Potent Adjuvant Effect Research Articles

Traditional Chinese Medicine as a Complementary Therapy in Patients with Ankylosing Spondylitis: An Open Pilot Study

Objectives: Ankylosing spondylitis (AS) is a chronic inflammatory autoimmune disease involving joints, entheses and spine. Therapies for AS are unsatisfying in some patients because of poor efficacy, adverse reactions, and high cost. Traditional Chinese Medicine (TCM) might have the potential to serve as adjuvant therapies in AS. Hence, we conducted this open pilot clinical trial to explore potential TCM formulae for further randomized controlled studies. Methods: Thirty-four patients with AS and stable background medication for 3 months, were enrolled. Patients received an additional TCM formula for 3 months according to their syndrome patterns in relation to traditional Chinese medicine. Five TCM formulae: Dang Gui Lian Tong Tang (A), Yi Ⅰ Ren Tang (B), Gui Zhi Shao Yao Zhi Mu Tang (C), Huang Qi Wu Wu Tang (D), and Qiang Huo Sheng Shi Tang (E), were chosen for this study. Outcome measurements included ASAS-20 response criteria, Bath AS Disease Activity Index (BASDAI), Functional Index (BASFI), Global Index (BAS-G), IgA, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). Intention-To-Treat (ITT) analysis and Wilcoxin Signed Rank Test were used for statistical analyses. Results: Among 34 patients enrolled, 9 patients dropped out, and 9 patients achieved ASAS-20 response criteria. No serious adverse events were reported in this 12-week trial. In patients who received Huang Qi Wu Wu Tang (D), 2 out of 6 (33.3%) reached ASAS-20 response criteria. In 10 patients who received Qiang Huo Sheng Shi Tang (E), 3 (30%) were responders. Conclusions: In this study, Qiang Huo Sheng Shi Tang had potential adjuvant effects in the treatment of AS. Further double blind randomized controlled trials are needed to prove their efficacy.

Diallyl Disulfide Prevention of Cis-Diammine Dichloroplatinum–Induced Nephrotoxicity and Leukopenia in Rats: Potential Adjuvant Effects

Cisplatin (CisPt) is an effective chemotherapeutic agent against several human cancers, but it produces important nephrotoxicity, leukopenia, and mortality. In this work, we report initial results on the potential ability of diallyl disulfide (DADS) to block these toxicities without compromising chemotherapy. Male Sprague Dawley rats were used (control, DADS, CisPt, and CisPt/DADS). CisPt was administered sc as a single dose (10.5 mg/kg) in saline. DADS was given daily intragastrically in olive oil (292.5 mg/kg) 1 h before CisPt administration the first day and 146.25 mg/kg during the next 3 days. The animals were sacrificed at the fifth day after CisPt administration. DADS significantly decreased CisPt-induced nephrotoxicity as evaluated by histology and by seric urea (CisPt: 11.05 ± 3.59; CisPt/DADS: 6.53 ± 1.74) and creatinine (CisPt: 24.74 ± 3.03; CisPt/DADS: 14.83 ± 2.07). DADS also decreased leukopenia (CisPt: 13.5% and CisPt/DADS: 43.4% respect the control), and mortality (CisPt: 50%; CisPt/DADS: 29%). DADS showed ability to interact with reactive oxygen species (H2O2, hydroperoxides, OH•) and with iron. DADS treatment does not change Platinum levels in kidney (CisPt: 15.2 ± 5.1; CisPt/DADS: 13.9 ± 4.5). Because DADS is known to inhibit cellular replication and to promote apoptosis of tumor cells, results suggest that DADS merit to be tested as a potential coadjuvant of CisPt chemotherapy in tumor-bearing animals.

Allogeneic CD3/CD28 cross-linked Th1 memory cells provide potent adjuvant effects for active immunotherapy of leukemia/lymphoma

The breaking of peripheral T-cell tolerance toward self-antigens expressed by tumor cells and the subsequent establishment of an effective tumor protective immune response remains a major challenge for cancer immunotherapy. We report that both protective and therapeutic anti-tumor immune responses can be achieved in a mouse leukemia/lymphoma tumor model through the strong adjuvant effects provided by allogeneic CD3/CD28 cross-linked Th1 memory cells. The adjuvant effect of these cells is mediated by their ability to produce a variety of ‘danger signals’ which serve to deviate native non-protective Th2 anti-leukemia immune responses to effective Th1 immune responses.

