CpG ODN佐剂对呼吸道合胞病毒重组疫苗诱导的细胞免疫应答的作用

目的:研究CpG2216佐剂对呼吸道合胞病毒(RSV)重组蛋白疫苗诱导的细胞免疫应答的作用。方法:重组RSV疫苗G1F/M2与CpG2216佐剂混合,或与CpG2216及常规佐剂Al(OH)3混合,鼻腔(i.n.)或腹腔注射(i.p.)免疫BALB/c小鼠三次,最后一次免疫后2周杀小鼠,取脾细胞,用乳酸脱氢酶(LDH)释放法检测脾细胞特异性杀伤活性;用ELISPOT法检测分泌IFNγ-和IL-4的细胞;用流式细胞仪检测CD4+/CD8+效应及LDH记忆细胞。结果:与G1F/M2相比,CpG+G1F/M2鼻腔或腹腔注射免疫均诱导了显著的杀伤活性;而且G1F/M2+Al+CpG(i.p.)诱导的杀伤活性显著高于CpG+G1F/M2(i.p.)。ELISPOT结果显示:CpG+G1F/M2鼻腔免疫和腹腔注射免疫组的分泌IFNγ-和IL-4的淋巴细胞数量明显多于G1F/M2组;CpG+Al+G1F/M2(i.p.)组的细胞数显著多于CpG+G1F/M2(i.p.)组;且各组分泌IFNγ-的淋巴细胞数显著多于分泌IL-4的淋巴细胞,即均诱导了Th1型优势应答,有利于宿主抗病毒。流式细胞仪检测结果表明:CpG+G1F/M2(i.n.)仅诱导CD44+单阳性的细胞,而CpG+G1F/M2(i.p.)和CpG+Al+G1F/M2(i.p.)既诱导产生了CD44+单阳性细胞,也产生了CD44+CD62L+双阳性的记忆细胞。结论:CpG2216作为RSV重组疫苗G1F/M2的佐剂,可显著增强细胞免疫应答。     

特异性免疫在呼吸道合胞病毒疫苗增强疾病过程中的作用

呼吸道合胞病毒（RSV）疫苗可诱发疫苗增强疾病,以肺组织广泛的炎细胞浸润和嗜酸性粒细胞增多为典型特征。探索RSV疫苗增强疾病的免疫机制,尤其是宿主体液和细胞免疫反应不平衡在疫苗增强疾病过程中的作用,有助于安全有效的RSV疫苗的研究。     

Phenotypic analysis of local cellular responses in calves infected with bovine respiratory syncytial virus

Changes in lymphocyte subsets in the trachea, pulmonary tissue, bronchoalveolar lavage (BAL), peripheral blood and bronchial lymph node (BLN) of gnotobiotic calves infected with bovine respiratory syncytial virus (BRSV) were analysed by flow cytometry. Following BRSV infection, virus titres in the nasopharynx reached a peak between days 5 and 7 and infection was resolving from day 10. Although calves did not develop signs of clinical respiratory disease, there was evidence of gross pneumonia and histological changes typical of BRSV bronchiolitis, which were most extensive from day 710 of infection. Following BRSV infection there was a recruitment of CD8+ T cells into the trachea and lung, which peaked on day 10 after infection. Thus, there were approximately equal numbers of CD8+ and CD4+ T cells in the lung and trachea of uninfected calves, whereas by day 10 of infection, CD8+ cells outnumbered CD4+ cells by 3:1 in the lungs and 6:1 in the trachea of the infected calves. Although the increase in CD4+ T cells into the lungs was less marked than that of CD8+ T cells, changes in expression of CD45R, CD45RO, L-selectin and interleukin-2 receptors all suggested that CD4+ T cells were activated during BRSV infection. Changes in gamma delta T cells were not observed in BRSV-infected calves. There was a marked increase in B cells in the BLN after infection and BLN CD4+ T cells changed from the majority expressing L-selectin and CD45R in uninfected calves to a predominance of L-selectin- CD45R- CD45RO+ phenotype, 10 days after infection. In conclusion, CD8+ T cells constitute the major lymphocyte subpopulation in the respiratory tract of calves recovering from BRSV infection.     

