Effect of Short-Term Tacrolimus Exposure on Rat Liver: An Insight into Serum Antioxidant Status, Liver Lipid Peroxidation, and Inflammation.

Tacrolimus (TAC) is an immunosuppressive drug, optimally used for liver, kidney, and heart transplant to avoid immune rejection. In retrospect, a multitude of studies have reported effects of TAC, such as nephrotoxicity, diabetes, and other complications. However, limited information is available regarding short-term exposure of TAC on the liver. Therefore, the present study was designed to unravel the effects of short-term exposure of TAC on a rat model. The animal model was established by TAC administration for 6, 12, 24, and 48 h time points. Liver histopathological changes were observed with PAS-D, reticulin stain, and immunostaining of PCNA and CK-7 coupled with glycogen quantification in a liver homogenate. TUNEL assay was performed to evaluate the DNA damage in the liver. Concentration of GSH and activities of SOD and CAT in the serum were measured to assess the antioxidant status, whereas liver tissue MDA level was measured as a biomarker of oxidative stress. Hepatic gene expression analysis of IL-10, IL-13, SOCS-2, and SOCS-3 was performed by RT-PCR. Results revealed marked changes in liver architecture of all TAC-treated groups, as evidenced by sinusoid dilation, hepatocyte derangement, glycogen deposition, and collapsed reticulin fibers. Significant increase in PCNA and CK-7 immunostaining along with the presence of TUNEL-positive cells was revealed in treatment groups as compared to the control group. Serum antioxidant enzyme status was markedly decreased, whereas the liver MDA level was increased in TAC treatment groups indicating oxidative stress induction. The gene expression profile of cytokines was significantly upregulated in treatment groups highlighting an inflammatory response. In conclusion, results of the current study propose that even a short-term TAC exposure can induce change in antioxidant status and lipid peroxidation. Therefore, these factors should be considered to avoid and minimize immunosuppression-related issues in a prolonged course of treatment.

In situ immunopathological changes in cutaneous leishmaniasis due to Leishmania donovani.

Cutaneous leishmaniasis in Sri Lanka is a newly established parasitic disease caused by the usually visceralizing Leishmania donovani. Skin lesions manifest as non-itchy, non-tender papules, nodules or ulcers. In situ cytokine expression provides clues for immunopathogenesis of this localized form of disease. Skin biopsies from 58 patients were analyzed for histological appearance and in situ cytokine expression of T-helper 1 (Th1) and T-helper 2 (Th2) cytokines, namely interferon (IFN)-γ, interleukin (IL)-12A, tumor necrosis factor (TNF)-α, IL-4 and IL-10 by real-time RT-PCR. Significant up-regulation of the Th1 cytokine IFN-γ and down-regulation of the Th2 cytokine IL-4 were seen in patients compared to healthy controls. Significantly elevated tissue expression of IFN-γ and TNF-α was seen in lesions that presented later than 6 months from the time of onset, while IL-4 expression was more prominent in lesions that responded poorly to antimony therapy. A prominent Th1 response appears to support resolving of lesions, whereas a Th2-biased milieu tends to favor poor responsiveness to antimony and delayed lesion healing in L. donovani infections in Sri Lanka.

Long-term efficacy of single-dose radiofrequency-induced heat therapy vs. intralesional antimonials for cutaneous leishmaniasis in India.

BACKGROUND: Radiofrequency-induced heat therapy (RFHT) has been found to be safe and effective against cutaneous leishmaniasis (CL) in the short term, but its long-term efficacy is unclear. OBJECTIVES: To compare the long-term efficacy of RFHT vs. intralesional sodium stibogluconate (SSG) injections in the treatment of CL in India. METHODS: One hundred patients with a confirmed diagnosis of CL were randomly assigned in a 1 : 1 ratio to receive topical RFHT for 30-60 s or seven intralesional injections of SSG (50 mg cm(-2) of lesion). Improvement and recurrence were monitored every 15 days after the initiation of treatment for 4 months and then at 5, 6, 9, 12 and 18 months post-treatment; the rates of complete cure were compared. RESULTS: Lesions were healed in 47 out of 50 patients (94%) in the RFHT group and in 46 out of 50 patients (92%) in the SSG group at week 12. Time to complete healing was comparable in the two groups. At 6 months post-treatment, cure rates in the RFHT and SSG groups were 98% [95% confidence interval (CI) 94-100%] and 94% (95% CI 86-100%), respectively. Age, sex and lesion size or number had no effect on cure rates. No relapse of infection was recorded in cured patients in either group up to 12-18 months after initiation of treatment. Skin biopsies of cured lesions in eight out of eight (100%) patients from the RFHT group and three of three from the SSG group at 12 months showed minimal fibrosis and were negative for Leishmania tropica by polymerase chain reaction test. CONCLUSIONS: A single application of RFHT is safe, cosmetically acceptable and effective in inducing a long-term cure of CL.

