Steven Patterson

Publications of Steven Patterson

• HIV-1 infection and induction of interferon alpha in plasmacytoid dendritic cells.

  Authors: Adel Benlahrech, Steven Patterson

  Current opinion in HIV and AIDS. 09/2011; 6(5):373-8.

  Loss of blood plasmacytoid dendritic cell (pDC) in HIV-1 infection is thought to impact on adaptive immune responses whilst the virus also induces aberrant interferon alpha (IFN-α) production thatLoss of blood plasmacytoid dendritic cell (pDC) in HIV-1 infection is thought to impact on adaptive immune responses whilst the virus also induces aberrant interferon alpha (IFN-α) production that may fuel chronic immune activation and drive disease progression. Recent attention has focussed on the pathway of HIV-induced IFN-α production by pDC and the new data are reviewed here together with the pathway leading to infection. Attachment to CD4 and chemokine co-receptors is essential for HIV-1 infection. Although CD4, but not co-receptor binding, is a major route for passage to endosomes and triggering of IFN-α secretion this may also occur by CD4-independent mechanisms involving other receptors. In contrast to other Toll-like receptor (TLR)-7 ligands and RNA viruses that stimulate pDC to secrete IFN-α for 2-3  h, HIV-1-stimulated pDC can give sustained IFN-α production for up to 48  h which may contribute to chronic immune activation. This may reflect retention of HIV in early endosomes which also seems to be associated with incomplete maturation induced by HIV. HIV-1-pDC interactions contribute to pathogenesis through depletion and aberrant IFN-α production. New data on the pathway of pDC HIV-stimulated IFN-α secretion may facilitate therapy to reduce chronic immune activation and slow disease progression.

• Loss of NK stimulatory capacity by plasmacytoid and monocyte-derived DC but not myeloid DC in HIV-1 infected patients.

  Authors: Adel Benlahrech, Frances Gotch, Peter Kelleher, Steven Patterson

  PloS one. 01/2011; 6(3):e17525.

  Dendritic cells (DC) are potent inducers of natural killer (NK) cells. There are two distinct populations in blood, myeloid (mDC) and plasmacytoid (pDC) but they can also be generated In vitro fromDendritic cells (DC) are potent inducers of natural killer (NK) cells. There are two distinct populations in blood, myeloid (mDC) and plasmacytoid (pDC) but they can also be generated In vitro from monocytes (mdDC). Although it is established that blood DC are lost in HIV-1 infection, the full impact of HIV-1 infection on DC-NK cell interactions remains elusive. We thus investigated the ability of pDC, mDC, and mdDC from viremic and anti-retroviral therapy-treated aviremic HIV-1+ patients to stimulate various NK cell functions. Stimulated pDC and mdDC from HIV-1+ patients showed reduced secretion of IFN-α and IL-12p70 respectively and their capacity to stimulate expression of CD25 and CD69, and IFN-γ secretion in NK cells was also reduced. pDC activation of NK cell degranulation in response to a tumour cell line was severely reduced in HIV-1+ patients but the ability of mDC to activate NK cells was not affected by HIV-1 infection, with the exception of HLA-DR induction. No differences were observed between viremic and aviremic patients indicating that anti-retroviral therapy had minimal effect on restoration on pDC and mdDC-mediated activation of NK cells. Results from this study provide further insight into HIV-1 mediated suppression of innate immune functions.

• CD34-derived human Langerhans cells stimulate a T helper type 2 response independently of extracellular-signal-regulated kinase phosphorylation.

  Authors: Sai S Duraisingham, Julia Hornig, Frances Gotch, Steven Patterson

  Immunology. 05/2010; 131(2):210-9.

