Targeted co-delivery of FOXM1 aptamer and DOX by nucleolin aptamer-functionalized pH-responsive biocompatible nanodelivery system to enhance therapeutic efficacy against breast cancer: in vitro and in vivo.

Targeted nanodelivery systems offer a promising approach to cancer treatment, including the most common cancer in women, breast cancer. In this study, a targeted, pH-responsive, and biocompatible nanodelivery system based on nucleolin aptamer-functionalized biogenic titanium dioxide nanoparticles (TNP) was developed for targeted co-delivery of FOXM1 aptamer and doxorubicin (DOX) to improve breast cancer therapy. The developed targeted nanodelivery system exhibited almost spherical morphology with 124.89 ± 12.97 nm in diameter and zeta potential value of - 23.78 ± 3.66 mV. FOXM1 aptamer and DOX were loaded into the nanodelivery system with an efficiency of 100% and 97%, respectively. Moreover, the targeted nanodelivery system demonstrated excellent stability in serum and a pH-responsive sustained drug release profile over a period of 240 h following Higuchi kinetic and Fickian diffusion mechanism. The in vitro cytotoxicity experiments demonstrated that the targeted nanodelivery system provided selective internalization and strong growth inhibition effects of about 45 and 51% against nucleolin-positive 4T1 and MCF-7 breast cancer cell lines. It is noteworthy that these phenomena were not observed in nucleolin-negative cells (CHO). The preclinical studies revealed that a single-dose intravenous injection of the targeted nanodelivery system into 4T1-bearing mice inhibited tumor growth by 1.7- and 1.4-fold more efficiently than the free drug and the non-targeted nanodelivery system, respectively. Our results suggested that the developed innovative targeted pH-responsive biocompatible nanodelivery system could serve as a prospectively potential platform to improve breast cancer treatment.

Antigenicity and immunogenicity of recombinant proteins comprising African swine fever virus proteins p30 and p54 fused to a cell-penetrating peptide.

African swine fever (ASF) is a highly fatal swine disease threatening the global pig industry. Currently, vaccine is not commercially available for ASF. Hence, it is desirable to develop effective subunit vaccines against ASF. Here, we expressed and purified two recombinant fusion proteins comprising ASFV proteins p30 and p54 fused to a novel cell-penetrating peptide Z12, which were labeled as ZPM (Z12-p30-modified p54) and ZPMT (Z12-p30-modified p54-T cell epitope). Purified recombinant p30 and modified p54 expressed alone or fused served as controls. The transduction capacity of these recombinant proteins was assessed in RAW264.7 cells. Both ZPM and ZPMT exhibited higher transduction efficiency than the other proteins. Subsequently, humoral and cellular immune responses elicited by these proteins were evaluated in mice. ZPMT elicited the highest levels of antigen-specific IgG responses, cytokines (interleukin-2, interferon-γ, and tumor necrosis factor-α) and lymphocyte proliferation. Importantly, sera from mice immunized with ZPM or ZPMT neutralized greater than 85% of ASFV in vitro. Our results indicate that ZPMT induces potent neutralizing antibody responses and cellular immunity in mice. Therefore, ZPMT may be a suitable candidate to elicit immune responses in swine, providing valuable information for the development of subunit vaccines against ASF.

Induction of Humoral and Cellular Immunity by Intradermal Delivery of SARS-CoV-2 Nucleocapsid Protein Using Dissolvable Microneedles.

The nucleocapsid protein (NP) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contains immunogenic epitopes that can induce cytotoxic T lymphocyte (CTL) against viral infection. This makes the nucleocapsid protein a suitable candidate for developing a vaccine against SARS-CoV-2 infection. This article reports the intradermal delivery of NP antigen using dissolvable microneedle skin patches that could induce both significant B cell and T cell responses.

SARS-CoV-2 nucleocapsid protein intranasal inoculation induces local and systemic T cell responses in mice.