Interaction of tacrolimus through hedgehog signaling pathway: An in vitro evaluation using rat hepatocytes.

Tacrolimus (TAC) is the drug of choice in immunosuppressive therapy for organ transplantation; however, adverse effects are still a major concern. The current study aims to decipher the short-term exposure of TAC on rat hepatocytes in relation to activation of hedgehog (HH) signaling pathway. Time dependent study was conducted using primary rat hepatocytes treated with TAC (36 µM) for 6, 12, 24 and 48 h. Western blot analysis was performed using cell lysate in order to analyze the regulation of HH pathway proteins including HHIP, SMO, PTCH, IHH, SHH, and GLI transcription factors. The study revealed change in protein expression of HH signaling molecules with activation of HH pathway, due to downregulation of HHIP, and enrichment of HH ligands with activation of SMO and GLI transcription factors. It is therefore, concluded that short term TAC exposure leads to upregulation of HH pathway in liver, which may initially act to repair the liver damage but can worsen the condition in case of prolonged immunosuppressive therapy. This insight could lead to understand association of off target effects of immunosuppressive drugs and occurrence of other liver diseases in transplant patients when it comes to long term immunosuppressive therapy. These findings also illuminate a novel direction that use of HH inhibitor might provide a therapeutic strategy for immune suppression related liver disorders.

Targeted disruption of migration inhibitory factor gene reveals its critical role in sepsis.

To study the biologic role of migration inhibitory factor (MIF), a pleiotropic cytokine, we generated a mouse strain lacking MIF by gene targeting in embryonic stem cells. Analysis of the role of MIF during sepsis showed that MIF-/- mice were resistant to the lethal effects of high dose bacterial lipopolysaccharide (LPS), or Staphylococcus aureus enterotoxin B (SEB) with D-galactosamine and had lower plasma levels of tumor necrosis factor alpha (TNF-alpha) than did wild-type mice, but normal levels of interleukin (IL)-6 and IL-10. When stimulated with LPS and interferon gamma, macrophages from MIF-/- mice showed diminished production of TNF-alpha, normal IL-6 and IL-12, and increased production of nitric oxide. MIF-/- animals cleared gram-negative bacteria Pseudomonas aeruginosa instilled into the trachea better than did wild-type mice and had diminished neutrophil accumulation in their bronchoalveolar fluid compared to the wild-type mice. Thioglycollate elicited peritoneal exudates in uninfected MIF-/- mice, but showed normal neutrophil accumulation. Finally, the findings of enhanced resistance to P. aeruginosa and resistance to endotoxin-induced lethal shock suggest that the counteraction or neutralization of MIF may serve as an adjunct therapy in sepsis.

Efficacy of short-duration (twice weekly) intralesional sodium stibogluconate in treatment of cutaneous Leishmaniasis in India.

BACKGROUND: Cutaneous leishmaniasis (CL) is caused by Leishmania major and L. tropica in the old world. Bikaner, the 'Thar Desert', situated in the north-western corner of India, is an endemic pocket for CL caused by L. tropica. Skin lesions of CL heal slowly, causing disfiguring scars if remaining untreated. Current recommended treatment for CL comprises systemic administration of sodium stibogluconate (SSG) for 2-3 weeks. Five to seven injections of SSG intralesionally have also been found to be effective. OBJECTIVES: To determine the efficacy of a short-duration, twice-weekly intralesional SSG treatment for CL. METHODS: Two hundred and twenty patients with CL having 298 lesions were included in the present study. They were divided into groups A and B (110 patients each). Patients were treated with five to seven intralesional injections of SSG in doses of 50 mg cm(-2) of lesion either once (group A) or twice (group B) weekly. Improvement was recorded at 6, 8, 10, 12, 16, 20 and 24 weeks and the rate of complete cure was compared. RESULTS: Complete cure rate at 6, 8 and 10 weeks was higher (20%, 57% and 73%, respectively) in group B as compared with group A (12%, 36% and 62%, respectively). The differences in cure rates at these time points were statistically significant (P < 0.05). The complete cure rate at 24 weeks was similar in both groups (96% in group B and 92% in group A). The remaining 4% and 8% of patients in groups B and A were 'nonresponders', respectively. No major side-effects were observed in either group. In all cured cases, there were no relapses reported up to 2 years after treatment. CONCLUSIONS: A short-duration, twice-weekly intralesional SSG treatment for CL accelerates cure and is highly effective and well tolerated.

