Summary CD55 is a protein that protects cells from complement-mediated attack. 791Tgp72 is an antigen which has been used succesfully as a target for both tumour imaging and cancer vaccines. 791Tgp72 has recently been identified as CD55. Quantitative expression of CD55 in the tumour environment was therefore studied. Tumour cells showed a 4-100-fold increase in CD55 cell surface expression when compared to normal cells. Immunohistochemical staining of colorectal tumours also revealed high expression of CD55 in the stroma. To examine the source of this stromal CD55 the ability of both epithelial cells and endothelial cells to produce extracellular CD55 was measured. Tumour cell lines deposit CD55 into their extracellular matrix (ECM) in direct proportion to their cell surface expression. In contrast the ECM from HUVEC cells contained large amounts of CD55 despite expressing low levels of CD55 on their cell surface. Furthermore expression of CD55 on HUVEC cells was increased by exposure to VEGF. Although it remains unclear why CD55 is upregulated in the tumour environment its high level of expression on tumour cells and associated endothelium may explain why it is a good target for both imaging and immunotherapy. © 2001 Cancer Research Campaign http://www.bjcancer.com Keywords: CD55 (DAF), tumour expression; endothelium; stroma; vascular endothelial growth factor (VEGF) 80Received 27 September 1999 Revised 3 February 2000 Accepted 15 March 2000 Correspondence to : LG Durrant British Journal of Cancer (2001) 84(1), 80-86 © 2001 Cancer Research Campaign doi: 10.1054/ bjoc.2000.1570, available online at http://www.idealibrary.com on http://www.bjcancer.com and tumour-conditioned medium or VEGF (10-300 µg ml -1 : Zeneca, Alderley Park, UK) respectively for 48 h prior to harvesting the HUVECs. Tumour-conditioned media was derived from the MDA 231 breast cancer cell line. These were grown to confluence and the media replaced with serum free M199:Hams F12 medium. Following 24 h incubation the resultant conditioned media was filtered for use with the HUVEC. Fresh media was used to culture the control HUVECs. Freshly resected tumours were finely minced and dissociated in collagenase (0.05%; Boehringer Mannheim) and DNase (0.1%; Boehringer Mannheim) for 1 h at 37˚C. Monoclonal antibodiesMonoclonal antibodies 791T/36 (IgG2b anti-791Tgp72;Embleton et al, 1981), BRIC 216 (IgG1 anti-SCR 3 of CD55; Tate et al, 1989), BRIC 220 (IgG1 anti-SCR 1 of CD55; Tate et al, 1989), BRIC 110 (IgG1 anti-SCR 2 of CD55; Spring et al, 1987;Coyne et al, 1992) have been reported previously. BRIC 229 and E4.3 (Sparrow and Mckenzie, 1983) recognize CD59 and CD46 respectively. The BRIC antibodies were purchased from the Blood Group Reference laboratory (Bristol, UK). Normal mouse IgG (Sigma, Dorset, UK) and 708 monoclonal antibody (IgG2b) was used as negative control antibodies. Indirect immunofluorescenceCell lines were incubated with monoclonal antibody for 1 h at 4˚C. Cells were washed twice in fresh media containing 1% FCS and then incubat...

Given the encouraging clinical results of both candidate subunit vaccines and revaccination with Bacillus Calmette-Guérin (BCG) against tuberculosis (TB), there is support for combining BCG and subunit vaccination for increased efficacy. BCG and Mycobacterium tuberculosis (Mtb) share ~98% of their genome and current subunit vaccines are almost exclusively designed as BCG boosters. The goal of this study is to design a TB subunit vaccine composed of antigens not shared with BCG and explore the advantages of this design in a BCG + subunit co-administration vaccine strategy. Eight protective antigens are selected to create an Mtb-specific subunit vaccine, named H107. Whereas traditional vaccines containing BCG-shared antigens exhibit in vivo cross-reactivity to BCG, H107 shows no cross-reactivity and does not inhibit BCG colonization. Instead, co-administering H107 with BCG leads to increased adaptive responses against both H107 and BCG. Importantly, rather than expanding BCG-primed T cells, H107 broadens the overall vaccine repertoire with new T cell clones and introduces ‘adjuvant-imprinted’ qualities including Th17 responses and less-differentiated Th1 cells. Collectively, these features of H107 are associated with a substantial increase in long-term protection.

Purpose: CpG oligodeoxynucleotides (CpG-ODN) are being investigated as cancer vaccine adjuvants because they mature plasmacytoid dendritic cells (PDC) into potent antigen-presenting cells. CpG-ODN also induce PDC to secrete chemokines that alter lymphocyte migration.Whether CpG-ODN TLR signals enhance antigen-specific immunity and/or trafficking in humans is unknown. Experimental Design: We conducted a phase I study of CpG-ODN (1018 ISS) given as a vaccine adjuvant with granulocyte-macrophage colony-stimulating factor (GM-CSF) to induce T-cell immunity to a peptide vaccine from the tumor-associated antigen hTERT. Results: The adjuvant effect was limited; only 1of 16 patients showed a high-frequency hTERTspecific tetramer CD8 + T-cell response. However, CpG-ODN induced marked, transient peripheral blood lymphopenia. Biopsies showed dense lymphocytic infiltration at the vaccine site clustered around activated PDC. In vitro, CpG-ODN-treated PDC induced T-cell migration, showing that CpG-ODN stimulation of human PDC was sufficient to chemoattract Tcells. Conclusions: Our results show that (a) CpG-ODN with GM-CSF may not be an effective adjuvant strategy for hTERT peptide vaccines but (b) GM-CSF/CpG-ODN causes a PDC-mediated chemokine response that recruits T-cellmigration to the peripheral tissues.These findings suggest a noveltherapeuticrole for targetedinjections of CpG-ODN to directlymphocytemigrationto specific sitessuchasthetumorbed.

