of cytokines (IL-2 and IFN-gamma) secretion by mitogen stimulated spleen cells. DHEA also suppressed the production of cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) by T helper 2 (Th2) cells which were otherwise stimulated by retrovirus infection. Thus, immune dysfunction and increased oxidation induced by murine retrovirus infection were largely prevented by DHEA.

Modulation of immune dysfunction during murine leukaemia retrovirus infection of old mice by dehydroepiandrosterone sulphate (DHEAS).

Ageing, leukaemia and acquired immune deficiency syndrome (AIDS) are conditions with dysregulated cytokine production. As dehydroepiandrosterone sulphate (DHEAS) restored normal cytokine production in old mice its effects on retrovirally infected old mice were investigated. Retrovirus infection and ageing-induced immune dysfunction. Murine retrovirus-infected old C57BL/6 female mice consumed 0.22 or 0.44 microgram of DHEAS/mouse/day beginning 2 weeks postinfection for 10 weeks. DHEAS largely prevented the retrovirus-induced reduction in T-cell and B-cell mitogenesis. DHEAS supplement prevented loss of cytokines [interleukin-2 (IL-2) and interferon-gamma] secretion by mitogen-stimulated splenocytes representing T helper 1 (Th1) cell phenotypes. It also suppressed the retrovirus-induced, excessive production of cytokines (IL-6 and IL-10) by Th2 cells. The highest dose of DHEAS reduced IL-6 production by splenocytes from uninfected old mice by 75% while increasing their IL-2 secretion by nearly 50%. Thus immune dysfunction induced by ageing, even when exacerbated by murine retrovirus infection, was largely prevented by DHEAS.

Effect of selenium supplementation on mice infected with LP-BM5 MuLV, a murine AIDS model.

LP-BM5 Murine leukemia virus (MuLV) infection of C57BL/6 mice develop a disease that has many features in common with human acquired immunodeficiency syndrome (AIDS), in particular abnormal lymphoproliferation and severe immunodeficiency. Thus, this MAIDS model may be useful for evaluation of potent antirival agents in vivo. Deficiency in antioxidant micronutrients such as selenium, zinc, and glutathione have been observed in AIDs and AIDS-related complex (ARC) patients. In the present study, the MAIDS model was used to evaluate immunological and oxidative effect of Se as sodium selenite. Results indicated that Se treatment 0.1 mg/kg/d (p.o.) inhibited splenomegaly and sera IgG elevation effectively. In addition to abnormal immunity, oxidative imbalance possibly existed in MAIDS model, as lipid peroxide increased significantly in spleen and whole blood glutathione peroxidase (GSH-Px) activity decreased markedly. Se supplementation had good protective effect.

Naturin: a potent bio-immunomodifier in experimental studies and clinical trials.

A number of traditional Chinese medicinal herbs have become extremely interesting in the search for potential BRMs in the international medical community, especially in the United States and Japan. Naturin, a new Chinese medical herb produced by XingYa Pharmaceutical Co., Ltd., has enhanced immune response, inhibited tumor metastases and retroviral infection in animal models as well as in clinical studies. The results demonstrated that the inhibition of Natural Killer (NK) and Lymphokine-activated Killer (LAK) cell activity and lymphocyte proliferation was compromised by tumor metastases and retrovirus infection (Murine AIDS), even immunosuppression induced by surgical amputation can be restored by Naturin. It is also shown that Naturin can protect the mice from lethal total body irradiation. These studies indicated that Naturin possesses immunomodulatory effects in vivo for a broad range of stresses. The results of the clinical studies on Naturin have demonstrated: (a) significantly improved symptoms of patients, including MDS, acute and chronic leukemia, aplastic anemia, lung cancer, and association with the increased number and percentage of CD4 (Helper T-cell) which have been reduced in some patients, (b) Lymphocyte proliferation and NK cell activity which were suppressed in cancer patients can be significantly restored by Naturin treatment, (c) the addition of Naturin treatment to patients receiving radiotherapy and chemotherapy augments immune response and reduces radiation and chemotherapy injury, and (d) no cytotoxic side effects were found in patients given Naturin treatment for up to eight months.