  Dendritic cell (DC) subsets can mediate diverse responses, but little is known about the Toll-like receptor (TLR) signalling pathways in different human DC subsets. Despite expressing many TLRs inDendritic cell (DC) subsets can mediate diverse responses, but little is known about the Toll-like receptor (TLR) signalling pathways in different human DC subsets. Despite expressing many TLRs in common, we found that in vitro-derived Langerhans cells (LCs) and monocyte-derived DCs (moDCs) undergo differential signalling events following TLR stimulation. TLR-stimulated LCs did not secrete interleukin (IL)-12p70 and thus induced a T helper type 2 (Th2)-biased response. moDCs secrete high levels of IL-12p70 and induce a Th1 response. Stimulation of moDCs through TLR2 or TLR7/8 was able to induce phosphorylation of the mitogen-activated protein kinase (MAPK) extracellular-signal-regulated kinase (ERK). However, phosphorylated ERK was not induced in TLR-stimulated LCs, suggesting an ERK-independent method of Th2 cell induction. Inhibition of p38 MAPK suppressed moDC maturation, but was much less effective at inhibiting LC maturation. Phosphatidylinositol-3 kinase (PI3K) was also found to play a greater role in moDC survival compared with the LCs. Polymerase chain reaction (PCR) arrays to compare the expression of signalling molecules in LCs and moDCs identified differences in TLR recognition molecules and cytokine response genes, suggesting that differential functional responses are probably mediated at the post-transcriptional level. Thus we have described differences in LC and moDC responses to TLR stimulation, and have identified key differences in ERK phosphorylation and the involvement of MAPK and PI3K.

• Adenovirus vector vaccination induces expansion of memory CD4 T cells with a mucosal homing phenotype that are readily susceptible to HIV-1.

  Authors: Adel Benlahrech, Julian Harris, Andrea Meiser, Timos Papagatsias, Julia Hornig, Peter Hayes, Andre Lieber, Takis Athanasopoulos, Veronique Bachy, Eszter Csomor, Rod Daniels, Kerry Fisher, Frances Gotch, Len Seymour, Karen Logan, Romina Barbagallo, Linda Klavinskis, George Dickson, Steven Patterson

  Proceedings of the National Academy of Sciences of the United States of America. 11/2009;

  In the recently halted HIV type 1 (HIV-1) vaccine STEP trial, individuals that were seropositive for adenovirus serotype 5 (Ad5) showed increased rates of HIV-1 infection on vaccination with an Ad5In the recently halted HIV type 1 (HIV-1) vaccine STEP trial, individuals that were seropositive for adenovirus serotype 5 (Ad5) showed increased rates of HIV-1 infection on vaccination with an Ad5 vaccine. We propose that this was due to activation and expansion of Ad5-specific mucosal-homing memory CD4 T cells. To test this hypothesis, Ad5 and Ad11 antibody titers were measured in 20 healthy volunteers. Dendritic cells (DCs) from these individuals were pulsed with replication defective Ad5 or Ad11 and co-cultured with autologous lymphocytes. Cytokine profiles, proliferative capacity, mucosal migration potential, and susceptibility to HIV infection of the adenovirus-stimulated memory CD4 T cells were measured. Stimulation of T cells from healthy Ad5-seropositive but Ad11-seronegative individuals with Ad5, or serologically distinct Ad11 vectors induced preferential expansion of adenovirus memory CD4 T cells expressing alpha(4)beta(7) integrins and CCR9, indicating a mucosal-homing phenotype. CD4 T-cell proliferation and IFN-gamma production in response to Ad stimulation correlated with Ad5 antibody titers. However, Ad5 serostatus did not correlate with total cytokine production upon challenge with Ad5 or Ad11. Expanded Ad5 and Ad11 memory CD4 T cells showed an increase in CCR5 expression and higher susceptibility to infection by R5 tropic HIV-1. This suggests that adenoviral-based vaccination against HIV-1 in individuals with preexisting immunity against Ad5 results in preferential expansion of HIV-susceptible activated CD4 T cells that home to mucosal tissues, increases the number of virus targets, and leads to a higher susceptibility to HIV acquisition.

• TLR-stimulated CD34 stem cell-derived human skin-like and monocyte-derived dendritic cells fail to induce Th17 polarization of naive T cells but do stimulate Th1 and Th17 memory responses.

  Authors: Sai Suda Duraisingham, Julia Hornig, Frances Gotch, Steven Patterson

  Journal of immunology (Baltimore, Md. : 1950). 09/2009; 183(4):2242-51.

