Influence on Response to Therapy and Overall Survival of Mediastinal Involvement by Hodgkin's Disease

To assess the prognostic significance of mediastinal involvement of Hodgkin's disease, 91 patients with stage I to III disease treated at our Institute were reclassified according to size of mediastinal disease and other clinical and therapeutic characteristics. Complete remission (CR) was achieved in 46 of 67 (81%) patients without mediastinal involvement, and in 16 of 17 (94%) patients with small mediastinal masses, but only in 10 of 17 (59%) patients with large masses (P < 0.05). Twenty-seven of 32 (84%) patients treated with irradiation alone and 26 of 28 (93%) patients treated with combined modality therapy reached a CR, whereas such a result was obtained only in 19 of 31 (61%) patients who received MOPP chemotherapy alone (P < 0.01). In particular, none of the patients with large masses had a CR when treated with chemotherapy alone, whereas no differences in response to therapy were found between patients with large vs. small or no masses when irradiation or combined treatments were utilized. Since combined treatment seems to reach a high proportion of CR and to prevent extranodal relapse, further randomized clinical trials are needed to decide its routine utilization in patients with poor prognostic factors such as large mediastinal adenopathies.

Combination Chemotherapy with Cyclophosphamide, Adriamycin, Vincristine and Prednisone (CHOP) for Non-Hodgkin's Lymphomas with Unfavorable Histology: Preliminary Results

From January 1978 to June 1979, 29 selected, previously untreated patients with unfavorable histology of non-Hodgkin's lymphomas (12 DPDL, 7 DM, 9 DH and 1 DU) were submitted to the combination chemotherapy CHOP (cyclophosphamide, 750 mg/m2 i.v. on day 1; adriamycin, 50 mg/m2 i.v. on day 1; vincristine, 1.4 mg/m2 i.v. on day 1, and prednisone, 100 mg p.o. on day 1 through 5) every 21 days. Eighteen patients were in early stage (I or II) and 11 of them were also submitted to involved field radiotherapy (60Co), immediately before (stage I) or during (stage II) the chemotherapy, with a mean dosage of 4,500 rad. The remaining 11 patients were in advanced stage (III or IV) of disease and were treated with chemotherapy alone. We obtained 20 complete remissions (68%), 8 partial remissions (28 %) and 1 no response (4 %) to therapy. Sixteen of 18 patients (89 %) in early stages and 4 of 11 patients (36 %) in advanced stages achieved a complete remission. The bone marrow toxicity of the chemotherapy was moderate. Nausea, vomiting and diarrhea were frequent but well controlled by the support therapy. The actuarial survival rate of patients, after 18 months of follow-up, is 41 % (40 % in complete remission). The patients who achieved a complete remission are all alive and 65 % of them still relapse free. We believe that the combination chemotherapy CHOP improves the complete remission rate as well as the survival of patients with unfavorable histology of non-Hodgkin's lymphomas.

Combination Chemotherapy (CVP or Chop)-Radiotherapy Approach in Early Stage Non-Hodgkin's Lymphomas

From January 1978 to December 1980, 42 patients with early stage non-Hodgkin's lymphoma other than of the gastrointestinal tract were treated with radiotherapy and combination chemotherapy. Eighteen patients in stage I were submitted to locally extended-field radiotherapy up to a mean dose of 48 Gy with a Co60 source and, after a 3-week rest period, to 6 cycles of combination chemotherapy. Twenty-four patients in stage II received 3 cycles of combination chemotherapy before and after irradiation, the same as for stage I. Combination chemotherapy consisted of cyclophosphamide, vincristine and prednisone (CVP) for 15 cases with favorable histology (3 NWDL, 1 NPDI, 11 DWDL), whereas it included cyclophosphamide, adriamycin, vincristine and prednisone (CHOP) for 27 cases with unfavorable histology (20 DPDL, 3 DM, 4 DH). Complete remission (CR) was achieved in 35/42 (83%) patients, with a highly significant difference between stage I (100%) and stage II (71%). After 42 months of follow-up, the probability of survival for all patients was 72%. Survival was better for stage I (88%) than for stage II (68%) and for favorable histology (87%) as compared to unfavorable histology (70%). Furthermore, survival was highly influenced by response to therapy. Indeed, actuarial survival rate for CR was 91% as compared to a median survival time of 10.2 months for the remaining patients. Four patients, all with poor histology, relapsed after 5–24 (mean 11) months of CR. Only one of them had an extension in extranodal sites and eventually died, despite the salvage treatment utilized. In our experience, locally extended-field irradiation combined with chemotherapy gave a high proportion of CR and seemed to prevent relapses, particularly in extranodal sites.