Therapeutic effects of glycyrrhizin in mice infected with LP-BM5 murine retrovirus and mechanisms involved in the prevention of disease progression.

Glycyrrhizin (GL), a plant extract, has been evaluated for its inhibitory effect on HIV replication in vitro and for its improvement of clinical symptoms in HIV-infected patients. In this study, we used GL in a murine AIDS model (MAIDS) to evaluate these effects. C57BL/6 mice were inoculated with LP-BM5 murine leukemia virus to cause MAIDS. Treatment with GL supplemented with glycine and cysteine (Stronger Neo-Minophagen C, SNMC) was then begun on day 0 or 4 wks after virus inoculation. SNMC was administered three times a week for up to 19 wks. Immunological abnormalities were monitored with respect to the surface phenotype identified by two-color staining for CD3 and IL-2 receptor beta-chain. All mice infected with the virus alone developed MAIDS and died by 14 wks after infection. The immunopathogenesis was estimated to be an abnormal expansion of intermediate CD3 cells (i.e., extrathymic T cells) as well as other types of lymphocytes. SNMC did not change the total mortality rate. However, some mice that began the treatment on day 0 or 4 wks after infection survived 3 wks longer. Splenomegaly and lymphadenopathy in such mice were suppressed. These mice showed normal phenotypic features and normal responses to Con A. These results suggest that SNMC is effective in some MAIDS mice in preventing the progression of disease. When lymphocytes isolated from the liver, spleen and lymph nodes of diseased mice were cultured in vitro, they showed a spontaneous proliferation. Interestingly, such proliferation was inhibited by addition of liver lymphocytes, but not splenic lymphocytes, obtained from normal or SNMC-treated mice. Since liver lymphocytes contains intermediate CD3 cells with autoreactivity, they may possibly suppress the progression of disease.

Immunomodulation by pycnogenol in retrovirus-infected or ethanol-fed mice.

Pycnogenol is a commercial mixture of bioflavonoids that exhibits antioxidative activity. The effects of dietary pycnogenol on immune dysfunction in normal mice as well as those fed ethanol or infected with the LP-BM5 murine retrovirus were determined. The ethanol consumption and retrovirus infection caused abnormalities in the function and/or structure of a broad array of cells involved in humoral and cellular immunity. Pycnogenol enhanced in vitro IL-2 production by mitogen-stimulated splenocytes if its production was suppressed in ethanol-fed or retrovirus-infected mice. Mitogenesis of splenocytes did not show a significant change in mice treated with pycnogenol. It reduced the elevated levels of interleukin-6 produced in vitro by cells from retrovirus infected mice and IL-10 secreted by spleen cells from mice consuming ethanol. Natural killer cell cytotoxicity was increased with pycnogenol treatment.

Vitamin E supplementation with interferon-gamma administration retards immune dysfunction during murine retrovirus infection.

Murine retrovirus infection induces loss of vitamin E and immune dysfunction with loss of cytokine production by T-helper cells. Therefore interferon-gamma (IFN-gamma) was given during dietary vitamin E supplementation to effectively prevent murine retrovirus-induced immunosuppression, cytokine dysregulation, and development of murine AIDS. Administration of IFN-gamma during vitamin E supplementation significantly prevented development of retrovirus-induced suppression of splenic natural killer cell activity and T cell proliferation. It also significantly slowed retrovirus-induced elevation of T helper (Th) 2 cytokine [interleukin (IL)-4, IL-5, and IL-10] production and monokine (IL-6 and tumor necrosis factor-alpha) secretion by splenocytes. The treatment also prevented loss of Th1 cytokine (IL-2 and IFN-gamma) secretion by splenocytes from retrovirus-infected mice alleviating splenomegaly and hypergammaglobulinemia. The combined therapy had an additive therapeutic impact. It was more effective than IFN-gamma treatment or vitamin E supplementation alone in delaying the development of retrovirus-induced immunosuppression with its cytokine dysregulation.

