Thalidomide-induced antigen-specific immune stimulation in patients with human immunodeficiency virus type 1 and tuberculosis

Potential Use of Thalidomide in Glioblastoma Treatment: An Updated Brief Overview

Glioblastoma is the most common malignant primary brain tumor in adults. Thalidomide is a vascular endothelial growth factor inhibitor that demonstrates antiangiogenic activity, and may provide additive or synergistic anti-tumor effects when co-administered with other antiangiogenic medications. This study is a comprehensive review that highlights the potential benefits of using thalidomide, in combination with other medications, to treat glioblastoma and its associated inflammatory conditions. Additionally, the review examines the mechanism of action of thalidomide in different types of tumors, which may be beneficial in treating glioblastoma. To our knowledge, a similar study has not been conducted. We found that thalidomide, when used in combination with other medications, has been shown to produce better outcomes in several conditions or symptoms, such as myelodysplastic syndromes, multiple myeloma, Crohn's disease, colorectal cancer, renal failure carcinoma, breast cancer, glioblastoma, and hepatocellular carcinoma. However, challenges may persist for newly diagnosed or previously treated patients, with moderate side effects being reported, particularly with the various mechanisms of action observed for thalidomide. Therefore, thalidomide, used alone, may not receive significant attention for use in treating glioblastoma in the future. Conducting further research by replicating current studies that show improved outcomes when thalidomide is combined with other medications, using larger sample sizes, different demographic groups and ethnicities, and implementing enhanced therapeutic protocol management, may benefit these patients. A meta-analysis of the combinations of thalidomide with other medications in treating glioblastoma is also needed to investigate its potential benefits further.

Risk factors for ischemic stroke in children with tuberculous meningitis

PURPOSE

Cerebrovascular complications are commonly observed in children with tuberculous meningitis. We aimed to determine which clinical factors were associated with stroke at admission in children with tuberculous meningitis and, in children stroke-free at admission, which factors were associated with development of stroke on treatment.

METHODS

We analysed a cohort of 474 children diagnosed with 'definite' and 'probable' tuberculous meningitis, with prospectively collected data, at Tygerberg Hospital, Cape Town, South Africa from 1985 to 2005. We considered either hemiparesis or radiological arterial ischemic infarction as evidence of stroke.

RESULTS

At admission, 339 (71.5%) children presented with stroke. Features associated with stroke at admission included age <3 years (odds ratio (OR) 3.70; 95% confidence interval (CI): 2.44-5.63; p < 0.01), convulsions (OR: 2.25; 95% CI: 1.46-3.45; p < 0.01) and hydrocephalus (OR: 1.63; 95% CI: 1.05-2.53; p = 0.03). In the group of children without stroke at admission (n = 135), 33 (24.4%) developed stroke by 1 month. Similar factors predicted stroke and included age <3 years (OR: 2.60; 95% CI: 1.17-5.80; p = 0.02), convulsions (OR: 2.25; 95% CI: 1.46-3.45; p < 0.01), CSF cell count <10 or >500/L (OR: 3.12; 95% CI: 1.03-9.43; p = 0.04) and hydrocephalus (OR: 2.99; 95% CI: 1.30-6.89; p = 0.01).

CONCLUSION

A large proportion of children with tuberculous meningitis present with stroke at admission. Of those with no evidence of stroke at admission, a quarter develop stroke by 1 month, suggesting that there could be a brief window in which to give preventive therapy.

Single-agent lenalidomide in relapsed/refractory mantle cell lymphoma: results from a UK phase II study suggest activity and possible gender differences

We present data from a phase II study investigating a novel treatment strategy for relapsed/refractory mantle cell lymphoma (MCL). Twenty-six patients received lenalidomide 25 mg/d (days 1-21 of a 28-d cycle) for up to 6 cycles followed by low-dose maintenance lenalidomide (15 mg) in responding patients. Eight patients achieved complete or partial response to give an overall response rate of 31% with median response duration of 22·2 months [95% confidence interval (CI) 0·0-53·6] and median progression-free survival (PFS) of 3·9 months (95% CI 0·0-11·1). An additional six patients (23%) achieved stable disease. Eleven patients received maintenance with median PFS of 14·6 months (95% CI 7·3-21·9). Correlative studies showed that peripheral T and Natural Killer (NK) cells increased in responding patients by 40-60% over the first 6 cycles with an initial dip in NK cells suggestive of tumour infiltration. Peripheral regulatory T cells were increased in MCL patients (P = 0·001) and expanded further following lenalidomide. Sequential plasma analysis showed increased IL12 p40 and IL7 alongside decreased MMP9, IL10, and adiponectin. Finally, a significant correlation (P = 0·02) between gender and response suggested that female MCL patients were more sensitive to lenalidomide than males. In summary, we confirm the activity, safety and immunomodulatory properties of lenalidomide in MCL and highlight its potential as a low-dose maintenance agent.