SARS-CoV-2 nucleocapsid (N) protein has been proposed as a good vaccine target. N-specific T cells were observed in SARS-CoV-2 N immunized mice and COVID-19 convalescents. It is of importance to identify the T cell responses triggered by SARS-CoV-2 N protein. Intradermal immunization with SARS-CoV N protein was demonstrated to elicit non-protective T cell responses which may be avoided by intranasal vaccination. Therefore, we conducted intranasal vaccination of BALB/c mice with recombinant adenovirus type-5 expressing SARS-CoV-2 N protein. Such procedure induced CD8 T cell responses in the lung. Meanwhile CD4 T cell responses were observed in the spleen, which was associated with robust antibody production. Our study further supports the notion that SARS-CoV-2 N protein can work as a target for vaccine development.

Combination of apolipoprotein-A-I/apolipoprotein-A-I binding protein and anti-VEGF treatment overcomes anti-VEGF resistance in choroidal neovascularization in mice.

Many patients of choroidal neovascularization (CNV) are unresponsive to the current anti-VEGF treatment. The mechanisms for anti-VEGF resistance are poorly understood. We explore the unique property of the apolipoprotein A-I (apoA-I) binding protein (AIBP) that enhances cholesterol efflux from endothelial cells and macrophages to thereby limit angiogenesis and inflammation to tackle anti-VEGF resistance in CNV. We show that laser-induced CNV in mice with increased age showed increased resistance to anti-VEGF treatment, which correlates with increased lipid accumulation in macrophages. The combination of AIBP/apoA-I and anti-VEGF treatment overcomes anti-VEGF resistance and effectively suppresses CNV. Furthermore, macrophage depletion in old mice restores CNV sensitivity to anti-VEGF treatment and blunts the synergistic effect of combination therapy. These results suggest that cholesterol-laden macrophages play a critical role in inducing anti-VEGF resistance in CNV. Combination therapy by neutralizing VEGF and enhancing cholesterol removal from macrophages is a promising strategy to combat anti-VEGF resistance in CNV.

Electrospray Synthesis of Poly(lactide-co-glycolide) Nanoparticles Encapsulating Peptides to Enhance Proliferation of Antigen-Specific CD8+ T Cells.

Polymer nanoparticles (NP) are of escalating interest for their application as immune stimulatory pharmaceutics. The production of nanosized carrier systems is currently being widely investigated, but commonly used techniques, such as the double emulsion technique, are limited by shortcomings of low encapsulation efficiency and poor control over size distribution. In this study, the electrospray technique was successfully implemented and optimized to produce monodisperse 200-nm poly(lactide-co-glycolide) (PLGA) NP. For cytomegalovirus (CMV) pp65 and IE-1 peptides, a consistent encapsulation efficiency of approximately 85% was achieved. In vitro stimulation of peripheral blood mononuclear cells (PBMCs) from CMV+ donors using electrosprayed pp65489-503 peptide-loaded NP revealed a significantly increased proliferation rate and frequency of antigen-specific CD8+ T cells as compared to the soluble peptide. The results of this study demonstrate the suitability of the electrospray technique for production of monodisperse PLGA NP with high drug encapsulation efficiency as promising peptide-based vaccine carriers.

Peptide vaccination in the presence of adjuvants in patients after hematopoietic stem cell transplantation with CD4+ T cell reconstitution elicits consistent CD8+ T cell responses.

Rationale: Patients receiving an allogeneic stem cell graft from cytomegalovirus (CMV) seronegative donors are particularly prone to CMV reactivation with a high risk of disease and mortality. Therefore we developed and manufactured a novel vaccine and initiated a clinical phase I trial with a CMV phosphoprotein 65 (CMVpp65)-derived peptide. Methods: Ten patients after allogeneic stem cell transplantation received four vaccinations at a biweekly interval. All patients were monitored for CMVpp65 antigenemia. Flow cytometry for CMV-specific CD8+ and γδ T cells as well as neutralizing anti-CMV antibodies were correlated to clinical parameters. Results: The vaccination was well tolerated. Seven of nine patients cleared CMVpp65 antigenemia after four vaccinations and are still free from antigenemia to this day. Two patients with CMV reactivation showed persisting CMV antigenemia. One patient received prophylactic vaccination and did not develop antigenemia. An increase of up to six-fold in frequency of both CMV-specific CD8+ T cells and/or Vδ2negative γδ T cells was detected. Titers of neutralizing antibodies increased up to the tenfold. Humoral and cellular immune responses correlated with clearance of CMV. Conclusion: In summary, CMVpp65 peptide vaccination for patients after allogeneic stem cell transplantation at high risk for CMV reactivation was safe, well tolerated and clinically encouraging. A study in solid-organ transplant patients is ongoing.

