Proteomic Identification ofsaeRS-Dependent Targets Critical for Protective Humoral Immunity against Staphylococcus aureus Skin Infection

RecurrentStaphylococcus aureusskin and soft tissue infections (SSTIs) are common despite detectable antibody responses, leading to the belief that the immune response elicited by these infections is not protective. We recently reported thatS. aureusUSA300 SSTI elicits antibodies that protect against recurrent SSTI in BALB/c but not C57BL/6 mice, and in this study, we aimed to uncover the specificity of the protective antibodies. Using a proteomic approach, we found thatS. aureusSSTI elicited broad polyclonal antibody responses in both BALB/c and C57BL/6 mice and identified 10S. aureusantigens against which antibody levels were significantly higher in immune BALB/c serum. Four of the 10 antigens identified are regulated by thesaeRSoperon, suggesting a dominant role forsaeRSin protection. Indeed, infection with USA300Δsaefailed to protect against secondary SSTI with USA300, despite eliciting a strong polyclonal antibody response against antigens whose expression is not regulated bysaeRS. Moreover, the antibody repertoire after infection with USA300Δsaelacked antibodies specific for 10saeRS-regulated antigens, suggesting that all or a subset of these antigens are necessary to elicit protective immunity. Infection with USA300Δhlaelicited modest protection against secondary SSTI, and complementation of USA300Δsaewithhlarestored protection but incompletely. Together, these findings support a role for both Hla and othersaeRS-regulated antigens in eliciting protection and suggest that host differences in immune responses tosaeRS-regulated antigens may determine whetherS. aureusinfection elicits protective or nonprotective immunity against recurrent infection.

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Protective Immunity against Recurrent Staphylococcus aureus Skin Infection Requires Antibody and Interleukin-17A

Infection and Immunity ◽

10.1128/iai.01491-14 ◽

2014 ◽

Vol 82 (5) ◽

pp. 2125-2134 ◽

Cited By ~ 67

Author(s):

Christopher P. Montgomery ◽

Melvin Daniels ◽

Fan Zhao ◽

Maria-Luisa Alegre ◽

Anita S. Chong ◽

...

Keyword(s):

Staphylococcus Aureus ◽

B Cell ◽

Adoptive Transfer ◽

Protective Immunity ◽

Adaptive Immune Response ◽

Recurrent Infection ◽

Skin Lesions ◽

Content Type ◽

Interleukin 17A ◽

Ifn Γ

ABSTRACTAlthough many microbial infections elicit an adaptive immune response that can protect against reinfection, it is generally thought thatStaphylococcus aureusinfections fail to generate protective immunity despite detectable T and B cell responses. No vaccine is yet proven to preventS. aureusinfections in humans, and efforts to develop one have been hampered by a lack of animal models in which protective immunity occurs. Our results describe a novel mouse model of protective immunity against recurrent infection, in whichS. aureusskin and soft tissue infection (SSTI) strongly protected against secondary SSTI in BALB/c mice but much less so in C57BL/6 mice. This protection was dependent on antibody, because adoptive transfer of immune BALB/c serum or purified antibody into either BALB/c or C57BL/6 mice resulted in smaller skin lesions. We also identified an antibody-independent mechanism, because B cell-deficient mice were partially protected against secondaryS. aureusSSTI and adoptive transfer of T cells from immune BALB/c mice resulted in smaller lesions upon primary infection. Furthermore, neutralization of interleukin-17A (IL-17A) abolished T cell-mediated protection in BALB/c mice, whereas neutralization of gamma interferon (IFN-γ) enhanced protection in C57BL/6 mice. Therefore, protective immunity against recurrentS. aureusSSTI was advanced by antibody and the Th17/IL-17A pathway and prevented by the Th1/IFN-γ pathway, suggesting that targeting both cell-mediated and humoral immunity might optimally protect against secondaryS. aureusSSTI. These findings also highlight the importance of the mouse genetic background in the development of protective immunity againstS. aureusSSTI.

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Antibodies to Borrelia burgdorferi OspA, OspC, OspF, and C6 Antigens as Markers for Early and Late Infection in Dogs

Clinical and Vaccine Immunology ◽

10.1128/cvi.05653-11 ◽

2012 ◽

Vol 19 (4) ◽

pp. 527-535 ◽

Cited By ~ 32

Author(s):

Bettina Wagner ◽

Heather Freer ◽

Alicia Rollins ◽

David Garcia-Tapia ◽

Hollis N. Erb ◽

...