A phase II trial of radiation plus temozolomide followed by adjuvant temozolomide and poly-ICLC in patients with newly diagnosed glioblastoma multiforme (NABTT #0501)

2055 Background: Polyinosinic-polycytidylic acid stabilized with polylysine and carboxymethylcellulose (poly-ICLC), is a double-stranded RNA that stimulates a broad variety of host defense mechanisms including T-cell and natural killer cell activation, cytokine release, and also has a potent adjuvant effect and specific antiproliferative and antiviral effects. The objective of this study is to determine the safety and efficacy of poly-ICLC when it is added as an adjuvant treatment for newly diagnosed glioblastoma (GB). Methods: New diagnosed patients > 18 years with histologically proven GB received standard external beam radiation therapy with concurrent low-dose temozolomide (TMZ)(75 mg/m2) followed by adjuvant cycles consisting of TMZ for 5 days (150- 200 mg/m2) (week 1), intramuscular injections of poly-ICLC (20 mcg/kg) 3 times a week (weeks 2–8; total 21 injections), week 9 off. There is no limit to the number of adjuvant cycles and imaging evaluations are performed before every cycle. Results: There were 96 patients enrolled (59 men); median age 57 yrs (range 22–85); median KPS 90 (range 60–100). Fourteen patients did not start adjuvant treatment (5 patient request and 4 investigator withdrawal; 2 progressive disease; 1 death; 1 toxicity; 1 other). The most frequent grade 3–4 toxicities (occurring in > 5% of subjects) possibly related to the study regimen were leukopenia (20%), thrombocytopenia (13%), anemia (13%), neutropenia (9%), and SGPT elevation (7%). The two deaths during adjuvant treatment were considered unlikely related to the regimen. Based on these data and an interim safety evaluation of the first 30 subjects completing 19 weeks of treatment, no safety reason was found to suspend the trial. As of 9/30/07 59 patients are alive and 37 have died; 42 patients remain on study. Conclusions: The addition of poly-ICLC to a modified adjuvant treatment regimen for newly diagnosed GB is well tolerated. Further safety and interim efficacy data will be presented. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Oncovir Oncovir Oncovir Oncovir

Co-administration of polyphosphazenes with CpG oligodeoxynucleotides strongly enhances immune responses in mice immunized with Hepatitis B virus surface antigen

An emerging paradigm in vaccinology is that multiple adjuvant combinations may be more effective than individual adjuvants in enhancing immune responses to vaccine antigens. We investigated whether the polyphosphazenes used in combination with CpG oligodeoxynucleotides (ODN) were potent adjuvant formulations. BALB/c mice were immunized subcutaneously with Hepatitis B surface antigen (HBsAg) alone, or in various combinations with poly[di(sodium carboxylatophenoxy)phosphazene] (PCPP), poly[di(sodium carboxylatoethylphenoxy)phosphazene] (PCEP) or CpG ODN. All three adjuvants enhanced HBsAg-specific IgG1 antibody responses with PCEP inducing the highest responses. PCEP and CpG ODN significantly enhanced the Th1-associated antibody isotype IgG2a. As expected CpG ODN induced predominantly Th1-type immune responses while PCEP was associated with mixed Th1/Th2 immune responses. Interestingly, PCEP and PCPP synergized with CpG ODN to further enhance antibody responses. Since the mechanisms which mediate the adjuvant activity of polyphosphazenes are not fully understood, we investigated whether PCEP and PCPP could stimulate innate immune responses. Incubation of mouse splenocytes with PCEP or PCPP (in the absence of antigen) stimulated production of IL-4 and IL-12, but only PCEP induced significant IFNgamma production. Additionally, IL-12 was not required for PCEP induced IFNgamma response. We conclude that the polyphosphazene-CpG ODN combination is a potent adjuvant formulation that is more effective in enhancing immune responses than either of the individual adjuvants. In addition, we provide evidence that PCEP and PCPP can stimulate innate cytokine production, suggesting a potential mechanism by which polyphosphazenes achieve their potent adjuvant effects.