Expansion of polyfunctional HIV-specific T cells upon stimulation with mRNA electroporated dendritic cells in the presence of immunomodulatory drugs

Recently, it has been demonstrated that disease progression during HIV infection is not determined merely by the number of HIV-specific T cells but also by their quality (J. R. Almeida, et al., J. Exp. Med. 204:2473-2485, 2007; C. T. Berger, et al., J. Virol. 85:9334-9345, 2011; M. R. Betts, et al., Blood 107:4781-4789, 2006; V. V. Ganusov, et al., J. Virol. 85:10518-10528, 2011; P. Kiepiela, et al., Nat. Med. 13:46-53, 2007; and F. Pereyra, et al., J. Infect. Dis. 197:563-571, 2008). Therefore, strategies to specifically enhance or induce high-quality, HIV-specific T-cell responses are necessary to develop effective immune therapies. Thalidomide, lenalidomide, and pomalidomide have a strong capacity to boost immune responses and are therefore referred to as immunomodulatory drugs (IMiDs). We evaluated the effects of lenalidomide and pomalidomide on HIV-specific T cells. We found that the presence of IMiDs during in vitro T-cell stimulation with dendritic cells electroporated with Gag- or Nef-encoding mRNA resulted in higher numbers of cytokine-secreting HIV-specific CD8(+) T cells, particularly inducing polyfunctional HIV-specific CD8(+) T cells with an enhanced lytic capacity. Furthermore, CD8(+) T-cell responses were detected upon stimulation with lower antigenic peptide concentrations, and a higher number of Gag epitopes was recognized upon addition of IMiDs. Finally, IMiDs reduced the proliferation of the HIV-specific CD4(+) T cells while increasing the number of polyfunctional CD4(+) T cells. These results provide new information about the effects of IMiDs on antigen-specific T cells and suggest that these drugs increase the efficacy of immune therapies for infectious diseases and cancer.

Phosphodiesterase-4 inhibition alters gene expression and improves isoniazid-mediated clearance of Mycobacterium tuberculosis in rabbit lungs

Tuberculosis (TB) treatment is hampered by the long duration of antibiotic therapy required to achieve cure. This indolent response has been partly attributed to the ability of subpopulations of less metabolically active Mycobacterium tuberculosis (Mtb) to withstand killing by current anti-TB drugs. We have used immune modulation with a phosphodiesterase-4 (PDE4) inhibitor, CC-3052, that reduces tumor necrosis factor alpha (TNF-α) production by increasing intracellular cAMP in macrophages, to examine the crosstalk between host and pathogen in rabbits with pulmonary TB during treatment with isoniazid (INH). Based on DNA microarray, changes in host gene expression during CC-3052 treatment of Mtb infected rabbits support a link between PDE4 inhibition and specific down-regulation of the innate immune response. The overall pattern of host gene expression in the lungs of infected rabbits treated with CC-3052, compared to untreated rabbits, was similar to that described in vitro in resting Mtb infected macrophages, suggesting suboptimal macrophage activation. These alterations in host immunity were associated with corresponding down-regulation of a number of Mtb genes that have been associated with a metabolic shift towards dormancy. Moreover, treatment with CC-3052 and INH resulted in reduced expression of those genes associated with the bacterial response to INH. Importantly, CC-3052 treatment of infected rabbits was associated with reduced ability of Mtb to withstand INH killing, shown by improved bacillary clearance, from the lungs of co-treated animals compared to rabbits treated with INH alone. The results of our study suggest that changes in Mtb gene expression, in response to changes in the host immune response, can alter the responsiveness of the bacteria to antimicrobial agents. These findings provide a basis for exploring the potential use of adjunctive immune modulation with PDE4 inhibitors to enhance the efficacy of existing anti-TB treatment.

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is a leading infectious cause of morbidity and mortality. Although current antibiotic regimens can cure TB, treatment requires at least six months for completion. Recent studies indicate that bacteria in a less metabolically active state are less responsive to antibiotic killing and suggest that this may partly explain the long duration required for TB treatment. In this study, using a rabbit model of pulmonary TB, we show that immune modulation of Mtb infected animals with CC-3052, a phosphodiesterase-4 (PDE4) inhibitor that reduces tumor necrosis factor alpha (TNF-α) production by increasing intracellular cAMP levels, resulted in the down-regulation of host genes involved in the innate immune response. Bacteria from the lungs of CC-3052 treated rabbits displayed differential expression of those genes associated with stress responses. In addition, co-treatment of INH with CC-3052 abolished the INH-induced Mtb gene expression in the infected rabbits. Importantly, bacillary clearance from the lungs of rabbits co-treated with CC-3052 and INH was improved over that in animals treated with INH alone. The results of this study provide a basis for novel use of immune modulation to improve the efficacy of antibiotic therapy and to shorten the duration of TB treatment.

