Influenza: viral determinants of the pathogenicity and epidemicity of an invariant disease of variable occurrence

1980 ◽  
Vol 288 (1029) ◽  
pp. 291-297 ◽  
Keyword(s):  
Surface Antigens ◽  
Structural Alteration ◽  
Antigenic Structure ◽  
Viral Antigens ◽  
Variable Surface ◽  
Viral Genes ◽  
Viral Determinants ◽  
Viral Form

If influenza is a riddle wrapped in mystery inside an enigma, then the viral genes are the riddle, the variable surface antigens for which they code are the mystery, and the course and cause of epidemics the ultimate enigma. Paradoxically, the disease itself has remained a stable and recognizable entity through the years, whether initiated by A/PR/8/34 or A/USSR/90/77 variant viruses. Thus, evolution appears to have preserved the disease but not the virus. Among the questions before us are: (1) Have we become obsessed with differences instead of similarities, and have we overemphasized minor differences in viral (antigenic) structure as epidemic determinants? (2) To what extent do viral antigens reflect selection by population antibody ? (3) To what extent is antigenic change the pleiotropic consequence of protein structural alteration for purposes other than escape from specific neutralization ? These and other questions are discussed in relating viral form to function.

scholarly journals The importance of antineuraminidase antibodies in resistance to influenza A and immunologic memory for their synthesis

1983 ◽  
Vol 91 (1) ◽  
pp. 131-138 ◽  
Author(s):  
A. N. Naikhin ◽  
I. M. Tsaritsina ◽  
E. V. Oleinikova ◽  
L. G. Syrodoeva ◽  
N. L. Korchanova ◽  
...  
Keyword(s):  
Protective Effect ◽  
Influenza A ◽  
Natural Infection ◽  
Haemagglutination Inhibition ◽  
Surface Antigens ◽  
Antigenic Structure ◽  
Immunologic Memory ◽  
Antibody Synthesis ◽  
Influenza A H1n1 ◽  
Simplified Method

SUMMARYEight hundred and seventy-seven sera from 360 adults aged 18–50 who were under permanent observation from October 1980 to March 1981 have been studied by haemagglutination-inhibition (HI) and erythrocyte elution-inhibition (EI) tests – a simplified method of antineuraminidase antibody titration. It was demonstrated in some subjects infected with influenza A H1N1 and H3N2 viruses that the antibody rise was to one of the surface antigens only – haemagglutinin or neuraminidase. These subjects made up 5·2–25·8% of all examinees. The protective effect of antibodies to neuraminidase was similar to that of antihaemagglutinins. Interaction of both types of antibodies was observed in protection against the disease. Data have been obtained on the influence of antineuraminidase antibodies in decreasing the severity of natural infection with influenza A.A study of heterologous immunologic responses to haemagglutinin and neuraminidase among persons immunized with live influenza A H1N1 and H3N2 vaccines and among children naturally infected with influenza A H3N2 demonstrated the presence of immunologic memory for antineuraminidase antibody synthesis. Thus, the suggestion of a common antigenic structure for neuraminidase Nl and N2 is made.

Identification of the fragment containing cross-reacting antigenic determinants in the variable surface glycoprotein of Trypanosoma brucei

Parasitology ◽  
1981 ◽  
Vol 83 (3) ◽  
pp. 623-637 ◽  
Author(s):  
A. F. Barbet ◽  
A. J. Musoke ◽  
S. Z. Shapiro ◽  
G. Mpimbaza ◽  
T. C. McGuire
Keyword(s):  
Leucine Aminopeptidase ◽  
Periodate Oxidation ◽  
Surface Glycoprotein ◽  
Antigenic Structure ◽  
Antigenic Determinants ◽  
Free System ◽  
Variable Surface Glycoprotein ◽  
Variable Surface ◽  
Reticulocyte Lysate

SUMMARY125I-labelled, isolated variable surface glycoproteins (VSGs) of Trypanosoma b. brucei bind both homologous and heterologous anti-VSG sera and binding to heterologous antisera may be blocked by other unlabelled VSGs (Barbet & McGuire, 1978). This paper presents results which suggest that oligosaccharide residues have importance in the antigenic structure of VSG cross-reacting determinants. The ability of VSG to bind heterologous anti-VSG sera was destroyed by periodate oxidation but not by extensive proteolysis. A VSG glycopeptide fragment was isolated from two different VSGs, which blocked by 100 % the binding of VSG to heterologous anti-VSG sera and therefore contained the cross-reacting determinants. The native glycopeptide fragment was resistant to digestion with trypsin, pronase or leucine aminopeptidase and prolidase. We also show that a VSG synthesized in the reticulocyte lysate cell-free system was not immunoprecipitated by heterologous anti-VSG sera in contrast to the same VSG labelled by metabolic incorporation of [35S]methionine in vivo.

