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Articles 1 - 18 of 18
Full-Text Articles in Medicine and Health Sciences
Metabolic Diversity Of Human Macrophages: Potential Influence On Staphylococcus Aureus Intracellular Survival, Blake P. Bertrand, Dhananjay Shinde, Vinai C. Thomas, Marvin Whiteley, Carolyn B. Ibberson, Tammy Kielian
Metabolic Diversity Of Human Macrophages: Potential Influence On Staphylococcus Aureus Intracellular Survival, Blake P. Bertrand, Dhananjay Shinde, Vinai C. Thomas, Marvin Whiteley, Carolyn B. Ibberson, Tammy Kielian
Journal Articles: Pathology and Microbiology
Staphylococcus aureus is a leading cause of medical device-associated biofilm infections. This is influenced by the ability of S. aureus biofilm to evade the host immune response, which is partially driven by the anti-inflammatory cytokine interleukin-10 (IL-10). Here, we show that treatment of human monocyte-derived macrophages (HMDMs) with IL-10 enhanced biofilm formation, suggesting that macrophage anti-inflammatory programming likely plays an important role during the transition from planktonic to biofilm growth. To identify S. aureus genes that were important for intracellular survival in HMDMs and how this was affected by IL-10, transposon sequencing was performed. The size of the S. aureus …
Human Dectin-1 Deficiency Impairs Macrophage-Mediated Defense Against Phaeohyphomycosis, Rebecca A. Drummond, Jigar V. Desai, Amy P. Hsu, Vasileios Oikonomou, Donald C. Vinh, Joshua A. Acklin, Michael S. Abers, Magdalena A. Walkiewicz, Sarah L. Anzick, Muthulekha Swamydas, Simon Vautier, Mukil Natarajan, Andrew J. Oler, Daisuke Yamanaka, Katrin D. Mayer-Barber, Yoichiro Iwakura, David Bianchi, Brian Driscoll, Ken Hauck, Ahnika Kline, Nicholas S.P. Viall, Christa S. Zerbe, Elise M.N. Ferré, Monica M. Schmitt, Tom Dimaggio, Stefania Pittaluga, John A. Butman, Adrian M. Zelazny, Yvonne R. Shea, Cesar A. Arias, Cameron Ashbaugh, Maryam Mahmood, Zelalem Temesgen, Alexander G. Theofiles, Masayuki Nigo, Varsha Moudgal, Karen C. Bloch, Sean G. Kelly, M. Suzanne Whitworth, Ganesh Rao, Cindy J. Whitener, Neema Mafi, Juan Gea-Banacloche, Lawrence C. Kenyon, William R. Miller, Katia Boggian, Andrea Gilbert, Matthew Sincock, Alexandra F. Freeman, John E. Bennett, Rodrigo Hasbun, Constantinos M. Mikelis, Kyung J. Kwon-Chung, Yasmine Belkaid, Gordon D. Brown, Jean K. Lim, Douglas B. Kuhns, Steven M. Holland, Michail S. Lionakis
Human Dectin-1 Deficiency Impairs Macrophage-Mediated Defense Against Phaeohyphomycosis, Rebecca A. Drummond, Jigar V. Desai, Amy P. Hsu, Vasileios Oikonomou, Donald C. Vinh, Joshua A. Acklin, Michael S. Abers, Magdalena A. Walkiewicz, Sarah L. Anzick, Muthulekha Swamydas, Simon Vautier, Mukil Natarajan, Andrew J. Oler, Daisuke Yamanaka, Katrin D. Mayer-Barber, Yoichiro Iwakura, David Bianchi, Brian Driscoll, Ken Hauck, Ahnika Kline, Nicholas S.P. Viall, Christa S. Zerbe, Elise M.N. Ferré, Monica M. Schmitt, Tom Dimaggio, Stefania Pittaluga, John A. Butman, Adrian M. Zelazny, Yvonne R. Shea, Cesar A. Arias, Cameron Ashbaugh, Maryam Mahmood, Zelalem Temesgen, Alexander G. Theofiles, Masayuki Nigo, Varsha Moudgal, Karen C. Bloch, Sean G. Kelly, M. Suzanne Whitworth, Ganesh Rao, Cindy J. Whitener, Neema Mafi, Juan Gea-Banacloche, Lawrence C. Kenyon, William R. Miller, Katia Boggian, Andrea Gilbert, Matthew Sincock, Alexandra F. Freeman, John E. Bennett, Rodrigo Hasbun, Constantinos M. Mikelis, Kyung J. Kwon-Chung, Yasmine Belkaid, Gordon D. Brown, Jean K. Lim, Douglas B. Kuhns, Steven M. Holland, Michail S. Lionakis
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