Adoptive Transfer of Phosphoantigen-Specific γδ T Cell Subset Attenuates Mycobacterium tuberculosis Infection in Nonhuman Primates.

The dominant Vγ2Vδ2 T cell subset recognizes phosphoantigen and exists only in humans and nonhuman primates. Despite the discovery of γδ T cells >30 y ago, a proof-of-concept study has not been done to prove the principle that the Vγ2Vδ2 T cell subset is protective against Mycobacterium tuberculosis and other infections. In this study, we used an adoptive cell-transfer strategy to define the protective role of Vγ2Vδ2 T cells in a primate tuberculosis (TB) model. Vγ2Vδ2 T cells for adoptive transfer displayed central/effector memory and mounted effector functions, including the production of anti-M. tuberculosis cytokines and inhibition of intracellular mycobacteria. They also expressed CXCR3/CCR5/LFA-1 trafficking/tissue-resident phenotypes and consistently trafficked to the airway, where they remained detectable from 6 h through 7 d after adoptive transfer. Interestingly, the test group of macaques receiving transfer of Vγ2Vδ2 T cells at weeks 1 and 3 after high-dose (500 CFU) M. tuberculosis infection exhibited significantly lower levels of M. tuberculosis infection burdens in lung lobes and extrapulmonary organs than did the control groups receiving PBLs or saline. Consistently, adoptive transfer of Vγ2Vδ2 T cells attenuated TB pathology and contained lesions primarily in the infection site of the right caudal lung lobe, with no or reduced TB dissemination to other lobes, spleen, or liver/kidney; in contrast, the controls showed widespread TB dissemination. The proof-of-concept finding supports the view that the dominant Vγ2Vδ2 T cell subset may be included in the rational design of a TB vaccine or host-directed therapy.

Secreted phosphoprotein 24kD (Spp24) inhibits growth of hepatocellular carcinoma in vivo.

Several studies have shown that secreted phosphoprotein 24kD (Spp24) inhibits tumor growth. However, the effects of spp24 on hepatocellular carcinoma are not quite clear. In this study, we observed the inhibitory effect of spp24 on hepatocellular carcinoma in vivo. A subcutaneous hepatocellular carcinoma mice model was established by using Hep G2 cells. After sacrifice at day 40, tumor growth was assessed and tumor cell apoptosis and tumor cells proliferation were assessed by TUNEL assay and immunochemical analysis, respectively. BMP2 slightly stimulated the subcutaneous tumor growth compared with the control. Spp24 significantly inhibited the tumor growth and also abolished the BMP2-induced tumor growth (p<0.05). TUNEL assay and immunochemical analysis further showed that spp24 could enhance tumor cell apoptosis and inhibit cell proliferation (p<0.01). Our data show that spp24 can inhibit the growth of hepatocellular carcinoma. Spp24 may have great potential for cancer treatment.

Ex vivo chemical cytometric analysis of protein tyrosine phosphatase activity in single human airway epithelial cells.