Keyword(s):

Lyme Disease ◽

Borrelia Burgdorferi ◽

The United States ◽

Sensu Stricto ◽

Antibody Responses ◽

Surface Proteins ◽

Early Infection ◽

Enzyme Linked Immunosorbent Assay ◽

Content Type ◽

Antibody Levels

ABSTRACTLyme disease in the United States is caused byBorrelia burgdorferisensu stricto, which is transmitted to mammals by infected ticks.Borreliaspirochetes differentially express immunogenic outer surface proteins (Osp). Our aim was to evaluate antibody responses to Osp antigens to aid the diagnosis of early infection and the management of Lyme disease. We analyzed antibody responses during the first 3 months after the experimental infection of dogs using a novel multiplex assay. Results were compared to those obtained with two commercial assays detecting C6 antigen. Multiplex analysis identified antibodies to OspC and C6 as early as 3 weeks postinfection (p.i.) and those to OspF by 5 weeks p.i. Antibodies to C6 and OspF increased throughout the study, while antibodies to OspC peaked between 7 and 11 weeks p.i. and declined thereafter. A short-term antibody response to OspA was observed in 3/8 experimentally infected dogs on day 21 p.i. Quant C6 enzyme-linked immunosorbent assay (ELISA) results matched multiplex results during the first 7 weeks p.i.; however, antibody levels subsequently declined by up to 29%. Immune responses then were analyzed in sera from 125 client-owned dogs and revealed high agreement between antibodies to OspF and C6 as robust markers for infection. Results from canine patient sera supported that OspC is an early infection marker and antibodies to OspC decline over time. The onset and decline of antibody responses toB. burgdorferiOsp antigens and C6 reflect their differential expression during infection. They provide valuable tools to determine the stage of infection, treatment outcomes, and vaccination status in dogs.

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Multifactorial seroprofiling dissects the contribution of pre-existing human coronaviruses responses to SARS-CoV-2 immunity

Nature Communications ◽

10.1038/s41467-021-27040-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Irene A. Abela ◽

Chloé Pasin ◽

Magdalena Schwarzmüller ◽

Selina Epp ◽

Michèle E. Sickmann ◽

...

Keyword(s):

Protective Immunity ◽

Rapid Development ◽

Antibody Responses ◽

Human Coronavirus ◽

Neutralization Activity ◽

Accurate Definition ◽

Human Coronaviruses ◽

Definition Of ◽

Antibody Levels

AbstractDetermination of SARS-CoV-2 antibody responses in the context of pre-existing immunity to circulating human coronavirus (HCoV) is critical for understanding protective immunity. Here we perform a multifactorial analysis of SARS-CoV-2 and HCoV antibody responses in pre-pandemic (N = 825) and SARS-CoV-2-infected donors (N = 389) using a custom-designed multiplex ABCORA assay. ABCORA seroprofiling, when combined with computational modeling, enables accurate definition of SARS-CoV-2 seroconversion and prediction of neutralization activity, and reveals intriguing interrelations with HCoV immunity. Specifically, higher HCoV antibody levels in SARS-CoV-2-negative donors suggest that pre-existing HCoV immunity may provide protection against SARS-CoV-2 acquisition. In those infected, higher HCoV activity is associated with elevated SARS-CoV-2 responses, indicating cross-stimulation. Most importantly, HCoV immunity may impact disease severity, as patients with high HCoV reactivity are less likely to require hospitalization. Collectively, our results suggest that HCoV immunity may promote rapid development of SARS-CoV-2-specific immunity, thereby underscoring the importance of exploring cross-protective responses for comprehensive coronavirus prevention.

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Characteristic Age Distribution of Plasmodium vivax Infections after Malaria Elimination on Aneityum Island, Vanuatu

Infection and Immunity ◽

10.1128/iai.00931-13 ◽

2013 ◽

Vol 82 (1) ◽

pp. 243-252 ◽

Cited By ~ 27

Author(s):

Akira Kaneko ◽

Luis F. Chaves ◽

George Taleo ◽

Morris Kalkoa ◽

Rie Isozumi ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Malaria Elimination ◽