Modulation of immune function and cytokine production by various levels of vitamin E supplementation during murine AIDS.

Female C57BL/6 mice were infected with LP-BM5 retrovirus, causing murine AIDS which is functionally similar to human AIDS. Dietary supplementation, with a 15-, 150- and 450-fold increase of vitamin E in a liquid diet, significantly restored levels of interleukin-2 (IL) and interferon-gamma produced by splenocytes, which were suppressed by retrovirus infection. Retrovirus infection elevated levels of IL-6 and IL-10 produced by splenocytes, which were significantly normalized by all levels of vitamin E supplementation, respectively. Increased levels of IL-6 and tumor necrosis factor-alpha, produced by splenocytes during progression to murine AIDS, were also significantly normalized by all levels of vitamin E supplementation. Vitamin E supplementation restored retrovirus-suppressed splenocyte proliferation and natural killer cell cytotoxicity. Vitamin E supplementation also alleviated the AIDS symptoms: splenomegaly and hypergammaglobulinemia. These data indicate that dietary vitamin E supplementation at extremely high levels was not immunotoxic, and can modulate cytokine release and normalize immune dysfunctions during progression to murine AIDS. It should favorably affect host resistance and thereby retard the development of AIDS.

Nutritional status and immune responses in mice with murine AIDS are normalized by vitamin E supplementation.

Female C57BL/6 mice were infected with LP-BM5 retrovirus, causing murine AIDS, which is functionally similar to human AIDS. Vitamin E effects on immune functions, cytokine production and nutritional concentrations in retrovirus-infected mice were determined. Retrovirus infection inhibited release of interleukin-2 (IL) and interferon-gamma (IFN) and some immune functions, whereas it stimulated secretion of IL-4, IL-5, IL-6 and tumor necrosis factor-alpha (TNF) and immunoglobulin (Ig) production. Furthermore, retrovirus infection induced some nutritional deficiencies in the tissues. A 15-fold increase in dietary vitamin E largely restored concentrations of some micronutrients (vitamins A and E, zinc and copper) in the liver, intestine, serum and thymus. It also partially restored production of IL-2 and IFN-gamma by splenocytes. Retrovirus-induced elevated production of IL-4, IL-5 and IL-6 by splenocytes in vitro was normalized by vitamin E. Elevated release of IL-6, TNF-alpha, IgA and IgG produced by splenocytes in vitro during murine AIDS were also completely or partially normalized by vitamin E. Vitamin E also prevented retrovirus-induced suppression of splenocyte proliferation and natural killer cell activity. These data indicate that vitamin E supplementation during murine AIDS can help to ameliorate the disorders during murine AIDS, suggesting vitamin E usefulness in treatment of AIDS in humans.

Long-term dietary vitamin E retards development of retrovirus-induced disregulation in cytokine production.

A 15-fold increase in dietary vitamin E (160 IU/liter) normalized hepatic and serum levels of vitamin E normally reduced by retrovirus infection. It also significantly retarded development of splenomegaly and hypergammaglobulinemia induced by retrovirus infection, while significantly restoring release of interleukin-2 (IL) and interferon-gamma by splenocytes which are suppressed by retrovirus infection. Retrovirus infection elevated production of IL-4 and IL-6 by splenocytes, but this elevation was inhibited by vitamin E. Increased levels of IL-6 and tumor necrosis factor-alpha produced by splenocytes during progression to murine AIDS were also inhibited by vitamin E. Vitamin E supplementation also helped restore retrovirus-suppressed splenocyte proliferation. These data indicate that vitamin E supplementation can help overcome retrovirus-induced reduction in tissue vitamin E, modulate cytokine release, and normalize immune dysfunctions during progression to murine AIDS.

Ethanol, immune responses, and murine AIDS: the role of vitamin E as an immunostimulant and antioxidant.