Subcutaneous phaeohyphomycosis typically affects immunocompetent individuals following traumatic inoculation. Severe or disseminated infection can occur in CARD9 deficiency or after transplantation, but the mechanisms protecting against phaeohyphomycosis remain unclear. We evaluated a patient with progressive, refractory Corynespora cassiicola phaeohyphomycosis and found that he carried biallelic deleterious mutations in CLEC7A encoding the CARD9-coupled, β-glucan-binding receptor, Dectin-1. The patient's PBMCs failed to produce TNF-α and IL-1β in response to β-glucan and/or C. cassiicola. To confirm the cellular and molecular requirements for immunity against C. cassiicola, we developed a mouse model of this infection. Mouse macrophages required Dectin-1 and CARD9 for IL-1β and …
Caspase-8 Inactivation Drives Autophagy-Dependent Inflammasome Activation In Myeloid Cells., Yung-Hsuan Wu, Shu-Ting Mo, I-Ting Chen, Fu-Yi Hsieh, Shie-Liang Hsieh, Jianke Zhang, Ming-Zong Lai
Caspase-8 Inactivation Drives Autophagy-Dependent Inflammasome Activation In Myeloid Cells., Yung-Hsuan Wu, Shu-Ting Mo, I-Ting Chen, Fu-Yi Hsieh, Shie-Liang Hsieh, Jianke Zhang, Ming-Zong Lai
Department of Microbiology and Immunology Faculty Papers
Caspase-8 activity controls the switch from cell death to pyroptosis when apoptosis and necroptosis are blocked, yet how caspase-8 inactivation induces inflammasome assembly remains unclear. We show that caspase-8 inhibition via IETD treatment in Toll-like receptor (TLR)-primed Fadd-/-Ripk3-/- myeloid cells promoted interleukin-1β (IL-1β) and IL-18 production through inflammasome activation. Caspase-8, caspase-1/11, and functional GSDMD, but not NLRP3 or RIPK1 activity, proved essential for IETD-triggered inflammasome activation. Autophagy became prominent in IETD-treated Fadd-/-Ripk3-/- macrophages, and inhibiting it attenuated IETD-induced cell death and IL-1β/IL-18 production. In contrast, inhibiting GSDMD or autophagy did not prevent IETD-induced septic …
Multiple Autonomous Cell Death Suppression Strategies Ensure Cytomegalovirus Fitness, Pratyusha Mandal, Lynsey Nagrani, Liliana Hernandez, Anita Louise Mccormick, Christopher Dillon, Heather Koehler, Linda Roback, Emad S Alnemri, Douglas Green, Edward Mocarski
Multiple Autonomous Cell Death Suppression Strategies Ensure Cytomegalovirus Fitness, Pratyusha Mandal, Lynsey Nagrani, Liliana Hernandez, Anita Louise Mccormick, Christopher Dillon, Heather Koehler, Linda Roback, Emad S Alnemri, Douglas Green, Edward Mocarski
Department of Biochemistry and Molecular Biology Faculty Papers
Programmed cell death pathways eliminate infected cells and regulate infection-associated inflammation during pathogen invasion. Cytomegaloviruses encode several distinct suppressors that block intrinsic apoptosis, extrinsic apoptosis, and necroptosis, pathways that impact pathogenesis of this ubiquitous herpesvirus. Here, we expanded the understanding of three cell autonomous suppression mechanisms on which murine cytomegalovirus relies: (i) M38.5-encoded viral mitochon-drial inhibitor of apoptosis (vMIA), a BAX suppressor that functions in concert with M41.1-encoded viral inhibitor of BAK oligomerization (vIBO), (ii) M36-encoded viral inhibitor of caspase-8 activation (vICA), and (iii) M45-encoded viral inhibitor of RIP/RHIM activation (vIRA). Following infection of bone marrow-derived macrophages, the virus initially …
Staphylococcus Aureus Atp Synthase Promotes Biofilm Persistence By Influencing Innate Immunity, Megan E. Bosch, Blake P. Bertrand, Cortney E. Heim, Abdulelah A. Alqarzaee, Sujata S. Chaudhari, Amy L. Aldrich, Paul D. Fey, Vinai C. Thomas, Tammy Kielian
Staphylococcus Aureus Atp Synthase Promotes Biofilm Persistence By Influencing Innate Immunity, Megan E. Bosch, Blake P. Bertrand, Cortney E. Heim, Abdulelah A. Alqarzaee, Sujata S. Chaudhari, Amy L. Aldrich, Paul D. Fey, Vinai C. Thomas, Tammy Kielian
Journal Articles: Pathology and Microbiology
No abstract provided.