The PorB porin from commensal Neisseria lactamica induces Th1 and Th2 immune responses to ovalbumin in mice and is a potential immune adjuvant

Porins from pathogenic Neisseriae are among several bacterial products with immune adjuvant activity. Neisseria meningitidis (Nme) PorB, has been shown to induce immune cells activation in a TLR2-dependent manner and acts as a vaccine immune adjuvant. The PorB porin from Neisseria lactamica (Nlac), a common nasopharyngeal commensal, shares significant structural and functional similarities with Nme PorB. In this work we ask whether the immune adjuvant ability of porins from pathogenic Neisserial strains is a characteristic shared with porins from non-pathogenic Neisserial species or whether it is unique for bacterial products derived from microorganisms capable of inducing inflammation and disease. We evaluated the potential immune adjuvant effect of Nlac PorB in mice using ovalbumin (OVA) as a prototype antigen. Immunization with Nlac PorB/OVA induced high OVA-specific IgG and IgM titers compared to OVA alone, similar to other adjuvants such as Nme PorB and alum. High titers of IgG1 and IgG2b were detected as well as production of IL-4, IL-10, IL-12 and INF-gamma in response to Nlac PorB, consistent with induction of both a Th1-type and a Th2-type immune response. OVA-specific proliferation was also determined in splenocytes from Nlac PorB/OVA-immunized mice. In addition, B cell activation in vitro and cytokine production in response to Nlac PorB was found to be mediated by TLR2, in a similar manner to Nme PorB.

In Vivo Sampling of Extracellular β‐Thymosin by Ultrafiltration Probes

In vivo detection and monitoring of extracellular beta-thymosin will facilitate the understanding of their biological function and association with disease progression. A novel technique using capillary ultrafiltration (CUF) probes linked to mass spectrometry is capable of sensing extracellular thymosin beta-4 and/or thymosin beta-10 in vivo in wounded skin and other tissue microenvironments. In this review, we highlight the association of extracellular beta-thymosin with skin wound healing and the potential adjuvant effects on vaccination. The fabrication and biological application of CUF probes are also described. Data from CUF probe-captured beta-thymosin may guide future exploration of extracellular beta-thymosin.

Repetitive Transcranial Magnetic Stimulation as an Adjunct to Constraint-Induced Therapy

To test the potential adjuvant effect of repetitive transcranial magnetic stimulation (rTMS) on motor learning in a group of stroke survivors undergoing constraint-induced therapy (CIT) for upper-limb hemiparesis. This was a prospective randomized, double-blind, sham-controlled, parallel group study. Nineteen individuals, one or more years poststroke, were randomized to either a rTMS + CIT (n = 9) or a sham rTMS + CIT (n = 10) group and participated in the 2-wk intervention. Regardless of group assignment, participants demonstrated significant gains on the primary outcome measures: the Wolf Motor Function Test (WMFT) and the Motor Activity Log (MAL)--Amount of Use, and on secondary outcome measures including the Box and Block Test (BBT) and the MAL--How Well. Participants receiving rTMS failed to show differential improvement on either primary outcome measure. Although this study provided further evidence that even relatively brief sessions of CIT can have a substantial effect, it provided no support for adjuvant use of rTMS.

Oral bacterial lipopolysaccharide acts in mice to promote sensitisation to ovalbumin and to augment anaphylaxis via platelets

Microbial infection is thought to modulate allergic disorders, and we previously demonstrated that not only mast cells (which release histamine), but also platelets are involved in the anaphylaxis induced in mice sensitised to ovalbumin (OVA). Here, we examined the effects of a lipopolysaccharide (LPS) from the oral bacterium Prevotella intermedia ( Pi) on OVA-induced anaphylaxis. Upon intraperitoneal co-injection of Pi-LPS plus OVA into BALB/c mice, the Pi-LPS displayed a potent adjuvant effect comparable to that of alum (a standard adjuvant) in terms of its abilities to induce both anaphylactic shock and histamine-release following an antigen (OVA)-challenge. Moreover, an injection of Pi-LPS given to OVA+alum-sensitised mice shortly before an OVA-challenge augmented the shock-response. This LPS-pretreatment did not affect histamine-release, but did augment pulmonary platelet accumulation. Histamine was not by itself causal for shock-induction in sensitised mice. These results suggest that oral bacteria and/or their constituents (such as LPS) may help to sensitise the host to an antigen or exacerbate the host's allergic reactions (“aggravation effect”), probably by enhancing the platelet response to the antigen OVA.