We describe a novel method for the measurement of protein tyrosine phosphatase (PTP) activity in single human airway epithelial cells (hAECs) using capillary electrophoresis. This technique involved the microinjection of a fluorescent phosphopeptide that is hydrolyzed specifically by PTPs. Analyses in BEAS-2B immortalized bronchial epithelial cells showed rapid PTP-mediated dephosphorylation of the substrate (2.2 pmol min(-1) mg(-1)) that was blocked by pretreatment of the cells with the PTP inhibitors pervanadate, Zn(2+), and 1,2-naphthoquinone (76%, 69%, and 100% inhibition relative to PTP activity in untreated controls, respectively). These studies were then extended to a more physiologically relevant model system: primary hAECs cultured from bronchial brushings of living human subjects. In primary hAECs, dephosphorylation of the substrate occurred at a rate of 2.2 pmol min(-1) mg(-1) and was also effectively inhibited by preincubation of the cells with the inhibitors pervanadate, Zn(2+), and 1,2-naphthoquinone (91%, 88%, and 87% median PTP inhibition, respectively). Reporter proteolysis in single BEAS-2B cells occurred at a median rate of 43 fmol min(-1) mg(-1) resulting in a mean half-life of 20 min. The reporter displayed a similar median half-life of 28 min in these single primary cells. Finally, single viable epithelial cells (which were assayed for PTP activity immediately after collection by bronchial brushing of a human volunteer) showed dephosphorylation rates ranging from 0.34 to 36 pmol min(-1) mg(-1) (n = 6). These results demonstrate the utility and applicability of this technique for the ex vivo quantification of PTP activity in small, heterogeneous, human cells and tissues.

Efficacy and safety of a liposome-based vaccine against protein Tau, assessed in tau.P301L mice that model tauopathy.

Progressive aggregation of protein Tau into oligomers and fibrils correlates with cognitive decline and synaptic dysfunction, leading to neurodegeneration in vulnerable brain regions in Alzheimer's disease. The unmet need of effective therapy for Alzheimer's disease, combined with problematic pharmacological approaches, led the field to explore immunotherapy, first against amyloid peptides and recently against protein Tau. Here we adapted the liposome-based amyloid vaccine that proved safe and efficacious, and incorporated a synthetic phosphorylated peptide to mimic the important phospho-epitope of protein Tau at residues pS396/pS404. We demonstrate that the liposome-based vaccine elicited, rapidly and robustly, specific antisera in wild-type mice and in Tau.P301L mice. Long-term vaccination proved to be safe, because it improved the clinical condition and reduced indices of tauopathy in the brain of the Tau.P301L mice, while no signs of neuro-inflammation or other adverse neurological effects were observed. The data corroborate the hypothesis that liposomes carrying phosphorylated peptides of protein Tau have considerable potential as safe and effective treatment against tauopathies, including Alzheimer's disease.

Aerosol delivery of eukaryotic translation initiation factor 4E-binding protein 1 effectively suppresses lung tumorigenesis in K-rasLA1 mice.

Conventional radiotherapy or chemotherapy for the long-term survival of patients with lung cancer is still difficult for treatment in metastatic and advanced tumors. Therefore, the safe and effective approaches to the treatment of lung cancer are needed. In this study, the effect of delivered eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1) on lung cancer progression was evaluated. Recombinant adeno-associated virus (rAAV)-M3/4E-BP1 was delivered into 6-week-old K-rasLA1 lung cancer model mice through a nose-only inhalation system twice a week for 4 weeks. Long-term repeated delivery of 4E-BP1 effectively reduced tumor progression in the lungs of K-rasLA1 mice. Reduction of eIF4E by overexpression of 4E-BP1 resulted in suppression of cap-dependent protein expression of basic fibroblast growth factor (bFGF or FGF-2) and vascular endothelial growth factor (VEGF). In addition, delivered 4E-BP1 inhibited the proliferation of lung cancer cells in K-rasLA1 mice model. Our results suggest that long-term repeated viral delivery of 4E-BP1 may provide a useful tool for designing lung cancer treatment.

The requirement of linker for activation of T cells in the primary and memory responses of CD8 T cells.

Linker for activation of T cells (LAT) is a transmembrane adaptor protein that links TCR engagement to downstream signaling events. Although it is clear that LAT is essential in thymocyte development and initiation of T cell activation, its function during T cell expansion, contraction, and memory formation remains unknown. To study the role of TCR-mediated signaling in CD8 T cells during the course of pathogen infection, we used an inducible mouse model to delete LAT in Ag-specific CD8 T cells at different stages of Listeria infection and analyzed the effect of deletion on T cell responses. Our data showed that LAT is important for maintaining CD8 T cell expansion during the priming phase; however, it is not required for CD8 T cell contraction and memory maintenance. Moreover, LAT deficiency accelerates memory differentiation during the effector-to-memory transition, leading to a higher frequency of KLRG1(low)IL-7R(high)CD62L(high) memory T cells. Nonetheless, these LAT-deficient memory T cells were unable to proliferate or produce cytokines upon secondary infection. Our data demonstrated that, although TCR-mediated signaling is dispensable for contraction and memory maintenance, it regulates CD8 T cell memory differentiation and is essential for the memory response against pathogens.