Gene Pool ◽

Age Distribution ◽

Age Groups ◽

Antibody Responses ◽

The Other ◽

Content Type ◽

Younger Age ◽

Antibody Levels

ABSTRACTResurgence is a major concern after malaria elimination. After the initiation of the elimination program on Aneityum Island in 1991, microscopy showed thatPlasmodium falciparumdisappeared immediately, whereasP. vivaxdisappeared from 1996 onward, untilP. vivaxcases were reported in January 2002. By conducting malariometric surveys of the entire population of Aneityum, we investigated the age distribution of individuals with parasites during this epidemic in the context of antimalarial antibody levels and parasite antigen diversity. In July 2002,P. vivaxinfections were detected by microscopy in 22/759 individuals: 20/298 born after the beginning of the elimination program in 1991, 2/126 born between 1982 and 1991, and none of 335 born before 1982. PCR increased the number of infections detected to 77, distributed among all age groups. Prevalences were 12.1%, 16.7%, and 6.0%, respectively (P< 0.001). In November, a similar age pattern was found, but with fewer infections: 6/746 and 39/741 individuals were found to be infected by microscopy and PCR, respectively. The frequencies of antibody responses toP. vivaxwere significantly higher in individuals born before 1991 than in younger age groups and were similar to those on Malakula Island, an area of endemicity. Remarkably low antigen diversity (h, 0.15) ofP. vivaxinfections was observed on Aneityum compared with the other islands (h, 0.89 to 1.0). AP. vivaxresurgence was observed among children and teenagers on Aneityum, an age distribution similar to those before elimination and on islands whereP. vivaxis endemic, suggesting that in the absence of significant exposure, immunity may persist, limiting infection levels in adults. The limited parasite gene pool on islands may contribute to this protection.

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Protein A Suppresses Immune Responses during Staphylococcus aureus Bloodstream Infection in Guinea Pigs

mBio ◽

10.1128/mbio.02369-14 ◽

2015 ◽

Vol 6 (1) ◽

Cited By ~ 17

Author(s):

Hwan Keun Kim ◽

Fabiana Falugi ◽

Lena Thomer ◽

Dominique M. Missiakas ◽

Olaf Schneewind

Keyword(s):

Staphylococcus Aureus ◽

Guinea Pig ◽

B Cell ◽

Bloodstream Infection ◽

Guinea Pigs ◽

Protective Immunity ◽

Protein A ◽

Pig Model ◽

Content Type ◽

Guinea Pig Model

ABSTRACT Staphylococcus aureusinfection is not associated with the development of protective immunity, and disease relapses occur frequently. We hypothesize that protein A, a factor that binds immunoglobulin Fcγ and cross-links VH3 clan B cell receptors (IgM), is the staphylococcal determinant for host immune suppression. To test this, vertebrate IgM was examined for protein A cross-linking. High VH3 binding activity occurred with human and guinea immunoglobulin, whereas mouse and rabbit immunoglobulins displayed little and no binding, respectively. Establishing a guinea pig model of S. aureus bloodstream infection, we show that protein A functions as a virulence determinant and suppresses host B cell responses. Immunization with SpAKKAA, which cannot bind immunoglobulin, elicits neutralizing antibodies that enable guinea pigs to develop protective immunity.IMPORTANCE Staphylococcus aureusis the leading cause of soft tissue and bloodstream infections; however, a vaccine with clinical efficacy is not available. Using mice to model staphylococcal infection, earlier work identified protective antigens; however, corresponding human clinical trials did not reach their endpoints. We show that B cell receptor (IgM) cross-linking by protein A is an important immune evasion strategy of S. aureus that can be monitored in a guinea pig model of bloodstream infection. Further, immunization with nontoxigenic protein A enables infected guinea pigs to elicit antibody responses that are protective against S. aureus. Thus, the guinea pig model may support preclinical development of staphylococcal vaccines.

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Diversity of Antibody Responses to Borrelia burgdorferi in Experimentally Infected Beagle Dogs

Clinical and Vaccine Immunology ◽

10.1128/cvi.00018-14 ◽

2014 ◽

Vol 21 (6) ◽

pp. 838-846 ◽

Cited By ~ 9

Author(s):

Elisabeth Baum ◽

Deborah A. Grosenbaugh ◽

Alan G. Barbour

Keyword(s):