17Beta-estradiol increases Leishmania mexicana killing in macrophages from DBA/2 mice by enhancing production of nitric oxide but not pro-inflammatory cytokines.

We have previously shown that female DBA/2 mice are significantly more resistant to Leishmania mexicana compared with males. Here, we have analyzed the effect of 17beta-estradiol (E(2)) on function and cytokine production in male and female DBA/2 macrophages in vitro. We show that E(2) increases NO production and parasite killing in L. mexicana-infected male and female DBA/2 macrophages without increasing production of pro-inflammatory cytokines. These data indicate that E(2) may enhance leishmanicidal activity in macrophages by directly regulating production of NO.

Interleukin-4-deficient BALB/c mice develop an enhanced Th1-like response but control cardiac inflammation following Borrelia burgdorferi infection.

Interleukin-4 has been reported to critically modulate Borrelia burgdorferi infection and Lyme arthritis in experimental murine models. To determine the in vivo role of IL-4 in controlling Lyme carditis, we compared immunological responses and the severity of cardiac inflammation in wild-type BALB/c (IL-4 +/+) and IL-4 deficient BALB/c (IL-4 -/-) mice infected with B. burgdorferi by tick-bite. At day 15 and 30 post-infection IL-4 -/- mice produced significantly greater titers of spirochete-specific IgG2a than the wild-type IL-4 +/+ mice, which produced significantly more spirochete-specific IgG1. Following in vitro antigenic stimulation with B. burgdorferi antigen, splenocytes from infected IL-4 -/- and IL-4 +/+ mice displayed similar magnitudes of proliferative responses at day 15 and 30 post-infection. At day 30 antigen-stimulated splenocytes from infected IL-4 -/- mice, however, produced significantly more IFN-gamma than those derived from similarly infected IL-4 +/+ mice, suggesting that Th1-influenced responses predominated in IL-4 -/- mice. Moreover, inflamed hearts from IL-4 -/- mice displayed higher levels of IFN-gamma and TNF-alpha transcripts as compared to IL-4 +/+ mice. At both time points antigen-stimulated splenocytes from IL-4 +/+ and IL-4 -/- mice produced significant amounts of IL-10 but those from IL-4 +/+ mice produced either no or little IL-4. Histopathology demonstrated typical Lyme carditis in both IL-4 +/+ and IL-4 -/- mice at day 15 and day 30. Although Borrelia-infected IL-4 -/- mice developed a more severe carditis on day 30, the carditis resolved by day 50, as it did in IL4 +/+ mice. These results indicate that although IL-4 may help limit the severity of Lyme carditis, its absence does not preclude resolution of cardiac lesions.

Whither short-course chemotherapy for tuberculous meningitis?

Short-course chemotherapy is well established for the treatment of pulmonary tuberculosis but not for extrapulmonary disease. We present a series of 35 cases in which chemotherapy for tuberculous meningitis was given for a period of less than 2 years. Short-term therapy was associated with recrudescence of tuberculous meningitis and, in some cases, with the development of deep cerebral infarcts and permanent neurological deficits. We think short-term chemotherapy for tuberculosis of the central nervous system is inadequate.

Leishmaniasis: clinical syndromes and treatment.

Leishmaniasis is a global term for cutaneous and visceral anthroponotic and zoonotic diseases caused by the vector-borne parasites of the genus Leishmania. These diseases afflict at least 2 million people each year with more than 350 million at risk in 98 countries worldwide. These are diseases mostly of the impoverished making prevention, diagnosis and treatment difficult. Therapy of leishmaniasis ranges from local treatment of cutaneous lesions to systemic, often toxic, therapy for disseminated cutaneous, mucocutaneous and deadly visceral disease. This review is a summary of the clinical syndromes caused by Leishmania and treatment regimens currently used for various forms of leishmaniasis.

