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ABSTRACT: OBJECTIVE: Silymarin, a flavonolignan complex isolated from milk thistle, is a cytoprotective, antioxidant, and hepatoprotective agent. The present study was designed to investigate the immunomodulatory effects of orally administered silymarin in patients with β-thalassemia major. METHODS: The immunomodulatory effects of silymarin were investigated in a 12-week clinical trial in two groups of patients. In combined therapy group (n=25), patients continued desferrioxamine at the dose of 40mg/kg/day and Legalon® tablets (420mg daily) were added to desferrioxamine. In silymarin group (n=5), patients who were unable or unwilling to use desferrioxamine received only silymarin. Immunological tests were assessed at the beginning and the end of the trial. RESULTS: No differences were detected between treatment groups regarding the percentage of lymphocyte subsets, concentration of serum immunoglobulins, complement levels, or T cell proliferation in vitro. Serum tumor necrosis factor (TNF-α) levels were significantly decreased in both groups, whereas the serum levels of neopterin significantly decreased in both groups after silymarin therapy. The analysis of cell culture supernatants of activated T cells showed increased production of interferon gamma (IFNγ) and interleukin (IL)-4 after silymarin treatment in both groups. CONCLUSION: Silymarin stimulates cell-mediated immune response in β-thalassemia major, possibly through a direct action on cytokine-producing mononuclear cells. Because of its immunostimulatory, antioxidant, and iron-chelating activities, silymarin could be a good candidate in the therapy of chronic iron overload in combination with routine iron chelators in clinical use like desferrioxamine.
International immunopharmacology 04/2013; · 2.21 Impact Factor
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ABSTRACT: Silymarin, a complex flavonolignan from the 'milk thistle' (Silybum marianum) plant, exhibits anti-carcinogenic, anti-inflammatory and cytoprotective effects. Several reports have demonstrated immunosuppressive activity of silymarin; however, the molecular mechanisms involved in immunomodulatory activities of silymarin are not fully understood yet. In this study, the effect of silymarin on cell cycle and PI3K/Akt/mTOR signaling pathway of activated T lymphocytes were investigated in vitro. Peripheral blood mononuclear cells (PBMC) were isolated from healthy volunteers and activated with anti-CD3 (5μg/ml) and anti-CD28 (2μg/ml) monoclonal antibodies. Cells were cultured in RPMI complete medium with 10, 50 and 100μM silymarin or dimethyl sulfoxide (DMSO) and incubated for 24-96 hr. Cell cycle analysis was performed by PI staining and flow cytometry. The effect of silymarin on PI3K/AKT signaling pathway and mTOR activity were determined in activated T cells after 72-hr incubation with silymarin or DMSO. A significant G1 arrest in cell cycle of activated T lymphocytes was found after 96-hr incubation with 100μM silymarin without causing cell death. Silymarin also significantly inhibited the level of phospho-S6 ribosomal protein and mTOR activity in cell lysates of activated T cells after 72-hr incubation in comparison with DMSO. This study shows that silymarin inhibits cell proliferation through G1 cell cycle arrest and also through the suppression of the mTOR signaling pathway in human activated T lymphocytes in vitro. Characterizing molecular mechanism of such immunomodulatory effects may have a great potential in future practical application of silymarin in transplantation and autoimmunity.
Basic & Clinical Pharmacology & Toxicology 11/2012; · 2.18 Impact Factor
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ABSTRACT: Aim: The CD133 antigen has been identified as a putative stem cell marker in colorectal cancer tissues. The aim of this study was to investigate the cell cycle state of CD133 + and CD133 - cells, isolated from primary human colorectal tumors. Materials and Methods: After mechanical and enzymatic dissociation of the tumor samples, CD133 + and CD133 - subsets were identified and separated by magnetic cell sorting. Flow cytometric analysis was performed to compare the cell cycle of both CD133 + and CD133 - cells isolated from primary and liver metastatic cancer cells. Results: The results indicated that CD133 + cells isolated from both primary and liver metastatic colorectal cancers were found in higher percentage in the G0/G1 phases. However, the CD133 - cells isolated from primary colorectal cancers were predominantly found in the S and G2/M phases. Surprisingly, the CD133 - cells isolated from liver metastatic colorectal cancers were mostly found in the G0/G1 phase. Conclusion: The present study provides evidence that CD133 + cells are in a quiescent state in colorectal cancer, representing a mechanism that would at least partially explain chemotherapy resistance and tumor recurrence in post-therapy patients.