Human Dendritic Cell Interactions with Whole Recombinant Yeast: Implications for HIV-1 Vaccine Development

Defects in number and function of dendritic cells (DCs) have been observed during HIV-1 infection, so therapeutic HIV-1 vaccine approaches that target or activate DCs may improve vaccine immunogenicity. To determine the potential of recombinant Saccharomyces cerevisiae yeast as an HIV-1 vaccine, we investigated interactions between yeast and human DCs. Yeast induced direct phenotypic maturation of monocyte-derived DCs (MDDCs) and enriched blood myeloid DCs (mDCs), but only indirectly matured blood plasmacytoid DCs (pDCs). Yeast-pulsed MDDCs and blood mDCs produced inflammatory cytokines and stimulated strong allo-reactive T cell proliferation. Both blood DC subsets internalized yeast, and when pulsed with yeast recombinant for HIV-1 Gag protein, both stimulated in vitro expansion of Gag-specific CD8+ memory T cells. These results suggest that S. cerevisiae yeast have potent adjuvant effects on human DCs. Furthermore, recombinant yeast-derived antigens are processed by human blood DCs for MHC class-I cross-presentation. These DC-targeting characteristics of yeast suggest that it may be an effective vaccine vector for induction of HIV-1-specific cellular immune responses.

Generation of a multimeric form of CD40L with potent immunostimulatory activity using streptavidin as a chaperon

Effective aggregation of cell surface immune receptors with their ligands is critical in promoting humoral and cellular immune responses. Simulation of these interactions using soluble multimeric ligands having potent adjuvant effects may prove an effective alternative to agonistic antibodies as immunotherapeutics. Multimeric ligands may effectively engage their receptors, leading to aggregation and effective signal transduction. We exploited the structural characteristics of streptavidin (SA) for the generation of multimeric chimeric proteins. Streptavidin forms stable tetramers and oligomers under physiological conditions, and, as such, chimeric molecules with SA are expected to possess similar features. Two chimeric molecules consisting of the extracellular domains of human and mouse CD40L and a modified form of core streptavidin were generated. These proteins form stable oligomers that could only be dissociated into monomers by heating at 100°C, but not 60°C, under denaturing conditions. The chimeric proteins vigorously stimulated B cells, monocytes, and dendritic cells for the production of cytokines and chemokines and upregulation of immunostimulatory molecules. The use of SA as a chaperon presents a novel approach to generate multimeric immunological molecules with potent activities and their use as potential therapeutics for the treatment of cancer and other immune-based disorders.

Cholera Toxin Indirectly Activates Human Monocyte-Derived Dendritic Cells In Vitro through the Production of Soluble Factors, Including Prostaglandin E2and Nitric Oxide

Cholera toxin (CT) is a potent adjuvant that activates dendritic cells (DC) by increasing intracellular cyclic AMP (cAMP) levels. In vivo and in vitro, very small amounts of CT induce potent adjuvant effects and activate DC. We hypothesized that DC intoxicated by CT may release factors that enhance their own maturation and induce the maturation of toxin-free bystander DC. Through the use of mixed cultures and transwell cultures, we found that human monocyte-derived DC (MDDC) pulsed with CT or other cAMP-elevating agonists induce the maturation of bystander DC. Many DC agonists including CT increase the production of prostaglandin E(2) (PGE(2)) and nitric oxide (NO). For this reason, we determined whether the actions of PGE(2) or NO are involved in the maturation of MDDC induced by CT or dibutyryl-cAMP (d-cAMP). We found that blocking the production of PGE(2) or blocking prostaglandin receptors inhibited MDDC maturation induced by CT and d-cAMP. Likewise, sequestering NO or blocking the downstream actions of NO resulted in the inhibition of MDDC maturation induced by CT and d-cAMP. These results indicate that endogenously produced factors including PGE(2) and NO contribute to the maturation of DC induced by CT and that these factors participate in bystander DC maturation. The results of this study may help explain why bacterial toxins that elevate cAMP are such potent adjuvants.

