Candidin: comparison of two antigens for cutaneous delayed hypersensitivity testing

A candidin, which is a suspension of killed yeast cells, is commonly used for intradermal tests of delayed hypersensitivity, to evaluate the immunological cellular competence of the patient, when the test is applied along with other similar tests. When working with a cellular antigen, the histopathology of positive skin tests reveals a cellular infiltrate which not only presents a characteristic hypersensitivity reaction but also a neutrophilic abscess in the central part. This research presents the results of a comparison between the yeast cell suspension and the polysaccharide antigens, both obtained from the same strains of Candida albicans. The results obtained by skin tests in one hundred individuals were 61.0% with the polysaccharide antigen and 69.0% with the yeast cell suspension antigen. Concordant results concerning the two antigens were observed in 82.0% of the individuals. The discussion section presents an assumption to explain the differences of positivity obtained with the two antigens. We conclude that the polysaccharide antigen can be utilized in the intradermal test of delayed hypersensitivity to Candida albicans.

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THE CUTANEOUS REACTION TO EGGWHITE

PEDIATRICS ◽

10.1542/peds.24.6.1009 ◽

1959 ◽

Vol 24 (6) ◽

pp. 1009-1015

Author(s):

Richard L. London ◽

Jerome Glaser

Keyword(s):

Skin Test ◽

Skin Testing ◽

Intradermal Test ◽

Skin Tests ◽

Etiologic Factor ◽

Initial Reaction ◽

Age Group ◽

Positive Skin ◽

Clinical Sensitivity ◽

Number Of Patients

A study of 400 allergic patients of all ages, who were skin tested with eggwhite, is reported. The authors agree with those who believe that a positive reaction in infants who have in no known way been exposed to eggwhite after birth is in all probability due to intrauterine sensitization. There is a possibility, however, that some reactions to eggwhite may be due to a primary histamine or serotonin releasing substance present in the eggwhite which has no relationship to antigen-antibody reaction. The circumstances under which this takes place are not known. In all age groups the family history was positive in about 65% of cases. It was surprising to find, in view of previous opinions, that in the youngest age group (infants up to 2 years of age), the skin test was positive in less than half the patients (42%) in the presence of clinical sensitivity. It was also unexpected to find that the number of patients clinically sensitive to eggwhite but giving negative skin tests increased as age advanced. This justifies the common practice of eliminating egg as a trial measure in the diet of the first age group, regardless of the results of skin testing, and suggests that this should be done in any age group where food is considered a possible etiologic factor. In the youngest age group somewhat more than one-third (34%) of the patients reacted positively to eggwhite but were not clinically sensitive. This finding was completely unexpected as it had been thought that in this age group a positive skin test to eggwhite was practically pathognomonic of clinical sensitivity. In this study more positive reactions in children to eggwhite were obtained (70.5%) than in a somewhat comparable series where the incidence was much less (20%). We attribute this to the fact that in our series both scratch and intradermal tests were made while in the other series only scratch tests were done. This reflects the greater sensitivity of the intradermal test. Only about half the patients of all ages who react to eggwhite are also clinically sensitive. Attention is drawn to a theory which explains why a positive cutaneous test to a food, as eggwhite, may be clinically significant in atopic dermatitis even though the test (wheal reaction) does not reproduce the type of dermatitis being studied. There was no definite evidence, because the number of cases studied is far too small, to indicate that the severity of asthma which may ultimately develop in infants not asthmatic at the time of skin testing is proportional to the strength of the initial reaction to eggwhite.