Alteration of leukocyte populations in calves concurrently infected with bovine respiratory syncytial virus and bovine viral diarrhea virus

Bovine viral diarrhea virus (BVDV) infection altered leukocyte populations in calves that were reflected by depression of T, BoCD4+, and BoCD8+ lymphocytes in the thymus and depression of B lymphocytes in Peyer's patches (PP). The present study was based on mononuclear leukocyte preparations from eighteen 9- to 12-month-old crossbred calves that were each exposed to either bovine respiratory syncytial virus (BRSV), BVDV, or BRSV and BVDV concurrently, or served as mock-infected controls. Peripheral blood leukocytes were collected on postinfection days (PID) 0, 2, 4, 6, and 8, and cell populations from thymus, spleen, mesenteric lymph node, and PP were collected at necropsy on PID 9. The leukocytes were analyzed using flow cytometry for lymphocyte subpopulations expressing antigens specific for BoCD2, BoCD4, BoCD8, BoWC1, lambda light chain of bovine immunoglobulin, BoCD11b and major histocompatibility complex (MHC) class II. Concurrent BRSV and BVDV infections caused exaggerated alterations in leukocyte populations with a greater percentage of T-lymphocytes harvested from the PP. Alterations in the leukocyte populations in lymphatic tissues and in peripheral circulation due to BVDV infection may be an important mechanism for causation of clinically severe diseases of the respiratory and digestive tracts during concurrent BRSV and BVDV infections.     

The early cellular signatures of protective immunity induced by live viral vaccination

Here, we have used primary vaccination of healthy donors with attenuated live yellow fever virus 17D (YFV-17D) as a model to study the generation of protective immunity. In short intervals after vaccination, we analyzed the induction of YFV-17D specific T- and B-cell immunity, bystander activation, dendritic cell subsets, changes in serum cytokine levels, and YFV-17D-specific antibodies. We show activation of innate immunity and a concomitant decline of numbers of peripheral blood T and B cells. An early peak of antigen-specific T cells at day 2, followed by mobilization of innate immune cells, preceded the development of maximal adaptive immunity against YFV-17D at day 14 after vaccination. Interestingly, potent adaptive immunity as measured by high titers of neutralizing YFV-17D-specific antibodies, correlated with early activation and recruitment of YFV-17D-specific CD4(+) T cells and higher levels of sIL-6R. Thus our data might provide new insights into the interplay of innate and adaptive immunity for the induction of protective immunity.     

猪瘟基因疫苗免疫小鼠体液及细胞免疫动态变化研究

目的：探讨猪瘟基因疫苗免疫小鼠后机体产生体液和细胞免疫发生规律，为猪瘟基因疫苗推广应用提供科学依据。方法：应用FACS、MTT法及间接ELISA试验对猪瘟基因疫苗免疫小鼠脾脏及外周血中CD4^ 和CD8^ 淋巴细胞数、淋巴细胞的转化功能及特异的抗猪瘟病毒血清IgG抗体水平等动态变化进行了观察。结果：猪瘟基因疫苗免疫小鼠后脾细胞及外周血淋巴细胞对ConA和LPS均有明显的反应性。CD4^ 和CD8^ 细胞数量在免疫后20天开始反应，32天达到高峰后开始下降。鼠血清特异性猪瘟病毒血清抗体IgG随免疫时间延长而增加。结论：猪瘟基因疫苗免疫动物可诱导机体体液及细胞免疫。     

DNA vaccination against pseudorabies virus and bovine respiratory syncytial virus infections of young animals in the face of maternally derived immunity

DNA vaccination represents a unique opportunity to overcome the limitations of conventional early life vaccine strategy which is restricted by the effects of maternally derived immunity. The pseudorabies virus (PRV) infection model in neonatal piglets was employed to demonstrate that a single DNA vaccination was able to prime memory humoral immune responses in the face of high concentrations of maternally derived antibodies. Immunity induced under these conditions protected against challenge with virulent PRV at the end of the fattening period, but long-term protective responses were not correlated with the kinetics of the initial serological responses. The bovine respiratory syncytial virus (BRSV) infection model in young calves was similarly studied, however the ability of DNA vaccination to prime memory humoral responses in the face of high concentrations of maternally derived antibodies was not confirmed, illustrating that the performance of DNA vaccination varies between species and/or infectious disease targets. However, in the BRSV model system it was evident that DNA vaccination could prime cell-mediated immunity in the face of high concentrations of maternally derived antibodies. Although not sufficient to ensure protection against clinical disease or viral excretion as a standalone vaccination strategy, priming by DNA vaccination was proven to establish cell-mediated immune responses for subsequent recall with an inactivated vaccine booster. Under these conditions, protection against challenge virus re-excretion was correlated with interferon (IFN) gamma-producing T-cell responses. The safety and the efficacy of DNA vaccine priming in very young animals in the face of high concentrations of maternally derived antibody provides a unique opportunity to design innovative and flexible vaccination programs to ensure uninterrupted protection under field conditions.     