  Dendritic cells (DCs) are important in linking innate and adaptive immune responses by priming and polarizing naive CD4(+) Th cells, but little is known about the effect of different human DC subsetsDendritic cells (DCs) are important in linking innate and adaptive immune responses by priming and polarizing naive CD4(+) Th cells, but little is known about the effect of different human DC subsets on Th cells, particularly Th17 cells. We have investigated the ability of TLR-stimulated human Langerhans cells (LC), dermal DCs (dDC), and monocyte-derived DCs (moDC) to affect naive and memory Th17 and Th1 responses. MoDCs stimulated greater memory T cell proliferation while LCs and dDCs more potently stimulated naive T cell proliferation, indicating functionally distinct subsets of DCs. TLR stimulation of all three DC types was unable to induce Th17 polarization from naive T cell precursors, despite inducing Th1 polarization. Dectin stimulation of DCs in IMDM was however able to produce Th17 cells. TLR-stimulated DCs were capable of inducing IL-17A and IFN-gamma production from memory T cells, although the mechanism used by each DC subset differed. MoDCs partially mediated this effect on memory Th1 and Th17 cells by the production of soluble factors, which correlated with their ability to secrete IL-12p70 and IL-23. In contrast, LCs and dDCs were able to elicit a similar memory response to moDCs, but in a contact dependent manner. Additionally, the influence of microbial stimulation was demonstrated with TLR3 and TLR7/8 agonists inducing a Th1 response, whereas TLR2 or dectin stimulation of moDCs enhanced the IL-17 response. This study emphasizes the differences between human DC subsets and demonstrates that both the DC subset and the microbial stimulus influence the Th cell response.

• Monocyte-Derived Dendritic Cells from HIV Type 1-Infected Individuals Show Reduced Ability to Stimulate T Cells and Have Altered Production of Interleukin (IL)-12 and IL-10.

  Authors: Sandrine Buisson, Adel Benlahrech, Brian Gazzard, Frances Gotch, Peter Kelleher, Steven Patterson

  The Journal of infectious diseases. 07/2009; 199(12):1862-71.

  Monocyte-derived dendritic cells (MDDCs) have been used in therapeutic vaccination for cancer. A small number of studies have employed a similar approach to vaccinate human immunodeficiency virusMonocyte-derived dendritic cells (MDDCs) have been used in therapeutic vaccination for cancer. A small number of studies have employed a similar approach to vaccinate human immunodeficiency virus (HIV)-infected individuals. We have thus analyzed the functional properties of MDDCs generated from HIV-infected individuals who either are receiving highly active antiretroviral therapy or are therapy naive. There was no difference in the MDDC phenotype or efficiency of MDDC generation between HIV-infected individuals and healthy control subjects. Despite this, the MDDCs derived from both groups of infected individuals were severely impaired in their ability to stimulate the proliferation of allogeneic T cells. Furthermore, production of interferon-gamma was reduced in T cells stimulated by MDDCs. These functional changes may be at least partly explained by reduced interleukin-12 and increased interleukin-10 secretion on stimulation with lipopolysaccharide and CD40 ligand. Our findings suggest that MDDCs used in therapeutic vaccination of HIV-infected individuals may show reduced potency.

• Use of Adenovirus in Vaccines for HIV.

  Authors: Steven Patterson, Timos Papagatsias, Adel Benlahrech

  Handbook of experimental pharmacology. 02/2009;

  The best hope of controlling the HIV pandemic is the development of an effective vaccine. In addition to the stimulation of virus neutralising antibodies, a vaccine will need an effective T-cellThe best hope of controlling the HIV pandemic is the development of an effective vaccine. In addition to the stimulation of virus neutralising antibodies, a vaccine will need an effective T-cell response against the virus. Vaccines based on recombinant adenoviruses (rAd) are promising candidates to stimulate anti-HIV T-cell responses. This review discusses the different rAd vector types, problems raised by host immune responses against them and strategies that are being adopted to overcome this problem. Vaccines need to target and stimulate dendritic cells and thus the tropism and interaction of rAd-based vaccines with these cells is covered. Different rAd vaccination regimes and the need to stimulate mucosal responses are discussed together with data from animal studies on immunogenicity and virus challenge experiments. The review ends with a discussion of the recent disappointing Merck HIV vaccine trial.

• Human NK Cell Up-regulation of CD69, HLA-DR, Interferon γ Secretion and Cytotoxic Activity by Plasmacytoid Dendritic Cells is Regulated through Overlapping but Different Pathways.

  Authors: Adel Benlahrech, Heather Donaghy, George Rozis, Martin Goodier, Linda Klavinskis, Frances Gotch, Steven Patterson

  Sensors (Basel, Switzerland). 01/2009; 9(1):386-403.