CD4+ CD25+ FOXP3+ Treg cells induced by rSSP4 derived from T. cruzi amastigotes increase parasitemia in an experimental Chagas disease model.

Currently, there is a considerable controversy over the participation of Treg cells during Trypanosoma cruzi infection, the main point being whether these cells play a negative or a positive role. In this work, we found that the adoptive transfer of CD4(+)CD25(+)FOXP3(+) T cells from rSSP4- (a recombinant Trypanosoma cruzi amastigote derived protein, previously shown to have immunomodulatory properties on macrophages) immunized BALB/c donors into syngenic recipients simultaneously with T. cruzi challenge reduces cardiac inflammation and prolongs hosts' survival but increases blood parasitemia and parasite loads in the heart. These CD4(+)CD25(+)FOXP3(+) Treg cells from immunized mice have a relatively TGF-ß-dependent suppressive activity on CD4(+) T cells. Therefore, regulatory CD4(+)CD25(+) T cells play a positive role in the development of acute T. cruzi infection by inducing immunosuppressive activity that controls early cardiac inflammation during acute Chagas disease, prolonging survival, but at the same time promoting parasite growth.

Nasal exposure to Staphylococcal enterotoxin enhances the development of allergic rhinitis in mice.

BACKGROUND: Staphylococcal enterotoxins (SEs) appear to play a role in the pathogenesis of allergic disease. However, little is known whether the nasal exposure to SE affects the development of allergic rhinitis (AR). OBJECTIVE: We sought to determine the in vivo effect of nasal exposure to SE on the development of AR using mouse model. METHODS: BALB/c mice were intranasally sensitized with Schistosoma mansoni egg antigen (SmEA) in the presence or absence of staphylococcal enterotoxin B (SEB). Control mice were intranasally sensitized with either SEB or SmEA alone. The production of antigen-specific antibodies including IgE, nasal eosinoplilia and cytokines by nasal mononuclear cells was compared among mice that had or had not received SEB treatment. RESULTS: Nasal exposure to SEB enhanced the development of AR in SmEA-sensitized mice, as manifested by SmEA-specific IgE production, nasal eosinophilia, and IL-4 and IL-5 production by nasal mononuclear cells after Ag challenge. This treatment also elicited IFN-gamma production by SmEA-primed cells. In addition, these mice produced SEB-specific IgE whereas mice treated with SEB without SmEA sensitization did not produce SEB-specific IgE or demonstrate nasal eosinophilia. CONCLUSION: These results suggest that the nasal exposure to SEB enhances susceptibility to AR although the exposure to SE solely does not induce AR.

Leishmania species: models of intracellular parasitism.

Leishmania species are obligate intracellular parasites of cells of the macrophage-dendritic cell lineage. Indeed, the ability to survive and multiply within macrophages is a feature of a surprising number of infectious agents of major importance to public health, including Mycobacterium tuberculosis, Mycobacterium leprae, Listeria monocytogenes, Salmonella typhimurium, Toxoplasma gondii and Trypanosoma cruzi. The relationship between such organisms and their host cells is particularly intriguing because, not only are macrophages capable of potent microbicidal activity, but in their antigen-presenting capacity they can orchestrate the developing immune response. Thus, to initiate a successful infection parasites must gain entry into macrophages, and also withstand or circumvent their killing and degradative functions. However, to sustain a chronic infection, parasites must also subvert macrophage-accessory-cell activities and ablate the development of protective immunity. The leishmanias produce a wide spectrum of disease in mice, and as such they have provided excellent models for studying problems associated with intracellular parasitism. In recent years, largely using these organisms, we have made enormous progress in elucidating the mechanisms by which successful intracellular infection occurs. Furthermore, characterization of immunological pathways that are responsible for resistance or susceptibility to Leishmania has given rise to the Th1/Th2 paradigm of cellular/humoral dominance of the immune response.

Susceptibility to Leishmania mexicana infection is due to the inability to produce IL-12 rather than lack of IL-12 responsiveness.