Phosphodiesterase-4 inhibition combined with isoniazid treatment of rabbits with pulmonary tuberculosis reduces macrophage activation and lung pathology

Tuberculosis (TB) is responsible for significant morbidity and mortality worldwide. Even after successful microbiological cure of TB, many patients are left with residual pulmonary damage that can lead to chronic respiratory impairment and greater risk of additional TB episodes due to reinfection with Mycobacterium tuberculosis. Elevated levels of the proinflammatory cytokine tumor necrosis factor-α and several other markers of inflammation, together with expression of matrix metalloproteinases, have been associated with increased risk of pulmonary fibrosis, tissue damage, and poor treatment outcomes in TB patients. In this study, we used a rabbit model of pulmonary TB to evaluate the impact of adjunctive immune modulation, using a phosphodiesterase-4 inhibitor that dampens the innate immune response, on the outcome of treatment with the antibiotic isoniazid. Our data show that cotreatment of M. tuberculosis infected rabbits with the phosphodiesterase-4 inhibitor CC-3052 plus isoniazid significantly reduced the extent of immune pathogenesis, compared with antibiotic alone, as determined by histologic analysis of infected tissues and the expression of genes involved in inflammation, fibrosis, and wound healing in the lungs. Combined treatment with an antibiotic and CC-3052 not only lessened disease but also improved bacterial clearance from the lungs. These findings support the potential for adjunctive immune modulation to improve the treatment of pulmonary TB and reduce the risk of chronic respiratory impairment.

Tuberculous meningitis-related optic neuritis: recovery of vision with thalidomide in 4 consecutive cases

Blindness is an uncommon but devastating complication of tuberculosis meningitis. The main causes are chronically raised intracranial pressure (hydrocephalus and/or tuberculomas) or direct involvement of the optic chiasm or optic nerves by the basal arachnoiditis (inflammation and/or compression). Antituberculosis therapy combined with corticosteroids and control of intracranial pressure constitutes the mainstay of therapy for tuberculous meningitis. Despite these treatment measures, some patients develop blindness, mainly as a result of progressive optochiasmatic arachnoiditis. This led us to explore the role of adjuvant thalidomide therapy, and we describe the dramatic recovery of vision in 4 consecutive cases. Clinical recovery was accompanied by marked radiological improvement on magnetic resonance imaging (MRI) of the brain.

Alpha-galactosylceramide as a therapeutic agent for pulmonary Mycobacterium tuberculosis infection

RATIONALE

Invariant natural killer T (iNKT) cells are a unique subset of T cells that recognize lipid antigens presented by CD1d molecules. Recent studies have shown that iNKT cells can protect mice against Mycobacterium tuberculosis (Mtb) infection. We sought to determine whether pharmacological activation of iNKT cells by α-galactosylceramide (α-GalCer) could be used to treat tuberculosis (TB).

OBJECTIVES

We hypothesized that α-GalCer, either alone or in combination with isoniazid, could be used to treat pulmonary TB.

METHODS

The ability of α-GalCer-activated iNKT cells to suppress Mtb replication was evaluated using an in vitro coculture system. To test its potency in vivo, mice infected with virulent Mtb were treated with α-GalCer alone or in combination with isoniazid.

MEASUREMENTS AND MAIN RESULTS

Quantitative colony-forming unit counts were compared for both experimental systems. Our results show that α-GalCer plus isoniazid controls bacterial growth better than α-GalCer or INH alone, and single or multiple α-GalCer administrations prolong the survival of the mice infected via the aerosol route.

CONCLUSIONS

Our results demonstrate that α-GalCer administration can improve the outcome of Mtb infection, even when transmitted by the aerosol route. However, a combination of isoniazid and α-GalCer treatment has a synergistic effect on infection control. We conclude that more efficient treatment of TB will be achieved through a combination of classic chemotherapy and modulation of the host immune response.

Management of patients with the immune reconstitution inflammatory syndrome

A significant proportion of patients present with the immune reconstitution inflammatory syndrome (IRIS) after commencing antiretroviral therapy (ART). This syndrome is most frequently associated with infective causes. The lack of evidence-based treatment guidelines poses challenges in the management of these patients. Alternative causes for deterioration should be excluded, and optimization of treatment for the underlying opportunistic infection is essential. In addition, anti-inflammatory or immunomodulatory therapy may be considered, particularly in severe cases. Corticosteroids, the only treatment for which clinical trial data exist (for treating paradoxical tuberculosis-associated IRIS), are the treatment most frequently used in IRIS. Limited anecdotal reports of benefit exist for other agents, including NSAIDs, pentoxifylline, montelukast, thalidomide, and hydroxychloroquine. Therapeutic procedures (eg, aspiration of pus collections) play an important role in some patients. Interruption of ART may be considered in life-threatening forms of IRIS.