IL-12体外促进慢性乙型肝炎患者PBMC IFN-γ的产生

目的：探讨体外IL-12对慢性乙型病毒性肝炎患者细胞免疫功能的影响，为临床治疗慢性乙型病毒性肝炎提供理论依据。方法：慢性乙型肝炎患者PBMCs与HBsAg、HBsAg＋IL-12、HBcAg或HBcAg＋IL-12孵育后，利用酶联免疫吸附实验（ELISA）检测细胞培养上清中IFN-γ的含量；用酶联免疫斑点实验（ELISPOT）在单个细胞水平上检测PBMCs中IFN-γ产生细胞的频率；用流式细胞记数仪（FACS）检测PBMCs中IFN-γ^＋的细胞亚群。结果：当乙肝患者PBMCs与HBsAg或HBcAg孵育后，只有少数病例发生反应，产生低水平的IFN-γ。当IL-12加入细胞培养后，能显著地增加HBsAg或HBcAg诱导IFN-γ的产生；分泌IFN-γ的细胞频率显著增加；IFN-γ^＋的细胞主要包括CD8^＋T细胞和非T细胞。结论：IL-12体外能增强慢性乙型肝炎患者的细胞免疫应答。     

Live viral vaccines in patients with partial DiGeorge syndrome: clinical experience and cellular immunity

Partial DiGeorge syndrome (pDGS) is an inherited primary immunodeficiency syndrome (incidence, 1:3000 live births) primarily affecting cellular immune function; partial, infers thymic hypoplasia with detectable circulating T-lymphocytes and adequate function. No guidelines exist regarding the recommendations for use of live viral vaccines (LVVs) in this extensive population of pediatric patients. We reviewed the experience with live viral vaccines in our cohort of patients with pDGS. Of 53 patients, 25 (47%) had received a live viral vaccine. No significant adverse events were recorded in association with administration of live viral vaccines. There was no statistically significant difference between cellular immune function at initial presentation between those patients that received live viral vaccines and those that did not. Adequate cellular immune function was documented for 15 of the 25 LVV recipients at the time of vaccine administration without significant change from baseline. These observations suggest that live viral vaccines appear safe in patients with pDGS and stable immune function.     

Infection of gnotobiotic calves with a bovine and human isolate of respiratory syncytial virus. Modification of the response by dexamethasone

Summary A bovine and a human strain of RSV both adapted to bovine cell culture, have been inoculated separately into 13 and 7 gnotobiotic calves respectively by 3 different methods.Both strains infected calves and showed similar growth patterns. Virus was recovered from the nasopharynx between one and 11 days with peak titres between 3 and 8 days following inoculation.With the exception of 4 calves treated with dexamethasone no clinical signs and only minimal macroscopic lesions of the lung were induced, which histologically comprised a mononuclear infiltration of alveolar walls and of the peribronchiolar tissue.The serological response to both strains was similar. Antibody was detected by virus neutralisation or single radial haemolysis from 12 days after inoculation. Specific anti-RSV IgM was detected from 10 days and IgG from 16 days after inoculation.Treatment with dexamethasone (0.5 mgm/Kg daily for 10 days) enhanced lung lesions produced by the bovine strain, prolonged the period of virus shedding and increased peak titres. The specific IgM response was suppressed.     

Gradual development of the interferon-gamma response of swine to porcine reproductive and respiratory syndrome virus infection or vaccination

Infection of swine with virulent porcine reproductive and respiratory syndrome (PRRS) virus induced a rapid, robust antibody response that comprised predominantly nonneutralizing antibodies and waned after approximately 3 months. In contrast, the initial onset of virus-specific interferon (IFN)-gamma-secreting cells (SC) in the pig lymphocyte population remained at a fairly low level during this period and then increased gradually in frequency, plateauing at 6 months postinfection. A similar polarization of the host humoral and cellular immune responses was also observed in pigs immunized with a PRRS-modified live virus (MLV) vaccine. Even coadministration of an adjuvant that enhanced the immune response to a pseudorabies (PR) MLV vaccine failed to alter the induction of PRRS virus-specific IFN-gamma SC (comprising predominantly CD4/CD8 alpha double positive memory T cells with a minority being typical CD4(-)/CD8 alpha beta(+) T cells) and the generation of neutralizing antibodies. Moreover, unlike inactivated PR virus, nonviable PRRS virus did not elicit virus-neutralizing antibody production. Presumably, an intrinsic property of this pathogen delays the development of the host IFN-gamma response and preferentially stimulates the synthesis of antibodies incapable of neutralization.     

