Neurological manifestations are a significant complication of coronavirus disease (COVID-19), but... more Neurological manifestations are a significant complication of coronavirus disease (COVID-19), but underlying mechanisms aren’t well understood. The development of animal models that recapitulate the neuropathological findings of autopsied brain tissue from patients who died from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are critical for elucidating the neuropathogenesis of infection and disease. Here, we show neuroinflammation, microhemorrhages, brain hypoxia, and neuropathology that is consistent with hypoxic-ischemic injury in SARS-CoV-2 infected non-human primates (NHPs), including evidence of neuron degeneration and apoptosis. Importantly, this is seen among infected animals that do not develop severe respiratory disease, which may provide insight into neurological symptoms associated with “long COVID”. Sparse virus is detected in brain endothelial cells but does not associate with the severity of central nervous system (CNS) injury. We anticipate ou...
The novel coronavirus SARS-CoV-2 has caused a worldwide pandemic resulting in widespread efforts ... more The novel coronavirus SARS-CoV-2 has caused a worldwide pandemic resulting in widespread efforts in development of animal models that recapitulate human disease for evaluation of medical countermeasures, and to dissect COVID-19 immunopathogenesis. We tested whether route of experimental infection substantially changes COVID-19 disease characteristics in two species (Macaca mulatta; rhesus macaques; RM, Chlorocebus atheiops; African green monkeys; AGM) of nonhuman primates. Species-specific cohorts of RM and AGM Rhesus macaques (Macaca mulatta, RMs) and African green monkeys (Chlorocebus aethiops, AGMs) were experimentally infected with homologous SARS-CoV-2 by either direct mucosal instillation or small particle aerosol in route-discrete subcohorts. Both species demonstrated equivalent infection initially by either exposure route although the magnitude and duration of viral loading was greater in AGMs than that of the RM. Clinical onset was nearly immediate (+1dpi) in mucosally-expo...
Frontiers in Cellular and Infection Microbiology, 2021
SARS-CoV-2 is a respiratory borne pathogenic beta coronavirus that is the source of a worldwide p... more SARS-CoV-2 is a respiratory borne pathogenic beta coronavirus that is the source of a worldwide pandemic and the cause of multiple pathologies in man. The rhesus macaque model of COVID-19 was utilized to test the added benefit of combinatory parenteral administration of two high-affinity anti-SARS-CoV-2 monoclonal antibodies (mAbs; C144-LS and C135-LS) expressly developed to neutralize the virus and modified to extend their pharmacokinetics. After completion of kinetics study of mAbs in the primate, combination treatment was administered prophylactically to mucosal viral challenge. Results showed near complete virus neutralization evidenced by no measurable titer in mucosal tissue swabs, muting of cytokine/chemokine response, and lack of any discernable pathologic sequalae. Blocking infection was a dose-related effect, cohorts receiving lower doses (6, 2 mg/kg) resulted in low grade viral infection in various mucosal sites compared to that of a fully protective dose (20 mg/kg). A su...
Chikungunya is an emerging threat, spreading across multiple continents. The immune response to i... more Chikungunya is an emerging threat, spreading across multiple continents. The immune response to infection can lead to protection and convalescence, or result in long term sequelae such as arthritis. Early innate immune events during acute infection have been characterized for some cell types, but more must be elucidated with respect to cellular responses of monocytes and other myeloid lineage cells. In addition to their roles in protection and inflammation resolution, monocytes and macrophages are sites for viral replication and reservoirs for the virus. They are also found in joints post-infection, possibly playing a role in long term CHIKV-induced pathology. We examined kinetic and phenotypic changes in myeloid lineage cells, including monocytes, in cynomolgus macaques early after infection with CHIKV. We found increased turnover of monocytes and mDCs early during infection, with an accompanying decreases in both cell types, as well as a simultaneous increase in pDC number. An inc...
