Th1 CD41 T cells and their derived cytokines are crucial for protection against Mycobacterium tuberculosis. Using multiparametric flow cytometry, we have evaluated the distribution of seven distinct functional states (IFN-c/IL-2/TNF-a triple expressors, IFN-c/IL-2, IFN-c/TNF-a or TNF-a/IL-2 double expressors or IFN-c, IL-2 or TNF-a single expressors) of CD4 1 T cells in individuals with latent M. tuberculosis infection (LTBI) and active tuberculosis (TB). We found that triple expressors, while detectable in 85-90%TB patients, were only present in 10-15% of LTBI subjects. On the contrary, LTBI subjects had significantly higher (12-to 15-fold) proportions of IL-2/IFN-c double and IFN-c single expressors as compared with the other CD4 1 T-cell subsets. Proportions of the other double or single CD4 1 T-cell expressors did not differ between TB and LTBI subjects. These distinct IFN-c, IL-2 and TNF-a profiles of M. tuberculosis-specific CD4 1 T cells seem to be associated with live bacterial loads, as indicated by the decrease in frequency of multifunctional T cells in TB-infected patients after completion of anti-mycobacterial therapy. Our results suggest that phenotypic and functional signatures of CD4 1 T cells may serve as immunological correlates of protection and curative host responses, and be a useful tool to monitor the efficacy of anti-mycobacterial therapy. IntroductionInfections with Mycobacterium tuberculosis (M. tuberculosis) cause a global epidemic with almost 9 million new cases and over 1.6 million deaths per year [1,2]. Outcome of M. tuberculosis infection depends on early identification and proper treatment of individuals with active tuberculosis (TB), but the lack of accurate diagnostic techniques has contributed to the re-emergence of TB as a global health threat. More than 2 billion individuals are estimated to be latently infected with M. tuberculosis (LTBI). To date, however, Ã These authors have contributed equally to this work. There were a number of differences between TB patients and subjects with LTBI following stimulation with ESAT-6, Ag85B and the 16-kDa antigen (Fig. 2). Most notably, and in contrast with the previously reported results in chronic viral infections, we found a significantly higher proportion of 31 CD4 1 T cells simultaneously secreting IFN-g, IL-2 and TNF-a in patients with TB, as compared with LTBI subjects, upon stimulation with any of the three tested M. tuberculosis antigens (Fig. 2). Using a threshold of 0.01% to avoid systematic biases incurred by zeroing negative values (frequency values o0.01% were set to zero), we found that 31 CD4 1 T cells were detectable in very few LTBI subjects (3/18, 3/18 and 2/18 in response to Ag85B, ESAT-6 and 16 kDa, respectively), but were frequently detected in most TB patients (17/20, 18/20 and 17/20, in Eur. J. Immunol. 2010. 40: 2211-2220 Nadia Caccamo et al. 2212& 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.eji-journal.eu response to Ag85B, ESAT-6 and 16 kDa, respectively; see also Table 1 for comparison).In contrast, ...

SummaryThe potent anti-tumour activities of gd T cells have prompted the development of protocols in which gd-agonists are administered to cancer patients. Encouraging results from small Phase I trials have fuelled efforts to characterize more clearly the application of this approach to unmet clinical needs such as metastatic carcinoma. To examine this approach in breast cancer, a Phase I trial was conducted in which zoledronate, a Vg9Vd2 T cell agonist, plus low-dose interleukin (IL)-2 were administered to 10 therapeutically terminal, advanced metastatic breast cancer patients. Treatment was well tolerated and promoted the effector maturation of Vg9Vd2 T cells in all patients. However, a statistically significant correlation of clinical outcome with peripheral Vg9Vd2 T cell numbers emerged, as seven patients who failed to sustain Vg9Vd2 T cells showed progressive clinical deterioration, while three patients who sustained robust peripheral Vg9Vd2 cell populations showed declining CA15-3 levels and displayed one instance of partial remission and two of stable disease, respectively. In the context of an earlier trial in prostate cancer, these data emphasize the strong linkage of Vg9Vd2 T cell status to reduced carcinoma progression, and suggest that zoledronate plus low-dose IL-2 offers a novel, safe and feasible approach to enhance this in a subset of treatmentrefractory patients with advanced breast cancer.

