Campylobacter jejuni is a major cause of infectious diarrhea worldwide. Increasing incidence of C... more Campylobacter jejuni is a major cause of infectious diarrhea worldwide. Increasing incidence of C. jejuni is attributed to new non-culture based detection methods and antibiotic resistance is unfortunately on the rise, necessitating development of interventions. Therapeutics development like vaccines have been hampered by lack of a small animal model that recapitulates campylobacteriosis symptoms. To better facilitate vaccine efficacy testing, we adapted a recently-published mouse C. jejuni infection model to adult mice fed a zinc-deficient diet and pre-treated with antibiotics prior to oral infection with C. jejuni strain 81–176. Non-vaccinated infected mice develop diarrhea, lose weight and show increased expression of fecal inflammatory markers indicating development of campylobacteriosis. We tested whether an 81–176 C. jejuni capsule conjugate vaccine delivered with a potent liposome adjuvant containing monophosphoryl lipid A and QS-21 known as ALFQ could protect mice against 81–176. Vaccinated mice developed high levels of anti-CPS IgG1 and IgG2b titers and serum bactericidal responses against 81–176. Vaccinated infected mice were protected against development of diarrhea, did not lose weight, and had significantly lower levels of fecal inflammatory marker expression. Importantly, vaccinated infected animals were protected against C. jejuni colonization indicating that parenteral vaccination with a conjugate vaccine plus the ALFQ adjuvant may provide protection against both C. jejuni disease and colonization. These promising results support further development of a multivalent C. jejuni conjugate vaccine platform delivered with potent adjuvant systems for use in human clinical studies.
ABSTRACT Introduction: An efficacious vaccine for HIV-1 has been sought for over 30 years to elim... more ABSTRACT Introduction: An efficacious vaccine for HIV-1 has been sought for over 30 years to eliminate the virus from the human population. Many challenges have occurred in the attempt to produce a successful immunogen, mainly caused by the basic biology of the virus. Immunogens have been developed focusing on inducing one or more of the following types of immune responses; neutralizing antibodies, non-neutralizing antibodies, and T-cell mediated responses. One way to better present and develop an immunogen for HIV-1 is through the use of nanotechnology and nanoparticles. Areas covered: This article gives a basic overview of the HIV-1 vaccine field, as well as nanotechnology, specifically nanovaccines. It then covers the application of nanovaccines made from biological macromolecules to HIV-1 vaccine development for neutralizing antibodies, non-neutralizing antibodies, and T-cell-mediated responses. Expert opinion: Nanovaccines are an area that is ripe for further exploration in HIV-1 vaccine field. Not only are nanovaccines capable of carrying and presenting antigens in native-like conformations, but they have also repeatedly been shown to increase immunogenicity over recombinant antigens alone. Only through further research can the true role of nanovaccines in the development of an efficacious HIV-1 vaccine be established.
International Journal of Pharmaceutics, Jul 1, 2019
Liposomes are potent adjuvant constituents for licensed vaccines and vaccine candidates and carri... more Liposomes are potent adjuvant constituents for licensed vaccines and vaccine candidates and carriers for drug delivery. Depending on the method of preparation, liposomes vary in size distribution, either forming uniform small size vesicles or a heterogeneous mixture of small to large vesicles. Importantly, differences in liposomal size have been demonstrated to induce differential immune responses. Determination of particle size distribution could therefore be crucial for the efficacy and stability of vaccine formulations. We compared the techniques of dynamic light scattering, laser diffraction, and conventional nanoparticle tracking analysis with a novel multispectral advanced nanoparticle tracking analysis (MANTA) for particle size determination of mono- and polydisperse liposomes. MANTA reported an average 146 nm size of monodisperse liposomes but showed a multimodal distribution of polydisperse liposomes with continuous sizes from 50 to 2000 nm. However, approximately 95% of particles were in the size range of 50-1500 nm and only few particles were identified in the 1500-2000 nm range for the investigated volume. Based on our results, we conclude that MANTA is the most suitable approach and can serve as stand-alone technique for particle size characterization of heterogeneous liposome samples in the 50-2000 nm size range.
An efficacious HIV-1 vaccine has remained an elusive target for almost 40 years. The sheer divers... more An efficacious HIV-1 vaccine has remained an elusive target for almost 40 years. The sheer diversity of the virus is one of the major roadblocks for vaccine development. HIV-1 frequently mutates and various strains predominate in different geographic regions, making the development of a globally applicable vaccine extremely difficult. Multiple approaches have been taken to overcome the issue of viral diversity, including sequence optimization, development of consensus and mosaic sequences and the use of different prime-boost approaches. To develop an efficacious vaccine, these approaches may need to be combined. One way to potentially synergize these approaches is to use a rationally designed protein nanoparticle that allows for the native-like presentation of antigens, such as the self-assembling protein nanoparticle.