Journal of Aerosol Medicine and Pulmonary Drug Delivery, 2021
Background: Bacillus Calmette-Guérin (BCG) is a vaccine used to protect against tuberculosis prim... more Background: Bacillus Calmette-Guérin (BCG) is a vaccine used to protect against tuberculosis primarily in infants to stop early infection in areas of the world where the disease is endemic. Normally administered as a percutaneous injection, BCG is a live significantly attenuated bacteria that is now being investigated for its potential within an inhalable vaccine formulation. This study investigates the feasibility and performance of two jet and two vibrating mesh nebulizers aerosolizing BCG and the resulting particle characteristics and residual viability of the bacteria postaerosolization. Methods: A jet nebulizer (Collison), outfitted either with a 3- or 6-jet head, was compared with two clinical nebulizers, the vibrating mesh Omron MicroAir and Aerogen Solo devices. Particle characteristics, including aerodynamic particle sizing, was performed on all devices within a common aerosol chamber configuration and comparable BCG innocula concentrations. Integrated aerosol samples were collected for each generator and assayed for bacterial viability using conventional microbiological technique. Results: A batch lot of BCG (Danish) was grown to titer and used in all generator assessments. Aerosol particles within the respirable range were generated from all nebulizers at four different concentrations of BCG. The jet nebulizers produced a uniformly smaller particle size than the vibrating mesh devices, although particle concentrations by mass were similar across all devices tested with the exception of the Aerogen Solo, which resulted in a low concentration of BCG aerosols. Conclusions: The resulting measured viable BCG aerosol concentration fraction produced by each device approximated one another; however, a measurable decrease of efficiency and overall viability reduction in the jet nebulizer was observed in higher BCG inoculum starting concentrations, whereas the vibrating mesh nebulizer returned a remarkably stable viable aerosol fraction irrespective of inoculum concentration.
Inhalation of ricin toxin (RT), a Category B biothreat agent, provokes an acute respiratory distr... more Inhalation of ricin toxin (RT), a Category B biothreat agent, provokes an acute respiratory distress syndrome marked by pro-inflammatory cytokine and chemokine production, neutrophilic exudate, and pulmonary edema. The severity of RT exposure is attributed to the tropism of the toxin’s B subunit (RTB) for alveolar macrophages and airway epithelial cells, coupled with the extraordinarily potent ribosome-inactivating properties of the toxin’s enzymatic subunit (RTA). While there are currently no vaccines or treatments approved to prevent RT intoxication, we recently described a humanized anti-RTA IgG1 MAb, huPB10, that was able to rescue non-human primates (NHPs) from lethal dose RT aerosol challenge if administered by intravenous (IV) infusion within hours of toxin exposure. We have now engineered an extended serum half-life variant of that MAb, huPB10-LS, and evaluated it as a pre-exposure prophylactic. Five Rhesus macaques that received a single intravenous infusion (25 mg/kg) of h...
Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococ... more Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococcus aureus that is the source for multiple pathologies in man. When purified and concentrated in aerosol form, SEB can cause an acute and often fatal intoxication, and thus is considered a biological threat agent. There are currently no vaccines or treatments approved for human use. Studies in rodent models of SEB intoxication show that antibody therapy may be a promising treatment strategy, however many have used antibodies only prophylactically or well before any clinical signs of intoxication are apparent. We assessed and compared the protective efficacy of two monoclonal antibodies, Ig121 and c19F1, when administered after aerosol exposure in a uniformly lethal nonhuman primate model of SEB intoxication. Rhesus macaques were challenged using small particle aerosols of SEB, and then were infused intravenously with a single dose of either Ig121 or c19F1 (10 mg/kg) at either 0.5, 2 or 4...
Ricin toxin (RT) ranks at the top of the list of potential bioweapons of concern to civilian and ... more Ricin toxin (RT) ranks at the top of the list of potential bioweapons of concern to civilian and military personnel alike due to its high potential for morbidity and mortality after inhalation. In non-human primates, aerosolized ricin triggers a severe acute respiratory distress characterized by perivascular and alveolar edema, neutrophilic infiltration, and severe necrotizing bronchiolitis and alveolitis. There are currently no approved countermeasures for ricin intoxication. In this report, we demonstrate the therapeutic potential of huPB10, a toxin-neutralizing humanized monoclonal antibody (MAb) against an immunodominant epitope on ricin’s enzymatic A chain (RTA). Five rhesus macaques that received intravenous huPB10 (10 mg/kg) four hours after lethal dose ricin aerosol exposure all survived the toxin challenge, as compared to control animals, which succumbed to ricin intoxication within 30 h. Antibody treatment at 12 h after ricin exposure resulted in the survival of only one o...
Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococ... more Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococcus aureus that is the source for multiple pathologies in humans. When purified and concentrated in aerosol form, SEB can cause an acute and often fatal intoxication and thus is considered a biological threat agent.
