The increasing evidence that ;D T cells have potent antitumor activity suggests their value in immunotherapy, particularly in areas of unmet need such as metastatic carcinoma. To this end, we initiated a phase I clinical trial in metastatic hormonerefractory prostate cancer to examine the feasibility and consequences of using the ;D T-cell agonist zoledronate, either alone or in combination with low-dose interleukin 2 (IL-2), to activate peripheral blood ;D cells. Nine patients were enlisted to each arm. Neither treatment showed appreciable toxicity. Most patients were treated with zoledronate + IL-2, but conversely only two treated with zoledronate displayed a significant longterm shift of peripheral ;D cells toward an activated effectormemory-like state (T EM ), producing IFN-; and perforin. These patients also maintained serum levels of tumor necrosis factorrelated apoptosis inducing ligand (TRAIL), consistent with a parallel microarray analysis showing that TRAIL is produced by ;D cells activated via the T-cell receptor and IL-2. Moreover, the numbers of T EM ;D cells showed a statistically significant correlation with declining prostate-specific antigen levels and objective clinical outcomes that comprised three instances of partial remission and five of stable disease. By contrast, most patients treated only with zoledronate failed to sustain either ;D cell numbers or serum TRAIL, and showed progressive clinical deterioration. Thus, zoledronate + IL-2 represents a novel, safe, and feasible approach to induce immunologic and clinical responses in patients with metastatic carcinomas, potentially providing a substantially increased window for specific approaches to be administered. Moreover, ;D cell phenotypes and possibly serum TRAIL may constitute novel biomarkers of prognosis upon therapy with zoledronate + IL-2 in metastatic carcinoma. [Cancer Res 2007;67(15):7450-7]

Vδ2 T lymphocytes recognize nonpeptidic antigens without presentation by MHC molecules and mount both immediate effector functions and memory responses after microbial infection. However, how Vδ2 T cells mediate different facets of a memory response remains unknown. Here, we show that the expression of CD45RA and CD27 antigens defines four subsets of human Vδ2 T cells with distinctive compartmentalization routes. Naive CD45RA+CD27+ and memory CD45RA−CD27+ cells express lymph node homing receptors, abound in lymph nodes, and lack immediate effector functions. Conversely, memory CD45RA−CD27− and terminally differentiated CD45RA+CD27− cells, which express receptors for homing to inflamed tissues, are poorly represented in the lymph nodes while abounding at sites of inflammation, and display immediate effector functions. These observations and additional in vitro experiments indicate a lineage differentiation pattern for human Vδ2 T cells that generates naive cells circulating in lymph nodes, effector/memory cells patrolling the blood, and terminally differentiated effector cells residing in inflamed tissues.