Reversed isoniazids: Design, synthesis and evaluation against Mycobacterium tuberculosis

Novel reversed isoniazid (RINH) agents were synthesized by covalently linking isoniazid with various efflux pump inhibitor (EPI) cores and their structural motifs. These RINH agents were then evaluated for anti-mycobacterial activity against sensitive, isoniazid mono-resistant and MDR clinical isolates of M. tuberculosis and a selected number of compounds were also tested ex vivo for intracellular activity as well as in the ethidium bromide (EB) assay for efflux pump inhibition efficacy. The potency of some compounds against various strains of M. tuberculosis (4a-c, 7 and 8; H37Rv-MIC₉₉ ≤1.25 µM, R5401-MIC₉₉ ≤2.5 µM, X_61-MIC₉₉ ≤5 µM) demonstrated the potential of the reversed anti-TB agent strategy towards the development of novel anti-mycobacterial agents to address the rapidly growing issue of resistance. Further, macrophage activity with >90% inhibition by 1a-c and 3b (MIC₉₀ ≤13.42 µM) and inhibition of EB efflux demonstrated by these compounds are encouraging.

Risk factors and outcomes for multidrug-resistant Gram-negative bacilli bacteremia

Background

The incidence of multidrug-resistant (MDR) organisms is increasing along with mortality. Identifying risk factors for the development of MDR Gram-negative bacilli (GNB) bacteremia could greatly impact patient care and management.

Methods

Data from the electronic health record of patients with GNB over 13-month period were collected at a single university medical center. Baseline demographic data, risk factor, microbiological data, recurrence of bacteremia, and mortality were recorded.

Results

A total of 177 patients were included in the analysis. MDR GNB occurred in 46 patients (26%). The mortality rate in the MDR group was 34.8% compared to 13.7% in non-MDR group (p = 0.002). In multivariate analysis, diabetes mellitus [DM; odds ratio (OR): 2.8, 95% confidence interval (CI): 1-4.88], previous antibiotic use (OR: 2.93, 95% CI: 1.25-6.87), and urinary catheter as a source of infection (OR 5.96, 95% CI: 1.78-19.94) were significant risk factors for the development of MDR GNB. In addition, end-stage liver disease (OR: 3.64, 95% CI: 1.07-12.3), solid organ malignancy (OR: 3.64, 95% CI: 1.25-10.56), intra-abdominal source of infection (OR: 3.66, 95% CI: 1.14-11.73), inappropriate empiric antibiotics (OR 7.59, 95% CI: 1.68-34.34) and urinary catheter as a source of infection (OR 5.68, 95% CI: 1.37-23.5) were significant factors for mortality in patients with MDR GNB.

Conclusion

Our study provides important information about the risk factors for the development of MDR GNB bacteremia and helps prognosticate patient with MDR GNB.