Proceedings of the National Academy of Sciences of the United States of America, Sep 6, 2016
The synergy between Mycobacterium tuberculosis (Mtb) and HIV in coinfected patients has profoundl... more The synergy between Mycobacterium tuberculosis (Mtb) and HIV in coinfected patients has profoundly impacted global mortality because of tuberculosis (TB) and AIDS. HIV significantly increases rates of reactivation of latent TB infection (LTBI) to active disease, with the decline in CD4(+) T cells believed to be the major causality. In this study, nonhuman primates were coinfected with Mtb and simian immunodeficiency virus (SIV), recapitulating human coinfection. A majority of animals exhibited rapid reactivation of Mtb replication, progressing to disseminated TB and increased SIV-associated pathology. Although a severe loss of pulmonary CD4(+) T cells was observed in all coinfected macaques, a subpopulation of the animals was still able to prevent reactivation and maintain LTBI. Investigation of pulmonary immune responses and pathology in this cohort demonstrated that increased CD8(+) memory T-cell proliferation, higher granzyme B production, and expanded B-cell follicles correlated...
Tuberculosis (TB) is a global pandaemic, partially due to the failure of vaccination approaches. ... more Tuberculosis (TB) is a global pandaemic, partially due to the failure of vaccination approaches. Novel anti-TB vaccines are therefore urgently required. Here we show that aerosol immunization of macaques with the Mtb mutant in SigH (MtbΔsigH) results in significant recruitment of inducible bronchus-associated lymphoid tissue (iBALT) as well as CD4+ and CD8+ T cells expressing activation and proliferation markers to the lungs. Further, the findings indicate that pulmonary vaccination with MtbΔsigH elicited strong central memory CD4+ and CD8+ T-cell responses in the lung. Vaccination with MtbΔsigH results in significant protection against a lethal TB challenge, as evidenced by an approximately three log reduction in bacterial burdens, significantly diminished clinical manifestations and granulomatous pathology and characterized by the presence of profound iBALT. This highly protective response is virtually absent in unvaccinated and BCG-vaccinated animals after challenge. These result...
Chikungunya, "that which bends up" in the Makonde dialect, is an emerging global health... more Chikungunya, "that which bends up" in the Makonde dialect, is an emerging global health threat, with increasing incidence of neurological complications. Until 2013, Chikungunya infection had been largely restricted to East Africa and the Indian Ocean, with cases within the USA reported to be from foreign travel. However, in 2014, over 1 million suspected cases were reported in the Americas, and a recently infected human could serve as an unwitting reservoir for the virus resulting in an epidemic in the continental USA. Chikungunya infection is increasingly being associated with neurological sequelae. In this study, we sought to understand the role of astrocytes in the neuropathogenesis of Chikungunya infection. Even after virus has been cleared form the circulation, astrocytes were activated with regard to TLR2 expression. In addition, white matter astrocytes were hypertrophic, with increased arbor volume in gray matter astrocytes. Combined, these would alter the number an...
American journal of respiratory and critical care medicine, Jan 2, 2015
Rationale: Hypoxia promotes dormancy by causing physiological changes to actively replicating Myc... more Rationale: Hypoxia promotes dormancy by causing physiological changes to actively replicating Mycobacterium tuberculosis (Mtb). DosR controls the response of Mtb to hypoxia. Objectives: To understand its contribution in the persistence of Mtb, we compared the phenotype of various DosR regulon mutants and a complemented strain, to Mtb in macaques, which faithfully model Mtb infection. Methods: We measured clinical and microbiological correlates of infection with Mtb, relative to mutant/complemented strains in the DosR regulon, studied lung pathology and hypoxia and compared immune responses in lung, using transcriptomics and flow-cytometry. Measurements and Main Results: Despite being able to replicate initially, mutants in DosR regulon failed to persist or cause disease. On the contrary, Mtb and a complemented strain were able to establish infection and TB. The attenuation of pathogenesis in animals infected with the mutants coincided with the appearance of a Th1 response and organi...