  Human plasmacytoid dendritic cells secrete high levels of IFNα and are thus implicated in the activation of NK cells. Activated NK cells are characterised by the up-regulation of CD69 and MHC classHuman plasmacytoid dendritic cells secrete high levels of IFNα and are thus implicated in the activation of NK cells. Activated NK cells are characterised by the up-regulation of CD69 and MHC class II DR expression, secretion of IFN γ and enhanced cytotoxicity. We show that pDC mediate these processes by different mechanisms, some of which overlap. Human NK cells were analysed after co-culture with immature or CpG-matured blood pDC or with supernatant from these cells. Maximal CD69 expression by NK cells was mediated by supernatant from mature pDC and did not require pDC contact. Up-regulation was due in part to IFNα but also to factors in IFNα negative supernatant from immature DC. HLA-DR expression was independent of secreted molecules but required contact with immature or mature DC. Enhanced NK cytotoxicity, measured by killing of K562 targets and expression of CD107a, was mediated by multiple factors including type I IFN, supernatant from immature pDC cultures and contact with immature or mature pDC. These factors act cumulatively to enhance cytotoxcity. Thus different parameters of pDC mediated NK cell activation are regulated by distinct pathways.

• Human Langerhans' cells and dermal-type dendritic cells generated from CD34 stem cells express different toll-like receptors and secrete different cytokines in response to toll-like receptor ligands.

  Authors: George Rozis, Adel Benlahrech, Sai Duraisingham, Frances Gotch, Steven Patterson

  Immunology. 08/2008; 124(3):329-38.

  Langerhans' cells (LC) and dermal dendritic cells (dDC) are located in the superficial and deeper layers of the skin respectively and represent the main dendritic cell (DC) populations of the skin.Langerhans' cells (LC) and dermal dendritic cells (dDC) are located in the superficial and deeper layers of the skin respectively and represent the main dendritic cell (DC) populations of the skin. LC-like and dDC-like DC can be generated from CD34 stem cells and this system is widely used as a model for investigating these cells and in therapeutic vaccination. Here we report toll-like receptor (TLR) expression in human LC and dDC derived from CD34 stem cells. In vitro-generated DC expressed TLR-1, 2, 4, 6, 8 and 10. LC, but not dDC, expressed TLR-5, whereas only dDC expressed TLR-3. Maturation of LC was mediated by TLR-2, 4 and 5 ligands, but not by a TLR-3 ligand. dDC maturation was induced by TLR-3 and -4, but not with TLR-5 ligand and only weakly by a TLR-2 ligand. Stimulated LC secreted interleukin (IL)-1beta, low levels of tumour necrosis factor-alpha (TNF-alpha) and IL-8, but not IL-6 or IL-10. dDC secreted TNF-alpha, IL-6, IL-8 and IL-10, but little IL-1beta. IL-12p70 was not produced by ligand-stimulated dDC or LC, but was secreted by monocyte-derived DC (mdDC) stimulated with lipopolysaccharide (LPS). Thus, in vitro-generated LC and dDC detect different pathogen-associated molecules and show different cytokine-secretion profiles in response to TLR ligands.

• Activity of different vaccine-associated promoter elements in human dendritic cells.

  Authors: Timoleon Papagatsias, George Rozis, Takis Athanasopoulos, Frances Gotch, George Dickson, Steven Patterson

  Immunology letters. 02/2008; 115(2):117-25.

  Vaccine design approaches that target dendritic cells (DC) aim at achieving high levels of transgene expression. Careful selection of the promoter element driving the foreign gene is thereforeVaccine design approaches that target dendritic cells (DC) aim at achieving high levels of transgene expression. Careful selection of the promoter element driving the foreign gene is therefore important. We have constructed adenovirus vectors carrying the gene for enhanced green fluorescent protein (eGFP) driven by three different promoters, CMV, CMV5 and ubiquitin C (UbC) promoter, and analysed their activity in different populations of human DC, namely blood plasmacytoid (pDC) and myeloid DC (mDC), monocyte-derived DC (moDC), Langerhans (LC) and dermal type DC (dDC). Although the CMV5 promoter was more active than the other two promoters in the HeLa and 911HER cell lines, in human DC the highest level of transgene expression was seen with the CMV promoter. There was very low-level eGFP expression in all cell types transduced with the UbC promoter. Highest eGFP expression levels were observed in moDC, cultured mDC and LC and the lowest levels in pDC. Expression of eGFP was augmented in all DC populations upon stimulation with CD40 ligand (CD40L). These findings demonstrate that the CMV promoter is the most effective of the three promoters tested in a range of different human DC populations.