Design, Synthesis, and Evaluation of Novel Hybrid Efflux Pump Inhibitors for Use against Mycobacterium tuberculosis

Efflux pumps are considered a major potential contributor to the development of various forms of resistance in Mycobacterium tuberculosis leading to the emergence of multidrug-resistant tuberculosis (TB). Verapamil (VER) and tricyclic chemosensitizers such as the phenothiazines are known to possess efflux pump inhibition properties and have demonstrated significant efficacy in various TB disease models. Novel hybrid molecules based on fusion of the VER substructure with various tricyclic, as well as nontricyclic, chemosensitizer cores or their structural motifs are described. These hybrid compounds were evaluated in vitro and ex vivo individually for their intrinsic activity and in combination for their potentiating potential with the frontline anti-TB drugs, rifampin and isoniazid. In addition, efflux pump inhibition was assessed in an ethidium bromide assay. This study led to the identification of novel compounds, termed hybrid efflux pump inhibitors, with intrinsic antimycobacterial activities (MIC₉₀ ≤ 3.17 μg/mL) and intracellular activity in macrophages at a low concentration (≤6.25 μg/mL).

Immunotherapy for tuberculosis: future prospects

Tuberculosis (TB) is still a major global health problem. A third of the world’s population is infected with Mycobacterium tuberculosis. Only ~10% of infected individuals develop TB but there are 9 million TB cases with 1.5 million deaths annually. The standard prophylactic treatment regimens for latent TB infection take 3–9 months, and new cases of TB require at least 6 months of treatment with multiple drugs. The management of latent TB infection and TB has become more challenging because of the spread of multidrug-resistant and extremely drug-resistant TB. Intensified efforts to find new TB drugs and immunotherapies are needed. Immunotherapies could modulate the immune system in patients with latent TB infection or active disease, enabling better control of M. tuberculosis replication. This review describes several types of potential immunotherapies with a focus on those which have been tested in humans.

Safety and Immunogenicity of the Recombinant BCG Vaccine AERAS-422 in Healthy BCG-naïve Adults: A Randomized, Active-controlled, First-in-human Phase 1 Trial

BACKGROUND

We report a first-in-human trial evaluating safety and immunogenicity of a recombinant BCG, AERAS-422, over-expressing TB antigens Ag85A, Ag85B, and Rv3407 and expressing mutant perfringolysin.

METHODS

This was a randomized, double-blind, dose-escalation trial in HIV-negative, healthy adult, BCG-naïve volunteers, negative for prior exposure to Mtb, at one US clinical site. Volunteers were randomized 2:1 at each dose level to receive a single intradermal dose of AERAS-422 (>10(5)-<10(6)CFU=low dose, ≥10(6)-<10(7)CFU=high dose) or non-recombinant Tice BCG (1-8×10(5)CFU). Randomization used an independently prepared randomly generated sequence of treatment assignments. The primary and secondary outcomes were safety and immunogenicity, respectively, assessed in all participants through 182days post-vaccination. ClinicalTrials.gov registration number: NCT01340820.

FINDINGS

Between Nov 2010 and Aug 2011, 24 volunteers were enrolled (AERAS-422 high dose, n=8; AERAS-422 low dose, n=8; Tice BCG, n=8); all were included in the safety and immunogenicity analyses. All 24 subjects had at least one adverse event, primarily expected local reactions. High dose AERAS-422 vaccination induced Ag85A- and Ag85B-specific lymphoproliferative responses and marked anti-mycobacterial activity in a whole blood bactericidal activity culture assay (WBA), but was associated with varicella zoster virus (VZV) reactivation in two vaccinees. These volunteers displayed high BCG-specific IFN-γ responses pre- and post-vaccination possibly predisposing them to autocrine/paracrine negative regulation of immune control of latent VZV. A systems biology transcriptomal approach identified positive correlations between post-vaccination T cell expression modules and WBA, and negative correlations between post-vaccination monocyte expression modules and WBA. The expression of one key macrophage marker (F4/80) was constitutively elevated in the two volunteers with zoster.

INTERPRETATION

The unexpected development of VZV in two of eight healthy adult vaccine recipients resulted in discontinuation of AERAS-422 vaccine development. Immunological and transcriptomal data identified correlations with the development of TB immunity and VZV that require further investigation.

