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Cherry Kingsley Barry Peters Kaboutar Babaahmady Laura Pomeroy Durdana Rahman Robert Vaughan Thomas Lehner 《PloS one》2009,4(11)
Background
Epidemiological studies suggest that allogeneic immunity may inhibit HIV-1 transmission from mother to baby and is less frequent in multiparous than uniparous women. Alloimmune responses may also be elicited during unprotected heterosexual intercourse, which is associated ex vivo with resistance to HIV infection.Methodology/Principal Findings
The investigation was carried out in well-defined heterosexual and homosexual monogamous partners, practising unprotected sex and a heterosexual cohort practising protected sex. Allogeneic CD4+ and CD8+ T cell proliferative responses were elicited by stimulating PBMC with the partners'' irradiated monocytes and compared with 3rd party unrelated monocytes, using the CFSE method. Significant increase in allogeneic proliferative responses was found in the CD4+ and CD8+ T cells to the partners'' irradiated monocytes, as compared with 3rd party unrelated monocytes (p≤0.001). However, a significant decrease in proliferative responses, especially of CD8+ T cells to the partners'' compared with 3rd party monocytes was consistent with tolerization, in both the heterosexual and homosexual partners (p<0.01). Examination of CD4+CD25+FoxP3+ regulatory T cells by flow cytometry revealed a significantly greater proportion of these cells in the homosexual than heterosexual partners practising unprotected sex (p<0.05). Ex vivo studies of infectivity of PBMC with HIV-1 showed significantly greater inhibition of infectivity of PBMC from heterosexual subjects practising unprotected compared with those practising protected sex (p = 0.02).Conclusions/Significance
Both heterosexual and homosexual monogamous partners practising unprotected sex develop allogeneic CD4+ and CD8+ T cell proliferative responses to the partners'' unmatched cells and a minority may be tolerized. However, a greater proportion of homosexual rather than heterosexual partners developed CD4+CD25FoxP3+ regulatory T cells. These results, in addition to finding greater inhibition of HIV-1 infectivity in PBMC ex vivo in heterosexual partners practising unprotected, compared with those practising protected sex, suggest that allogeneic immunity may play a significant role in the immuno-pathogenesis of HIV-1 infection. 相似文献104.
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Martin K.‐F. Bader Wilhelm Ehrenberger Rebecca Bitter Jason Stevens Ben P. Miller Jerome Chopard Simon Rüger Giles E. S. J. Hardy Pieter Poot Kingsley W. Dixon Ulrich Zimmermann Erik J. Veneklaas 《Physiologia plantarum》2014,152(2):301-315
Southwest Australian Banksia woodlands are highly diverse plant communities that are threatened by drought‐ or temperature‐induced mortality due to the region's changing climate. We examined water relations in dominant Banksia menziesii R. Br. trees using magnetic leaf patch clamp pressure (ZIM‐) probes that allow continuous, real‐time monitoring of leaf water status. Multiple ZIM‐probes across the crown were complemented by traditional ecophysiological measurements. During summer, early stomatal downregulation of transpiration prevented midday balancing pressures from exceeding 2.5 MPa. Diurnal patterns of ZIM‐probe and pressure chamber readings agreed reasonably well, however, ZIM‐probes recorded short‐term dynamics, which are impossible to capture using a pressure chamber. Simultaneous recordings of three ZIM‐probes evenly spaced along leaf laminas revealed intrafoliar turgor gradients, which, however, did not develop in a strictly basi‐ or acropetal fashion and varied with cardinal direction. Drought stress manifested as increasing daily signal amplitude (low leaf water status) and occasionally as rising baseline at night (delayed rehydration). These symptoms occurred more often locally than across the entire crown. Microclimate effects on leaf water status were strongest in crown regions experiencing peak morning radiation (East and North). Extreme spring temperatures preceded the sudden death of B. menziesii trees, suggesting a temperature‐ or humidity‐related tipping point causing rapid hydraulic failure as evidenced by collapsing ZIM‐probe readings from an affected tree. In a warmer and drier future, increased frequency of B. menziesii mortality will result in significantly altered community structure and ecosystem function. 相似文献
106.