Stimulated γδ T cells increase the in vivo efficacy of trastuzumab in HER-2+ breast cancer.

One fourth of women with HER-2(+) metastatic breast carcinoma are treated with a combination regimen with trastuzumab, but the frequent resistance to this Ab requires definition of new means to improve its bioactivity. The mechanisms of action of trastuzumab involve several pathways including Ab-dependent cellular cytotoxicity. Because human γδ T lymphocytes mediate Ab-dependent cellular cytotoxicity and can be activated further by phosphoantigens, these cells are prone to improve the efficacy of Abs, as recently demonstrated for CD20(+) B cell lymphomas. Whether this concept applies as well with carcinomas remained to be demonstrated in vivo, however. In this study, we asked whether a combination of trastuzumab and phosphoantigen-stimulated γδ lymphocytes increases the efficacy of trastuzumab against HER-2(+) breast carcinoma cell lines in vivo. We report that repeated infusions of this combination had a better efficacy than that of trastuzumab alone against HER-2(+) mammary carcinoma xenografts in mice. In these models, reduction of tumor growth was observed together with trastuzumab opsonization of HER-2(+) cells and tumor infiltration by γδ lymphocytes. In addition in humans, the mammary carcinomas of 27 of 30 patients showed significant γδ T cell infiltrates. Altogether, these findings indicate that combination of trastuzumab and stimulated γδ cells represents a new strategy to improve the efficacy of Herceptin (trastuzumab) in HER-2(+) breast cancer.

Cloning and characterization of the acidic ribosomal protein P2 of Cryptosporidium parvum, a new 17-kilodalton antigen.

Cryptosporidium infection is commonly observed among children and immunocompromised individuals in developing countries, but large-scale outbreaks of disease among adults have not been reported. In contrast, outbreaks of cryptosporidiosis in the United States and Canada are increasingly common among patients of all ages. Thus, it seems likely that residents of regions where Cryptosporidium is highly endemic acquire some level of immunity, while residents of the developed world do not. A new immunodominant Cryptosporidium parvum antigen in the 15- to 17-kDa size range was identified as the Cryptosporidium parvum 60S acidic ribosomal protein P2 (CpP2). We developed a recombinant protein-based enzyme-linked immunosorbent assay for serologic population surveillance for antibodies that was 89% sensitive and 92% specific relative to the results of the large-format Western blot assay. The human IgG response is directed almost exclusively toward the highly conserved, carboxy-terminal 15 amino acids of the protein. Although IgG antibody cross-reactivity was documented with sera from patients with acute babesiosis, the development of an anti-CpP2 antibody response in our Peru study population correlated better with Cryptosporidium infection than with infection by any other parasitic protozoan. In Haiti, the prevalence of antibodies to CpP2 plateaus at 11 to 20 years of age. Because anti-CpP2 IgG antibodies were found only among residents of countries in the developing world where Cryptosporidium infection occurs early and often, we propose that this response may be a proxy for the intensity of infection and for acquired immunity.

Treatment with transducible phosphopeptide analogues of the small heat shock-related protein, HSP20, after experimental subarachnoid hemorrhage: prevention and reversal of delayed decreases in cerebral perfusion.