• Langerhans cells are more efficiently transduced than dermal dendritic cells by adenovirus vectors expressing either group C or group B fibre protein: implications for mucosal vaccines.

  Authors: George Rozis, Shamika de Silva, Adel Benlahrech, Timos Papagatsias, Julian Harris, Frances Gotch, George Dickson, Steven Patterson

  European journal of immunology. 10/2005; 35(9):2617-26.

  Vaccines against viruses need to target dendritic cells (DC) and stimulate mucosal immunity. Most vaccine studies have focussed on monocyte-derived or dermal DC (dDC) but recent evidence suggestsVaccines against viruses need to target dendritic cells (DC) and stimulate mucosal immunity. Most vaccine studies have focussed on monocyte-derived or dermal DC (dDC) but recent evidence suggests that Langerhans cells (LC) may stimulate mucosal immunity more effectively. New chimeric adenovirus vectors expressing fibre protein from group B adenoviruses (rAd5/11), which utilise CD46 rather than the Coxsackie adenovirus receptor (CAR), have been developed as vaccines to improve transduction and overcome problems of pre-existing vector immunity. Transduction of LC and dDC by rAd5/11 and standard rAd5 expressing green fluorescent protein (GFP) showed that both DC types were more efficiently transduced by rAd5/11 than by rAd5. Although expression of CD46 and the integrins alphavbeta3 and alphavbeta5, which recognise the adenovirus penton base and mediate virus internalisation, was similar in LC and dDC, LC expressed higher levels of GFP. Transduction by electroporation of plasmid also resulted in higher GFP expression in LC, suggesting differences between the two DC populations at a post-entry stage. Transduction with either vector did not induce maturation of LC or dDC and did not affect their ability to stimulate T cells. These findings suggest that vaccine strategies that target LC with adenovirus vectors may be worthy of exploration.

• Human BDCA-1-positive blood dendritic cells differentiate into phenotypically distinct immature and mature populations in the absence of exogenous maturational stimuli: differentiation failure in HIV infection.

  Authors: Steven Patterson, Heather Donaghy, Parisa Amjadi, Brian Gazzard, Frances Gotch, Peter Kelleher

  Journal of immunology (Baltimore, Md. : 1950). 07/2005; 174(12):8200-9.

  Current immunological opinion holds that myeloid dendritic cell (mDC) precursors migrate from the blood to the tissues, where they differentiate into immature dermal- and Langerhans-type dendriticCurrent immunological opinion holds that myeloid dendritic cell (mDC) precursors migrate from the blood to the tissues, where they differentiate into immature dermal- and Langerhans-type dendritic cells (DC). Tissue DC require appropriate signals from pathogens or inflammatory cytokines to mature and migrate to secondary lymphoid tissue. We show that purified blood mDC cultured in vitro with GM-CSF and IL-4, but in the absence of added exogenous maturation stimuli, rapidly differentiate into two maturational and phenotypically distinct populations. The major population resembles immature dermal DC, being positive for CD11b, CD1a, and DC-specific ICAM-3-grabbing nonintegrin. They express moderate levels of MHC class II and low levels of costimulatory molecules. The second population is CD11b(-/low) and lacks CD1a and DC-specific ICAM-3-grabbing nonintegrin but expresses high levels of MHC class II and costimulatory molecules. Expression of CCR7 on the CD11b(-/low) population and absence on the CD11b(+) cells further supports the view that these cells are mature and immature, respectively. Differentiation into mature and immature populations was not blocked by polymyxin B, an inhibitor of LPS. Neither population labeled for Langerin, E-cadherin, or CCR6 molecules expressed by Langerhans cells. Stimulation of 48-h cultured DC with LPS, CD40L, or poly(I:C) caused little increase in MHC or costimulatory molecule expression in the CD11b(-/low) DC but caused up-regulated expression in the CD11b(+) cells. In HIV-infected individuals, there was a marked decrease in the viability of cultured blood mDC, a failure to differentiate into the two populations described for normal donors, and an impaired ability to stimulate T cell proliferation.

• Antigen presentation and the role of dendritic cells in HIV.