DNA vaccines in sheep: CTLA-4 mediated targeting and CpG motifs enhance immunogenicity in a DNA prime/protein boost strategy

DNA vaccines have proven to be an efficient means of inducing immune responses in small laboratory animals; however, their efficacy in large out-bred animal models has been much less promising. In addressing this issue, we have investigated the ability of ovine cytotoxic lymphocyte antigen 4 (CTLA-4) mediated targeting and ruminant specific CpG optimised plasmids, both alone and in combination, to enhance immune responses in sheep to the pro cathepsin B (FhCatB) antigen from Fasciola hepatica. In this study, CTLA-4 mediated targeting enhanced the speed and magnitude of the primary antibody response and effectively primed for a potent memory response compared to conventional DNA vaccination alone, which failed to induce a detectable immune response. While the CpG-augmentation of the CTLA-4 targeted construct did not further enhance the magnitude or isotype profile of the CTLA-4 induced antibody titres, it did result in the induction of significant antigen-specific, lymphocyte-proliferative responses that were not observed in any other treatment group, showing for the first time that significant cellular responses can be induced in sheep following DNA vaccination. In contrast, CpG-augmentation in the absence of CTLA-4 mediated targeting failed to induce a detectable immune response. This is the first study to explore the potential adjuvant effects of ruminant specific CpG motifs on DNA vaccine induced immune responses in sheep. The ability of CpG-augmented CTLA-4 mediated targeting to induce both humoral and cellular immune responses in this study suggests that this may be an effective approach for enhancing the efficacy of DNA vaccines in large out-bred animal models.

Hsp70-Like Protein 1 Fusion Protein Enhances Induction of Carcinoembryonic Antigen–Specific CD8+ CTL Response by Dendritic Cell Vaccine

Heat shock proteins (HSP) have been revealed to interact with antigen-presenting cells and have potent adjuvant capability to induce antigen-specific CD8+ CTL and Th1 responses. Our previous work shows how Hsp70-like protein 1 (Hsp70L1), as a new member of the Hsp70 subfamily, acts as potent Th1 adjuvant. Here, we report the efficient induction of tumor antigen-specific immune response by dendritic cells pulsed with recombinant fusion protein of Hsp70L1 and CEA(576-669) fragment of the carcinoembryonic antigen (CEA) containing CAP-1 (a HLA-A2-restricted CTL epitope). Fusion protein CEA(576-669)-Hsp70L1 can promote dendritic cell maturation and activate dendritic cells to produce cytokines, such as interleukin-12, interleukin-1beta, and tumor necrosis factor-alpha, and chemokines, such as macrophage inflammatory protein-1alpha, macrophage inflammatory protein-1beta, and regulated on activation, normal T expressed and secreted, indicating the adjuvant ability of Hsp70L1 in the fusion protein. CEA-specific HLA-A2.1-restricted CD8+ CTLs either from patients with CEA+/HLA-A2.1+ colon carcinoma or from splenocytes of immunized HLA-A2.1/Kb transgenic mice can be generated more efficiently after stimulations or immunizations with dendritic cells pulsed by CEA(576-669)-Hsp70L1 than with dendritic cells pulsed by CEA(576-669) alone, resulting in secreting more Th1 cytokine IFN-gamma and killing target cells more potently in an antigen-specific and HLA-A2.1-restricted manner. Adoptive transfer of splenocytes from transgenic mice immunized with CEA(576-669)-Hsp70L1-pulsed dendritic cells can inhibit tumor growth and prolong survival in nude mice bearing CEA+/HLA-A2.1+ human colon carcinoma more markedly. Therefore, Hsp70L1 has potent adjuvant effect in form of fusion protein, indicating that Hsp70L1 may be widely used as Th1 adjuvant to prepare antigenic fusion protein for the therapeutics of cancer or infectious diseases.