OBJECT: Delayed vasospasm is a significant cause of morbidity and mortality after subarachnoid hemorrhage (SAH). Proteomic therapeutics offers a new modality in which biologically active proteins or peptides are transduced into cells via covalent linkage to cell permeant peptides (CPPs). The hypothesis of this study was that either intrathecal or intravenous delivery of a phosphopeptide mimetic of the small heat shock-related protein, HSP20, linked to a CPP, would inhibit delayed decreases in cerebral perfusion after experimental SAH in a rat model. METHODS: This study was conducted in 3 parts: 1) prevention and 2) reversal of delayed decreases in cerebral perfusion via either intrathecal or intravenous administration of a CPP linked to phosphopeptide mimetics of HSP20 (AZX100) and 3) determining the effect of intravenous administration of AZX100 on blood pressure and heart rate. Subarachnoid hemorrhage was induced in rats by endovascular perforation. Subsequently, AZX100 was administered intrathecally via a cisternal catheter or intravenously. Cerebral perfusion was determined by laser Doppler monitoring. Blood pressure was monitored by telemetry in a separate group of naïve animals treated with AZX100 for 24 hours. RESULTS: The maximal decrease in cerebral perfusion occurred 3 days after SAH. Cisternal administration of AZX100 (0.14-0.57 mg/kg) 24 hours after hemorrhage prevented decreases in cerebral perfusion after SAH. Animals receiving lower doses of AZX100 (0.068 mg/kg) or a scrambled sequence of the active HSP20 peptide linked to CPP developed decreases in cerebral perfusion similar to those seen in control animals. Intravenous administration of AZX100 (1.22 mg/kg) 24 hours after hemorrhage prevented the decreases in cerebral perfusion seen in the controls. Intravenous administration (0.175 mg/kg and 1.22 mg/kg) of AZX100 on Days 2 and 3 after SAH reversed decreases in cerebral perfusion as early as Day 3. There was no impact of AZX100 on blood pressure or heart rate at doses up to 2.73 mg/kg. CONCLUSIONS: Cisternal administration of AZX100 24 hours after hemorrhage prevented decreases in cerebral perfusion. Intravenous administration of AZX100 also prevented and reversed decreases in cerebral perfusion at doses that did not induce hypotension. Transduction of biologically active motifs of downstream regulators like HSP20 represents a potential novel treatment for SAH.

Internalization and intracellular trafficking of a PTD-conjugated anti-fibrotic peptide, AZX100, in human dermal keloid fibroblasts.

A challenge in advanced drug delivery is selectively traversing the plasma membrane, a barrier that prohibits the intracellular delivery of most peptide and nucleic acid-based therapeutics. A variety of short amino acid sequences termed protein transduction domains (PTDs) first identified in viral proteins have been utilized for over 20 years to deliver proteins nondestructively into cells, however, the mechanisms by which this occurs are varied and cell-specific. Here we describe the results of live cell imaging experiments with AZX100, a cell-permeable anti-fibrotic peptide bearing an "enhanced" PTD (PTD4). We monitored fluorescently labeled AZX100 upon cell surface binding and subsequent intracellular trafficking in the presence of cellular process inhibitors and various well-defined fluorescently labeled cargos. We conclude that AZX100 enters cells via caveolae rapidly, in a manner that is independent of glycoconjugates, actin/microtubule polymerization, dynamins, multiple GTPases, and clathrin, but is associated with lipid rafts as revealed by methyl-beta-cylodextrin. AZX100 treatment increases the expression of phospho-caveolin (Y14), a critical effector of focal adhesion dynamics, suggesting a mechanistic link between caveolin-1 phosphorylation and actin cytoskeleton dynamics. Our results reveal novel and interesting properties of PTD4 and offer new insight into the cellular mechanisms facilitating an advanced drug delivery tool.

IFN-gamma and Fas/FasL pathways cooperate to induce medial cell loss and neointimal lesion formation in allograft vasculopathy.

Using a clinically relevant, fully disparate, allogeneic aortic transplant mouse model of allograft vasculopathy, we have demonstrated that neointimal proliferation is dependent on CD8(+) T cell effector pathways in the presence of therapeutic doses of calcineurin inhibitor (CNI) immunosuppression. CD4(+) T cell pathways are ablated by CNI immunosuppression. In the current study, we examined the relationship between CD8(+) T cell activities, medial SMC loss and neointimal hyperplasia. We demonstrate that at 5-6wk post transplantation in a wild type/wild type transplant CD8(+) T cell infiltration, CD8(+) CTL effector cell mediator expression and medial SMC loss all occur within aortic interposition grafts in the face of CNI immunosuppression. Both IFN-gamma and CTL mediated effector function is required for SMC loss and lesion formation under these conditions. Using strain combinations and reconstitution models, we provide data that blockade of the perforin/granzyme pathway does not prevent lesion formation but that blockade of the Fas/FasL pathway of cytotoxicity dramatically reduces SMC loss and prevents neointimal lesion formation. Both of these blockade strategies are in the face of an active IFN-gamma pathway. These data suggest a cooperative role between Fas/FasL and IFN-gamma mediated effector functions in medial SMC loss and neointimal lesion formation.