Enhancement of efficacy of tuberculosis drugs with Immunoxel (Dzherelo™) in HIV-infected patients with active pulmonary tuberculosis

Immunoxel (Dzherelo™) is an oral, herbal immunomodulator used in Ukraine for adjunct therapy of infectious and autoimmune diseases. Antiretroviral drug-naive, tuberculosis (TB)/HIV coinfected patients with active pulmonary TB were divided into two arms, A (n = 20) and B (n = 20), to receive first-line anti-TB therapy (ATT) or ATT + Dzherelo, respectively. As a result, three (16%) versus 12 (67%; p = 0.003) patients had Mycobacterium tuberculosis culture conversion, with time to negative culture of 6 and 4 months in arms A and B, respectively. In the ATT-alone arm, the healing of pulmonary cavitations was observed in 25% of patients at weeks 24–28, while 60% of individuals in arm B healed at 16–18 weeks (p = 0.025). The TB lesions, on chest x-ray, had cleared in 46 and 84%, with time-to-clearance of 24–28 and 16–18 weeks in arms A and B, respectively. In the ATT-alone arm, the bodyweight at baseline was 64 ± 6.3 kg, with 13 cachexic patients who had an average weight deficit of -5.2 ± 1.7 kg. At the end of 6 months of follow-up, they have lost an additional 0.6 kg (-5.8 ± 2.4). The study entry-level weight in arm B was 52 ± 5.7 kg, with 12 individuals who had a body mass deficit of -8.5 ± 2.7 kg. The immunotherapeutic intervention increased bodyweight by an average of 5.8 ± 2.6 kg above baseline (p < 0.0001). The inclusion of Dzherelo into the ATT regimen decreased the incidence of new opportunistic infections (OI) with three episodes of OI versus 12 in arm A (p = 0.003). These findings indicate that Dzherelo contributes positively to the clinical efficacy of TB drugs.

Recovery of vision after adjuvant thalidomide in a child with tuberculous meningitis and acute lymphoblastic leukemia

A 7-year-old child, on maintenance chemotherapy for acute lymphoblastic leukemia, developed tuberculous meningitis complicated by progressive basal meningeal inflammation and abscess formation, in spite of adequate tuberculosis treatment and adjunctive corticosteriod therapy. The child became blind as a result of involvement of the optic chiasm. After 2 months of adjunctive thalidomide therapy, the child regained vision and cranial magnetic resonance imaging showed marked reduction of the inflammatory changes previously demonstrated. Progression of intracranial tuberculous infection, in spite of a treatment that is generally considered to be adequate, is well recognized. Previous reports of a possible beneficiary role of thalidomide in these cases support an immunological basis. The present case suggests a role for thalidomide in the treatment of blindness due to involvement of the optic chiasm in progressive basal tuberculous meningitis.

Treatment Options for HIV-Associated Tuberculosis

The vicious interaction between the human immunodeficiency virus (HIV) infection and tuberculosis (TB) pandemics poses special challenges to national control programs and individual physicians. Although recommendations for the treatment of TB in HIV-infected patients do not significantly differ from those for HIV-uninfected patients, the appropriate management of HIV-associated TB is complicated by health system issues, diagnostic difficulties, adherence concerns, overlapping adverse-effect profiles and drug interactions, and the occurrence of paradoxical reactions after the initiation of effective antiretroviral therapy. In this article, recommended treatment strategies and novel approaches to the management of HIV-associated TB are reviewed, including adjuvant treatment and options for treatment simplification. A focused research agenda is proposed in the context of the limitations of the current knowledge framework.

Linkage and association analysis of candidate genes for TB and TNFalpha cytokine expression: evidence for association with IFNGR1, IL-10, and TNF receptor 1 genes

Tuberculosis (TB) is a growing public health threat globally and several studies suggest a role of host genetic susceptibility in increased TB risk. As part of a household contact study in Kampala, Uganda, we have taken a unique approach to the study of genetic susceptibility to TB by developing an intermediate phenotype model for TB susceptibility, analyzing levels of tumor necrosis factor-alpha (TNFalpha) in response to culture filtrate as the phenotype. In the present study, we analyzed candidate genes related to TNFalpha regulation and found that interleukin (IL)-10, interferon-gamma receptor 1 (IFNGR1), and TNFalpha receptor 1 (TNFR1) genes were linked and associated to both TB and TNFalpha. We also show that these associations are with progression to active disease and not susceptibility to latent infection. This is the first report of an association between TB and TNFR1 in a human population and our findings for IL-10 and IFNGR1 replicate previous findings. By observing pleiotropic effects on both phenotypes, we show construct validity of our intermediate phenotype model, which enables the characterization of the role of these genetic polymorphisms on TB pathogenesis. This study further illustrates the utility of such a model for disentangling complex traits.

Intractable intracranial tuberculous infection responsive to thalidomide: report of four cases

Paradoxical enlargement and development of new intracranial tuberculomas and tuberculous brain abscesses on adequate antituberculosis treatment are well recognized and supposedly cytokine mediated. These lesions are often unresponsive to conventional antituberculosis treatment, corticosteroids, and surgery. We therefore assessed the effect of adjunctive thalidomide, a tumor necrosis factor alpha-modulating drug, in intractable intracranial tuberculosis that did not respond to standard medical and surgical therapy. Four consecutive children (three children with bacteriologic proof and one child with clinical evidence of intracranial tuberculosis) were studied. Three patients each had a giant tuberculous abscess, and the fourth had chronic basal arachnoiditis with progressive loss of vision. Three of the four patients had relentless neurologic deterioration, and all showed disease progression on neuroimaging despite full medical and appropriate surgical treatment. Marked clinical and neuroradiologic improvement occurred after thalidomide was added to the antituberculosis treatment regimen of these four patients. Adjunctive thalidomide might have a role in the management of intractable intracranial tuberculosis and needs further investigation in this regard.