Journal of cancer research and therapeutics 07/2012; 8(3):399-403. · 0.83 Impact Factor
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Journal of Genetics 04/2012; 84(1):47-48. · 1.09 Impact Factor
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ABSTRACT: Silymarin, a mixture of bioactive flavonolignans isolated from Silybum marianum, exhibits anti-carcinogenic, anti-inflammatory and cytoprotective effects. In this study, the in vitro immunomodulatory activity of silymarin was investigated using CD4+ splenocytes from C57/Bl6 mice. Proliferation assay revealed that silymarin, at 50 microM concentration, significantly inhibited CD4+ cells proliferation. ELISA analyses indicated that silymarin significantly inhibited IL-2 and IFN-gamma production. Immunofluorescence staining performed on the mouse hybridoma T cell line (3DO) revealed a block of nuclear translocation of transcription factor kappaB (NF-kappaB), which is known to be responsible for IL-2 transcriptional activation. Moreover, silymarin inhibited p65/NF-kappaB phosphorylation in CD4+ T cell. These results suggest that silymarin is able to inhibit T cell activation and proliferation, notably acting on pathways of NF-kappaB activation/translocation.
Pharmacological Research 05/2010; 61(5):405-9. · 4.44 Impact Factor
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ABSTRACT: Recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses prior to the 20th week of gestation. The aim of this study was to investigate the expression of T helper (Th)1- and Th2-related chemokine receptors on CD4(+) T helper and CD8(+) T cytotoxic (Tc) cells in RM and control subjects. The effects of lymphocyte immunotherapy on the balance of Th1/Th2 and Tc1/Tc2 chemokine receptors were further evaluated in RM women.
The expression of Th1-related (CCR5 and CXCR3) and Th2-related (CCR3 and CCR4) chemokine receptors on CD4(+) or CD8(+) T cells from RM women were analyzed and compared with controls using flow cytometry. The expression of chemokine receptors in RM women was also compared before and after lymphocyte immunotherapy.
The ratios of Th1/Th2 and Tc1/Tc2 chemokine receptors were higher in RM women compared to controls. The ratio of Th1/Th2 chemokine receptors was decreased in RM women after immunotherapy, while no significant change was identified in the Tc1/Tc2 after immunotherapy.
This study indicates the Th1 dominant immune responses in circulation of RM women compared to controls. Moreover, lymphocyte immunotherapy might influence pregnancy outcome via a shift in the balance of the Th1/Th2 chemokine receptors.
American Journal Of Reproductive Immunology 03/2010; 64(2):104-12. · 2.17 Impact Factor
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ABSTRACT: Silymarin, a flavonolignan complex isolated from Silybum marianum, has a strong antioxidant, hepatoprotective, and iron chelating activities. The present study was designed to investigate the therapeutic activity of orally administered silymarin in patients with thalassemia major under conventional iron chelation therapy. A 3-month randomized, double-blind, clinical trial was conducted in 59 beta-thalassemia major patients in two well-matched groups. Patients were randomized to receive a silymarin tablet (140 mg) three times a day plus conventional desferrioxamine therapy. The second group received the same therapy but a placebo tablet instead of silymarin. Clinical laboratory tests were assessed at the beginning and the end of the trial, except for serum ferritin level that was assessed at the middle of the trial as well. Results of this study revealed that the combined therapy was well tolerated and more effective than desferrioxamine in reducing serum ferritin level. Significant improvement in liver alkaline phosphatase and glutathione levels of red blood cells was also observed in silymarin-treated beta-thalassemia patients. However, no significant difference in serum ferritin levels was detected between silymarin and placebo groups after 1.5 and 3 months treatment, probably because of insufficient sample size to detect subtle changes in ferritin levels between groups. This is the first report showing the beneficial effects of silymarin in thalassemia patients and suggests that silymarin in combination with desferrioxamine can be safely and effectively used in the treatment of iron-loaded patients.