Almost all inbred mice are highly susceptible to parasites of the Leishmania mexicana complex that includes L. amazonensis and L. mexicana. Recent studies have reported that T cells from L. amazonensis-infected mice fail to respond to IL-12 due to impaired IL-12R expression. Here, we demonstrate that lymph node cells from L. mexicana-infected C57BL/6 and 129Sv/Ev mice respond efficiently to exogenous IL-12 in vitro and produce IFN-gamma. Moreover, we also show that deletion of signal transducer and activator of transcription (STAT)4 gene in resistant STAT6-/- mice renders them susceptible to L. mexicana. These findings indicate that an inability to produce IL-12 rather than unresponsiveness to this cytokine is responsible for susceptibility to L. mexicana. Moreover, the data also demonstrate that the STAT4-mediated pathway is critical for the development of protective immunity against cutaneous leishmaniasis, regardless of the species of Leishmania and/or genetic background of the mice.

Intracranial ectopic pituitary tumour.

Pituitary tumours originating primarily from sites other than the sella turcica are rare. A case of an ectopic pituitary tumour in the region of the lesser wing of the sphenoid is reported. The patient presented with signs and symptoms of a progressive increase in intracranial pressure. CT scan appearances resembled those of a sphenoid wing meningioma. The vascular lesion was partially excised. Histology showed it to be a pituitary tumour.

Cutting edge: selective IL-18 requirements for induction of compartmental IFN-gamma responses during viral infection.

Optimal protective effects for defense against infection require orchestration of immune responses spanning multiple host compartments and divergent local regulation at particular sites. During murine cytomegalovirus infections known to target spleen and liver, IL-12-induced IFN-gamma from NK cells is crucial for resistance. However, the roles for IL-18 and/or IL-12 in regulating hepatic IFN-gamma responses, as compared with systemic or splenic responses, have not been defined. In this report, mice genetically deficient in either IL-18 or IL-12p35 exhibited up to 95% reductions in systemic and splenic IFN-gamma responses. Surprisingly, IFN-gamma responses were preserved in the livers of IL-18-deficient, but not IL-12p35-deficient, mice. Cytokine requirements for host survival also differed. Under conditions where mice lacking IL-12p35 exhibited 100% mortality, those lacking IL-18 survived. Taken together, our results delineate contrasting compartmental requirements for IL-18 and suggest that preservation of local, hepatic IFN-gamma production is critical for host defense during murine cytomegalovirus challenge.

Migration-inhibitory factor gene-deficient mice are susceptible to cutaneous Leishmania major infection.

To determine the role of endogenous migration-inhibitory factor (MIF) in the development of protective immunity against cutaneous leishmaniasis, we analyzed the course of cutaneous Leishmania major infection in MIF gene-deficient mice (MIF(-/-)) and wild-type (MIF(+/+)) mice. Following cutaneous L. major infection, MIF(-/-) mice were susceptible to disease and developed significantly larger lesions and greater parasite burdens than MIF(+/+) mice. Interestingly, antigen-stimulated lymph node cells from MIF(-/-) mice produced more interleukin-4 (IL-4) and gamma interferon (IFN-gamma) than those from MIF(+/+) mice, although the differences were statistically not significant. IFN-gamma-activated resting peritoneal macrophages from MIF(-/-) mice showed impaired macrophage leishmanicidal activity and produced significantly lower levels of nitric oxide and superoxide in vitro. The macrophages from MIF(-/-) mice, however, produced much more IL-6 than macrophages from wild-type mice. These findings demonstrate that endogenous MIF plays an important role in the development of protective immunity against L. major in vivo. Furthermore, they indicate that the susceptibility of MIF(-/-) mice to L. major infection is due to impaired macrophage leishmanicidal activity rather than dysregulation of Th1 and Th2 responses.

Lacto-N-fucopentaose III found on Schistosoma mansoni egg antigens functions as adjuvant for proteins by inducing Th2-type response.

