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Biomedical subjects

S Shai

Publications and source records attributed to S Shai.

3 recordsLinked to original sources

Identification of human sperm antigens reacting with antisperm antibodies from sera and genital tract secretions.

OBJECTIVE: To identify sperm antigens reacting with antisperm antibodies relevant in human infertility. DESIGN: The reactions of separated sperm antigens with antibodies present in sera and genital tract secretions from infertile and fertile females and males were examined by immunoblotting techniques. SETTING: The patients were followed in an outpatient setting of a hospital clinic. PATIENTS: One hundred consecutive infertile males and females, referred for determinations of antisperm antibodies, comprised the study group. Fifty hospital and faculty employees with proven fertility served as a control group. RESULTS: A high proportion of sera from fertile and infertile humans contained antibodies reacting with at least one sperm antigen. However, two discrete bands of antigenic proteins with molecular weights of 44 and 72 kd reacted significantly more frequently with serum antibodies from infertile females than from fertile females. No apparent correlation could be demonstrated between any particular antigen and serum antibodies from infertile males. Nevertheless, antigenic proteins of 62 kd were identified as the major sperm antigens reacting with antibodies present in seminal plasmas from infertile males. CONCLUSIONS: The major sperm antigens reacting with systemic antibodies differ from the antigens recognized by local antisperm antibodies. Sperm antigens exhibiting relative molecular weights of 62 kd are major antigens reactive with local antisperm antibodies from infertile humans.

Autoantibodies

A malaria merozoite surface protein (MSP1)-structure, processing and function.

Merozoite surface protein-1 (MSP-1, also referred to as P195, PMMSA or MSA 1) is one of the most studied of all malaria proteins. The protein is found in all malaria species investigated and structural studies on the gene indicate that parts of the molecule are well-conserved. Studies on Plasmodium falciparum have shown that the protein is in a processed form on the merozoite surface, a result of proteolytic cleavage of the large precursor molecule. Recent studies have identified some of these cleavage sites. During invasion of the new red cell most of the MSP1 molecule is shed from the parasite surface except for a small C-terminal fragment which can be detected in ring stages. Analysis of the structure of this fragment suggests that it contains two growth factor-like domains that may have a functional role.

Amino Acid Sequence

A reverse (antibody capture) enzyme-linked immunosorbent assay for detection of antisperm antibodies in sera and genital tract secretions.

A reverse (antibody capture) enzyme-linked immunosorbent assay (ELISA) for detection of antisperm antibodies has been developed. The assay enables detection of immunoglobulin (Ig) M, IgG, IgA, or IgM, IgG, and IgA--antisperm antibodies in serum, cervical mucus, and seminal plasma samples. The reverse ELISA is more specific and sensitive than conventional ELISA in detecting human antisperm antibodies of different isotypes. Using this assay, statistically significant differences in levels of antibodies between infertile and fertile individuals were demonstrated in sera and in genital tract secretions. Studies with 143 infertile couples revealed that the presence of antibodies in sera was not necessarily reflected in individual's genital tract secretion and vice versa. These data emphasize the importance of detecting antisperm antibodies in sera as well as in genital tract secretions for correct evaluation of sperm immunity.

Adult