Revaccination of neonatal calves with Mycobacterium bovis BCG reduces the level of protection against bovine tuberculosis induced by a single vaccination

Cattle may provide a suitable model for testing ways of improving tuberculosis vaccine efficacy in human infants. A vaccination and challenge study was undertaken in calves to determine the optimal time to vaccinate neonatal animals with Mycobacterium bovis bacillus Calmette-Guérin (BCG) for protection against tuberculosis and to determine whether revaccination with BCG was beneficial. Calves (10 per group) were vaccinated with BCG within 8 h of birth or at 6 weeks of age, when immune responses to antigens of environmental mycobacteria were detectable, or vaccinated at birth and revaccinated at 6 weeks. A control group was not vaccinated. BCG vaccination at birth induced strong antigen-specific gamma interferon (IFN-gamma) and interleukin-2 (IL-2) responses and antigen-specific activation in CD4(+), CD8(+), and WC1(+) gammadelta T-cell subsets from blood. The proportions of animals per group with macroscopic tuberculous lesions after challenge were 0/10 for BCG at birth, 1/9 for BCG at 6 weeks, 4/10 for the revaccinated group, and 10/10 for the nonvaccinated group. There was no significant difference in the levels of protection between groups vaccinated at birth or at 6 weeks, while animals vaccinated both at birth and at 6 weeks had significantly less protection than those vaccinated only at birth. The revaccinated calves that subsequently developed tuberculous lesions had significantly stronger IFN-gamma and IL-2 responses to bovine purified protein derivative after the BCG booster than those in the same group that did not develop lesions. The results indicated that BCG vaccination at birth induced a high level of immunity and that the sensitization of very young animals to antigens of environmental mycobacteria by 6 weeks of age did not affect the effectiveness of BCG. However, BCG revaccination of these young animals was contraindicated.     

Long-term persistence of antibodies induced by vaccination and safety follow-up, with the first combined vaccine against hepatitis A and B in children and adults

It is important to monitor the long-term persistence of antibodies induced by vaccination. Four cohorts were followed for their long-term immunity after vaccination with a combined hepatitis A and B vaccine (Twinrix; SmithKline Beecham Biologicals, Rixsenart, Belgium). Two cohorts of adults (ages 17-60 years), one of 1-6-year-olds, and one of 6-15-year-olds were vaccinated following a 0, 1, and 6-month schedule. Follow-up data until month 72 (adults) and month 60 (children) are available. At month 72, antibody to hepatitis A virus (anti-HAV) seropositivity (S+) was 100% for both adult cohorts (n = 40 and n = 47) and 95% and 89% of the vaccinees were seroprotected against hepatitis B virus (HBV), respectively. The geometric mean titres (GMTs; mIU/ml) for anti-HAV were 977 and 542 and the GMTs for the antibody to hepatitis B surface antigen (anti-HBs) were 322 and 90. For 1-6-year-olds at month 60 (n = 39), anti-HAV S+ was 100% with a GMT of 479 and 97% were protected against HBV with a GMT of 195. At month 60 for the 6-15-year-olds (n = 42), anti-HAV S+ was 100% with a GMT of 990 and 95% were protected against HBV with a GMT of 263. There have been no safety issues during the follow-up. In the past 5 years, a postmarketing surveillance system was available. Using this system, all spontaneous adverse events are collected and archived. Although infrequent, the most commonly reported adverse events after more than 13 million doses were allergic-type reactions followed by fever and injection site reactions. The combined hepatitis A and B vaccine is safe and is well tolerated. Immunity provided by the vaccine remains high in adults and children with comparable results to those obtained with monovalent vaccines.     