  Authors: Heather Donaghy, Justin Stebbing, Steven Patterson

  Current opinion in infectious diseases. 03/2004; 17(1):1-6.

  PURPOSE OF REVIEW: As initiators of primary immune responses and one of the first cell types encountered and infected by HIV, the role of dendritic cells in retroviral infection has been the subjectPURPOSE OF REVIEW: As initiators of primary immune responses and one of the first cell types encountered and infected by HIV, the role of dendritic cells in retroviral infection has been the subject of intense scrutiny. We review recent publications regarding the effect of HIV-1 infection on the numbers and function of dendritic cells, as well as progress in the use of dendritic cells in immunotherapeutic protocols. RECENT FINDINGS: The numbers of both plasmacytoid and myeloid dendritic cells in the blood are reduced during HIV-1 infection. The ability of dendritic cells to stimulate T-cell proliferation is impaired, probably as a result of defective co-stimulatory molecule expression. In addition, a decreased production of IFN-alpha may reflect the loss or dysfunction of plasmacytoid dendritic cells. There is evidence that dendritic cells may promote the induction of peripheral tolerance to self peptides, and HIV may utilize this function of dendritic cells to inhibit the immune response. The data on improvements in dendritic cell numbers and function during antiretroviral therapy are conflicting, whereas current vaccine initiatives involving pulsing dendritic cells with virus proteins, infected apototic or whole inactivated virions is proving a useful tool in the induction, expansion and maintenance of antiviral cell-mediated immunity. SUMMARY: This review summarizes the current literature regarding the effects of HIV on the dendritic cell populations, with particular interest in understanding how the function of dendritic cells is affected by HIV infection.

• Dysfunction and infection of freshly isolated blood myeloid and plasmacytoid dendritic cells in patients infected with HIV-1.

  Authors: Heather Donaghy, Brian Gazzard, Frances Gotch, Steven Patterson

  Blood. 07/2003; 101(11):4505-11.

  Recently it has been shown that the 2 populations of blood dendritic cells (DCs), termed plasmacytoid (pcDCs) and myeloid (myDCs), are reduced in HIV-1 infection. This study aimed to determineRecently it has been shown that the 2 populations of blood dendritic cells (DCs), termed plasmacytoid (pcDCs) and myeloid (myDCs), are reduced in HIV-1 infection. This study aimed to determine whether these 2 populations are targets for HIV-1 infection and whether their ability to stimulate T-lymphocyte proliferation is affected. Highly purified populations of myDCs and pcDCs were isolated from the blood of antiretroviral treatment-naive patients and assessed for the level of HIV provirus by polymerase chain reaction (PCR). We show that both populations are targets for HIV-1 infection as indicated by the presence of provirus in 12 of 14 pcDC and 13 of 14 myDC samples tested. A proportion of this provirus is integrated in myDCs. The ability of both myDCs and pcDCs from HIV-1-infected patients to stimulate allogeneic T-lymphocyte proliferation in a 6-day mixed leukocyte reaction was severely impaired, but was not mediated by secondary infection of T lymphocytes. Thus, in addition to depletion, both myeloid and plasmacytoid DCs are infected and show impaired functional capacity. These findings suggest that infection, depletion, and dysfunction of dendritic cells may contribute to the immunosuppression associated with HIV-1 disease.

• Recruitment of CD4 T lymphocytes and macrophages into the cervical epithelium of women after coitus.

  Authors: Manyu Prakash, Steven Patterson, Frances Gotch, Moses S Kapembwa

  American journal of obstetrics and gynecology. 02/2003; 188(2):376-81.

  OBJECTIVE: T lymphocytes and macrophages are considered essential components of the immune response. Many factors are known to influence the presence and distribution these cells in genital mucosa.OBJECTIVE: T lymphocytes and macrophages are considered essential components of the immune response. Many factors are known to influence the presence and distribution these cells in genital mucosa. This study investigated the effect of sexual intercourse on cervical intraepithelial T lymphocytes and macrophages in healthy uninfected women. STUDY DESIGN: Cervical intraepithelial samples were obtained with an endocervical brush from 31 women; the cervical T lymphocytes and macrophages were analyzed by flow cytometry. Eleven women with a history of last sexual intercourse at <3 days were compared against 20 women with last sexual intercourse of >3 days. Furthermore, cellular activation markers (CD69, CD25, HLA-DR) on T lymphocytes and costimulatory molecules (CD80, CD86) on macrophages were studied. RESULTS: Women with last sexual intercourse at <3 days showed predominance of CD4(+) T lymphocytes compared with women with last sexual intercourse of >3 days (P <.02); the numbers of macrophages were higher in the latter (P <.005). No difference was found in the density of T-lymphocyte activation and macrophage costimulatory markers between the two cohorts. CONCLUSION: Within cervical epithelium, the distribution of mononuclear leucocytes may be altered after coitus. The higher proportion of cervical intraepithelial CD4(+) T cells that were observed in the early postcoital period suggests a mechanism by which the relative risk of the acquisition of human immunodeficiency virus infection is increased in women.