Characterization of major surface and excretory-secretory immunogens ofTrypanosoma cruzitrypomastigotes and identification of potential protective antigen

Parasitology ◽  
1990 ◽  
Vol 100 (1) ◽  
pp. 115-124 ◽  
Author(s):  
M. A. Ouaissi ◽  
A. Taibi ◽  
J. Cornette ◽  
P. Velge ◽  
B. Marty ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Dimensional Analysis ◽  
Polyclonal Antibody ◽  
Protective Antigen ◽  
Surface Antigens ◽  
Antigenic Structure ◽  
Enzyme Linked Immunosorbent Assay ◽  
Two Dimensional ◽  
Wide Range ◽  
Isoelectric Points

SummaryThe surface antigens ofTrypanosoma cruzitrypomastigotes were identified by immunoprecipitation and were compared with metabolically labelled excretory—secretory products (ES) released by the parasitesin vitro. A series of major immunogenic components in the ES antigens were revealed (160 kDa, 130 kDa and 80–110 kDa). The trypomastigote surface also bears the 130 kDa band and the 80–110 kDa complex. Competition experiments demonstrated the common antigenic structure of the ES and the surface antigens. Two-dimensional analysis of ES antigens immunoprecipitated by human Chagasic serum revealed several spots in the 80–110 kDa region with a wide range of isoelectric points (PI between 5·4 and 6·7). This reflects a charge heterogeneity of these polypeptides. The trypomastigote 85 kDa polypeptide was also identified in the ES antigens by using a monoclonal antibody against this antigen. Two-dimensional analysis of the 85 kDa proteins shed from the surface of trypomastigotes and immunoprecipitated by the monoclonal antibody 155D3 showed 2 major spots: a major part of the 85 kDa polypeptide was found at pH 6·5–6·6, whereas a substantial amount of the antigen was found at pH 5·7. An additional component with molecular weight of approximately 58 kDa and isoelectric points of 6·5 and 6·6, was also visualized. Detection of the 85 kDa polypeptide circulating in serum from patients with acute and chronic Chagas' disease was achieved using an enzyme-linked immunosorbent assay. In addition, the data obtained showed that a polyclonal antibody to the 85 kDa polypeptide could be used to passively induce a partial protection of Fischer rats against acute lethal infection. Thus, the antigens recognized by polyclonal antibody appear to play a role in the development of protective immunity againstT. cruzi.

SURFACE ANTIGENS OF NORMAL EARLY EMBRYOS AND A TUMOUR MODEL SYSTEM USEFUL FOR THEIR FURTHER STUDY

1975 ◽  
Vol 80 (2_Suppl) ◽  
pp. S336-S356 ◽  
Author(s):  
Michael Edidin ◽  
Linda R. Gooding ◽  
Martin Johnson
Keyword(s):  
Surface Antigens ◽  
Model System ◽  
Tumour Cells ◽  
Antigenic Structure ◽  
Tumour Model ◽  
System A ◽  
Early Embryos ◽  
Transplantation Antigens ◽  
Tumour System

ABSTRACT We review experiments on the presence of strong transplantation antigens, H-2 antigens, in mouse gametes and early embryos. Parallels are drawn between antigenic structure of embryos and tumour cells, and experiments with a model tumour system, a teratoma, are presented indicating the presence in early embryos of surface antigens which are shared with the tumour.

scholarly journals Neisseria gonorrhoeae Elicits Extracellular Traps in Primary Neutrophil Culture While Suppressing the Oxidative Burst

mBio ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Carl W. Gunderson ◽  
H. Steven Seifert
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Oxidative Burst ◽  
Bacterial Species ◽  
Immune Surveillance ◽  
Large Body ◽  
Surface Antigens ◽  
Neutrophil Extracellular Traps ◽  
Content Type ◽  
Extracellular Traps ◽  
Variable Surface