Fundamental and Clinical Pharmacology 06/2009; 23(3):359-65. · 1.80 Impact Factor
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ABSTRACT: Iron is an essential trace element in cell proliferation. Several investigations demonstrate that iron deprivation inhibits cell proliferation. However, the impact of iron on telomerase activity of activated lymphocytes remains unexplained to date.
In this study, the effect of iron on the proliferation and telomerase activity of lymphocytes stimulated by phytohemagglutinin (PHA) were investigated.
Iron loading was performed by incubating peripheral blood mononuclear cells in 500microM FeSO4.7H2O for 24 h and iron chelation was done by exposing cells to desferrioxamine, a potent iron chelator. The effects of silymarin, a flavonoid with both antioxidant and iron chelating activities, on the proliferation and telomerase activity of PHA-activated lymphocytes were also compared with desferrioxamine. Proliferation and telomerase activity were assessed using BrdU incorporation assay and Telomeric Repeat Amplification Protocol (TRAP), respectively.
The proliferations of lymphocytes were significantly inhibited by 10 and 20 microg/ml desferrioxamine in a dose dependent manner, while iron loading recovered suppressed cell proliferation to the normal level. Silymarin at 20 microg/ml significantly increased the proliferation of lymphocytes in both normal and iron-treated conditions. Telomerase activity of lymphocytes was markedly increased by iron treatment and suppressed by desferrioxamine. Conversely, iron treatment had no effect on the telomerase activity of lymphocytes incubated with silymarin.
Iron plays a significant role in the proliferation and telomerase activity of lymphocytes. The effects of silymarin on the proliferation and telomerase activity of lymphocytes were completely different from those of desferrioxamine, suggesting that the immunomodulatory effect of silymarin is probably not associated with its iron chelating activity.
Iranian journal of immunology: IJI 04/2009; 6(1):33-9.
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ABSTRACT: Several researches have demonstrated a suppressed cell mediated immunity in patients with beta-thalassemia major. To know whether the premature aging of T cells is involved in abnormalities of cell mediated immunity, the biomarkers of immunosenescence including telomerase activity, apoptosis, and the expression of CD28 and CD95 were evaluated in T lymphocytes from beta-thalassemia major patients. The ex vivo spontaneous apoptosis in CD4(+) or CD8(+) T cells from patients and healthy subjects was assessed by an in situ TdT mediated dUTP-biotin nick end labelling (TUNEL) assay after 24h incubation in medium. Flow cytometric data revealed that lymphocytes from beta-thalassemia patients were resistant to spontaneous apoptosis compared to the normal lymphocytes. Moreover, the percentages of TUNEL(+)CD4(+) or TUNEL(+)CD8(+) T cells from patients were significantly lower than those control cells. Quantitative determination of telomerase activity in resting and activated T cells was performed using the Telomeric Repeat Amplification Protocol (TRAP). The results showed a decreased telomerase activity of activated T cells in patients with thalassemia major compared to that in healthy controls. However, the percentages of CD8(+)CD28(-) and CD3(+)CD95(+) T lymphocytes were significantly higher in thalassemia patients, indicating the phenotypes associated with senescent T lymphocytes. These data provide evidences for the occurrence of accelerated aging of T cells in beta-thalassemia major; possibly result in abnormal T cell function leading to suppressed cell mediated immunity.