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Use of a Genetically Engineered Strain To Evaluate the Pathogenic Potential of Yeast Cell and Filamentous Forms during Candida albicans Systemic Infection in Immunodeficient Mice

Infection and Immunity ◽

10.1128/iai.00982-07 ◽

2007 ◽

Vol 76 (1) ◽

pp. 97-102 ◽

Cited By ~ 34

Author(s):

Stephen P. Saville ◽

Anna L. Lazzell ◽

Ashok K. Chaturvedi ◽

Carlos Monteagudo ◽

Jose L. Lopez-Ribot

Keyword(s):

Candida Albicans ◽

Yeast Cell ◽

Systemic Infection ◽

Genetically Engineered ◽

Yeast Cells ◽

Pathogenic Potential ◽

Immunodeficient Mice ◽

Host Immune Responses ◽

Immune Defects ◽

Immunosuppressed Mice

ABSTRACT The pathogenesis of Candida albicans systemic infection is complex and results from the balance between its intrinsic virulence attributes and the host immune responses. Morphogenetic transitions between yeast cell and filamentous forms are considered one of the main virulence attributes in C. albicans. We have examined the pathogenesis of a genetically engineered C. albicans strain in which morphogenetic conversions can be externally manipulated in immunodeficient mice; these included B-cell deficient, nude (T cell deficient), SCID (lacking both functional T and B cells), and DBA/2N (C5 deficient with impaired neutrophil activity) mice. We also tested mice severely immunosuppressed by cyclophosphamide-cortisone acetate treatment. Mice with specific immune defects were able to survive an infection by yeast cells but not filamentous forms. However, yeast cells displayed a pathogenic effect leading to lethality in the severely immunosuppressed mice.

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Role of Glucosyltransferase B in Interactions of Candida albicans with Streptococcus mutans and with an Experimental Pellicle on Hydroxyapatite Surfaces

Applied and Environmental Microbiology ◽

10.1128/aem.05203-11 ◽

2011 ◽

Vol 77 (18) ◽

pp. 6357-6367 ◽

Cited By ~ 98

Author(s):

S. Gregoire ◽

J. Xiao ◽

B. B. Silva ◽

I. Gonzalez ◽

P. S. Agidi ◽

...

Keyword(s):

Candida Albicans ◽

Cell Surface ◽

Yeast Cell ◽

Fluorescence Imaging ◽

Streptococcus Mutans ◽

Tooth Enamel ◽

Yeast Cells ◽

Content Type ◽

Yeast Cell Surface

ABSTRACTCandida albicansand mutans streptococci are frequently detected in dental plaque biofilms from toddlers afflicted with early childhood caries. Glucosyltransferases (Gtfs) secreted byStreptococcus mutansbind to saliva-coated apatite (sHA) and to bacterial surfaces, synthesizing exopolymersin situ, which promote cell clustering and adherence to tooth enamel. We investigated the potential role Gtfs may play in mediating the interactions betweenC. albicansSC5314 andS. mutansUA159, both with each other and with the sHA surface. GtfB adhered effectively to theC. albicansyeast cell surface in an enzymatically active form, as determined by scintillation spectroscopy and fluorescence imaging. The glucans formed on the yeast cell surface were more susceptible to dextranase than those synthesized in solution or on sHA and bacterial cell surfaces (P< 0.05), indicating an elevated α-1,6-linked glucose content. Fluorescence imaging revealed that larger numbers ofS. mutanscells bound toC. albicanscells with glucans present on their surface than to yeast cells without surface glucans (uncoated). The glucans formedin situalso enhancedC. albicansinteractions with sHA, as determined by a novel single-cell micromechanical method. Furthermore, the presence of glucan-coated yeast cells significantly increased the accumulation ofS. mutanson the sHA surface (versusS. mutansincubated alone or mixed with uncoatedC. albicans;P< 0.05). These data reveal a novel cross-kingdom interaction that is mediated by bacterial GtfB, which readily attaches to the yeast cell surface. Surface-bound GtfB promotes the formation of a glucan-rich matrixin situand may enhance the accumulation ofS. mutanson the tooth enamel surface, thereby modulating the development of virulent biofilms.