Reassessment of the impact of mucosal immunity in infection with the human immunodeficiency virus (HIV) and design of relevant vaccines

Conclusions The development of vaccines that would induce specific immune responses in the genital tract secretions would have far-reaching implications for not only the prevention of AIDS and sexually transmitted diseases but also the immunological control of fertility (4, 76, 88, 89, 123, 124, 149). Most of the currently studied vaccines utilize systemic routes of immunization which are of limited value for the prevention of mucosa-contracted diseases. The relative contribution of antigensensitized cells from PP or other inductive sites (e.g., rectal tonsils) to remote or adjacent effector sites (e.g., genital tract) as manifested by the appearance of corresponding S-IgA antibodies has not been studied extensively in humans despite its unquestionable practical importance. Exploration of immunization routes that are effective for induction of mucosal immune responses and that are based primarily on current knowledge of the origin of antibodies and of specific antibody-forming cells in mucosal tissues, together with novel antigen delivery systems (1, 76, 89, 130), is likely to reduce the incidence of many infectious diseases including AIDS and also reduce the cost of administration of such vaccines.     

Vaccination of cattle with a CpG oligodeoxynucleotide-formulated mycobacterial protein vaccine and Mycobacterium bovis BCG induces levels of protection against bovine tuberculosis superior to those induced by vaccination with BCG alone

The development of a subunit protein vaccine for bovine tuberculosis which could be used either in combination with Mycobacterium bovis BCG (to improve the efficacy of that vaccine) or alone would offer significant advantages over currently available strategies. A study was conducted with cattle to determine the protective efficacy of a strategy based on concurrent immunization with an M. bovis culture filtrate (CFP) vaccine and BCG compared to vaccination with either vaccine alone. One group of calves (10 animals per group) was vaccinated subcutaneously with CFP formulated with Emulsigen and combined with a CpG oligodeoxynucleotide (ODN). A second group was vaccinated with both the CFP vaccine and BCG injected at adjacent sites (CFP-BCG). One further group was vaccinated subcutaneously with BCG, while another group served as nonvaccinated control animals. Vaccination with CFP-BCG induced levels of antigen-specific gamma interferon (IFN-gamma) and interleukin-2 (IL-2) in whole-blood cultures that were higher than those induced by vaccination with BCG alone. The combination of CFP and BCG did not enhance the production of antibodies to M. bovis CFP compared to vaccination with CFP alone. Vaccination with CFP alone led to delayed antigen-specific IFN-gamma and IL-2 responses. Vaccination with CFP-BCG induced a high level of protection against an intratracheal challenge with virulent M. bovis, based on a significant enhancement of six pathological and microbiological parameters of protection compared with the nonvaccinated group. In contrast, vaccination with BCG alone induced a significant enhancement of protection in only one parameter, while CFP alone induced no protection. These results suggest that a combination of a CpG ODN-formulated protein vaccine and BCG offers better protection against bovine tuberculosis than does BCG alone.     

Parameters of humoral and cellular immunity following vaccination of pigs with a European modified-live strain of porcine reproductive and respiratory syndrome virus (PRRSV)

Parameters of humoral and cellular immunity were investigated in pigs experimentally infected with a modified-live European porcine reproductive and respiratory syndrome virus (PRRSV, strain DV). PRRSV was detected by real-time RT-PCR and PRRSV-specific antibodies by a commercial ELISA test-kit, respectively. Interleukins IL-1alpha, IL-2, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor (TNF-alpha) and interferon-gamma (IFN-gamma) as well as IL-2 receptor (IL-2R) were quantified at mRNA level using RT-PCR. Subpopulations of blood lymphocytes were assayed using flow cytometry. No significant changes neither in cytokine expression nor in shifts of CD4 and CD8 markers could be found, but similar curve diagrams concerning CD8 single positive T cells could be observed in all vaccinated animals with an initial decrease and an increase between post-infection days (PIDs) 7 and 14. In the vaccination group, TNF-alpha and IL-6 tended to be increased at PIDs 22 and 40, whereas no increase could be seen in IFN-gamma. When comparing the in vivo immune response to that being seen in in vitro experiments, similar shifts of CD4/CD8 lymphocyte subpopulations may be seen. Cytokine curve diagrams, however, do not reflect the in vitro findings to that extent.     