IntroductionIL-17 is a cytokine that induces mobilization and activation of neutrophils and triggers the production of proinflammatory cytokines and chemokines by a broad range of cellular targets. 1 It is predominantly produced by ␣␤ T cells, but also by natural killer (NK) T cells, 2 ␥␦ T cells, 3 and other non-T cells, such as macrophages and neutrophils. 4,5 Differentiation of CD4 T cells producing IL-17 (Th17) is initiated in naive Th cells by antigen-specific stimulation in the presence of the polarizing cytokines IL-1␤, TGF-␤, and IL-6 (and autocrine IL-21), which induce the expression of IL-23 receptor (IL-23R), the chemokine receptor CCR6, and the Th17-specifying transcription factor ROR␥t, which is necessary and sufficient for induction of IL-17. 1,6 In mice, ␥␦ T cells represent an innate source of IL-17 and precede the development of the adaptive Th17-cell response. For instance, during Mycobacterium tuberculosis and Escherichia coli infection, ␥␦ T cells are the primary source of 8 and their depletion causes decreased IL-17 production and neutrophil infiltration into the peritoneal cavity. 8 In Listeria monocytogenes infection, ␥␦ T cells producing IL-17 enhance the antibacterial activity of nonphagocytic cells, which correlates with the induction of ␤-defensin gene expression. 9 These results indicate a novel IL-17-dependent protective mechanism of ␥␦ T cells that acts against intracellular bacterial infections in the mouse. The authors of several recent studies have provided data on the differentiation, phenotype, and functions of murine ␥␦ T cells producing IL-17 [10][11][12][13][14][15] and have demonstrated that signals through the ␥␦ TCR are not required for IL-17 production; instead, this process seems to be controlled by innate cytokines produced by accessory cells such as macrophages or dendritic cells (DCs). 11,15,16 Conversely, few groups have investigated IL-17 production by human ␥␦ T cells.Most human peripheral blood ␥␦ T cells express a TCR consisting of the V␥9 and the V␦2 chains (here and thereafter referred to as V␥9V␦2 T cells) and recognize nonpeptidic phosphorylated metabolites of isoprenoid biosynthesis produced by microorganisms and stressed cells. [17][18][19] On activation, V␥9V␦2 T cells promote DC maturation, 20 B-cell activation, 21 and polarize adaptive immunity toward a Th1 immune response. 10 Such a broad plasticity emphasizes the capacity of V␥9V␦2 T cells to influence the nature of immune response to different challenges. Human ␥␦ T cells producing IL-17 have been detected in the peripheral blood of patients with tuberculosis 22 or HIV infection, 23 but in neither of these studies did the authors characterize the IL-17-and IL-22-producing ␥␦ T cells or examine the cytokine requirements for IL-17 production.The authors of a very recent study have demonstrated that IL-17A-and IL-22-producing V␥9V␦2 T cells exist at low but significant frequencies in human and nonhuman primates, 24 and have suggested that V␥9V␦2 T cells can be polarized into Th17 (producing only IL-17),...

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.

Colon cancer comprises a small population of cancer stem cells (CSC) that is responsible for tumor maintenance and resistant to cancer therapies, possibly allowing for tumor recapitulation once treatment stops. We previously demonstrated that such chemoresistance is mediated by autocrine production of IL-4 through the up-regulation of antiapoptotic proteins. Several innate and adaptive immune effector cells allow for the recognition and destruction of cancer precursors before they constitute the tumor mass. However, cellular immune-based therapies have not been experimented yet in the population of CSCs. Here, we show that the bisphosphonate zoledronate sensitizes colon CSCs to Vγ9Vδ2 T cell cytotoxicity. Proliferation and production of cytokines (TNF-α and IFN-γ) and cytotoxic and apoptotic molecules (TRAIL and granzymes) were also induced after exposure of Vγ9Vδ2 T cells to sensitized targets. Vγ9Vδ2 T cell cytotoxicity was mediated by the granule exocytosis pathway and was highly dependent on isoprenoid production by of tumor cells. Moreover, CSCs recognition and killing was mainly TCR mediated, whereas NKG2D played a role only when tumor targets expressed several NKG2D ligands. We conclude that intentional activation of Vγ9Vδ2 T cells by zoledronate may substantially increase antitumor activities and represent a novel strategy for colon cancer immunotherapy.

marrow complete remission (CR), and standard non-Hodgkin lymphoma (NHL) doses of rituximab in untreated CLL patients 4 cleared the bone marrow in only 9% of patients. We, therefore, would offer an alternative focus for future investigation with rituximab. Specifically, efforts should be focused on understanding potential factors such as stromal cell interaction that disrupt apoptosis, 5 CLL cell density, antibody penetration, and decreased access to complement and effector cells within the bone marrow that might prevent efficient clearance of tumor cells in the majority of patients. Such studies will facilitate development of alternative combination strategies to improve bone marrow responses with this promising combination therapy.

Contribution of Vgamma9/Vdelta2 T lymphocytes to immune protection against Mycobacterium tuberculosis is still a matter of debate. It was reported earlier that Vgamma9/Vdelta2 T lymphocytes kill macrophages harboring live M. tuberculosis through a granule-dependent mechanism that results in killing of intracellular bacilli. This study found that Vgamma9/Vdelta2 T lymphocytes reduce the viability of both extracellular and intracellular M. tuberculosis. Granulysin and perforin, both detected in Vgamma9/Vdelta2 T lymphocytes, play a major role, which indicates that Vgamma9/Vdelta2 T lymphocytes directly contribute to a protective host response against M. tuberculosis infection.