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IMMUNOLOGIC COMPETENCE OF THORACIC DUCT CELLS

Journal of Experimental Medicine ◽

10.1084/jem.123.2.267 ◽

1966 ◽

Vol 123 (2) ◽

pp. 267-281 ◽

Cited By ~ 35

Author(s):

John E. Coe ◽

Joseph D. Feldman ◽

Sun Lee

Keyword(s):

Thoracic Duct ◽

Skin Testing ◽

Specific Antigen ◽

Delayed Hypersensitivity ◽

Skin Tests ◽

Thoracic Duct Lymph ◽

Skin Reactions ◽

Positive Skin ◽

Duct Cells ◽

Successful Transfer

Delayed hypersensitivity was produced in donor Lewis rats by sensitization with soluble protein antigens emulsified in complete Freund's adjuvant. Cells of their thoracic duct lymph were collected for varying periods of time and transferred intravenously to isogenic Lewis recipients. With this model the following conclusions were reached: 1. Delayed hypersensitivity was transferred by thoracic duct cells. 2. The longer the drainage of the thoracic duct, the fewer cells were needed to achieve a successful transfer. With continuing drainage the proportion of small lymphocytes decreased and large cells increased. There was, therefore, a better correlation between successful transfer of delayed hypersensitivity and the number of large cells transfused than between positive skin reactions and transfer of small lymphocytes. 3. Prolonged fistula of the thoracic duct did not diminish the skin reaction of sensitized donors to specific antigen. 4. Delayed hypersensitivity was elicited in recipients 3 wk after transfer of sensitized cells. There was evidence that delayed hypersensitivity was enhanced in recipients, possibly because of prior skin testing. 5. Total body X-irradiation abolished the lesions of passively transferred delayed hypersensitivity. Recovery of positive skin tests was observed 19 to 20 days later. 6. The lesions of delayed hypersensitivity were probably mediated by cells. There was no evidence that a circulating high affinity antibody played a role in this type of immunologic reaction.

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Ability of caregivers to read delayed hypersensitivity skin tests in children exposed to and infected by HIV*1

Journal of Pediatric Health Care ◽

10.1016/s0891-5245(00)77641-3 ◽

2000 ◽

Vol 14 (2) ◽

pp. 50-55

Author(s):

FORTHEPEDIATRICPULMONARYANDCA ◽

H COHEN ◽

X CHEN ◽

S SUNKLE ◽

L DAVIS ◽

...

Keyword(s):

Delayed Hypersensitivity ◽

Skin Tests ◽

Hypersensitivity Skin ◽

Hiv 1

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Optimizing Transformation Frequency of Cryptococcus neoformans and Cryptococcus gattii Using Agrobacterium tumefaciens

Journal of Fungi ◽

10.3390/jof7070520 ◽

2021 ◽

Vol 7 (7) ◽

pp. 520

Author(s):

Jianmin Fu ◽

Nohelli E. Brockman ◽

Brian L. Wickes

Keyword(s):

Agrobacterium Tumefaciens ◽

Yeast Cell ◽

Transformation Efficiency ◽

Transformation Frequency ◽

Yeast Cells ◽

Agar Concentration ◽

Genetic Tool ◽

Number Of Factors ◽

Cryptococcus Spp ◽

Transformation Systems

The transformation of Cryptococcus spp. by Agrobacterium tumefaciens has proven to be a useful genetic tool. A number of factors affect transformation frequency. These factors include acetosyringone concentration, bacterial cell to yeast cell ratio, cell wall damage, and agar concentration. Agar concentration was found to have a significant effect on the transformant number as transformants increased with agar concentration across all four serotypes. When infection time points were tested, higher agar concentrations were found to result in an earlier transfer of the Ti-plasmid to the yeast cell, with the earliest transformant appearing two h after A. tumefaciens contact with yeast cells. These results demonstrate that A. tumefaciens transformation efficiency can be affected by a variety of factors and continued investigation of these factors can lead to improvements in specific A. tumefaciens/fungus transformation systems.

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Early Adhesion of Candida albicans onto Dental Acrylic Surfaces

Journal of Dental Research ◽

10.1177/0022034517706354 ◽

2017 ◽

Vol 96 (8) ◽

pp. 917-923 ◽

Cited By ~ 12

Author(s):

S. Aguayo ◽

H. Marshall ◽

J. Pratten ◽

D. Bradshaw ◽

J.S. Brown ◽

...