The co-administrating of recombinant porcine IL-2 could enhance protective immune responses to PRV inactivated vaccine in pigs

Three candidate cytokines: recombinant porcine interleukin-2 (rpIL-2), rpIL-6 and the fusion protein rpIL6-IL2 were used as adjuvants in this study to investigate the enhanced immune responses to PRV inactivated vaccine (IAV) in pigs. In this natural host trial, we demonstrated that rpIL-2 showed potential adjuvant effects on PRV IAV, which was characterized not only in antigen-specific immune responses, but also in protection against PRV infection. The use of rpIL-2 resulted in significantly higher virus neutralizing (VN) antibody levels and CTL activities on PRV IAV vaccination. The increased PRV-specific secretion of pIL-4 and pIFN-γ from PBMC of pigs also demonstrated the adjuvant effects of rpIL-2. In addition, the co-administration of the rpIL-2 also produced an improved protection to the viral challenge, demonstrated by significant reduction of the ratios of fever and viral excretion in nasal swabs. However, there was no additional effect of adjuvant induced enhancement of immune responses and protection against challenge with the use of rpIL-6 and rpIL6-IL2 in this study.

Effect of recombinantfowlpox virusexpressing chicken interferon-γ on active immunity induced by avian influenza vaccines of H5 subtype in chickens

AbstractTo evaluate the potential adjuvant effect of chicken interferon-γ (IFN-γ) expressed by recombinantfowlpox virus(rFPV–IFN-γ), SPF chickens and commercial chickens with (MAb+) and without (MAb−) maternal antibodies were immunized with rFPV–IFN-γ plus either H5 subtype avian influenza vaccine based on recombinantfowlpox virus(rFPV–HA) or conventional inactivated vaccine. In the assay of humoral responses, rFPV–IFN-γ plus vaccines induced a slightly lower titre of haemagglutinin inhibition (HI) antibody response than either rFPV–HA or inactivated vaccine alone, in both MAb−and MAb+chickens. As for protective efficacy, the combinations of rFPV–IFN-γ and both vaccines induced 95–100% protection against lethal challenge withhighly pathogenic avian influenza virusin SPF chickens and MAb−chickens, which were equal to those induced by either vaccine alone. However, immunization of MAb+chickens with 106pfu rFPV–HA plus 105pfu rFPV–IFN-γ showed higher protection efficacy (33.5%) than that (11.4–15.8%) induced by treatments with other dosage combinations. These findings show that IFN-γ expressed by recombinantfowlpox viruscould not promote HI antibody response induced by H5 avian influenza vaccines in chickens. The results also suggest that rFPV–IFN-γ enhances the protection of chickens in a dose-dependent and immune status-dependent manner.

Requirements for the development of IL-4-producing T cells during intestinal nematode infections: what it takes to make a Th2 cell in vivo.

Components of the type 2 immune response may mediate host protection against both helminthic parasites and harmful allergic responses. A central player in this response is the T-helper 2 (Th2) effector cell, which produces interleukin (IL)-4, IL-5, IL-13, and other Th2 cytokines during the primary and memory response. Specific aspects of the parasite that trigger Th2-cell differentiation are not yet defined. Furthermore, the cell types and cell surface and secreted molecules that provide the immune milieu required for the development of Th2 effector cells and also Th2 memory cells are not well understood. They will probably vary with the particular helminth or other antigen inducing the Th2 response. We have used third stage larvae of intestinal nematode parasites as adjuvants to promote naïve nonparasite antigen-specific T cells to differentiate into Th2 cells. This model system avoids possible parasite antigen-specific T-cell clones or cross-reactive memory T cells that may preferentially differentiate into Th2 effector cells during the course of infection and confound the stereotypical components of parasite-induced Th2 cell differentiation. We have found that these parasites have a potent adjuvant effect and have used our model system to begin to investigate the events that lead to the development of polarized Th2 cells in vivo.

Intranasal coadministration of the Cry1Ac protoxin with amoebal lysates increases protection against Naegleria fowleri meningoencephalitis.