Caspase-11 Mediates Neutrophil Chemotaxis And Extracellular Trap Formation During Acute Gouty Arthritis Through Alteration Of Cofilin Phosphorylation, Kyle Caution, Nicholas Young, Frank Robledo-Avila, Kathrin Krause, Arwa Abu Khweek, Kaitlin Hamilton, Asmaa Badr, Anup Vaidya, Kylene Daily, Hawin Gosu, Midhun N. K. Anne, Mostafa Eltobgy, Duaa Dakhlallah, Sudha Argwal, Shady Estfanous, Xiaoli Zhang, Santiago Partida-Sanchez, Mikhail A. Gavrilin, Wael N. Jarjour, Amal O. Amer
Caspase-11 Mediates Neutrophil Chemotaxis And Extracellular Trap Formation During Acute Gouty Arthritis Through Alteration Of Cofilin Phosphorylation, Kyle Caution, Nicholas Young, Frank Robledo-Avila, Kathrin Krause, Arwa Abu Khweek, Kaitlin Hamilton, Asmaa Badr, Anup Vaidya, Kylene Daily, Hawin Gosu, Midhun N. K. Anne, Mostafa Eltobgy, Duaa Dakhlallah, Sudha Argwal, Shady Estfanous, Xiaoli Zhang, Santiago Partida-Sanchez, Mikhail A. Gavrilin, Wael N. Jarjour, Amal O. Amer
Faculty & Staff Scholarship
Gout is characterized by attacks of arthritis with hyperuricemia and monosodium urate (MSU) crystal-induced inflammation within joints. Innate immune responses are the primary drivers for tissue destruction and inflammation in gout. MSU crystals engage the Nlrp3 inflammasome, leading to the activation of caspase-1 and production of IL-1β and IL-18 within gout-affected joints, promoting the influx of neutrophils and monocytes. Here, we show that caspase-11−/− mice and their derived macrophages produce significantly reduced levels of gout-specific cytokines including IL-1β, TNFα, IL-6, and KC, while others like IFNγ and IL-12p70 are not altered. IL-1β induces the expression of caspase-11 in an IL-1 …
Parasite Manipulation Of The Invariant Chain And The Peptide Editor H2-Dm Affects Major Histocompatibility Complex Class Ii Antigen Presentation During Toxoplasma Gondii Infection, Louis-Philippe Leroux, Manami Nishi, Sandy El-Hage, Barbara A. Fox, David I Bzik, Florence Dzierszinsk
Parasite Manipulation Of The Invariant Chain And The Peptide Editor H2-Dm Affects Major Histocompatibility Complex Class Ii Antigen Presentation During Toxoplasma Gondii Infection, Louis-Philippe Leroux, Manami Nishi, Sandy El-Hage, Barbara A. Fox, David I Bzik, Florence Dzierszinsk
Dartmouth Scholarship
Toxoplasma gondii is an obligate intracellular protozoan parasite. This apicomplexan is the causative agent of toxoplasmosis, a leading cause of central nervous system disease in AIDS. It has long been known that T. gondii interferes with major histocompatibility complex class II (MHC-II) antigen presentation to attenuate CD4(+) T cell responses and establish persisting infections. Transcriptional downregulation of MHC-II genes by T. gondii was previously established, but the precise mechanisms inhibiting MHC-II function are currently unknown. Here, we show that, in addition to transcriptional regulation of MHC-II, the parasite modulates the expression of key components of the MHC-II antigen presentation pathway, …
Staphylococcus Aureus Biofilms Induce Macrophage Dysfunction Through Leukocidin Ab And Alpha-Toxin., Tyler D. Scherr, Mark L. Hanke, Ouwen Huang, David B.A. James, Alexander R. Horswill, Kenneth W. Bayles, Paul D. Fey, Victor J. Torres, Tammy Kielian
Staphylococcus Aureus Biofilms Induce Macrophage Dysfunction Through Leukocidin Ab And Alpha-Toxin., Tyler D. Scherr, Mark L. Hanke, Ouwen Huang, David B.A. James, Alexander R. Horswill, Kenneth W. Bayles, Paul D. Fey, Victor J. Torres, Tammy Kielian
Journal Articles: Pathology and Microbiology
UNLABELLED: The macrophage response to planktonic Staphylococcus aureus involves the induction of proinflammatory microbicidal activity. However, S. aureus biofilms can interfere with these responses in part by polarizing macrophages toward an anti-inflammatory profibrotic phenotype. Here we demonstrate that conditioned medium from mature S. aureus biofilms inhibited macrophage phagocytosis and induced cytotoxicity, suggesting the involvement of a secreted factor(s). Iterative testing found the active factor(s) to be proteinaceous and partially agr-dependent. Quantitative mass spectrometry identified alpha-toxin (Hla) and leukocidin AB (LukAB) as critical molecules secreted by S. aureus biofilms that inhibit murine macrophage phagocytosis and promote cytotoxicity. A role for Hla …