Evidence that thalidomide modifies the immune response of patients suffering from actinic prurigo

BACKGROUND

Actinic prurigo (AP) is a photodermatosis with a restricted ethnic distribution, mainly affecting Mestizo women (mixed Indian and European). The lesions are polymorphic and include macules, papules, crusts, hyperpigmentation and lichenification. Thalidomide, an effective immunomodulatory drug, was first used successfully to treat AP in 1973. In this work we describe the effect that thalidomide had on TNF-alpha sera levels and on IL-4- and IFN gamma (IFNgamma)-producing lymphocytes of actinic prurigo (AP) patients.

METHODS

Actinic prurigo patients were analyzed before and after thalidomide treatment. The percentage of IL-4+ or IFNgamma+ CD3+ lymphocytes was analyzed in eight of them by flow cytometry. TNFalpha in sera was measured by ELISA in 11 patients.

RESULTS

A direct correlation was observed between resolution of AP lesions and an increase in IFNgamma+ CD3+ peripheral blood mononuclear cells (P < or = 0.001) and a decrease in TNFalpha serum levels (no statistical difference). No IL-4+ CD3+ cells were detected.

CONCLUSIONS

Our findings confirm that AP is a disease that has an immunological component and that thalidomide clinical efficacy is exerted not only through inhibition of TNFalpha synthesis, but also through modulation of INFgamma-producing CD3+ cells. These cells could be used as clinical markers for recovery.

The induction of Toll-like receptor tolerance enhances rather than suppresses HIV-1 gene expression in transgenic mice

Microbial-induced proinflammatory pathways are thought to play a key role in the activation of human immunodeficiency virus type 1 (HIV-1) gene expression. The induction of Toll-like receptor (TLR) tolerance leads to a complex reprogramming in the pattern of inflammatory gene expression and down-modulates tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-1, and IL-6 production. Using transgenic (Tg) mice that incorporate the entire HIV-1 genome, including the long-terminal repeat, we have previously demonstrated that a number of different TLR ligands induce HIV-1 gene expression in cultured splenocytes as well as purified antigen-presenting cell populations. Here, we have used this model to determine the effect of TLR-mediated tolerance as an approach to inhibiting microbial-induced viral gene expression in vivo. Unexpectedly, Tg splenocytes and macrophages, rendered tolerant in vitro to TLR2, TLR4, and TLR9 ligands as assessed by proinflammatory cytokine secretion and nuclear factor-kappaB activation, showed enhanced HIV-1 p24 production. A similar enhancement was observed in splenocytes tolerized and then challenged with heterologous TLR ligands. Moreover, TLR2- and TLR4-homotolerized mice demonstrated significantly increased plasma p24 production in vivo despite lower levels of TNF-alpha. Together, these results demonstrate that HIV-1 expression is enhanced in TLR-reprogrammed host cells, possibly reflecting a mechanism used by the virus to escape the effects of microbial-induced tolerance during natural infection in vivo.

Mycobacterium tuberculosis pathogenesis and molecular determinants of virulence

Tuberculosis (TB), one of the oldest known human diseases. is still is one of the major causes of mortality, since two million people die each year from this malady. TB has many manifestations, affecting bone, the central nervous system, and many other organ systems, but it is primarily a pulmonary disease that is initiated by the deposition of Mycobacterium tuberculosis, contained in aerosol droplets, onto lung alveolar surfaces. From this point, the progression of the disease can have several outcomes, determined largely by the response of the host immune system. The efficacy of this response is affected by intrinsic factors such as the genetics of the immune system as well as extrinsic factors, e.g., insults to the immune system and the nutritional and physiological state of the host. In addition, the pathogen may play a role in disease progression since some M. tuberculosis strains are reportedly more virulent than others, as defined by increased transmissibility as well as being associated with higher morbidity and mortality in infected individuals. Despite the widespread use of an attenuated live vaccine and several antibiotics, there is more TB than ever before, requiring new vaccines and drugs and more specific and rapid diagnostics. Researchers are utilizing information obtained from the complete sequence of the M. tuberculosis genome and from new genetic and physiological methods to identify targets in M. tuberculosis that will aid in the development of these sorely needed antitubercular agents.