Immunology letters 01/2009; 122(1):84-8. · 2.91 Impact Factor
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ABSTRACT: Angiogenic therapy is one of the new treatments of ischaemic heart disease. Oestrogen has angiogenic properties under hypoxic condition, and if oestrogen also induces angiogenesis under normoxic condition, it could be used in combination with other angiogenic therapies in the treatment of ischaemic heart disease. In this study, we evaluated the angiogenic effect of high-dose oestrogen treatment in normoxic rat heart tissue. Fifty-two ovariectomized rats were randomized in oestrogen-treated and control groups. 17beta-oestradiol (1 mg/week) and normal saline (1 mg/week) were administered intramuscularly in the treatment and control groups for 2 months. After that, coronary capillary density and coronary vessel permeability were measured. The serum vascular endothelial growth factor (VEGF) level was also measured before and after the treatment. The results indicate that coronary capillary density (number of capillary per square millimetre) and coronary vessel permeability (fluorescence intensity) were significantly higher in the oestrogen-treated group than in the control group (628 +/- 26 per mm(2) versus 540 +/- 26 per mm(2); P < 0.05 and 207 +/- 10 versus 147 +/- 19 per gram tissue; P < 0.05). Oestrogen treatment increased serum VEGF level in the oestrogen-treated group compared to the control group (52 +/- 3 versus 33 +/- 6 pg/ml; P < 0.05), but interestingly VEGF was also increased in the control group after placebo treatment. It seems that high-dose oestrogen administration has angiogenic properties even in normoxic conditions. These angiogenic properties may result from oestrogen's direct effect on VEGF or other mechanisms, such as endothelial progenitor cell mobilization. Because of the broad effect of oestrogen on angiogenic growth factors and endothelial cells, more studies are required to clarify angiogenic properties of high-dose oestrogen.
Basic & Clinical Pharmacology & Toxicology 10/2008; 103(3):273-7. · 2.18 Impact Factor
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ABSTRACT: In this study, the immunologic abnormalities of Iranian beta-thalassemia major patients were characterized, considering their clinical parameters including splenectomy status and iron overload. Serum samples and peripheral blood mononuclear cells were collected from 28 patients and 30 age- and sex-matched healthy individuals. Patients with thalassemia showed significantly increased absolute lymphocyte counts compared with the control group. An increased number of activated T cells and higher levels of serum neopterin were also observed in thalassemia patients, which suggest chronic stimulation of immune system. On the contrary, T-cell proliferation and interleukin 2 (IL-2), interferon gamma (IFN-gamma), and IL-4 production were suppressed in patients compared to controls. Patients with high serum ferritin levels produced significantly less IFN-gamma and IL-2, indicating the immunosuppressive effect of iron overload in beta-thalassemia patients. The serum levels of tumor necrosis factor alpha and absolute counts and percentages of B and T cells were higher in splenectomized patients; however, serum levels of neopterin significantly decreased in splenectomized patients compared to the non-splenectomized group. Taken together, T lymphocytes express activated phenotype in polytransfused beta-thalassemia major patients, while T cell proliferation and effector function are significantly suppressed. Multiple blood transfusion and continuous immune stimulation could be responsible for making such a double-faced immune response.
Annals of Hematology 09/2008; 88(1):21-7. · 2.62 Impact Factor
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ABSTRACT: Silybin is a flavonoid with antioxidant and free radical scavenging abilities. Silybin also acts as an iron chelator by binding Fe (III). The present study was undertaken to assess the biological effects of silybin on T leukemia cells in the presence or absence of iron and compare its effects with a well-known iron chelator; desferrioxamine. In these experiments, we studied the growth capacity of Jurkat while varying iron availability in the environment. Desferrioxamine significantly inhibited growth and proliferation of Jurkat cells, blocking treated cells in the G0/G1 phase and inducing apoptosis. In contrast, silybin showed a bimodal effect, inducing cell proliferation at lower concentrations whereas inhibition of DNA synthesis and significant cell death was observed at higher concentrations. Chelation of Fe totally abrogated antiproliferative, cytotoxic and apoptotic effects of desferrioxamine on Jurkat cells. Conversely, the silybin-Fe complex had no appreciable effect on its antiproliferative and cytotoxic activities. The cytotoxic effect of desferrioxamine was also prevented in iron-loaded Jurkat cells; however, the effect of silybin on the growth and viability of iron-loaded cells was similar to the effect of its iron complex on untreated Jurkat cells. Despite the Fe chelating activity of silybin that suggests its possible application in chelation therapy of chronic iron overload, the biological effects of silybin on Jurkat cells are different than those of desferrioxamine, probably due to antioxidant activity of silybin, which causes pro-oxidant effect via iron-catalyzed oxidation with the subsequent generation of reactive oxygen species.