Journal of immunology (Baltimore, Md. : 1950), Jan 15, 2014
Development of a vaccine against pulmonary tuberculosis may require immunization strategies that ... more Development of a vaccine against pulmonary tuberculosis may require immunization strategies that induce a high frequency of Ag-specific CD4 and CD8 T cells in the lung. The nonhuman primate model is essential for testing such approaches because it has predictive value for how vaccines elicit responses in humans. In this study, we used an aerosol vaccination strategy to administer AERAS-402, a replication-defective recombinant adenovirus (rAd) type 35 expressing Mycobacterium tuberculosis Ags Ag85A, Ag85B, and TB10.4, in bacillus Calmette-Guérin (BCG)-primed or unprimed rhesus macaques. Immunization with BCG generated low purified protein derivative-specific CD4 T cell responses in blood and bronchoalveolar lavage. In contrast, aerosolized AERAS-402 alone or following BCG induced potent and stable Ag85A/b-specific CD4 and CD8 effector T cells in bronchoalveolar lavage that largely produced IFN-γ, as well as TNF and IL-2. Such responses induced by BCG, AERAS-402, or both failed to con...
D24. TUBERCULOSIS TREATMENT AND OUTCOMES: ANIMAL AND HUMAN STUDIES, 2010
Tulane University, Covington, LA, United States of America, Nanotherapeutics, Alachua, FL, United... more Tulane University, Covington, LA, United States of America, Nanotherapeutics, Alachua, FL, United States of America 1 ... Tuberculosis continues to kill over 1.8 million people each year despite continuous use of the currently available Introduction: treatments. New drugs and ...
Ricin toxin, a type 2 ribosome-inactivating protein and a category B bioterrorism agent, is produ... more Ricin toxin, a type 2 ribosome-inactivating protein and a category B bioterrorism agent, is produced from the seeds of castor oil plant ( Ricinus communis). Chronic pathological changes in survivors of aerosolized ricin exposure have not been reported in primates. Here we compare and contrast the pathological changes manifested between rhesus macaques (RM) that succumbed to lethal dose of ricin (group I) and survivor RM exposed to low dose of ricin (group II). All animals in group I exhibited severe diffuse, necrotizing bronchiolitis and alveolitis with fibrinopurulent bronchointerstitial pneumonia, massive alveolar, perivascular and peribronchial/bronchiolar edema with hemorrhage, and necropurulent and hemorrhagic tracheobronchial lymphadenitis. All animals from group II had multifocal, fibrosing interstitial pneumonia with prominent alveolar histiocytosis and type II pneumocyte hyperplasia. Subacute changes like infiltration by lymphocytes and plasma cells and persistence of edema...
Neurological manifestations are a significant complication of coronavirus disease (COVID-19), but... more Neurological manifestations are a significant complication of coronavirus disease (COVID-19), but underlying mechanisms aren’t well understood. The development of animal models that recapitulate the neuropathological findings of autopsied brain tissue from patients who died from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are critical for elucidating the neuropathogenesis of infection and disease. Here, we show neuroinflammation, microhemorrhages, brain hypoxia, and neuropathology that is consistent with hypoxic-ischemic injury in SARS-CoV-2 infected non-human primates (NHPs), including evidence of neuron degeneration and apoptosis. Importantly, this is seen among infected animals that do not develop severe respiratory disease, which may provide insight into neurological symptoms associated with “long COVID”. Sparse virus is detected in brain endothelial cells but does not associate with the severity of central nervous system (CNS) injury. We anticipate ou...
The novel coronavirus SARS-CoV-2 has caused a worldwide pandemic resulting in widespread efforts ... more The novel coronavirus SARS-CoV-2 has caused a worldwide pandemic resulting in widespread efforts in development of animal models that recapitulate human disease for evaluation of medical countermeasures, and to dissect COVID-19 immunopathogenesis. We tested whether route of experimental infection substantially changes COVID-19 disease characteristics in two species (Macaca mulatta; rhesus macaques; RM, Chlorocebus atheiops; African green monkeys; AGM) of nonhuman primates. Species-specific cohorts of RM and AGM Rhesus macaques (Macaca mulatta, RMs) and African green monkeys (Chlorocebus aethiops, AGMs) were experimentally infected with homologous SARS-CoV-2 by either direct mucosal instillation or small particle aerosol in route-discrete subcohorts. Both species demonstrated equivalent infection initially by either exposure route although the magnitude and duration of viral loading was greater in AGMs than that of the RM. Clinical onset was nearly immediate (+1dpi) in mucosally-expo...