Prolonged-Acting, Multi-Targeting Gallium Nanoparticles Potently Inhibit Growth Of Both Hiv And Mycobacteria In Co-Infected Human Macrophages., Prabagaran Narayanasamy, Barbara L. Switzer, Bradley E. Britigan
Prolonged-Acting, Multi-Targeting Gallium Nanoparticles Potently Inhibit Growth Of Both Hiv And Mycobacteria In Co-Infected Human Macrophages., Prabagaran Narayanasamy, Barbara L. Switzer, Bradley E. Britigan
Journal Articles: Pathology and Microbiology
Human immunodeficiency virus (HIV) infection and Mycobacterium tuberculosis (TB) are responsible for two of the major global human infectious diseases that result in significant morbidity, mortality and socioeconomic impact. Furthermore, severity and disease prevention of both infections is enhanced by co-infection. Parallel limitations also exist in access to effective drug therapy and the emergence of resistance. Furthermore, drug-drug interactions have proven problematic during treatment of co-incident HIV and TB infections. Thus, improvements in drug access and simplified treatment regimens are needed immediately. One of the key host cells infected by both HIV and TB is the mononuclear phagocyte (MP; monocyte, …
Extracellular Traps Are Associated With Human And Mouse Neutrophil And Macrophage Mediated Killing Of Larval Strongyloides Stercoralis., Sandra Bonne-Annee, Laura A. Kerepesi, Jessica A. Hess, Jordan Wesolowski, Fabienne Paumet, James B. Lok, Thomas J. Nolan, David Abraham
Extracellular Traps Are Associated With Human And Mouse Neutrophil And Macrophage Mediated Killing Of Larval Strongyloides Stercoralis., Sandra Bonne-Annee, Laura A. Kerepesi, Jessica A. Hess, Jordan Wesolowski, Fabienne Paumet, James B. Lok, Thomas J. Nolan, David Abraham
Department of Microbiology and Immunology Faculty Papers
Neutrophils are multifaceted cells that are often the immune system's first line of defense. Human and murine cells release extracellular DNA traps (ETs) in response to several pathogens and diseases. Neutrophil extracellular trap (NET) formation is crucial to trapping and killing extracellular pathogens. Aside from neutrophils, macrophages and eosinophils also release ETs. We hypothesized that ETs serve as a mechanism of ensnaring the large and highly motile helminth parasite Strongyloides stercoralis thereby providing a static target for the immune response. We demonstrated that S. stercoralis larvae trigger the release of ETs by human neutrophils and macrophages. Analysis of NETs revealed …
Avirulent Strains Of Toxoplasma Gondii Infect Macrophages By Active Invasion From The Phagosome, Yanlin Zhao, Andrew H. Marple, David J. P. Ferguson, David J. Bzik, George S. Yap
Avirulent Strains Of Toxoplasma Gondii Infect Macrophages By Active Invasion From The Phagosome, Yanlin Zhao, Andrew H. Marple, David J. P. Ferguson, David J. Bzik, George S. Yap
Dartmouth Scholarship
Unlike most intracellular pathogens that gain access into host cells through endocytic pathways, Toxoplasma gondii initiates infection at the cell surface by active penetration through a moving junction and subsequent formation of a parasitophorous vacuole. Here, we describe a noncanonical pathway for T. gondii infection of macrophages, in which parasites are initially internalized through phagocytosis, and then actively invade from within a phagosomal compartment to form a parasitophorous vacuole. This phagosome to vacuole invasion (PTVI) pathway may represent an intermediary link between the endocytic and the penetrative routes for host cell entry by intracellular pathogens. The PTVI pathway is preferentially …