ABSTRACT Neisseria gonorrhoeae(the gonococcus) causes gonorrhea and is uniquely adapted to survive within the human reproductive tract. Gonococci evade host immune surveillance in part by varying their pili and opacity-associated proteins. These variable surface antigens influence interactions with host epithelial and immune cells. A potent polymorphonuclear leukocyte (PMN) response is a hallmark of symptomatic gonococcal infection, with vast numbers of PMNs recruited to the site of infection. A large body of literature describes gonococcus-PMN interactions, but the factors driving the outcome of infection are not fully understood. Gonococci have been described to both induce and suppress the PMN oxidative burst, but we determined that gonococci differentially affect induction of the PMN oxidative burst depending on the multiplicity of infection (MOI). Infecting PMN at an MOI of <20 gonococci elicits an oxidative burst, while an MOI of >20 suppresses the burst. Oxidative burst in response to gonococci is enhanced by, but does not require, expression of pili or opacity proteins. Neutrophil extracellular traps (NETs) were observed in gonococcus-infected PMNs, a process which requires an oxidative burst, yet gonococci induced NETs under suppressing conditions. The NETs were unable to kill gonococci despite killing the common vaginal bacteriumLactobacillus crispatus. Thus, gonococci influence PMN biology to promote their own survival by suppressing the oxidative burst of PMNs and stimulating the formation of NETs, which do not effectively kill gonococci, illustrating how N. gonorrhoeae has evolved to modulate PMN responses to promote infection.IMPORTANCE Neisseria gonorrhoeae, the gonococcus, is the only causative agent of gonorrhea and is exclusively found within the human host. Gonococci stochastically vary the composition of antigens on their surface to evade immune surveillance. We used gonococcal mutants which stably express different surface antigens to dissect interactions between gonococci and primary human polymorphonuclear leukocytes (PMNs). We found that gonococci, depending on the number of bacteria present, either induce or suppress the oxidative burst of PMNs regardless of other stimuli. Gonococci also cause PMNs to release DNA, forming neutrophil extracellular traps (NETs) independently of the oxidative burst. The NETs were unable to kill gonococci but were able to kill commensal bacteria, suggesting that NET production can help gonococci outcompete other bacterial species. We propose that gonococci have evolved to manipulate PMN responses to promote their own survival during infection.

Do the variable surface glycoproteins of parasites have a function?

Parasitology ◽  
1984 ◽  
Vol 88 (4) ◽  
pp. 631-631
Author(s):  
J. J. Skehel
Keyword(s):  
Monoclonal Antibodies ◽  
Antigenic Variation ◽  
Surface Antigens ◽  
Membrane Glycoprotein ◽  
Side Chains ◽  
Variable Surface ◽  
Antigenic Properties ◽  
Surface Glycoproteins

In common with a number of parasite surface antigens about which we have heard, the influenza haemagglutinin is a membrane glycoprotein which varies in antigenicity.A question which often arises concerns the contribution of the carbohydrate side-chains to antigenicity, and we have recently observed that a number of monoclonal antibodies are able to discriminate between glycosylated and nonglycosylated haemagglutinin molecules. Specifically these antibodies select antigenic variants with haemagglutinins which contain asparagine substitutions in the sequence asparagine–cysteine–threonine and the asparagine is glycosylated. By infecting cells incubated in medium containing tunicamycin non-glycosylated variant haemagglutinin can be obtained, and it is possible to show that such molecules are precipitated by the antibodies used to select the variant. These results directly indicate that carbohydrate side-chains can modulate the antigenic properties of glycoproteins and may be involved in antigenic variation.

scholarly journals Antibody Response to Lyme Disease Spirochetes in the Context of VlsE-Mediated Immune Evasion

2016 ◽  
Vol 85 (1) ◽  
Author(s):  
Artem S. Rogovskyy ◽  
David C. Gillis ◽  
Yurij Ionov ◽  
Ekaterina Gerasimov ◽  
Alex Zelikovsky
Keyword(s):  
Immune Response ◽  
Lyme Disease ◽  
Antibody Response ◽  
Antigenic Variation ◽  
Protective Efficacy ◽  
Surface Antigens ◽  
Mammalian Host ◽  
Term Survival ◽  
Content Type ◽  
Variable Surface

ABSTRACTLyme disease (LD), the most prevalent tick-borne illness in North America, is caused byBorrelia burgdorferi. The long-term survival ofB. burgdorferispirochetes in the mammalian host is achieved though VlsE-mediated antigenic variation. It is mathematically predicted that a highly variable surface antigen prolongs bacterial infection sufficiently to exhaust the immune response directed toward invariant surface antigens. If the prediction is correct, it is expected that the antibody response toB. burgdorferiinvariant antigens will become nonprotective asB. burgdorferiinfection progresses. To test this assumption, changes in the protective efficacy of the immune response toB. burgdorferisurface antigens were monitored via a superinfection model over the course of 70 days.B. burgdorferi-infected mice were subjected to secondary challenge by heterologousB. burgdorferiat different time points postinfection (p.i.). When the infected mice were superinfected with a VlsE-deficient clone (ΔVlsE) at day 28 p.i., the active anti-B. burgdorferiimmune response did not prevent ΔVlsE-induced spirochetemia. In contrast, most mice blocked culture-detectable spirochetemia induced by wild-typeB. burgdorferi(WT), indicating that VlsE was likely the primary target of the antibody response. As theB. burgdorferiinfection further progressed, however, reversed outcomes were observed. At day 70 p.i. the host immune response to non-VlsE antigens became sufficiently potent to clear spirochetemia induced by ΔVlsE and yet failed to prevent WT-induced spirochetemia. To test if any significant changes in the anti-B. burgdorferiantibody repertoire accounted for the observed outcomes, global profiles of antibody specificities were determined. However, comparison of mimotopes revealed no major difference between day 28 and day 70 antibody repertoires.

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