Frontiers in Cellular and Infection Microbiology, 2021
SARS-CoV-2 is a respiratory borne pathogenic beta coronavirus that is the source of a worldwide p... more SARS-CoV-2 is a respiratory borne pathogenic beta coronavirus that is the source of a worldwide pandemic and the cause of multiple pathologies in man. The rhesus macaque model of COVID-19 was utilized to test the added benefit of combinatory parenteral administration of two high-affinity anti-SARS-CoV-2 monoclonal antibodies (mAbs; C144-LS and C135-LS) expressly developed to neutralize the virus and modified to extend their pharmacokinetics. After completion of kinetics study of mAbs in the primate, combination treatment was administered prophylactically to mucosal viral challenge. Results showed near complete virus neutralization evidenced by no measurable titer in mucosal tissue swabs, muting of cytokine/chemokine response, and lack of any discernable pathologic sequalae. Blocking infection was a dose-related effect, cohorts receiving lower doses (6, 2 mg/kg) resulted in low grade viral infection in various mucosal sites compared to that of a fully protective dose (20 mg/kg). A su...
Chikungunya is an emerging threat, spreading across multiple continents. The immune response to i... more Chikungunya is an emerging threat, spreading across multiple continents. The immune response to infection can lead to protection and convalescence, or result in long term sequelae such as arthritis. Early innate immune events during acute infection have been characterized for some cell types, but more must be elucidated with respect to cellular responses of monocytes and other myeloid lineage cells. In addition to their roles in protection and inflammation resolution, monocytes and macrophages are sites for viral replication and reservoirs for the virus. They are also found in joints post-infection, possibly playing a role in long term CHIKV-induced pathology. We examined kinetic and phenotypic changes in myeloid lineage cells, including monocytes, in cynomolgus macaques early after infection with CHIKV. We found increased turnover of monocytes and mDCs early during infection, with an accompanying decreases in both cell types, as well as a simultaneous increase in pDC number. An inc...
Journal of Aerosol Medicine and Pulmonary Drug Delivery, 2021
Background: Bacillus Calmette-Guérin (BCG) is a vaccine used to protect against tuberculosis prim... more Background: Bacillus Calmette-Guérin (BCG) is a vaccine used to protect against tuberculosis primarily in infants to stop early infection in areas of the world where the disease is endemic. Normally administered as a percutaneous injection, BCG is a live significantly attenuated bacteria that is now being investigated for its potential within an inhalable vaccine formulation. This study investigates the feasibility and performance of two jet and two vibrating mesh nebulizers aerosolizing BCG and the resulting particle characteristics and residual viability of the bacteria postaerosolization. Methods: A jet nebulizer (Collison), outfitted either with a 3- or 6-jet head, was compared with two clinical nebulizers, the vibrating mesh Omron MicroAir and Aerogen Solo devices. Particle characteristics, including aerodynamic particle sizing, was performed on all devices within a common aerosol chamber configuration and comparable BCG innocula concentrations. Integrated aerosol samples were collected for each generator and assayed for bacterial viability using conventional microbiological technique. Results: A batch lot of BCG (Danish) was grown to titer and used in all generator assessments. Aerosol particles within the respirable range were generated from all nebulizers at four different concentrations of BCG. The jet nebulizers produced a uniformly smaller particle size than the vibrating mesh devices, although particle concentrations by mass were similar across all devices tested with the exception of the Aerogen Solo, which resulted in a low concentration of BCG aerosols. Conclusions: The resulting measured viable BCG aerosol concentration fraction produced by each device approximated one another; however, a measurable decrease of efficiency and overall viability reduction in the jet nebulizer was observed in higher BCG inoculum starting concentrations, whereas the vibrating mesh nebulizer returned a remarkably stable viable aerosol fraction irrespective of inoculum concentration.
Inhalation of ricin toxin (RT), a Category B biothreat agent, provokes an acute respiratory distr... more Inhalation of ricin toxin (RT), a Category B biothreat agent, provokes an acute respiratory distress syndrome marked by pro-inflammatory cytokine and chemokine production, neutrophilic exudate, and pulmonary edema. The severity of RT exposure is attributed to the tropism of the toxin’s B subunit (RTB) for alveolar macrophages and airway epithelial cells, coupled with the extraordinarily potent ribosome-inactivating properties of the toxin’s enzymatic subunit (RTA). While there are currently no vaccines or treatments approved to prevent RT intoxication, we recently described a humanized anti-RTA IgG1 MAb, huPB10, that was able to rescue non-human primates (NHPs) from lethal dose RT aerosol challenge if administered by intravenous (IV) infusion within hours of toxin exposure. We have now engineered an extended serum half-life variant of that MAb, huPB10-LS, and evaluated it as a pre-exposure prophylactic. Five Rhesus macaques that received a single intravenous infusion (25 mg/kg) of h...
Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococ... more Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococcus aureus that is the source for multiple pathologies in man. When purified and concentrated in aerosol form, SEB can cause an acute and often fatal intoxication, and thus is considered a biological threat agent. There are currently no vaccines or treatments approved for human use. Studies in rodent models of SEB intoxication show that antibody therapy may be a promising treatment strategy, however many have used antibodies only prophylactically or well before any clinical signs of intoxication are apparent. We assessed and compared the protective efficacy of two monoclonal antibodies, Ig121 and c19F1, when administered after aerosol exposure in a uniformly lethal nonhuman primate model of SEB intoxication. Rhesus macaques were challenged using small particle aerosols of SEB, and then were infused intravenously with a single dose of either Ig121 or c19F1 (10 mg/kg) at either 0.5, 2 or 4...
Ricin toxin (RT) ranks at the top of the list of potential bioweapons of concern to civilian and ... more Ricin toxin (RT) ranks at the top of the list of potential bioweapons of concern to civilian and military personnel alike due to its high potential for morbidity and mortality after inhalation. In non-human primates, aerosolized ricin triggers a severe acute respiratory distress characterized by perivascular and alveolar edema, neutrophilic infiltration, and severe necrotizing bronchiolitis and alveolitis. There are currently no approved countermeasures for ricin intoxication. In this report, we demonstrate the therapeutic potential of huPB10, a toxin-neutralizing humanized monoclonal antibody (MAb) against an immunodominant epitope on ricin’s enzymatic A chain (RTA). Five rhesus macaques that received intravenous huPB10 (10 mg/kg) four hours after lethal dose ricin aerosol exposure all survived the toxin challenge, as compared to control animals, which succumbed to ricin intoxication within 30 h. Antibody treatment at 12 h after ricin exposure resulted in the survival of only one o...
Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococ... more Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococcus aureus that is the source for multiple pathologies in humans. When purified and concentrated in aerosol form, SEB can cause an acute and often fatal intoxication and thus is considered a biological threat agent.
Proceedings of the National Academy of Sciences of the United States of America, Sep 6, 2016
The synergy between Mycobacterium tuberculosis (Mtb) and HIV in coinfected patients has profoundl... more The synergy between Mycobacterium tuberculosis (Mtb) and HIV in coinfected patients has profoundly impacted global mortality because of tuberculosis (TB) and AIDS. HIV significantly increases rates of reactivation of latent TB infection (LTBI) to active disease, with the decline in CD4(+) T cells believed to be the major causality. In this study, nonhuman primates were coinfected with Mtb and simian immunodeficiency virus (SIV), recapitulating human coinfection. A majority of animals exhibited rapid reactivation of Mtb replication, progressing to disseminated TB and increased SIV-associated pathology. Although a severe loss of pulmonary CD4(+) T cells was observed in all coinfected macaques, a subpopulation of the animals was still able to prevent reactivation and maintain LTBI. Investigation of pulmonary immune responses and pathology in this cohort demonstrated that increased CD8(+) memory T-cell proliferation, higher granzyme B production, and expanded B-cell follicles correlated...
Tuberculosis (TB) is a global pandaemic, partially due to the failure of vaccination approaches. ... more Tuberculosis (TB) is a global pandaemic, partially due to the failure of vaccination approaches. Novel anti-TB vaccines are therefore urgently required. Here we show that aerosol immunization of macaques with the Mtb mutant in SigH (MtbΔsigH) results in significant recruitment of inducible bronchus-associated lymphoid tissue (iBALT) as well as CD4+ and CD8+ T cells expressing activation and proliferation markers to the lungs. Further, the findings indicate that pulmonary vaccination with MtbΔsigH elicited strong central memory CD4+ and CD8+ T-cell responses in the lung. Vaccination with MtbΔsigH results in significant protection against a lethal TB challenge, as evidenced by an approximately three log reduction in bacterial burdens, significantly diminished clinical manifestations and granulomatous pathology and characterized by the presence of profound iBALT. This highly protective response is virtually absent in unvaccinated and BCG-vaccinated animals after challenge. These result...