Keyword(s):

Candida Albicans ◽

Clinical Isolate ◽

Force Spectroscopy ◽

Laboratory Strain ◽

Culture Conditions ◽

The Body ◽

Yeast Cells ◽

Adhesion Forces ◽

Reliable Technique ◽

Mother Cells

Denture-associated stomatitis is a common candidal infection that may give rise to painful oral symptoms, as well as be a reservoir for infection at other sites of the body. As poly (methyl methacrylate) (PMMA) remains the main material employed in the fabrication of dentures, the aim of this research was to evaluate the adhesion of Candida albicans cells onto PMMA surfaces by employing an atomic force microscopy (AFM) single-cell force spectroscopy (SCFS) technique. For experiments, tipless AFM cantilevers were functionalized with PMMA microspheres and probed against C. albicans cells immobilized onto biopolymer-coated substrates. Both a laboratory strain and a clinical isolate of C. albicans were used for SCFS experiments. Scanning electron microscopy (SEM) and AFM imaging of C. albicans confirmed the polymorphic behavior of both strains, which was dependent on growth culture conditions. AFM force-spectroscopy results showed that the adhesion of C. albicans to PMMA is morphology dependent, as hyphal tubes had increased adhesion compared with yeast cells ( P < 0.05). C. albicans budding mother cells were found to be nonadherent, which contrasts with the increased adhesion observed in the tube region. Comparison between strains demonstrated increased adhesion forces for a clinical isolate compared with the lab strain. The clinical isolate also had increased survival in blood and reduced sensitivity to complement opsonization, providing additional evidence of strain-dependent differences in Candida-host interactions that may affect virulence. In conclusion, PMMA-modified AFM probes have shown to be a reliable technique to characterize the adhesion of C. albicans to acrylic surfaces.

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Candida albicans Expresses a Focal Adhesion Kinase-Like Protein That Undergoes Increased Tyrosine Phosphorylation upon Yeast Cell Adhesion to Vitronectin and the EA.hy 926 Human Endothelial Cell Line

Infection and Immunity ◽

10.1128/iai.70.7.3804-3815.2002 ◽

2002 ◽

Vol 70 (7) ◽

pp. 3804-3815 ◽

Cited By ~ 11

Author(s):

Giorgio Santoni ◽

Roberta Lucciarini ◽

Consuelo Amantini ◽

Jordan Jacobelli ◽

Elisabetta Spreghini ◽

...

Keyword(s):

Endothelial Cells ◽

Candida Albicans ◽

Cell Adhesion ◽

Endothelial Cell ◽

Yeast Cell ◽

Focal Adhesion Kinase ◽

Cell Line ◽

Tyrosine Phosphorylation ◽

Focal Adhesion ◽

Human Endothelial Cell Line

ABSTRACT The signaling pathways triggered by adherence of Candida albicans to the host cells or extracellular matrix are poorly understood. We provide here evidence in C. albicans yeasts of a p105 focal adhesion kinase (Fak)-like protein (that we termed CaFak), antigenically related to the vertebrate p125Fak, and its involvement in integrin-like-mediated fungus adhesion to vitronectin (VN) and EA.hy 926 human endothelial cell line. Biochemical analysis with different anti-chicken Fak antibodies identified CaFak as a 105-kDa protein and immunofluorescence and cytofluorimetric analysis on permeabilized cells specifically stain C. albicans yeasts; moreover, confocal microscopy evidences CaFak as a cytosolic protein that colocalizes on the membrane with the integrin-like VN receptors upon yeast adhesion to VN. The protein tyrosine kinase (PTK) inhibitors genistein and herbimycin A strongly inhibited C. albicans yeast adhesion to VN and EA.hy 926 endothelial cells. Moreover, engagement of αvβ3 and αvβ5 integrin-like on C. albicans either by specific monoclonal antibodies or upon adhesion to VN or EA.hy 926 endothelial cells stimulates CaFak tyrosine phosphorylation that is blocked by PTK inhibitor. A role for CaFak in C. albicans yeast adhesion was also supported by the failure of VN to stimulate its tyrosine phosphorylation in a C. albicans mutant showing normal levels of CaFak and VNR-like integrins but displaying reduced adhesiveness to VN and EA.hy 926 endothelial cells. Our results suggest that C. albicans Fak-like protein is involved in the control of yeast cell adhesion to VN and endothelial cells.

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