FUNDING

Aeras, FDA, Bill and Melinda Gates Foundation.

A subset of protective γ9δ2 T cells is activated by novel mycobacterial antigens (MPF5P.740)

γ9δ2 T cells provide a natural bridge between innate and adaptive immunity and are prominently induced by both tuberculosis (TB) infection and bacillus Calmette Guérin (BCG) vaccination. Mycobacteria-expanded γ9δ2 T cells represent only a subset of the simple phosphoantigen (IPP and HMBPP)-responsive γ9δ2 T cells, this subset expresses a more oligoclonal set of TCR sequences, and only this subset efficiently recognizes and inhibits intracellular BCG/Mtb. We have been searching for new mycobacterial antigens capable of inducing the unique subset of γ9δ2 T cells that can recognize mycobacteria-infected macrophages and mediate protective effects inhibiting intracellular mycobacterial growth. We first ruled out protein, nucleic acid and apolar lipids with basic separations and enzymatic digestions. Acid hydrolysis, which digests complex carbohydrate structures, had the largest effect on eliminating Mtb fraction specific activity. Organic extractions resulted in sub-fractions with &gt;100 fold enriched specific activity. A combination of MS, NMR, TLC indicate that methyl-glucose lipopolysaccharides (mGLP) are predominant components of the most active fractions. We are currently attempting to use synthetic techniques to confirm the specific activity of mGLP for induction of protective γ9δ2 T cells. These results have important implications for the development of new immunotherapeutic approaches for prevention/treatment of TB.

Granzyme A produced by γ(9)δ(2) T cells induces human macrophages to inhibit growth of an intracellular pathogen

Human γ₉δ₂ T cells potently inhibit pathogenic microbes, including intracellular mycobacteria, but the key inhibitory mechanism(s) involved have not been identified. We report a novel mechanism involving the inhibition of intracellular mycobacteria by soluble granzyme A. γ₉δ₂ T cells produced soluble factors that could pass through 0.45 µm membranes and inhibit intracellular mycobacteria in human monocytes cultured below transwell inserts. Neutralization of TNF-α in co-cultures of infected monocytes and γ₉δ₂ T cells prevented inhibition, suggesting that TNF-α was the critical inhibitory factor produced by γ₉δ₂ T cells. However, only siRNA- mediated knockdown of TNF-α in infected monocytes, but not in γ₉δ₂ T cells, prevented mycobacterial growth inhibition. Investigations of other soluble factors produced by γ₉δ₂ T cells identified a highly significant correlation between the levels of granzyme A produced and intracellular mycobacterial growth inhibition. Furthermore, purified granzyme A alone induced inhibition of intracellular mycobacteria, while knockdown of granzyme A in γ₉δ₂ T cell clones blocked their inhibitory effects. The inhibitory mechanism was independent of autophagy, apoptosis, nitric oxide production, type I interferons, Fas/FasL and perforin. These results demonstrate a novel microbial defense mechanism involving granzyme A-mediated triggering of TNF-α production by monocytes leading to intracellular mycobacterial growth suppression. This pathway may provide a protective mechanism relevant for the development of new vaccines and/or immunotherapies for macrophage-resident chronic microbial infections.

A small subset of human T cells express γ₉δ₂ T cell receptors and recognize unique non-peptide phosphoantigens expressed by microbes and damaged cells, such as cancer. These cells are important because: 1) they reside within skin and mucosal surfaces at critical points of initial pathogen invasion, and 2) they are not restricted by polymorphic HLA types and thus can be activated by the same cognate antigens in highly diverse populations. Many important human pathogens such as the causes of AIDS, malaria, tuberculosis and others induce potent responses in γ₉δ₂ T cells that can be protective. However, the key mechanisms involved in γ₉δ₂ T cell-mediated protective immunity are not well defined. We have found that γ₉δ₂ T cells produce soluble granzyme A which correlates with their ability to protect against intracellular mycobacterial growth. We show directly that highly purified granzyme A alone can trigger human monocytes to control intracellular mycobacteria. We further show that the granzyme A-induced mycobacterial inhibition required production of TNF-α by infected monocytes. These studies may have important implications for future vaccine development and novel therapeutic strategies.