Borrelia Burgdorferi ◽

Binding Protein ◽

Protein Microarray ◽

Antibody Responses ◽

Domestic Dog ◽

Beagle Dogs ◽

Effective Population ◽

Content Type ◽

Immunogenic Proteins ◽

Antibody Levels

ABSTRACTLyme borreliosis (LB) is a common infection of domestic dogs in areas where there is enzootic transmission of the agentBorrelia burgdorferi. While immunoassays based on individual subunits have mostly supplanted the use of whole-cell preparations for canine serology, only a limited number of informative antigens have been identified. To more broadly characterize the antibody responses toB. burgdorferiinfection and to assess the diversity of those responses in individual dogs, we examined sera from 32 adult colony-bred beagle dogs that had been experimentally infected withB. burgdorferithrough tick bites and compared those sera in a protein microarray with sera from uninfected dogs in their antibody reactivities to various recombinant chromosome- and plasmid-encodedB. burgdorferiproteins, including 24 serotype-defining OspC proteins of North America. The profiles of immunogenic proteins for the dogs were largely similar to those for humans and natural-reservoir rodents; these proteins included the decorin-binding protein DbpB, BBA36, BBA57, BBA64, the fibronectin-binding protein BBK32, VlsE, FlaB and other flagellar structural proteins, Erp proteins, Bdr proteins, and all of the OspC proteins. In addition, the canine sera bound to the presumptive lipoproteins BBB14 and BB0844, which infrequently elicited antibodies in humans or rodents. Although the beagle, like most other domestic dog breeds, has a small effective population size and features extensive linkage disequilibrium, the group of animals studied here demonstrated diversity in antibody responses in measures of antibody levels and specificities for conserved proteins, such as DbpB, and polymorphic proteins, such as OspC.

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Intracellular Staphylococcus aureus Control by Virulent Bacteriophages within MAC-T Bovine Mammary Epithelial Cells

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01990-16 ◽

2016 ◽

Vol 61 (2) ◽

Cited By ~ 12

Author(s):

Lili Zhang ◽

Lichang Sun ◽

Ruicheng Wei ◽

Qiang Gao ◽

Tao He ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Epithelial Cells ◽

Treatment Failure ◽

Mammary Epithelial Cells ◽

Recurrent Infection ◽

Mammary Epithelial ◽

Time Dependent ◽

Dependent Manner ◽

Content Type ◽

Bovine Mammary Epithelial Cells

ABSTRACT Bacteriophages (phages) are known to effectively kill extracellular multiplying bacteria. The present study demonstrated that phages penetrated bovine mammary epithelial cells and cleared intracellular Staphylococcus aureus in a time-dependent manner. In particular, phage vB_SauM_JS25 reached the nucleus within 3 h postincubation. The phages had an endocytotic efficiency of 12%. This ability to kill intracellular host bacteria suggests the utility of phage-based therapies and may protect patients from recurrent infection and treatment failure.

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Antibody Responses in Patients with Staphylococcal Septicemia against Two Staphylococcus aureus Fibrinogen Binding Proteins: Clumping Factor and an Extracellular Fibrinogen Binding Protein

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.7.1.14-20.2000 ◽

2000 ◽

Vol 7 (1) ◽

pp. 14-20 ◽

Cited By ~ 35

Author(s):

Patricia Colque-Navarro ◽

Marco Palma ◽

Bo Söderquist ◽

Jan-Ingmar Flock ◽

Roland Möllby

Keyword(s):

Staphylococcus Aureus ◽

Antibody Response ◽

Binding Proteins ◽

Serum Antibody ◽

Antibody Responses ◽

Healthy Individuals ◽

Serum Samples ◽

Positive Serology ◽

Fibrinogen Binding ◽

Antibody Levels

ABSTRACT We analyzed the serum antibody responses against twoStaphylococcus aureus fibrinogen binding proteins, the cell-bound clumping factor (Clf) and an extracellular fibrinogen binding protein (Efb). The material consisted of 105 consecutive serum samples from 41 patients suffering from S. aureussepticemia and 72 serum samples from healthy individuals. An enzyme-linked immunosorbent assay (ELISA) was developed. Healthy individuals showed variable levels of antibodies against the studied antigens, and cutoff levels (upper 95th percentile) against these antigens were determined. No correlation was seen between serum antibody levels against Clf and Efb. In acute-phase samples 27% of patients showed positive antibody levels against Clf and 10% showed positive levels against Efb, while in convalescent-phase samples 63% (26 of 41) showed a positive serology against Clf and 49% (20 of 41) showed a positive serology against Efb. Antibody levels against Efb were significantly lower in the acute-phase sera than in sera from healthy individuals (P = 0.002). An antibody response against Clf was most frequent in patients suffering from osteitis plus septic arthritis and from endocarditis (80% positive). The antibody response against Efb appeared to develop later in the course of disease. A possible biological effect of measured antibodies was demonstrated with the help of an inhibition ELISA, in which both high-titer and low-titer sera inhibited the binding of bacteria to fibrinogen. In conclusion, we have demonstrated in vivo production ofS. aureus fibrinogen binding proteins during deep S. aureus infections and a possible diagnostic and prophylactic role of the corresponding serum antibodies in such infections.