Step-Wise Loss Of Bacterial Flagellar Torsion Confers Progressive Phagocytic Evasion, Rustin R. Lovewell, Ryan M. Collins, Julie L. Acker, George A. O'Toole, Matthew J. Wargo, Brent Berwin, Craig R. Roy
Step-Wise Loss Of Bacterial Flagellar Torsion Confers Progressive Phagocytic Evasion, Rustin R. Lovewell, Ryan M. Collins, Julie L. Acker, George A. O'Toole, Matthew J. Wargo, Brent Berwin, Craig R. Roy
Dartmouth Scholarship
Phagocytosis of bacteria by innate immune cells is a primary method of bacterial clearance during infection. However, the mechanisms by which the host cell recognizes bacteria and consequentially initiates phagocytosis are largely unclear. Previous studies of the bacterium Pseudomonas aeruginosa have indicated that bacterial flagella and flagellar motility play an important role in colonization of the host and, importantly, that loss of flagellar motility enables phagocytic evasion. Here we use molecular, cellular, and genetic methods to provide the first formal evidence that phagocytic cells recognize bacterial motility rather than flagella and initiate phagocytosis in response to this motility. We demonstrate …
Role Of Phosphoinositide 3-Kinase – Akt Signaling Pathway In The Age-Related Cytokine Dysregulation In Splenic Macrophages Stimulated Via Tlr-2 Or Tlr-4 Receptors, Mosoka Papa Fallah, R. Lakshman Chelvarajan, Beth A. Garvy, Subbarao Bondada
Role Of Phosphoinositide 3-Kinase – Akt Signaling Pathway In The Age-Related Cytokine Dysregulation In Splenic Macrophages Stimulated Via Tlr-2 Or Tlr-4 Receptors, Mosoka Papa Fallah, R. Lakshman Chelvarajan, Beth A. Garvy, Subbarao Bondada
Microbiology, Immunology, and Molecular Genetics Faculty Publications
Age-associated defects in both B-lymphocytes and macrophages in elderly result in a reduction in the efficacy of vaccines to many Gram positive bacteria like Streptococcus pneumoniae. Splenic macrophages from aged mice have been shown to have a defect in production of pro-inflammatory cytokines (IL-6, IL-12, IL-1β, TNF-α) but exhibit increased production of IL-10 upon TLR4 ligation. Here we showed that aged macrophages demonstrate similar cytokine dysregulation phenotype upon stimulation with TLR2 ligands, or killed S. pneumoniae. We hypothesized that an age-associated increase in activity of phosphatidyl inositol 3-kinase (PI3K)-Akt signaling pathway may be playing a causal role in …
Myd88 Is Pivotal For Immune Recognition Of Citrobacter Koseri And Astrocyte Activation During Cns Infection., Shuliang Liu, Tammy Kielian
Myd88 Is Pivotal For Immune Recognition Of Citrobacter Koseri And Astrocyte Activation During Cns Infection., Shuliang Liu, Tammy Kielian
Journal Articles: Pathology and Microbiology
Citrobacter koseri (C. koseri) is a Gram-negative bacterium that can cause a highly aggressive form of neonatal meningitis, which often progresses to establish multi-focal brain abscesses. The roles of Toll-like receptor 4 (TLR4) and its signaling adaptor MyD88 during CNS C. koseri infection have not yet been examined, which is important since recent evidence indicates that innate immune responses are tailored towards specific pathogen classes. Here TLR4 WT (C3H/FeJ) and TLR4 mutant (C3H/HeJ) mice as well as MyD88 KO animals were infected intracerebrally with live C. koseri, resulting in meningitis and ventriculitis with accompanying brain abscess formation. MyD88 KO mice …
Il-4(-/-) Mice With Lethal Mesocestoides Corti Infections--Reduced Th2 Cytokines And Alternatively Activated Macrophages., A. E. O'Connell, L. A. Kerepesi, G. L. Vandergrift, D. R. Herbert, T J. Van Winkle, D. C. Hooper, E J. Pearce, D. Abraham
Il-4(-/-) Mice With Lethal Mesocestoides Corti Infections--Reduced Th2 Cytokines And Alternatively Activated Macrophages., A. E. O'Connell, L. A. Kerepesi, G. L. Vandergrift, D. R. Herbert, T J. Van Winkle, D. C. Hooper, E J. Pearce, D. Abraham
Department of Microbiology and Immunology Faculty Papers