European Journal of Pharmacology 05/2008; 589(1-3):1-7. · 2.52 Impact Factor
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ABSTRACT: The frequency of SDF1-3'A and CCR5Delta32 in patients with head and neck cancer were determined in this study. The frequencies of alleles and genotypes of SDF-1 and CCR5 were assessed by PCR method in 156 patients with malignant head and neck cancer, 125 (80.1%) cases with squamous cell carcinoma and 31 (19.9%) cases with salivary gland tumors and compared with 262 age-sex matched healthy control individuals. SDF-1 genotypes in patients with SCC of head and neck, but not with salivary gland tumors, showed a statistically significant difference compared to the normal group (P < 0.005 for SCC and P = 0.3 for salivary gland tumors). There were no significant differences in the frequencies of SDF1-3'A allele, CCR5 genotypes and alleles between patients and controls. Based on the present study SDF1-3A may be associated with the susceptibility of patients to SCC of head and neck cancer.
Pathology & Oncology Research 02/2008; 14(1):45-50. · 1.37 Impact Factor
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ABSTRACT: Silymarin is a polyphenolic flavonoid that has a strong antioxidant activity and exhibits anti-carcinogenic, anti-inflammatory, and cytoprotective effects. Although its hepatoprotective effect has been well documented, the effect of silymarin on T cells is largely unknown. The purpose of this study was to analyze the effects of the silymarin on the proliferation and cell cycle progression of Jurkat cells, a human peripheral blood leukemia T cell line. Cells were incubated with various concentrations of silymarin for 24-72 h and examined for cell growth and proliferation using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and DNA 5-bromo 2'-deoxyuridine (BrdU) colorimetric assays. Cell cycle analysis by flow cytometry was also performed using propidium iodide staining. Results of the study revealed that silymarin increased proliferation of Jurkat cells at 50-400 microM concentrations with 24 h exposure, confirmed by both MTT and BrdU assays. However, Jurkat incubation with silymarin at higher concentrations of 400 microM for 48 h and 200-400 microM for 72 h caused inhibition of DNA synthesis, cell cycle arrest at the G2/M phase and significant cell death. Results of the present study also revealed a similarity of cell growth patterns between Jurkat, U937 and RPMI 8866 cells. In conclusion, this study demonstrated an in vitro growth stimulatory effect of silymarin on leukemia cells with monocyte, T and B cell origin that has not been previously reported for either solid tumors or other leukemia cells, suggesting a possible specific stimulatory effect of silymarin on the key cells of the immune system.
Journal of Cancer Research and Clinical Oncology 09/2007; 133(8):525-32. · 2.56 Impact Factor
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ABSTRACT: Iron toxicity in beta-thalassemia major is the main cause of oxidative stress and cell mediated immune deficiencies. Despite indicative signs of severe oxidative deficiencies associated with beta-thalassemia major, such as decreased level of plasma antioxidants and depletion of erythrocyte glutathione, little is known about intracellular redox status of immune cells. Since glutathione is a primary intracellular antioxidant and plays an essential role in several functions in T cells, in this study intracellular glutathione (GSH) levels as well as proliferation of PHA-activated peripheral blood mononuclear cells (PBMC) were investigated in 28 beta-thalassemia major patients and 28 healthy age-matched individuals. Considering the potential benefits of flavonoids in the therapy of oxidative stress, the effects of silymarin on the GSH levels and proliferation of PBMC from normal and thalassemia individuals were further examined. Quantitative determination of intracellular GSH and proliferative response of PBMC to PHA were performed before and after 72 h incubation of PBMC with various concentrations of silymarin (0, 5, 10, or 20 mug/ml). Results demonstrated a significant reduction of GSH and proliferation in beta-thalassemia major cells; however treatment with silymarin led to restoration of both GSH levels and PBMC proliferation in thalassemia patients. Considerably low levels of GSH and depressed proliferative response of PBMC in beta-thalassemia major may be responsible for the cell mediated immune abnormalities in iron overload conditions. Moreover, the GSH restoration and improvement of PBMC growth by silymarin is a possible explanation for its recently reported antioxidant and immunostimulatory activities. These data suggest the benefit of using flavonoids to normalize immune dysfunction in beta-thalassemia major. The immunomodulatory effects of silymarin in beta-thalassemia major are currently under further investigation in a double blind clinical trial.