The hypothesis that fibronectin binds the gangliosides G(,D1b) and G(,T1b) which are lost during ... more The hypothesis that fibronectin binds the gangliosides G(,D1b) and G(,T1b) which are lost during tumor metastasis was investigated. Fibronectin bound to erythrocytes and to 96 well dishes coated with gangliosides. The gangliosides, G(,D1a), G(,D1b), and G(,T1b) and mixed rat liver gangliosides bound fibronectin. The apparent dissociation constant for fibronectin binding to rat liver gangliosides was very similar to that of fibronectin binding to plasma membrane fractions isolated from rat liver. Analysis of the distribution of gangliosides in rat liver membrane fractions revealed that gangliosides were nonhomogeneously distributed. Approximately 85% of the total G(,D1b), G(,T1b) and G(,Q1b), but only 15% of the total G(,D1a), was present in the plasma membrane. Assuming a distribution in other cells and tissues similar to that in rat liver, the ganglioside G(,D1a), due to its intracellular localization, should be relatively unimportant in binding of fibronectin to the cell surface. In a series of squamous cell carcinomas and one mammary tumor, reductions in both fibronectin binding and the gangliosides G(,D1b) and G(,T1b) correlated with metastasis. No simple relationship among these three parameters, however, could be demonstrated in seven hepatomas and normal rat liver or eight lines of cultured cells. The complete lack of the gnagliosides G(,D1b) and G(,T1b), provides a demonstration of a block in the biosynthesis of the complex gangliosides of the disialoganglioside pathway in several transplantable and metastatic rodent tumors. In general, hepatomas with higher metastatic incidence bound less fibronectin than did the tumors with lower metastatic incidence. However, since fibronectin binding showed no simple relationship to ganglioside content and since fibronectin binding to rat liver plasma membranes was inhibited by proteases but was stimulated by neuraminidase, evidence for other fibronectin binding molecules was sought. Plasma membrane proteins of 220,000, 140,000, and 67,000 daltons bound fibronectin as demonstrated by western blots and gel overlays. These findings suggest that it may be necessary to evaluate simultaneously several parameters of the mammalian cell surface to account for reductions of fibronectin binding as one of the alterations that may contribute to metastatic ability
Campylobacter jejuni is a major cause of infectious diarrhea worldwide. Increasing incidence of C... more Campylobacter jejuni is a major cause of infectious diarrhea worldwide. Increasing incidence of C. jejuni is attributed to new non-culture based detection methods and antibiotic resistance is unfortunately on the rise, necessitating development of interventions. Therapeutics development like vaccines have been hampered by lack of a small animal model that recapitulates campylobacteriosis symptoms. To better facilitate vaccine efficacy testing, we adapted a recently-published mouse C. jejuni infection model to adult mice fed a zinc-deficient diet and pre-treated with antibiotics prior to oral infection with C. jejuni strain 81–176. Non-vaccinated infected mice develop diarrhea, lose weight and show increased expression of fecal inflammatory markers indicating development of campylobacteriosis. We tested whether an 81–176 C. jejuni capsule conjugate vaccine delivered with a potent liposome adjuvant containing monophosphoryl lipid A and QS-21 known as ALFQ could protect mice against 81–176. Vaccinated mice developed high levels of anti-CPS IgG1 and IgG2b titers and serum bactericidal responses against 81–176. Vaccinated infected mice were protected against development of diarrhea, did not lose weight, and had significantly lower levels of fecal inflammatory marker expression. Importantly, vaccinated infected animals were protected against C. jejuni colonization indicating that parenteral vaccination with a conjugate vaccine plus the ALFQ adjuvant may provide protection against both C. jejuni disease and colonization. These promising results support further development of a multivalent C. jejuni conjugate vaccine platform delivered with potent adjuvant systems for use in human clinical studies.
ABSTRACT Introduction: An efficacious vaccine for HIV-1 has been sought for over 30 years to elim... more ABSTRACT Introduction: An efficacious vaccine for HIV-1 has been sought for over 30 years to eliminate the virus from the human population. Many challenges have occurred in the attempt to produce a successful immunogen, mainly caused by the basic biology of the virus. Immunogens have been developed focusing on inducing one or more of the following types of immune responses; neutralizing antibodies, non-neutralizing antibodies, and T-cell mediated responses. One way to better present and develop an immunogen for HIV-1 is through the use of nanotechnology and nanoparticles. Areas covered: This article gives a basic overview of the HIV-1 vaccine field, as well as nanotechnology, specifically nanovaccines. It then covers the application of nanovaccines made from biological macromolecules to HIV-1 vaccine development for neutralizing antibodies, non-neutralizing antibodies, and T-cell-mediated responses. Expert opinion: Nanovaccines are an area that is ripe for further exploration in HIV-1 vaccine field. Not only are nanovaccines capable of carrying and presenting antigens in native-like conformations, but they have also repeatedly been shown to increase immunogenicity over recombinant antigens alone. Only through further research can the true role of nanovaccines in the development of an efficacious HIV-1 vaccine be established.