Excessive alcohol consumption is a major health problem in the United States. Prolonged consumption of alcohol results in alterations of immune responses, ultimately manifested by increasing susceptibility to infectious agents. Such changes can be due to the direct effects of alcohol or its metabolites on immune cells, as well as to nutritional deficiency, oxidative stress, and neutrophil dysfunctions. This ETOH-induced immunosuppression could be a potential cofactor in the progression to AIDS. As vitamin E supplementation has been associated with enhancement of immune response and improvement of host defense, it may provide a useful therapeutic approach for treatment of alcoholics to improve host defense. This article is a review of alcohol-related immunosuppression as a possible cofactor in the development of AIDS, and vitamin E-related immunoenhancing roles in animals and humans, showing why vitamin E supplementation could be used as a useful adjunct agent in alcoholics' treatment. Since there is little information available regarding nutritional therapy with alcohol users, our purpose is to provide evidence from animal models of the potential therapeutic role of vitamin E supplementation in the treatment of alcoholics.

Vitamin E supplementation at various levels alters cytokine production by thymocytes during retrovirus infection causing murine AIDS.

Female C57BL/6 mice were infected with LP-BM5 retrovirus, causing murine AIDS which is functionally similar to human AIDS. Retrovirus infection targets the thymus producing altered T-cell differentiation via the dysregulation of thymocyte cytokine production. Therefore the effects of dietary vitamin E at various levels were determined on cytokine production by ConA-stimulated thymocytes from uninfected (normal) and retrovirus-infected mice. Dietary supplementation, with a 15-, 150- and 450-fold increase of vitamin E in the diet modulated interleukin-2 (IL) production in both uninfected mice and retrovirus-infected mice. The 150- and 450-fold vitamin E supplementation significantly reduced IL-4 secretion by thymocytes from the uninfected, normal mice. Supplementation at all levels also significantly reduced IL-4 production by thymocytes, which was elevated by the retrovirus infection. Vitamin E significantly reduced IL-6 and interferon-gamma production increased during the progression to murine AIDS. The effects of dietary vitamin E on conA-induced proliferation of thymocytes were consistent with the finding on changes of IL-2 secretion. No effect of dietary vitamin E on thymus weight was observed in both uninfected and retrovirus-infected mice. These data indicate that dietary vitamin E supplementation at extremely high levels can modulate cytokine production by thymocytes. This could affect T-cell differentiation, especially during murine AIDS when cytokine production was partially normalized by vitamin E supplementation.

Enhancement of resistance to Cryptosporidium parvum by pooled bovine colostrum during murine retroviral infection.

The therapeutic efficacy of pooled bovine colostrum for the control of cryptosporidiosis was investigated during murine acquired immunodeficiency syndrome in female C57Bl/6 mice. Mice were infected with LP-BM5 murine leukemia retrovirus for four months and then inoculated with Cryptosporidium parvum oocysts. Persistent cryptosporidiosis was established in all retrovirus immunosuppressed mice, while control mice were refractory to infection. Parasite colonization of intestinal villi was significantly (P < 0.05) reduced in immunosuppressed animals that received dietary supplemental pooled bovine colostrum compared with to those that did not receive colostrum treatment. Similarly, shedding of oocysts in the feces of immunosuppressed animals that received dietary pooled bovine colostrum was significantly (P < 0.05) reduced compared with those that did not at 26 days post-parasite challenge. Since the nonimmune bovine colostrum contained no anti-Cryptosporidium antibodies, this suggests that passively transferred antibodies alone are unlikely to have provided the improved resistance shown in this study.

Resistance to intestinal parasites during murine AIDS: role of alcohol and nutrition in immune dysfunction.

A murine AIDS model with many similarities to human AIDS, LP-BM5 Murine Leukaemia, suppresses T and B cell numbers and functions in the intestine. This permits chronic colonization by Giardia and Cryptosporidium. Cocaine and the nutrient alcohol, which are immunosuppressive, further reduce resistance to intestinal parasites and intestinal lymphocyte numbers. Protein undernutrition, vitamin E supplementation, and alcohol use further modify immune dysfunction induced by the murine retrovirus infection. This suggests that both undernutrition and nutrient supplementation could affect parasite resistance during AIDS. Thus this murine model of human AIDS has great potential to accelerate studies of the role of nutrients in immune dysfunction and resistance to intestinal parasites.