Therapy of AIDS-associated Kaposi's sarcoma: targeting pathogenetic mechanisms

Only a small number of the many agents with the potential to inhibit factors known to stimulate KS growth have been tested clinically, and many were investigated at a time when treatment options for HIV infection were relatively ineffective. The failure of some of these agents to induce KS regression may not signify failure to achieve a relevant biologic effect in all cases, but may simply mean that in a neoplasm that expresses a broad array of growth factors, inhibition of a single factor may be insufficient to achieve tumor regression. Moreover, agents that inhibit angiogenesis may be expected to stabilize tumors rather then eradicate them, but tumor stabilization is a difficult endpoint to quantify. In fact, given the redundancy of growth factors believed to be involved in KS development, it is perhaps remarkable that members of several classes of agents (eg, a synthetic retinoid, an MMPI, thalidomide, IL-12) have induced KS regression in a substantial minority of patients. It is likely, however, that drug combinations that target several pathogenetic mechanisms will be more effective than will single drugs in suppressing KS growth. A particular need. especially in the early evaluation of therapies aimed at specific pathogenic targets, is the development of assays to measure specific biologic effects (eg, changes in the activity of signal transduction pathways within tumor biopsy specimens) related to the agent's putative mechanism of action. Greater availability and clinical application of these types of markers of biologic efficacy may speed the identification of potentially active agents that could then be "fast tracked" into larger efficacy trials and combination studies.

Activation of NKT cells protects mice from tuberculosis

The T-cell immune response to Mycobacterium tuberculosis is critical in preventing clinical disease. While it is generally accepted that both major histocompatibility complex class I (MHC-I)-restricted CD8(+) and MHC-II-restricted CD4(+) T cells are important for the immune response to M. tuberculosis, the role of non-MHC-restricted T cells is still not clearly delineated. We have previously reported that CD1d(-/-) mice do not differ from CD1d(+/+) mice in their survival following infection with M. tuberculosis. We now show that, although CD1d-restricted NKT cells are not required for optimum immunity to M. tuberculosis, specific activation of NKT cells by the CD1d ligand alpha-galactosylceramide protects susceptible mice from tuberculosis. Treatment with alpha-galactosylceramide reduced the bacterial burden in the lungs, diminished tissue injury, and prolonged survival of mice following inoculation with virulent M. tuberculosis. The capacity of activated NKT cells to stimulate innate immunity and modulate the adaptive immune response to promote a potent antimicrobial immune response suggests that alpha-galactosylceramide administration could have a role in new strategies for the therapy of infectious diseases.

Thalidomide can costimulate or suppress CD4+ cells' ability to incorporate [H3]-thymidine--dependence on the primary stimulant

Thalidomide is a drug that can enhance mitogen- and antigen-stimulated cells' ability to synthesize IL-2. To assess if thalidomide could concomitantly enhance the synthesis of IFN-gamma and incorporation of [H3]-thymidine, peripheral blood mononuclear cells (PBMC) were incubated in the presence or absence of thalidomide and staphylococcal enterotoxin A (SEA), anti-CD3, Con-A or PHA. After 18 h, the cultures were sampled for IL-2. At the termination of the 3-day cultures, they were assayed for IFN-gamma and incorporation of [H3]-thymidine. Regardless of the mitogen used to stimulate the PBMC, the thalidomide-treated PBMC produced more IL-2 than controls. Thalidomide enhanced IFN-gamma synthesis in the Con-A and anti-CD3-stimulated PBMC. It suppressed the ability of SEA and PHA-stimulated PBMC to incorporate [H3]-thymidine, whereas it enhanced incorporation of [H3]-thymidine in PBMCs stimulated with anti-CD3. When the PBMC were enriched for CD4+ or CD8+ cells, the SEA- and anti-CD3-stimulated CD4+ cells responded far better than the CD8+ cells in the synthesis of IL-2 and incorporation of [H3]-thymidine. In the thalidomide-treated SEA-stimulated CD4+ and CD8+ cells, thalidomide acted as a costimulant to enhance the synthesis of IL-2. In the anti-CD3-stimulated thalidomide-treated cultures of PBMC enriched for CD4+ cells, thalidomide acted as a costimulant to enhance the incorporation [H3]-thymidine. Thalidomide cooperated with all of the mitogens to enhance T-cell synthesis of IL-2. However, depending on the stimulant, thalidomide could suppress or enhance PBMC incorporation of [H3]-thymidine. The SEA-stimulated cells targeted by thalidomide to suppress incorporation of [H3]-thymidine were CD4+. CD4+ cells stimulated with anti-CD3 were enhanced by thalidomide in their ability to synthesize IL-2 and to incorporate [H3]-thymidine. Increased production of IL-2 by activated T cells may be a mechanism through which thalidomide exerts its immunomodulatory effects.

Automated in vitro screening of teratogens

We present a new in vitro assay for screening of potential teratogens, based on staining of cultured mouse fibroblastoid L929 cells for the determination of number of live and dead cells and of cell morphology, employing automatic video recording, followed by detection of the stained specimen and calculation of endpoint values by the use of a computerized microscope workstation. Ten different parameters were combined empirically into a single index describing general alterations in cell morphology, and, subsequently, measurements of alterations in morphology and proliferation were combined to produce a single empirical index aimed at predicting teratogenic potency. The assay was employed in two different laboratories on 10 coded compounds; 7 compounds that have demonstrated in vivo teratogenic potentials: valproic acid (VPA), pentyl-4-yn-VPA, retinoic acid (RA), 13-cis-RA, AM580, thalidomide, and alpha-EM12 and 3 compounds for which no teratogenic potential has been demonstrated: isobutyl-4-yn-VPA, phytanic acid, and beta-EM12. Within each of the three groups of compounds the nonteratogens generally caused smaller alterations in cell morphology than the teratogens, although the effects of thalidomide and related compounds generally were minor or insignificant. The data support the hypothesis that cell morphology and proliferation in combination with other endpoints may be employed for in vitro screenings of potential teratogens, although studies of additional compounds are needed in order to establish the general validity of the procedure.