International Journal of Pharmaceutics, Jul 1, 2019
Liposomes are potent adjuvant constituents for licensed vaccines and vaccine candidates and carri... more Liposomes are potent adjuvant constituents for licensed vaccines and vaccine candidates and carriers for drug delivery. Depending on the method of preparation, liposomes vary in size distribution, either forming uniform small size vesicles or a heterogeneous mixture of small to large vesicles. Importantly, differences in liposomal size have been demonstrated to induce differential immune responses. Determination of particle size distribution could therefore be crucial for the efficacy and stability of vaccine formulations. We compared the techniques of dynamic light scattering, laser diffraction, and conventional nanoparticle tracking analysis with a novel multispectral advanced nanoparticle tracking analysis (MANTA) for particle size determination of mono- and polydisperse liposomes. MANTA reported an average 146 nm size of monodisperse liposomes but showed a multimodal distribution of polydisperse liposomes with continuous sizes from 50 to 2000 nm. However, approximately 95% of particles were in the size range of 50-1500 nm and only few particles were identified in the 1500-2000 nm range for the investigated volume. Based on our results, we conclude that MANTA is the most suitable approach and can serve as stand-alone technique for particle size characterization of heterogeneous liposome samples in the 50-2000 nm size range.
An efficacious HIV-1 vaccine has remained an elusive target for almost 40 years. The sheer divers... more An efficacious HIV-1 vaccine has remained an elusive target for almost 40 years. The sheer diversity of the virus is one of the major roadblocks for vaccine development. HIV-1 frequently mutates and various strains predominate in different geographic regions, making the development of a globally applicable vaccine extremely difficult. Multiple approaches have been taken to overcome the issue of viral diversity, including sequence optimization, development of consensus and mosaic sequences and the use of different prime-boost approaches. To develop an efficacious vaccine, these approaches may need to be combined. One way to potentially synergize these approaches is to use a rationally designed protein nanoparticle that allows for the native-like presentation of antigens, such as the self-assembling protein nanoparticle.
The hypothesis that fibronectin binds the gangliosides G(,D1b) and G(,T1b) which are lost during ... more The hypothesis that fibronectin binds the gangliosides G(,D1b) and G(,T1b) which are lost during tumor metastasis was investigated. Fibronectin bound to erythrocytes and to 96 well dishes coated with gangliosides. The gangliosides, G(,D1a), G(,D1b), and G(,T1b) and mixed rat liver gangliosides bound fibronectin. The apparent dissociation constant for fibronectin binding to rat liver gangliosides was very similar to that of fibronectin binding to plasma membrane fractions isolated from rat liver. Analysis of the distribution of gangliosides in rat liver membrane fractions revealed that gangliosides were nonhomogeneously distributed. Approximately 85% of the total G(,D1b), G(,T1b) and G(,Q1b), but only 15% of the total G(,D1a), was present in the plasma membrane. Assuming a distribution in other cells and tissues similar to that in rat liver, the ganglioside G(,D1a), due to its intracellular localization, should be relatively unimportant in binding of fibronectin to the cell surface. In a series of squamous cell carcinomas and one mammary tumor, reductions in both fibronectin binding and the gangliosides G(,D1b) and G(,T1b) correlated with metastasis. No simple relationship among these three parameters, however, could be demonstrated in seven hepatomas and normal rat liver or eight lines of cultured cells. The complete lack of the gnagliosides G(,D1b) and G(,T1b), provides a demonstration of a block in the biosynthesis of the complex gangliosides of the disialoganglioside pathway in several transplantable and metastatic rodent tumors. In general, hepatomas with higher metastatic incidence bound less fibronectin than did the tumors with lower metastatic incidence. However, since fibronectin binding showed no simple relationship to ganglioside content and since fibronectin binding to rat liver plasma membranes was inhibited by proteases but was stimulated by neuraminidase, evidence for other fibronectin binding molecules was sought. Plasma membrane proteins of 220,000, 140,000, and 67,000 daltons bound fibronectin as demonstrated by western blots and gel overlays. These findings suggest that it may be necessary to evaluate simultaneously several parameters of the mammalian cell surface to account for reductions of fibronectin binding as one of the alterations that may contribute to metastatic ability
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Papers by Gary Matyas