scholarly journals Fecal Antibodies to Cryptosporidium parvum in Healthy Volunteers

2000 ◽  
Vol 68 (9) ◽  
pp. 5068-5074 ◽  
Author(s):  
Sara M. Dann ◽  
Pablo C. Okhuysen ◽  
Bassam M. Salameh ◽  
Herbert L. DuPont ◽  
Cynthia L. Chappell
Keyword(s):  
Antibody Response ◽  
Healthy Volunteers ◽  
Cryptosporidium Parvum ◽  
Immunoglobulin A ◽  
Reactivity Index ◽  
Secretory Immunoglobulin A ◽  
Low Doses ◽  
Previous Exposure ◽  
Oocyst Excretion ◽  
Secretory Immunoglobulin

ABSTRACT This study examined the intestinal antibody response in 26 healthy volunteers challenged with Cryptosporidium parvum oocysts. Fecal extracts were assayed for total secretory immunoglobulin A (IgA) and C. parvum-specific IgA reactivity. Specific IgA reactivity was standardized to IgA concentration and expressed as a reactivity index (RI). Anti-C. parvum fecal IgA (fIgA) increased significantly in 17 of 26 (65.4%) following oocyst ingestion. Of those with detectable responses, 59, 76.5, and 94.1% were positive by days 7, 14, and 30, respectively. Volunteers receiving high challenge doses (>1,000 and 300 to 500 oocysts) had higher RIs (RI = 5.57 [P = 0.027] and RI = 1.68 [P = 0.039], respectively) than those ingesting low doses (30 to 100 oocysts; RI = 0.146). Subjects shedding oocysts and experiencing a diarrheal illness had the highest fIgA reactivity. When evaluated separately, oocyst excretion was associated with an increased fIgA response compared to nonshedders (RI = 1.679 versus 0.024, respectively; P = 0.003). However, in subjects experiencing diarrhea with or without oocyst shedding, a trend toward a higher RI (P = 0.065) was seen. Extracts positive for fecal IgA were further examined for IgA subclass. The majority of stools contained both IgA1 and IgA2, and the relative proportions did not change following challenge. Also, no C. parvum-specific IgM or IgG was detected in fecal extracts. Thus, fecal IgA to C. parvum antigens was highly associated with infection in subjects who had no evidence of previous exposure and may provide a useful tool in detecting recent infections.

Different secretory immunoglobulin A antibody responses to cholera vaccination in Swedish and Pakistani women

1980 ◽  
Vol 30 (2) ◽  
pp. 427-430
Author(s):  
A M Svennerholm ◽  
L A Hanson ◽  
J Holmgren ◽  
B S Lindblad ◽  
B Nilsson ◽  
...  
Keyword(s):  
Antibody Response ◽  
Immunoglobulin A ◽  
Antibody Responses ◽  
Secretory Immunoglobulin A ◽  
Cholera Vaccine ◽  
Intestinal Immunity ◽  
Significant Difference ◽  
Pakistani Women ◽  
Cholera Vaccination ◽  
Secretory Immunoglobulin

The capacity of subcutaneous cholera vaccination to induce an antibody response in milk and saliva was studied in lactating Swedish and Pakistani women, since secretory immunoglobulin A (SIgA) antibody responses in these secretions may reflect intestinal immunity. Before immunization, most of the Pakistani women had significant titers of specific SIgA antibodies against Vibrio cholerae lipopolysaccharide in milk, whereas only a few of the Swedish women had measurable, low titers. In the Pakistani women a single subcutaneous injection of cholera vaccine gave rise to a significant SIgA titer rise in 70% of the milk and 45% of the saliva samples. The Swedish women, on the other hand, did not respond with a significant antibody response of any immunoglobulin class in milk or saliva, either after a single or after a booster dose 14 days later. In serum, however, the vaccination induced significant titer rises, mainly of IgG antibodies, also in the Swedish women, but these rises were of lower magnitude than those in the Pakistani group. The results suggest a significant difference in the capacity of parenterally administered cholera vaccine to stimulate SIgA antibody formation in naturally primed and nonprimed individuals.