Fournier gangrene from a thirty-two-centimeter rectosigmoid foreign body

BACKGROUND

Medical and surgical problems associated with rectal foreign bodies are rare. Although most rectal foreign bodies can be removed without subsequent sequelae, they pose significant risk of infection.

OBJECTIVES

We report a patient with a 32-cm rectosigmoid foreign body and subsequent development of Fournier gangrene despite successful removal of the foreign body.

CASE REPORT

A 63-year-old Caucasian man with past medical history of diabetes mellitus and depression presented with a chief complaint of "something stuck in my intestine." He admitted that he placed a foreign body in the rectum. Abdominal X-ray study and computed tomography of the abdomen/pelvis showed a conical-shaped 32-cm rectosigmoid foreign body. The foreign body was removed manually and follow-up colonoscopy was done. The patient's condition deteriorated in the first 2 days of hospital stay and he was diagnosed with Fournier gangrene. He required multiple surgeries and received broad-spectrum antibiotic coverage for mixed bacterial flora grown from deep tissue.

CONCLUSION

Rectal foreign bodies can cause Fournier gangrene. A close observation and follow-up is important after removal of rectal foreign bodies.

Spectrophotometric determination of acid volatile sulfide in river sediments by sequential injection analysis exploiting the methylene blue reaction

This paper demonstrates the application of sequential injection analysis to perform sulfide determination using the methylene blue chemistry, based on two reagents: 3.63 mmol l(-1)N,N dimethyl-p-phenylene diamine hydrochloride in 1.1 mol l(-1) HCl solution and 19 mmol l(-1) FeCl(3), also in 1.1 mol l(-1) HCl. These solutions are aspirated inside the holding coil of the sequential injection system as two reagent zones sandwiching the sample zone. Under optimized conditions, the detection limit was calculated at 40 mug l(-1) S(2-), with a linear dynamic range from 0.05 to 2 mg l(-1) S(2-). This linear range can be extended up to 32 mg l(-1) using in-line dilution for sulfide concentrations greater than 2 mg l(-1). The robust characteristic of the SI system with syringe pump leads to very stable analytical curves (precision of 4%), minimizing the laborious preparation of sulfide standards. The method was applied in the determination of acid volatile sulfide in river sediments.

Clinical and bacteriological characteristics of Klebsiella pneumoniae causing liver abscess with less frequently observed multi-locus sequences type, ST163, from Singapore and Missouri, US

BACKGROUND

Klebsiella pneumoniae is the major cause of liver abscesses in several Asian countries. Differences in the type of circulating Klebsiella strains and/or the genetic make up of the host seem to be plausible explanations for this.

METHODS

Two recent K. pneumoniae strains isolated from patients with liver abscess, one from Missouri in the US, and a second one from Singapore, were fully characterized by molecular typing, association of virulent genes, neutrophil phagocytosis, susceptibility to serum killing, and lethality in mice.

RESULTS

Both strains had mucoid colony morphology and were similar in multilocus sequence type (ST-163), drug-susceptibility profile, resistance to phagocytosis and susceptibility to serum killing. Although ST-163 is a single nucleotide variant (SNV) to the major ST-23, which is specific to serotype K1 K. pneumoniae that causes liver abscess in Taiwan, these two isolates differ in capsular serotype. One was serotype K1 and the other K29. Since a serotype K35 with ST163 was reported previously to cause peritonitis, serotype K29 with SNV to ST-23 was not impossible. Pulsed field gel electrophoresis by XbaI digestion showed different restriction patterns. The virulence-associated genes rmpA and aerobactin were only present in the serotype K1 isolate from Singapore and not in the serotype K29 isolate from Missouri. The serotype K1 isolate was also more virulent to mice.