Chikungunya, "that which bends up" in the Makonde dialect, is an emerging global health... more Chikungunya, "that which bends up" in the Makonde dialect, is an emerging global health threat, with increasing incidence of neurological complications. Until 2013, Chikungunya infection had been largely restricted to East Africa and the Indian Ocean, with cases within the USA reported to be from foreign travel. However, in 2014, over 1 million suspected cases were reported in the Americas, and a recently infected human could serve as an unwitting reservoir for the virus resulting in an epidemic in the continental USA. Chikungunya infection is increasingly being associated with neurological sequelae. In this study, we sought to understand the role of astrocytes in the neuropathogenesis of Chikungunya infection. Even after virus has been cleared form the circulation, astrocytes were activated with regard to TLR2 expression. In addition, white matter astrocytes were hypertrophic, with increased arbor volume in gray matter astrocytes. Combined, these would alter the number an...
American journal of respiratory and critical care medicine, Jan 2, 2015
Rationale: Hypoxia promotes dormancy by causing physiological changes to actively replicating Myc... more Rationale: Hypoxia promotes dormancy by causing physiological changes to actively replicating Mycobacterium tuberculosis (Mtb). DosR controls the response of Mtb to hypoxia. Objectives: To understand its contribution in the persistence of Mtb, we compared the phenotype of various DosR regulon mutants and a complemented strain, to Mtb in macaques, which faithfully model Mtb infection. Methods: We measured clinical and microbiological correlates of infection with Mtb, relative to mutant/complemented strains in the DosR regulon, studied lung pathology and hypoxia and compared immune responses in lung, using transcriptomics and flow-cytometry. Measurements and Main Results: Despite being able to replicate initially, mutants in DosR regulon failed to persist or cause disease. On the contrary, Mtb and a complemented strain were able to establish infection and TB. The attenuation of pathogenesis in animals infected with the mutants coincided with the appearance of a Th1 response and organi...
Journal of immunology (Baltimore, Md. : 1950), Jan 15, 2014
Development of a vaccine against pulmonary tuberculosis may require immunization strategies that ... more Development of a vaccine against pulmonary tuberculosis may require immunization strategies that induce a high frequency of Ag-specific CD4 and CD8 T cells in the lung. The nonhuman primate model is essential for testing such approaches because it has predictive value for how vaccines elicit responses in humans. In this study, we used an aerosol vaccination strategy to administer AERAS-402, a replication-defective recombinant adenovirus (rAd) type 35 expressing Mycobacterium tuberculosis Ags Ag85A, Ag85B, and TB10.4, in bacillus Calmette-Guérin (BCG)-primed or unprimed rhesus macaques. Immunization with BCG generated low purified protein derivative-specific CD4 T cell responses in blood and bronchoalveolar lavage. In contrast, aerosolized AERAS-402 alone or following BCG induced potent and stable Ag85A/b-specific CD4 and CD8 effector T cells in bronchoalveolar lavage that largely produced IFN-γ, as well as TNF and IL-2. Such responses induced by BCG, AERAS-402, or both failed to con...
D24. TUBERCULOSIS TREATMENT AND OUTCOMES: ANIMAL AND HUMAN STUDIES, 2010
Tulane University, Covington, LA, United States of America, Nanotherapeutics, Alachua, FL, United... more Tulane University, Covington, LA, United States of America, Nanotherapeutics, Alachua, FL, United States of America 1 ... Tuberculosis continues to kill over 1.8 million people each year despite continuous use of the currently available Introduction: treatments. New drugs and ...
Ricin toxin, a type 2 ribosome-inactivating protein and a category B bioterrorism agent, is produ... more Ricin toxin, a type 2 ribosome-inactivating protein and a category B bioterrorism agent, is produced from the seeds of castor oil plant ( Ricinus communis). Chronic pathological changes in survivors of aerosolized ricin exposure have not been reported in primates. Here we compare and contrast the pathological changes manifested between rhesus macaques (RM) that succumbed to lethal dose of ricin (group I) and survivor RM exposed to low dose of ricin (group II). All animals in group I exhibited severe diffuse, necrotizing bronchiolitis and alveolitis with fibrinopurulent bronchointerstitial pneumonia, massive alveolar, perivascular and peribronchial/bronchiolar edema with hemorrhage, and necropurulent and hemorrhagic tracheobronchial lymphadenitis. All animals from group II had multifocal, fibrosing interstitial pneumonia with prominent alveolar histiocytosis and type II pneumocyte hyperplasia. Subacute changes like infiltration by lymphocytes and plasma cells and persistence of edema...
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