We have recently demonstrated that induction of Th2 responses by Schistosoma mansoni egg Ag is largely due to carbohydrates on the Ag functioning as adjuvants. Lacto-N-fucopentaose III (LNFPIII), a polylactosamine sugar, is the predominant carbohydrate found in S. mansoni egg Ag. Therefore, using neoglycoprotein, we investigated whether LNFPIII induces in vivo Th2 response and functions as an adjuvant. Following intranasal immunization with LNFPIII linked to human serum albumin (HSA) (HSA-LNFPIII), BALB/c mice mounted a strong Th2 response and produced significantly higher levels of total IgE as well as HSA-specific IgG, IgG1, and IgE. HSA-LNFPIII was over 1000-fold more potent in inducing Ab production as compared with HSA alone. Although LNFPIII itself did not function as an epitope for either IgG or IgE, its conjugation with protein was essential for the adjuvant activity. Moreover, fucose residue on LNFPIII was crucial for induction of Ab production. Nasal lymphocytes from mice immunized with HSA-LNFPIII produced IL-4, IL-5, and IL-10, but not IFN-gamma following in vitro stimulation with HSA or HSA-LNFPIII. In addition, these activated nasal lymphocytes also showed a significant increase of B7-2 expression on B220-positive cells. Furthermore, not only intranasal but also both i.p. and s.c. immunization with HSA-LNFPIII induced significant production of HSA-specific Abs compared with the immunization with HSA alone, suggesting that the activity of LNFPIII was not restricted on particular route of immunization. These results demonstrate that Lewis type carbohydrate LNFPIII can function as an adjuvant by their ability to induce a Th2 response.

Stress-induced enhancement of skin immune function: A role for gamma interferon.

Contrary to the widespread belief that stress is necessarily immunosuppressive, recent studies have shown that, under certain conditions, stress can induce a significant enhancement of a skin cell-mediated immune response [delayed-type hypersensitivity (DTH) or contact hypersensitivity]. Adrenal stress hormones and a stress-induced trafficking of leukocytes from the blood to the skin have been identified as systemic mediators of this immunoenhancement. Because gamma interferon (IFNgamma) is an important cytokine mediator of DTH, the studies described here were designed to examine its role as a local mediator of the stress-induced enhancement of skin DTH. The effect of acute stress on skin DTH was examined in wild-type and IFNgamma receptor-deficient (IFNgammaR-/-) mice that had previously been sensitized with 2,4-dinitro-1-fluorobenzene. Acutely stressed wild-type mice showed a significantly larger DTH response than nonstressed mice. In contrast, IFNgammaR-/- mice failed to show a stress-induced enhancement of skin DTH. Immunoneutralization of IFNgamma in wild-type mice significantly reduced the stress-induced enhancement of skin DTH. In addition, an inflammatory response induced by direct IFNgamma administration to the skin was significantly enhanced by acute stress. Our results suggest that IFNgamma is an important local mediator of a stress-induced enhancement of skin DTH. These studies are clinically relevant because, depending on the nature of the antigen, DTH reactions mediate numerous protective (e.g., resistance to viral, bacterial, parasitic, and fungal infections) or pathological (e.g., autoimmune reactions and contact sensitivity reactions such as that to poison ivy) immune responses.

Involvement of carbohydrate on phospholipase A2, a bee-venom allergen, in in vivo antigen-specific IgE synthesis in mice.

BACKGROUND: Carbohydrates on allergens are known to be important for allergenicity. However, most findings have been made with epitope analysis. In this study, we investigated the involvement of N-glycan on phospholipase A2 (PLA2), the major allergen of honeybee venom, in in vivo synthesis of specific IgE in mice. METHODS: CBA/J and C57BL/6 mice were sensitized intranasally with either native or deglycosylated PLA2 in the absence of adjuvant. After repeated sensitization, serum Ab titers against PLA2 were determined. PLA2 was deglycosylated chemically with anhydrous trifluoromethanesulfonic acid (TFMS). RESULTS: CBA/J mice showed PLA2-specific IgE production after repeated sensitization with native PLA2. They also produced PLA2-specific IgG1 predominantly, suggesting that Th2-type Ab production was induced. When we used deglycosylated PLA2 as a competitor in ELISA for detecting PLA2-specific IgE, deglycosylated PLA2 completely inhibited the binding between native PLA2 and IgE. Deglycosylated PLA2 had the same potential for inducing specific IgE synthesis as native PLA2, since sensitization with deglycosylated PLA2 also elicited IgE production in CBA/J mice. CONCLUSIONS: These results suggest that carbohydrate on PLA2 is less important than previously thought not only as a dominant IgE epitope but also in synthesis of PLA2-specific IgE in vivo.