Specificity and immunochemical properties of anti-DNA antibodies induced in normal mice by immunization with mammalian DNA with a CpG oligonucleotide as adjuvant

To elucidate the role of DNA antigen drive in the anti-DNA response, the specificity and immunochemical properties of anti-DNA antibodies induced in normal mice by immunization with double stranded (ds) mammalian DNA with a CpG oligonucleotide (ODN) adjuvant were characterized. Like spontaneous anti-DNA from MRL/lpr mice, the induced anti-DNA bound cross-reactively to DNA from five different species by ELISA. The induced antibodies displayed a predominance of IgG2a and had much lower amount of IgG3 than spontaneous antibodies. Surface plasmon resonance indicated that the induced and spontaneous anti-DNA antibodies have a similar range of avidity and binding kinetics. While sera from the MRL/lpr mice had substantial binding to histones and nucleosomes, the immunized mice had antibody levels to these antigens similar to those of mice treated only with incomplete Freund's adjuvant. Together, these results indicate that normal mice can produce autoantibodies to dsDNA, with a CpG ODN allowing the generation of antibodies resembling those in spontaneous autoimmunity.     

Identification of surrogates and correlates of protection in protective immunity against Mycobacterium bovis infection induced in neonatal calves by vaccination with M. bovis BCG Pasteur and M. bovis BCG Danish

Vaccination of neonatal calves with Mycobacterium bovis bacillus Calmette-Guérin (BCG) induces a significant degree of protection against infection with virulent M. bovis, the causative agent of bovine tuberculosis (bTB). We compared two strains of BCG, Pasteur and Danish, in order to confirm that the current European human vaccine strain (BCG Danish) induced protective immunity in calves, and we assessed immune responses to determine correlates of protection that could assist future vaccine evaluation in cattle. Both vaccine strains induced antigen (purified protein derivate [PPD])-specific gamma interferon (IFN-γ) in whole-blood cultures. These responses were not significantly different for BCG Pasteur and BCG Danish and peaked at week 2 to 4 postvaccination. Vaccination with either BCG Danish or BCG Pasteur induced significant protection against bTB, with reductions in both lesion score and bacteriological burden evident in both groups of vaccinated calves compared with nonvaccinated control calves. Measurement of IFN-γ-expressing T lymphocytes postvaccination and postchallenge revealed both correlates and surrogates of protective efficacy. The frequency of central memory T lymphocytes present at 12 weeks postvaccination (at the time of M. bovis challenge) correlated significantly with protection. Conversely, the number of IFN-γ-expressing effector T cells present after M. bovis challenge was correlated with disease. These results demonstrate that vaccination of neonatal calves with either BCG Pasteur or BCG Danish induces protective immune responses against TB. In addition, we show that measurement of antigen-specific T lymphocyte populations may provide a reliable means for identifying protective vaccine candidates.     

Selective induction of cell-mediated immunity and protection of rhesus macaques from chronic SHIV(KU2) infection by prophylactic vaccination with a conserved HIV-1 envelope peptide-cocktail

Infection of Indian-origin rhesus macaques by the simian human immunodeficiency virus (SHIV) is considered to be a suitable preclinical model for directly testing efficacy of vaccine candidates based on the HIV-1 envelope. We used this model for prophylactic vaccination with a peptide-cocktail comprised of highly conserved HIV-1 envelope sequences immunogenic/antigenic in macaques and humans. Separate groups of macaques were immunized with the peptide-cocktail by intravenous and subcutaneous routes using autologous dendritic cells (DC) and Freund's adjuvant, respectively. The vaccine elicited antigen specific IFN-gamma-producing cells and T-cell proliferation, but not HIV-neutralizing antibodies. The vaccinated animals also exhibited efficient cross-clade cytolytic activity against target cells expressing envelope proteins corresponding to HIV-1 strains representative of multiple clades that increased after intravenous challenge with pathogenic SHIV(KU2). Virus-neutralizing antibodies were either undetectable or present only transiently at low levels in the control as well as vaccinated monkeys after infection. Significant control of plasma viremia leading to undetectable levels was achieved in majority of vaccinated monkeys compared to mock-vaccinated controls. Monkeys vaccinated with the peptide-cocktail using autologous DC, compared to Freund's adjuvant, and the mock-vaccinated animals, showed significantly higher IFN-gamma production, higher levels of vaccine-specific IFN-gamma producing CD4(+) cells and significant control of plasma viremia. These results support DC-based vaccine delivery and the utility of the conserved HIV-1 envelope peptide-cocktail, capable of priming strong cell-mediated immunity, for potential inclusion in HIV vaccination strategies.