CONCLUSION

The reasons underlying the high prevalence of ST-23 or its SNV in K. pueumonaie liver abscesses is worth further investigation.

Live and inactivated influenza vaccines induce similar humoral responses, but only live vaccines induce diverse T-cell responses in young children

BACKGROUND

Two doses of either trivalent live attenuated or inactivated influenza vaccines (LAIV and TIV, respectively) are approved for young children (≥ 24 months old for LAIV and ≥ 6 months old for TIV) and induce protective antibody responses. However, whether combinations of LAIV and TIV are safe and equally immunogenic is unknown. Furthermore, LAIV is more protective than TIV in children for unclear reasons.

METHODS

Children 6-35 months old were administered, 1 month apart, 2 doses of either TIV or LAIV, or combinations of LAIV and TIV in both prime/boost sequences. Influenza-specific antibodies were measured by hemagglutination inhibition (HAI), and T cells were studied in flow cytometric and functional assays. Highly conserved M1, M2, and NP peptides predicted to be presented by common HLA class I and II were used to stimulate interferon-γ enzyme-linked immunospot responses.

RESULTS

All LAIV and/or TIV combinations were well tolerated and induced similar HAI responses. In contrast, only regimens containing LAIV induced influenza-specific CD4(+), CD8(+), and γδ T cells, including T cells specific for highly conserved influenza peptides.

CONCLUSIONS

Prime/boost combinations of LAIV and TIV in young children were safe and induced similar protective antibodies. Only LAIV induced CD4(+), CD8(+), and γδ T cells relevant for broadly protective heterosubtypic immunity.

CLINICAL TRIALS REGISTRATION

NCT00231907.

Cedecea davisae bacteremia in a neutropenic patient with acute myeloid leukemia

Cedecea are the new members of Enterobacteriacea. Because of their inherent resistance to some antibiotics, the clinical response could be unpredictable making management of Cedecea infection in immunocompromised patients challenging. We report a case of acute myeloid leukemia with central line-related Cedecea bacteremia.

CD46-induced regulatory T cells suppress Mycobacterium tuberculosis-specific effector T cell responses (33.5)

Human regulatory T cells can be generated through a number of known pathways in vivo and in vitro. Simultaneous engagement of the TCR and complement regulator CD46 on human CD4+ T cells induces adaptive Treg development. These CD46-induced Treg, also known as 'complement-induced Treg' or 'cTreg,' have been shown to suppress bystander CD4+ T cells activated in vitro with crosslinking antibodies to CD3 and CD28. Here we offer the first description of cTreg suppression of human effector T cells in an APC-dependent system of pathogen infection. We found that soluble molecules secreted by cTreg suppress Mycobacterium tuberculosis-specific CD4+, CD8+, and γδ T cell responses. These immunosuppressive effects were mediated in part by IL-10 and in part by other as yet unidentified soluble factors acting synergistically with IL-10. In addition, our results indicate that different mechanisms may be involved in the suppression of αβ and γδ T cells. We further show that APC functions were not affected by cTreg, indicating direct suppression of pathogen-specific T cells. Modulating the immunosuppressive functions of this Treg subset could lead to improved tuberculosis therapeutics or vaccines.

A new recombinant bacille Calmette-Guérin vaccine safely induces significantly enhanced tuberculosis-specific immunity in human volunteers

BACKGROUND

One strategy for improving anti-tuberculosis (TB) vaccination involves the use of recombinant bacille Calmette-Guérin (rBCG) overexpressing protective TB antigens. rBCG30, which overexpresses the Mycobacterium tuberculosis secreted antigen Ag85b, was the first rBCG shown to induce significantly greater protection against TB in animals than parental BCG.

METHODS

We report here the first double-blind phase 1 trial of rBCG30 in 35 adults randomized to receive either rBCG30 or parental Tice BCG intradermally. Clinical reactogenicity was assessed, and state-of-the-art immunological assays were used to study Ag85b-specific immune responses induced by both vaccines.