Cry1Ac protoxin has potent mucosal and systemic adjuvant effects on antibody responses to proteins or polysaccharides. In this work, we examined whether Cry1Ac increased protective immunity against fatal Naegleria fowleri infection in mice, which resembles human primary amoebic meningoencephalitis. Higher immunoglobulin G (IgG) than IgA anti-N. fowleri responses were elicited in the serum and tracheopulmonary fluids of mice immunized by the intranasal or intraperitoneal route with N. fowleri lysates either alone or with Cry1Ac or cholera toxin. Superior protection against a lethal challenge with 5 x 10(4) live N. fowleri trophozoites was achieved for immunization by the intranasal route. Intranasal immunization of N. fowleri lysates coadministered with Cry1Ac increased survival to 100%; interestingly, immunization with Cry1Ac alone conferred similar protection to that achieved with amoebal lysates alone (60%). When mice intranasally immunized with Cry1Ac plus lysates were challenged with amoebae, both IgG and IgA mucosal responses were rapidly increased, but only the increased IgG response persisted until day 60 in surviving mice. The brief rise in the level of specific mucosal IgA does not exclude the role that this isotype may play in the early defense against this parasite, since higher IgA responses were detected in nasal fluids of mice intranasally immunized with lysates plus either Cry1Ac or cholera toxin, which, indeed, were the treatments that provided the major protection levels. In contrast, serum antibody responses do not seem to be related to the protection level achieved. Both acquired and innate immune systems seem to play a role in host defense against N. fowleri infection, but further studies are required to elucidate the mechanisms involved in protective effects conferred by Cry1Ac, which may be a valuable tool to improve mucosal vaccines.

CD40 antibody as an adjuvant induces enhanced T cell responses

Monoclonal antibodies against CD40, conjugated to antigen, act as potent immunological adjuvants for primary antibody responses. We show here that CD40mAbs can also act as strong adjuvants for memory antibody responses, and for T cell responses as measured by ex vivo T cell proliferation to antigen, and delayed type hypersensitivity. Interferon gamma secretion in response to antigen is also enhanced. Finally, the adjuvant effect of CD40mAbs for secondary antibody responses is transferred with T cells rather than B cells. CD40mAb apparently have potent adjuvant effects on both Th1-like cells, and on T cells able to promote B cell antibody production. It is possible that the adjuvant effects of CD40 are mediated at least in part, indirectly, through enhanced antigen presentation by specific B cells, to T cells.

Novel heat shock protein Hsp70L1 activates dendritic cells and acts as a Th1 polarizing adjuvant

AbstractHeat shock proteins (HSPs) are reported to act as effective adjuvants to elicit anti-tumor and anti-infection immunity. Here, we report that Hsp70-like protein 1 (Hsp70L1), a novel HSP derived from human dendritic cells (DCs), has potent adjuvant effects that polarize responses toward Th1. With a calculated molecular weight of 54.8 kDa, Hsp70L1 is smaller in size than Hsp70 but resembles it both structurally and functionally. Hsp70L1 shares common receptors on DCs with Hsp70 and can interact with DCs, promoting DC maturation and stimulating secretion of the proinflammatory cytokines interleukin 12p70 (IL-12p70), IL-1β, tumor necrosis factor-α (TNF-α), and the chemokines IP-10, macrophage inflammatory protein-1α (MIP-1α), MIP-1β, and normal T cell expressed and secreted (RANTES). The induction of interferon-γ–inducible protein 10 (IP-10) secretion by Hsp70L1 is not shared by Hsp70, and other functional differences include more potent stimulation of DC IL-12p70, CC-chemokine, and CCR7 and CXCR4 expression by Hsp70L1. Immunization of mice with the hybrid peptide Hsp70L1-ovalbumin(OVA)257-264 induces an OVA257-264-specific Th1 response and cytotoxic T lymphocyte (CTL) that results in significant inhibition of E.G7-OVA tumor growth. The ability of Hsp70L1 to activate DCs indicates its potential as a novel adjuvant for use with peptide immunizations; the Hsp70L1 antigen peptide hybrid may serve as a more effective vaccine for the control of cancer and infectious diseases.