International Immunopharmacology 09/2006; 6(8):1305-10. · 2.38 Impact Factor
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Journal of Genetics 05/2005; 84(1):47-8. · 1.09 Impact Factor
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ABSTRACT: Host genetic control of HIV infection involves certain polymorphisms of some chemokine receptor genes that are associated with susceptibility and progression of HIV-1 infection. Recent data suggest that two important polymorphisms in CCR2 and CCR5 chemokine receptors, CCR5Delta32 and CCR2-64I, prevent HIV transmission and delay disease progression. In this study allele and haplotype frequencies of the CCR5Delta32 and CCR2-64I mutations were determined in southern Iranian normal population using PCR and PCR restriction fragment length polymorphism (PCR-RFLP) assays. Allele frequencies and the fit to the Hardy-Weinberg equilibrium (HWE) were evaluated by Arlequin population genetic software. Frequencies of CCR5Delta32 and CCR2-64I alleles were 0.0146 and 0.1221, respectively. Moreover, higher and lower haplotype frequencies in 341 normal individuals were CCR2/CCR5 (0.8636) and CCR5/CCR2-64I (0.1217), respectively. Only one case with CCR5Delta32/CCR2-64I haplotype was found among the studied normal population. This data is the first finding on the frequencies of CCR5Delta32 and CCR2-64I alleles in Iranian population. Results of the present study suggest that low frequency of CCR5Delta32 allele may be related to higher genetic susceptibility to the HIV-1 infection in Iranians. Results also suggest that the CCR2-64I mutation is sufficiently common in Iranians and may be associated with slower HIV infection progression in Iran.
Immunology Letters 02/2005; 96(2):277-81. · 2.53 Impact Factor
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ABSTRACT: Several researches have demonstrated a suppressed cell mediated immunity in patients with β-thalassemia major. To know whether the premature aging of T cells is involved in abnormalities of cell mediated immunity, the biomarkers of immunosenescence including telomerase activity, apoptosis, and the expression of CD28 and CD95 were evaluated in T lymphocytes from β-thalassemia major patients. The ex vivo spontaneous apoptosis in CD4+ or CD8+ T cells from patients and healthy subjects was assessed by an in situ TdT mediated dUTP-biotin nick end labelling (TUNEL) assay after 24 h incubation in medium. Flow cytometric data revealed that lymphocytes from β-thalassemia patients were resistant to spontaneous apoptosis compared to the normal lymphocytes. Moreover, the percentages of TUNEL+CD4+ or TUNEL+CD8+ T cells from patients were significantly lower than those control cells. Quantitative determination of telomerase activity in resting and activated T cells was performed using the Telomeric Repeat Amplification Protocol (TRAP). The results showed a decreased telomerase activity of activated T cells in patients with thalassemia major compared to that in healthy controls. However, the percentages of CD8+CD28− and CD3+CD95+ T lymphocytes were significantly higher in thalassemia patients, indicating the phenotypes associated with senescent T lymphocytes. These data provide evidences for the occurrence of accelerated aging of T cells in β-thalassemia major; possibly result in abnormal T cell function leading to suppressed cell mediated immunity.
Immunology Letters.