Protection against Mesocestoides corti, a cestode that invades vital organs, is dependent on the production of IL-4, as IL-4(-/-) mice were found to have higher parasite burdens when compared with wild-type mice. The goal of this study was to investigate the role of IL-4 in immunity to M. corti, focusing on the immunological profile and on potential mediators of pathology. IL-4(-/-) mice infected with M. corti showed 100% mortality by 32 days, whereas wild-type mice survived for approximately 1 year. Parasite burdens were significantly increased in the liver, peritoneal, and thoracic cavities of IL-4(-/-) mice, associated with impaired recruitment of …
The Flagellum Of Pseudomonas Aeruginosa Is Required For Resistance To Clearance By Surfactant Protein A, Shiping Zhang, Francis X. Mccormack, Roger C. Levesque, George A. O'Toole, Gee W. Lau
The Flagellum Of Pseudomonas Aeruginosa Is Required For Resistance To Clearance By Surfactant Protein A, Shiping Zhang, Francis X. Mccormack, Roger C. Levesque, George A. O'Toole, Gee W. Lau
Dartmouth Scholarship
Surfactant protein A (SP-A) is an important lung innate immune protein that kills microbial pathogens by opsonization and membrane permeabilization. We investigated the basis of SP-A-mediated pulmonary clearance of Pseudomonas aeruginosa using genetically-engineered SP-A mice and a library of signature-tagged P. aeruginosa mutants. A mutant with an insertion into flgE, the gene that encodes flagellar hook protein, was preferentially cleared by the SP-A(+/+) mice, but survived in the SP-A(-/-) mice. Opsonization by SP-A did not play a role in flgE clearance. However, exposure to SP-A directly permeabilized and killed the flgE mutant, but not the wild-type parental strain. P. aeruginosa …
Characterization Of The Cd154-Positive And Cd40-Positive Cellular Subsets Required For Pathogenesis In Retrovirus-Induced Murine Immunodeficiency, Kathy A. Green, Randolph J. Noelle, Brigit G. Durell, William R. Green
Characterization Of The Cd154-Positive And Cd40-Positive Cellular Subsets Required For Pathogenesis In Retrovirus-Induced Murine Immunodeficiency, Kathy A. Green, Randolph J. Noelle, Brigit G. Durell, William R. Green
Dartmouth Scholarship
Genetically susceptible C57BL/6 (B6) mice that are infected with the LP-BM5 isolate of murine retroviruses develop profound splenomegaly, lymphadenopathy, hypergammaglobulinemia, terminal B-cell lymphomas, and an immunodeficiency state bearing many similarities to the pathologies seen in AIDS. Because of these similarities, this syndrome has been called murine AIDS (MAIDS). We have previously shown that CD154 (CD40 ligand)-CD40 molecular interactions are required both for the initiation and progression of MAIDS. Thus, in vivo anti-CD154 monoclonal antibody (MAb) treatment inhibited MAIDS symptoms in LP-BM5-infected wild-type mice when either a short course of anti-CD154 MAb treatment was started on the day of infection or …
Cellular Basis Of Decreased Immune Responses To Pneumococcal Vaccines In Aged Mice, Manju Garg, Wei Luo, Alan M. Kaplan, Subbarao Bondada
Cellular Basis Of Decreased Immune Responses To Pneumococcal Vaccines In Aged Mice, Manju Garg, Wei Luo, Alan M. Kaplan, Subbarao Bondada
Microbiology, Immunology, and Molecular Genetics Faculty Publications
Previously, model systems were developed in our laboratory to study murine immune responses to the 23-valent pneumococcal polysaccharide vaccine Pnu-Imune, both in vivo and in vitro (M. Garg and B. Subbarao, Infect. Immun. 60:2329-2336, 1992; M. Garg, A. M. Kaplan, and S. Bondada, J. Immunol. 152: 1589-1596, 1994). Using these systems, we found that aged mice did not respond to the vaccine in vivo or in vitro. Cell separation studies showed that the unresponsiveness of the aged spleen cells to the vaccine was not due to an intrinsic B-cell defect or to T-cell-mediated immunosuppression but resulted from an accessory cell …