Nonpulmonary manifestations of sarcoidosis

Sarcoidosis is one in a heterogeneous family of granulomatous disorders. The clinical manifestations of sarcoidosis can vary widely, depending on the patient and the tissues involved. Recent advances in our understanding of the immunologic steps leading to granuloma formation and persistence have yet to translate into more effective care for patients with this disease. This review discusses the immunology of granuloma formation and systemic disease, the various nonpulmonary expressions of the clinical disease, and the treatment options available to the practicing physician.

Thalidomide induces granuloma differentiation in sarcoid skin lesions associated with disease improvement

Sarcoidosis, a chronic granulomatous disease of unknown etiology, is treated with immune suppressive drugs such as corticosteroids. Sarcoidosis patients have been reported to benefit clinically from treatment with thalidomide. We administered thalidomide for 16 weeks to eight patients with chronic skin sarcoidosis and evaluated the drug's effects before and with treatment. After thalidomide treatment, all skin biopsies showed decreases in granuloma size and reduction in epidermal thickness. We also observed extensive T cell recruitment into the granulomas, the appearance of multinucleated giant cells, and increased numbers of dermal Langerhans cells (CD1a(+)) and mature dendritic cells (CD83(+) or DC-LAMP(+)). Plasma IL-12 levels increased and remained elevated during the treatment period. We noted increased HLA-DR expression on peripheral blood lymphocytes and a corresponding drop in the naive T cell marker CD45RA. Our data suggest that thalidomide treatment of sarcoidosis results in granuloma differentiation to a Th1-type cellular immune response usually associated with protective immunity to tuberculosis and tuberculoid leprosy.

Early studies on the safety and efficacy of thalidomide for symptomatic inflammatory bowel disease

BACKGROUND AND AIM

Thalidomide is clinically effective in the treatment of graft versus host disease in bone marrow transplantation and aphthous ulceration in HIV infection. It appears to exert a selective effect on tumor necrosis factor-alpha (TNF-alpha) production. Tumor necrosis factor-alpha is implicated in the pathogenesis of inflammatory bowel disease (IBD). The aim of this study was to assess the efficacy and safety of thalidomide in symptomatic IBD.

METHODS

Eleven patients (nine males, mean age 33 years, range 20-77 years) with chronic inflammatory bowel disease (six Crohn's disease (CD), four ulcerative colitis (UC), one indeterminate colitis (IC)) who were symptomatic despite standard medical therapy were administered a daily dose of thalidomide for 12 weeks in an open-labeled protocol. Their response was assessed by using clinical, colonoscopic, histological, and immunological methods.

RESULTS

Two patients withdrew at 3 weeks because of mood disturbances. Of the remaining nine patients, eight (five CD, two UC and one IC) had a marked clinical response, while one patient with CD had no response. The mean stool frequency decreased from 4.3 to 2.3 per day (P = 0.0012), and the stool consistency increased from 2.1 to 1.2 (P = 0.02). The mean Crohn's Disease Activity Index decreased from 117 to 48 (P = 0.0008). Endoscopic inflammatory and histological grade, C-reactive protein and erythrocyte sedimentation rate (ESR) all decreased significantly (P = 0.011, P = 0.03, P = 0.023 and P = 0.044, respectively). However, the serum TNF-alpha levels did not change. Side-effects included mild sedation, xerostomia and skin dryness in all, constipation in three, and minor abnormalities in nerve conduction in one patient.

CONCLUSION

These data strongly suggest that thalidomide is an effective short-term treatment for symptomatic IBD.

Management of Kaposi sarcoma: the role of interferon and thalidomide

Kaposi sarcoma (KS) remains the most commonly diagnosed cancer in HIV-infected patients. Although several chemotherapeutic agents have proven effective in controlling KS, the growing understanding of the factors contributing to the development of KS has provided a stronger rationale for using noncytotoxic agents that influence the mechanisms involved in KS pathogenesis. Two such agents, interferon and thalidomide, have shown activity against KS in clinical trials and have the potential to influence multiple steps believed to be important in KS development and progression. Studies are ongoing to explore the optimal way to use these agents and their mechanisms of action.

The Th1/Th2 paradigm in the pathogenesis of scleroderma, and its modulation by thalidomide

The immunity generated in response to an antigenic stimulus can result in at least two distinct subclasses of immune responses, commonly referred to as Th1 and Th2. This review describes Th1- and Th2-type immune responses in animal models and in human mediated disease. Evidence obtained from working within these models suggests that manipulating the Th1/Th2 balance in the immune response can alter disease processes. The possible application of this strategy in scleroderma is presented. The immune modulating effects of the drug thalidomide on Th1 and Th2 immunity are also described, along with the drug's potential application to disease processes like scleroderma.