Background Dysbiosis has been recently demonstrated in patients with ankylosing spondylitis (AS) but its implications in the modulation of intestinal immune responses have never been studied. The aim of this study was to investigate the role of ileal bacteria in modulating local and systemic immune responses in AS. Methods Ileal biopsies were obtained from 50 HLA-B27 + patients with AS and 20 normal subjects. Silver stain was used to visualise bacteria. Ileal expression of tight and adherens junction proteins was investigated by TaqMan real-Time (RT)-PCR and immunohistochemistry. Serum levels of lipopolysaccharide (LPS), LPS-binding protein (LPS-BP), intestinal fatty acid-BP (iFABP) and zonulin were assayed by ELISA. Monocyte immunological functions were studied in in vitro experiments. In addition the effects of antibiotics on tight junctions in human leukocyte antigen (HLA)-B27 transgenic (TG) rats were assessed. Results Adherent and invasive bacteria were observed in the gut of patients with AS with the bacterial scores significantly correlated with gut inflammation. Impairment of the gut vascular barrier (GVB) was also present in AS, accompanied by significant upregulation of zonulin, and associated with high serum levels of LPS, LPS-BP, iFABP and zonulin. In in vitro studies zonulin altered endothelial tight junctions while its epithelial release was modulated by isolated AS ileal bacteria. AS circulating monocytes displayed an anergic phenotype partially restored by ex vivo stimulation with LPS+sCD14 and their stimulation with recombinant zonulin induced a clear M2 phenotype. Antibiotics restored tight junction function in HLA-B27 TG rats. Conclusions Bacterial ileitis, increased zonulin expression and damaged intestinal mucosal barrier and GVB, characterises the gut of patients with AS and are associated with increased blood levels of zonulin, and bacterial products. Bacterial products and zonulin influence monocyte behaviour

Type 3 innate lymphoid cells producing IL-17 and IL-22 are expanded in the gut, in the peripheral blood, synovial fluid and bone marrow of patients with ankylosing spondylitis Conclusions Gut-derived IL-17 + and IL-22 + ILC3 are expanded in the peripheral blood, SF and inflamed BM of patients with AS, suggesting the presence of an active homing axis between the gut and the inflamed sacroiliac joints.

With 1.4 million deaths and 8.7 million new cases in 2011, tuberculosis (TB) remains a global health care problem and together with HIV and Malaria represents one of the three infectious diseases world-wide. Control of the global TB epidemic has been impaired by the lack of an effective vaccine, by the emergence of drug-resistant forms of Mycobacterium tuberculosis (Mtb) and by the lack of sensitive and rapid diagnostics. It is estimated, by epidemiological reports, that one third of the world’s population is latently infected with Mtb, but the majority of infected individuals develop long-lived protective immunity, which controls and contains Mtb in a T cell-dependent manner. Development of TB disease results from interactions among the environment, the host, and the pathogen, and known risk factors include HIV co-infection, immunodeficiency, diabetes mellitus, overcrowding, malnutrition, and general poverty; therefore, an effective T cell response determines whether the infection resolves or develops into clinically evident disease. Consequently, there is great interest in determining which T cells subsets mediate anti-mycobacterial immunity, delineating their effector functions. On the other hand, many aspects remain unsolved in understanding why some individuals are protected from Mtb infection while others go on to develop disease. Several studies have demonstrated that CD4+ T cells are involved in protection against Mtb, as supported by the evidence that CD4+ T cell depletion is responsible for Mtb reactivation in HIV-infected individuals. There are many subsets of CD4+ T cells, such as T-helper 1 (Th1), Th2, Th17, and regulatory T cells (Tregs), and all these subsets co-operate or interfere with each other to control infection; the dominant subset may differ between active and latent Mtb infection cases. Mtb-specific-CD4+ Th1 cell response is considered to have a protective role for the ability to produce cytokines such as IFN-γ or TNF-α that contribute to the recruitment and activation of innate immune cells, like monocytes and granulocytes. Thus, while other antigen (Ag)-specific T cells such as CD8+ T cells, natural killer (NK) cells, γδ T cells, and CD1-restricted T cells can also produce IFN-γ during Mtb infection, they cannot compensate for the lack of CD4+ T cells. The detection of Ag-specific cytokine production by intracellular cytokine staining (ICS) and the use of flow cytometry techniques are a common routine that supports the studies aimed at focusing the role of the immune system in infectious diseases. Flow cytometry permits to evaluate simultaneously the presence of different cytokines that can delineate different subsets of cells as having “multifunctional/polyfunctional” profile. It has been proposed that polyfunctional T cells, are associated with protective immunity toward Mtb, in particular it has been highlighted that the number of Mtb-specific T cells producing a combination of IFN-γ, IL-2, and/or TNF-α may be correlated with the mycobacterial load, while other studies have associate...