RESULTS

Similar clinical reactogenicity occurred with both vaccines. rBCG30 induced significantly increased Ag85b-specific T cell lymphoproliferation, interferon (IFN)-gamma secretion, IFN-gamma enzyme-linked immunospot responses, and direct ex vivo intracellular IFN-gamma responses. Additional flow cytometry studies measuring carboxyfluorescein succinimidyl ester dilution and intracellular cytokine production demonstrated that rBCG30 significantly enhanced the population of Ag85b-specific CD4(+) and CD8(+) T cells capable of concurrent expansion and effector function. More importantly, rBCG30 significantly increased the number of Ag85b-specific T cells capable of inhibiting intracellular mycobacteria.

CONCLUSIONS

These results provide proof of principal that rBCG can safely enhance human TB immunity and support further development of rBCG overexpressing Ag85b for TB vaccination.

Only a subset of phosphoantigen-responsive gamma9delta2 T cells mediate protective tuberculosis immunity

Mycobacterium tuberculosis and Mycobacterium bovis bacillus Calmette-Guérin (BCG) induce potent expansions of human memory Vgamma(9)(+)Vdelta(2)(+) T cells capable of IFN-gamma production, cytolytic activity, and mycobacterial growth inhibition. Certain phosphoantigens expressed by mycobacteria can stimulate gamma(9)delta(2) T cell expansions, suggesting that purified or synthetic forms of these phosphoantigens may be useful alone or as components of new vaccines or immunotherapeutics. However, we show that while mycobacteria-activated gamma(9)delta(2) T cells potently inhibit intracellular mycobacterial growth, phosphoantigen-activated gamma(9)delta(2) T cells fail to inhibit mycobacteria, although both develop similar effector cytokine and cytolytic functional capacities. gamma(9)delta(2) T cells receiving TLR-mediated costimulation during phosphoantigen activation also failed to inhibit mycobacterial growth. We hypothesized that mycobacteria express Ags, other than the previously identified phosphoantigens, that induce protective subsets of gamma(9)delta(2) T cells. Testing this hypothesis, we compared the TCR sequence diversity of gamma(9)delta(2) T cells expanded with BCG-infected vs phosphoantigen-treated dendritic cells. BCG-stimulated gamma(9)delta(2) T cells displayed a more restricted TCR diversity than phosphoantigen-activated gamma(9)delta(2) T cells. In addition, only a subset of phosphoantigen-activated gamma(9)delta(2) T cells functionally responded to mycobacteria-infected dendritic cells. Furthermore, differential inhibitory functions of BCG- and phosphoantigen-activated gamma(9)delta(2) T cells were confirmed at the clonal level and were not due to differences in TCR avidity. Our results demonstrate that BCG infection can activate and expand protective subsets of phosphoantigen-responsive gamma(9)delta(2) T cells, and provide the first indication that gamma(9)delta(2) T cells can develop pathogen specificity similar to alphabeta T cells. Specific targeting of protective gamma(9)delta(2) T cell subsets will be important for future tuberculosis vaccines.

Comparison of the safety and immunogenicity of ACAM1000, ACAM2000 and Dryvax in healthy vaccinia-naive adults

Currently, more than half of the world's population has no immunity against smallpox variola major virus. This phase I double-blind, randomized trial was conducted to compare the safety and immunogenicity of two clonally derived, cell-culture manufactured vaccinia strains, ACAM1000 and ACAM2000, to the parent vaccine, Dryvax. Thirty vaccinia-naïve subjects were enrolled into each of three groups and vaccines were administered percutaneously using a bifurcated needle at a dose of 1.0x10(8)PFU/mL. All subjects had a primary skin reaction indicating a successful vaccination. The adverse events, 4-fold neutralizing antibody rise and T cell immune responses were similar between the groups.