Adrian Scaffidi Mark T. Waters Yueming K. Sun Brian W. Skelton Kingsley W. Dixon Emilio L. Ghisalberti Gavin R. Flematti Steven M. Smith 《Plant physiology》2014,165(3):1221-1232
We speculate that multicopy transposons, carrying both fitness and unfitness genes, can provide new positive and negative selection options to intractable weed problems. Multicopy transposons rapidly disseminate through populations, appearing in approximately 100% of progeny, unlike nuclear transgenes, which appear in a proportion of segregating populations. Different unfitness transgenes and modes of propagation will be appropriate for different cases: (1) outcrossing Amaranthus spp. (that evolved resistances to major herbicides); (2) Lolium spp., important pasture grasses, yet herbicide-resistant weeds in crops; (3) rice (Oryza sativa), often infested with feral weedy rice, which interbreeds with the crop; and (4) self-compatible sorghum (Sorghum bicolor), which readily crosses with conspecific shattercane and with allotetraploid johnsongrass (Sorghum halepense). The speculated outcome of these scenarios is to generate weed populations that contain the unfitness gene and thus are easily controllable. Unfitness genes can be under chemically or environmentally inducible promoters, activated after gene dissemination, or under constitutive promoters where the gene function is utilized only at special times (e.g. sensitivity to an herbicide). The transposons can be vectored to the weeds by introgression from the crop (in rice, sorghum, and Lolium spp.) or from planted engineered weed (Amaranthus spp.) using a gene conferring the degradation of a no longer widely used herbicide, especially in tandem with an herbicide-resistant gene that kills all nonhybrids, facilitating the rapid dissemination of the multicopy transposons in a weedy population. 相似文献
107.
Awasthi S Lubinski JM Shaw CE Barrett SM Cai M Wang F Betts M Kingsley S Distefano DJ Balliet JW Flynn JA Casimiro DR Bryan JT Friedman HM 《Journal of virology》2011,85(20):10472-10486
Attempts to develop a vaccine to prevent genital herpes simplex virus 2 (HSV-2) disease have been only marginally successful, suggesting that novel strategies are needed. Immunization with HSV-2 glycoprotein C (gC-2) and gD-2 was evaluated in mice and guinea pigs to determine whether adding gC-2 to a gD-2 subunit vaccine would improve protection by producing antibodies that block gC-2 immune evasion from complement. Antibodies produced by gC-2 immunization blocked the interaction between gC-2 and complement C3b, and passive transfer of gC-2 antibody protected complement-intact mice but not C3 knockout mice against HSV-2 challenge, indicating that gC-2 antibody is effective, at least in part, because it prevents HSV-2 evasion from complement. Immunization with gC-2 also produced neutralizing antibodies that were active in the absence of complement; however, the neutralizing titers were higher when complement was present, with the highest titers in animals immunized with both antigens. Animals immunized with the gC-2-plus-gD-2 combination had robust CD4+ T-cell responses to each immunogen. Multiple disease parameters were evaluated in mice and guinea pigs immunized with gC-2 alone, gD-2 alone, or both antigens. In general, gD-2 outperformed gC-2; however, the gC-2-plus-gD-2 combination outperformed gD-2 alone, particularly in protecting dorsal root ganglia in mice and reducing recurrent vaginal shedding of HSV-2 DNA in guinea pigs. Therefore, the gC-2 subunit antigen enhances a gD-2 subunit vaccine by stimulating a CD4+ T-cell response, by producing neutralizing antibodies that are effective in the absence and presence of complement, and by blocking immune evasion domains that inhibit complement activation. 相似文献
108.
Humphries AD Townsend SM Kingsley RA Nicholson TL Tsolis RM Bäumler AJ 《FEMS microbiology letters》2001,201(2):121-125
The ascomycete Pulvinula constellatio was found to form competing ectomycorrhizal relationships with plants that had been inoculated with Tuber spp. and other edible ectomycorrhizal fungi. In order to be able to distinguish P. constellatio mycorrhizae from those of the Tuber spp., we determined the morphological and bio-molecular characteristics of P. constellatio. The complete sequence of the ITS regions was determined, in order to select specific primers. The ITS region was also studied using restriction fragment length polymorphism analyses with several restriction enzymes that allowed an unambiguous identification of the species. 相似文献
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Dele Ogunremi John Devenish Kingsley Amoako Hilary Kelly Andrée Ann Dupras Sebastien Belanger Lin Ru Wang 《BMC genomics》2014,15(1)