Mycobacterium bovis is the causative agent of bovine tuberculosis (TB), and it has the potential to induce disease in humans. CD8؉ T cells (CD8 cells) have been shown to respond to mycobacterial antigens in humans, cattle, and mice. In mice, CD8 cells have been shown to play a role in protection against mycobacterial infection. To determine the role of CD8 cells in bovine TB in vivo, two groups of calves were infected with the virulent M. bovis strain AF2122/97. After infection, one group was injected with a CD8 cell-depleting monoclonal antibody (MAb), and the other group was injected with an isotype control MAb. Immune responses to mycobacterial antigens were measured weekly in vitro. After 8 weeks, the animals were killed, and postmortem examinations were carried out. In vitro proliferation responses were similar in both calf groups, but in vitro gamma interferon (IFN-␥) production in 24-h whole-blood cultures was significantly higher in control cattle than in CD8 cell-depleted calves. Postmortem examination showed that calves in both groups had developed comparable TB lesions in the lower respiratory tract and associated lymph nodes. Head lymph node lesion scores, on the other hand, were higher in control calves than in CD8 cell-depleted calves. Furthermore, there was significant correlation between the level of IFN-␥ and the head lymph node lesion score. These experiments indicate that CD8 cells play a role in the immune response to M. bovis in cattle by contributing to the IFN-␥ response. However, CD8 cells may also play a deleterious role by contributing to the immunopathology of bovine TB.Mycobacterium bovis is the causative agent of bovine tuberculosis (TB). It is also responsible for a portion of human TB cases, particularly in developing countries, where there are no control programs for bovine TB and the risk of opportunistic infection with M. bovis is increased by infection with human immunodeficiency virus (6). Thus, infection of cattle with M. bovis constitutes a human health hazard as well as an animal welfare problem. Furthermore, the economic implications in terms of trade restrictions and productivity losses have direct and indirect implications for human health and the food supply.Studies of mice, humans, and cattle have shown that antigenspecific CD4 ϩ , CD8 ϩ , and ␥/␦ T cells are activated following exposure to mycobacteria or derived antigens (12,15,27,31,39). CD4 ϩ , CD8 ϩ , and ␥/␦ T cells are recruited to the site of infection and are capable of producing gamma interferon (IFN-␥) and tumor necrosis factor alpha (9).Murine studies, including depletion with monoclonal antibody (MAb), adoptive transfer, and gene disruption, have shown the critical involvement of CD4 ϩ and CD8 ϩ T cells in controlling infection (12). The role of ␥/␦ T cells in immunity to mycobacteria is less clear, as the susceptibility of ␦ T-cell receptor-deficient mice appears to be dependent on the dose and strain of mycobacterium used for infection (23,24). In cattle, depletion studies with MAbs have provided evidenc...

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CD55 is a complement regulatory protein expressed by cells to protect them from bystander killing by complement. CD55 is over-expressed 2-100-fold on tumour cells and is deposited in large amounts within tumour matrix. Vascular endothelial growth factor (VEGF) produced by tumours to stimulate angiogenesis, also up-regulates endothelial cell surface expression of CD55 and stimulates the release of matrix degrading metalloproteinases. This study investigated the effects of VEGF on CD55 deposition into matrix and the release of CD55 by metalloproteinases. In contrast to inflammatory cytokines, CD55 was up-regulated by VEGF at the cell surface and within the extracellular matrix (ECM). Interestingly, human umbilical vein endothelial cells (HUVEC) exposed to VEGF released similar amounts of CD55 into the ECM as a tumour cell line expressing 50-fold higher level of CD55 on its cell surface. Furthermore, in contrast to earlier studies, both tumour and HUVEC-derived CD55 was functionally active. However, in contrast to papain that degrades CD55, and collagenase that fails to release CD55, MMP-7 released intact CD55 from ECM. This suggests that it may have a further role to play in protecting cells during inflammation and invasion.

The goal of the End TB Strategy is to reduce TB deaths by 90% and TB incidence of new cases per year by 80% by year 2030, compared with 2015. 1 The ambitious goal of a fast deceleration of disease incidence could be achieved by a multipronged approach including increases in access to TB medical care, addressing socioeconomic factors, as well as research and technological breakthroughs especially in diagnostics, therapeutics, and vaccines. Despite significant worldwide control efforts over the last 20 years, the progress toward elimination of tuberculosis has slowed. The World Health Organization (WHO) estimates that approximately one-quarter of the world's population (1.7 billion total) is infected with Mtb. Mtb is responsible for 1.3 million deaths among HIV-negative individuals

1. A feeding trial involving 128 individually fed Large White pigs was carried out using four levels of dietary energy in combination with four levels of crude protein in the ‘growers’ rations of bacon pigs. Growth rate, food conversion efficiency, carcass quality and nitrogen balance were the parameters measured.