Immune-Based Therapies for the Management of HIV Infection: Highly Active Antiretroviral Therapy and Beyond

The widespread use of highly active antiretroviral therapy (HAART) has had a significant impact on reducing the incidence of opportunistic infections in patients with the Acquired Immunodeficiency Syndrome (AIDS) and reducing the overall morbidity and mortality associated with this disease. However, the use of HAART is often associated with adverse effects, significant drug interactions, high cost and the emergence of viral resistance in a significant percentage of treatment recipients. In addition, the clinical efficacy of HAART in terms of viral eradication appears to be limited due to the presence of reservoirs of latent virus within HAART-experienced patients. Because of these and other limitations associated with antiretroviral therapies, new therapeutic strategies are being developed to restore the normal function of the immune system and improve patient outcomes. The purpose of this article is to review some of the more promising investigational immune-based therapies and their potential role in the management of Human Immunodeficiency Virus infection.

Treatment of infections in the patient with Mendelian susceptibility to mycobacterial infection

Cytokines are increasingly used for the therapy of infections in patient populations with special defects in immunity (chemotherapy, bone marrow transplantation, chronic granulomatous disease). The recognition of multiple defects in the systems of the interferon-gamma (IFN-gamma) receptor, interleukin-12 (IL-12) receptor and IL-12 p40 emphasizes the critical roles that cytokines play in preventing and clearing infection. The cases of patients with partially responsive IFN-gamma receptors (autosomal dominant and partial defects) are ideal candidates for successful cytokine prophylaxis and therapy. Better understanding of the critical elements of the cytokine pathways may show us ways to circumvent these defects with complementary cytokine cascades.

Thalidomide for the treatment of AIDS-associated wasting

A double-blind, placebo-controlled trial of efficacy and safety of thalidomide in AIDS-associated wasting was carried out. Ninety-nine of 103 male patients had at least one on-study measurement (intent-to-treat [ITT] cohort). Patients were randomized to thalidomide at 100 mg/day (T100) or 200 mg/day (T200), or placebo for 8 weeks. By ITT analysis, the mean change in body weight of the placebo, T100, and T200 treatment groups was 0.3 kg (0.4%), 2.0 kg (3.0%), and 0.9 kg (1.4%), respectively (p = 0.021 for T100 versus placebo; p = 0.53 for T200 versus placebo). Of the 64 patients who completed the 8 weeks of study treatment, significant weight gain was observed in both the T100 group (2.2 kg, [33%]; p = 0.008 versus placebo) and the T200 group (1.5 kg [2.5%]; p = 0.019 versus placebo). Approximately half the weight gain was fat-free mass (bioimpedance analysis). Patients in the T100 or T200 groups had no significant change in CD4+ cell counts, neutrophil counts, or TNF-alpha levels, compared with placebo. HIV viral load measured as log10 copies/ml decreased by a median of 0.07 in the placebo group, and increased by a median of 0.29 (T100 group) and 0.23 (T200 group) (p = 0.024 andp = 0.018 versus placebo, respectively). Thalidomide therapy was associated with mild to moderate rashes and fevers, but not peripheral neuropathy. Although the anabolic benefits of high-dose thalidomide are limited by drug intolerance, 8 weeks of low-dose thalidomide results in significant weight gain in patients with AIDS-associated wasting.

A single oral dose of thalidomide enhances the capacity of lymphocytes to secrete gamma interferon in healthy humans

Thalidomide is increasingly being used as adjuvant therapy for patients with mycobacterial and human immunodeficiency virus (HIV) infections. The T-helper (Th)1 cytokine-Th2 cytokine balance critically determines the outcomes of these diseases. To obtain insight into the effect of thalidomide on the capacity of lymphocytes to produce Th1 and Th2 cytokines, six healthy volunteers received an oral dose (400 mg) of thalidomide. Before and at 3, 6, and 24 h after ingestion of thalidomide, peripheral blood mononuclear cells (PBMCs) were isolated and stimulated for 24 h with the T-cell stimulant staphylococcal enterotoxin B (SEB) or anti-CD3/CD28. In all six volunteers ingestion of thalidomide was associated with enhanced SEB- and anti-CD3/CD28-induced production of the Th1 cytokine gamma interferon (P < 0.05) and a decrease in the level of anti-CD3/CD28-induced interleukin-5 (IL-5) production (P < 0.05). The levels of IL-2 (Th1) and IL-4 (Th2) released remained unchanged. These changes were accompanied by an increase in the amount of IL-12p40 released by the PBMCs 6 h after ingestion of thalidomide (P < 0.05). Thus, a single oral dose of thalidomide causes a Th1-type response in healthy humans. This finding offers a potential explanation for the positive effect of thalidomide in patients with mycobacterial and HIV infections.