A panel of artificial APCs expressing prevalent HLA alleles permits generation of cytotoxic T cells specific for both dominant and subdominant viral epitopes for adoptive therapy.

Adoptive transfer of virus-specific T cells can treat infections complicating allogeneic hematopoietic cell transplants. However, autologous APCs are often limited in supply. In this study, we describe a panel of artificial APCs (AAPCs) consisting of murine 3T3 cells transduced to express human B7.1, ICAM-1, and LFA-3 that each stably express one of a series of six common HLA class I alleles. In comparative analyses, T cells sensitized with AAPCs expressing a shared HLA allele or autologous APCs loaded with a pool of 15-mer spanning the sequence of CMVpp65 produced similar yields of HLA-restricted CMVpp65-specific T cells; significantly higher yields could be achieved by sensitization with AAPCs transduced to express the CMVpp65 protein. T cells generated were CD8(+), IFN-gamma(+), and exhibited HLA-restricted CMVpp65-specific cytotoxicity. T cells sensitized with either peptide-loaded or transduced AAPCs recognized epitopes presented by each HLA allele known to be immunogenic in humans. Sensitization with AAPCs also permitted expansion of IFN-gamma(+) cytotoxic effector cells against subdominant epitopes that were either absent or in low frequencies in T cells sensitized with autologous APCs. This replenishable panel of AAPCs can be used for immediate sensitization and expansion of virus-specific T cells of desired HLA restriction for adoptive immunotherapy. It may be of particular value for recipients of transplants from HLA-disparate donors.

Induction of cross-serovar protection against genital chlamydial infection by a targeted multisubunit vaccination approach.

An important consideration for antichlamydial vaccine development is the induction of cross-serovar protection, since multiple serovars (D to L) of Chlamydia trachomatis cause genital infections. We have shown previously that vaccination with C. trachomatis-derived recombinant chlamydial protease-like activity factor (rCPAF) induced significant earlier resolution of Chlamydia muridarum infection and reduced oviduct pathology. However, the vaccinated mice continued to shed chlamydiae for up to 2 weeks after challenge. In this study, C. trachomatis serovar D recombinant proteins, such as recombinant major outer membrane protein (rMOMP), recombinant inclusion membrane protein A (rIncA), and rCPAF were administered intranasally, individually or in combinations, with murine interleukin-12 (IL-12) as an adjuvant, and cross-species immunity against intravaginal C. muridarum infection was examined. Immunization with rCPAF plus IL-12 (rCPAF+IL-12), compared to immunization with rIncA+IL-12 or rMOMP+IL-12, induced the greatest antigen-specific gamma interferon production from purified CD4(+) T cells and concurrently enhanced serum antibody production. All (100%) the animals vaccinated with rCPAF+IL-12 alone or in any combination completely resolved the infection by day 18 after challenge compared to animals vaccinated with rIncA+IL-12 (50%), rMOMP+IL-12 (33%), or phosphate-buffered saline (mock vaccinated; 0%). Moreover, oviduct pathology in mice vaccinated by any regimen that included rCPAF, but not rMOMP+IL-12 or rIncA+IL-12 alone, was markedly reduced compared to mock-immunized animals. The addition of rMOMP and/or rIncA did not significantly enhance the rCPAF+IL-12-induced effect on bacterial clearance or oviduct pathology. These results suggest a greater conservation of protective linear antigenic epitopes within CPAF than MOMP or IncA across the examined serovars and the need to identify other highly conserved antigens for use with rCPAF in a multisubunit recombinant vaccine.