scholarly journals Protective Levels of Diphtheria-Neutralizing Antibody Induced in Healthy Volunteers by Unilateral Priming-Boosting Intranasal Immunization Associated with Restricted Ipsilateral Mucosal Secretory Immunoglobulin A

2003 ◽  
Vol 71 (2) ◽  
pp. 726-732 ◽  
Author(s):  
Kingston H. G. Mills ◽  
Catherine Cosgrove ◽  
Edel A. McNeela ◽  
Amy Sexton ◽  
Rafaela Giemza ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Mucosal Immunity ◽  
Immunoglobulin A ◽  
Neutralizing Antibody ◽  
Secretory Immunoglobulin A ◽  
Neutralizing Activity ◽  
Intranasal Immunization ◽  
Immunodeficiency Virus ◽  
Secretory Immunoglobulin ◽  
Antibody Secreting Cells

ABSTRACT Subunit intranasal vaccines offer the prospect of inducing combined systemic-mucosal immunity against mucosally transmitted infections such as human immunodeficiency virus. However, although human studies have demonstrated the induction of active immunity, secretory immunoglobulin A (sIgA) responses are variable, and no study has demonstrated protection by accepted vaccine-licensing criteria as measured by direct toxin-neutralizing activity. Using the genetically inactivated mutant diphtheria toxoid CRM197 in a bioadhesive polycationic polysaccharide chitosan delivery system, we found that a single nasal immunization was well tolerated and boosted antitoxin neutralizing activity in healthy volunteers, which could be further boosted by a second immunization. The neutralizing activity far exceeded accepted protective levels and was equivalent to that induced by standard intramuscular vaccine and significantly greater than intranasal immunization with CRM197 in the absence of chitosan. A striking but unexpected observation was that although unilateral intranasal immunization induced circulating antitoxin antibody-secreting cells, a nasal antitoxin sIgA response was seen only after the second immunization and only in the vaccinated nostril. If these data are reproduced in larger studies, an intranasal diphtheria vaccine based on CRM197-chitosan could be rapidly licensed for human use. However, a restricted sIgA response suggests that care must be taken in the priming-boosting strategy and clinical sampling techniques when evaluating such vaccines for the induction of local mucosal immunity.

scholarly journals The immune landscape of IgA induction in the gut

2021 ◽  
Author(s):  
Claudia Seikrit ◽  
Oliver Pabst
Keyword(s):  
Protective Immunity ◽  
Immunoglobulin A ◽  
Antibody Responses ◽  
Dark Side ◽  
Secretory Immunoglobulin A ◽  
Antibody Isotype ◽  
Mucosal Antibody ◽  
Key Concepts ◽  
Basic Understanding ◽  
Secretory Immunoglobulin

AbstractAntibodies are key elements of protective immunity. In the mucosal immune system in particular, secretory immunoglobulin A (SIgA), the most abundantly produced antibody isotype, protects against infections, shields the mucosal surface from toxins and environmental factors, and regulates immune homeostasis and a peaceful coexistence with our microbiota. However, the dark side of IgA biology promotes the formation of immune complexes and provokes pathologies, e.g., IgA nephropathy (IgAN). The precise mechanisms of how IgA responses become deregulated and pathogenic in IgAN remain unresolved. Yet, as the field of microbiota research moved into the limelight, our basic understanding of IgA biology has been taking a leap forward. Here, we discuss the structure of IgA, the anatomical and cellular foundation of mucosal antibody responses, and current concepts of how we envision the interaction of SIgA and the microbiota. We center on key concepts in the field while taking account of both historic findings and exciting new observations to provide a comprehensive groundwork for the understanding of IgA biology from the perspective of a mucosal immunologist.

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