• Oral contraceptive use induces upregulation of the CCR5 chemokine receptor on CD4(+) T cells in the cervical epithelium of healthy women.

  Authors: Manyu Prakash, Moses S Kapembwa, Frances Gotch, Steven Patterson

  Journal of reproductive immunology. 04/2002; 54(1-2):117-31.

  Heterosexual transmission of human immunodeficiency virus type I (HIV-1) is the predominant mode of infection worldwide. Increased risk of HIV-1 transmission has been reported with oral contraceptiveHeterosexual transmission of human immunodeficiency virus type I (HIV-1) is the predominant mode of infection worldwide. Increased risk of HIV-1 transmission has been reported with oral contraceptive use. To elucidate the underlying mechanism of this observation, intraepithelial endocervical T lymphocytes from women using oral contraceptives were analysed for expression of activation and chemokine receptors. T lymphocytes from the cervical epithelium and peripheral blood of women using combined oral contraceptives (COC) and those using no contraceptive method (NONE) were compared. Cervical T lymphocytes were obtained with a cytobrush and in parallel, mononuclear leukocytes were separated from blood by centrifugation over a ficoll-hypaque gradient. Cellular activation markers and HIV-1 chemokine co-receptors, CXCR4 and CCR5, were analysed by flow cytometry. Activation markers (CD69, CD25 and HLA-DR) on T cells were expressed at higher levels in the cervical epithelium than peripheral blood T cells but were no different in those women using COC. CXCR4 was widely expressed on cervical and on blood T cells, but was not influenced by COC use. By contrast, the number of T cells expressing CCR5 increased in women using COC (P<0.05). The level of cervical CCR5 expression per cell was shown to increase on both activated CD4(+) (CD69(+), P<0.05; HLA-DR(+), P<0.01) and CD8(+) (CD69(+), P<0.05; HLA-DR(+), P<0.05) T lymphocytes compared with COC use. These data show that with COC use, the expression of CCR5 on CD4(+) T lymphocytes is increased. Furthermore, the cell surface density of CCR5 is increased on both CD4(+) and CD8(+) T lymphocyte subsets. These findings suggest a mechanism by which oral contraceptive use can increase the risk of HIV-1 transmission.

• Activity of different vaccine-associated promoter elements in human dendritic cells

  Authors: Timoleon Papagatsias, George Rozis, Takis Athanasopoulos, Frances Gotch, George Dickson, Steven Patterson

  Immunology Letters.

  Vaccine design approaches that target dendritic cells (DC) aim at achieving high levels of transgene expression. Careful selection of the promoter element driving the foreign gene is thereforeVaccine design approaches that target dendritic cells (DC) aim at achieving high levels of transgene expression. Careful selection of the promoter element driving the foreign gene is therefore important. We have constructed adenovirus vectors carrying the gene for enhanced green fluorescent protein (eGFP) driven by three different promoters, CMV, CMV5 and ubiquitin C (UbC) promoter, and analysed their activity in different populations of human DC, namely blood plasmacytoid (pDC) and myeloid DC (mDC), monocyte-derived DC (moDC), Langerhans (LC) and dermal type DC (dDC). Although the CMV5 promoter was more active than the other two promoters in the HeLa and 911HER cell lines, in human DC the highest level of transgene expression was seen with the CMV promoter. There was very low-level eGFP expression in all cell types transduced with the UbC promoter. Highest eGFP expression levels were observed in moDC, cultured mDC and LC and the lowest levels in pDC. Expression of eGFP was augmented in all DC populations upon stimulation with CD40 ligand (CD40L). These findings demonstrate that the CMV promoter is the most effective of the three promoters tested in a range of different human DC populations.