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Characterization of Alpha-ToxinhlaGene Variants, Alpha-Toxin Expression Levels, and Levels of Antibody to Alpha-Toxin in Hemodialysis and Postsurgical Patients with Staphylococcus aureus Bacteremia

Journal of Clinical Microbiology ◽

10.1128/jcm.02023-14 ◽

2014 ◽

Vol 53 (1) ◽

pp. 227-236 ◽

Cited By ~ 29

Author(s):

Batu K. Sharma-Kuinkel ◽

Yuling Wu ◽

David E. Tabor ◽

Hoyin Mok ◽

Bret R. Sellman ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Monoclonal Antibody ◽

Clinical Outcome ◽

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Enzyme Linked Immunosorbent Assay ◽

Alpha Toxin ◽

Content Type ◽

Antibody Levels

Alpha-toxin is a majorStaphylococcus aureusvirulence factor. This study evaluated potential relationships betweenin vitroalpha-toxin expression ofS. aureusbloodstream isolates, anti-alpha-toxin antibody in serum of patients withS. aureusbacteremia (SAB), and clinical outcomes in 100 hemodialysis and 100 postsurgical SAB patients. Isolates underwentspatyping andhlasequencing. Serum anti-alpha-toxin IgG and neutralizing antibody levels were measured by using an enzyme-linked immunosorbent assay and a red blood cell (RBC)-based hemolysis neutralization assay. Neutralization of alpha-toxin by an anti-alpha-toxin monoclonal antibody (MAb MEDI4893) was tested in an RBC-based lysis assay. Most isolates encodedhla(197/200; 98.5%) and expressed alpha-toxin (173/200; 86.5%).In vitroalpha-toxin levels were inversely associated with survival (cure, 2.19 μg/ml, versus failure, 1.09 μg/ml;P< 0.01). Both neutralizing (hemodialysis, 1.26 IU/ml, versus postsurgical, 0.95;P< 0.05) and IgG (hemodialysis, 1.94 IU/ml, versus postsurgical, 1.27;P< 0.05) antibody levels were higher in the hemodialysis population. Antibody levels were also significantly higher in patients infected with alpha-toxin-expressingS. aureusisolates (P< 0.05). Levels of both neutralizing antibodies and IgG were similar among patients who were cured and those not cured (failures). Sequence analysis ofhlarevealed 12 distincthlagenotypes, and all genotypic variants were susceptible to a neutralizing monoclonal antibody in clinical development (MEDI4893). These data demonstrate that alpha-toxin is highly conserved in clinicalS. aureusisolates. Higherin vitroalpha-toxin levels were associated with a positive clinical outcome. Although patients infected with alpha-toxin-producingS. aureusexhibited higher anti-alpha-toxin antibody levels, these levels were not associated with a better clinical outcome in this study.

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A Colanic Acid Operon Deletion Mutation Enhances Induction of Early Antibody Responses by Live Attenuated Salmonella Vaccine Strains

Infection and Immunity ◽

10.1128/iai.00097-13 ◽

2013 ◽

Vol 81 (9) ◽

pp. 3148-3162 ◽

Cited By ~ 13

Author(s):

Shifeng Wang ◽

Huoying Shi ◽

Yuhua Li ◽

Zhaoxing Shi ◽

Xin Zhang ◽

...

Keyword(s):

Salmonella Enterica ◽

Protective Immunity ◽

Protective Antigen ◽

Deletion Mutation ◽

Antibody Responses ◽

Content Type ◽

Colanic Acid ◽

Iga Antibody ◽

Ifn Γ

ABSTRACTColanic acid (CA) is a common exopolysaccharide produced by many genera in theEnterobacteriaceae. It is critical for biofilm formation on HEp-2 cells and on chicken intestinal tissue bySalmonella. In this study, we generated different CA synthesis gene mutants and evaluated the immune responses induced by these mutants. One of these mutations, Δ(wza-wcaM)8, which deleted the whole operon for CA synthesis, was introduced into twoSalmonellavaccine strains attenuated by auxotrophic traits or by the regulated delayed attenuation strategy (RDAS). The mice immunized with the auxotrophicSalmonellavaccine strain with the deletion mutation Δ(wza-wcaM)8developed higher vaginal IgA titers against the heterologous protective antigen and higher levels of antigen-specific IgA secretion cells in lungs. InSalmonellavaccine strains with RDAS, the strain with the Δ(wza-wcaM)8mutation resulted in higher levels of protective antigen production duringin vitrogrowth. Mice immunized with this strain developed higher serum IgG and mucosal IgA antibody responses at 2 weeks. This strain also resulted in better gamma interferon (IFN-γ) responses than the strain without this deletion at doses of 108and 109CFU. Thus, the mutation Δ(wza-wcaM)8will be included in various recombinant attenuatedSalmonellavaccine (RASV) strains with RDAS derived fromSalmonella entericaserovar Paratyphi A andSalmonella entericaserovar Typhi to induce protective immunity against bacterial pathogens.

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