J. Figueroa

Tinea capitis in south-western Ethiopia: a study of risk factors for infection and carriage

Background Tinea capitis is a common dermatophyte infection which constitutes an important public health problem among children worldwide. The endemic nature of scalp ringworm in Africa is perpetuated mainly by the lack of knowledge about the prevalence and carrier status, and the absence of control measures.

A murine monoclonal antibody exhibiting high species specificity for Histoplasma capsulatum var. capsulatum.

A monoclonal antibody (mAb) exhibiting a high degree of species specificity for the yeast phase of the dimorphic fungus Histoplasma capsulatum was produced by a modification of the standard mAb production protocol. The technique for generating mAbs involved the use of the immunosuppressive drug cyclophosphamide to diminish the response in mice to immunodominant cross-reactive epitopes. This mAb exhibited clear specificity and did not react by ELISA with the closely related genera Blastomyces, Paracoccidioides and Sporothrix. In Western blots it recognized a linear determinant on a 70-75 kDa molecule in H. capsulatum antigen, with an extremely faint reactivity to antigens of identical molecular mass derived from Sporothrix and Paracoccidioides, and no reactivity against Blastomyces antigen.

Evidence that the M antigen of Histoplasma capsulatum var. capsulatum is a catalase which exhibits cross-reactivity with other dimorphic fungi

A panel of monoclonal antibodies (Mabs) was raised against histoplasmin, the antigen derived from the mycelial phase of Histoplasma capsulatum var. capsulatum which contains the diagnostically useful H and M antigens. A number of Mabs were obtained which recognized a 70-75 kD component of an antigenic preparation of H. capsulatum var. capsulatum by Western blotting. When reacted with histoplasmin by Western blotting the Mabs recognized a similar 70-75 kD band, together with a series of higher molecular mass bands at approximately 130, 190 and 230 kD, a pattern which correlates strongly with both the published relative molecular mass (Mr) of the M antigen and the known subunit structure of the enzyme catalase. These Mabs were also shown to recognize a commercial preparation of Aspergillus niger catalase by ELISA. Other dimorphic fungi were also reactive with these Mabs by Western blotting, indicating the presence of common epitopes on the catalase molecules of these species.

Murine monoclonal antibodies recognizing a non-capsular antigen that distinguishes between Cryptococcus neoformans var. neoformans and C. neoformans var. gattii

A panel of 4 monoclonal antibodies (mabs) of the IgG1 subclass have been made against a cytoplasmic antigen of Cryptococcus neoformans. Mab 4E2 recognized isolates of C. neoformans var. gatti by enzyme-linked immunosorbent assay (ELISA), whilst the other antibodies did not recognize these antigens. By Western blot 4E2 recognized determinants at 110-125, 65-70, 45-50 and 36-38 kDa. Mabs 9E6, 7C7 and 5D9 recognized bands at 36-38 and approximately 30 kDa. All 4 mabs (4E2, 9E6, 7C7 and 5D9) recognized both non-encapsulated and encapsulated isolates of C. neoformans var. neoformans by ELISA, and in addition showed reactivity to only the cytoplasm and cell membrane of yeasts by immunofluorescence. Mab 7C7 recognized antigens of the closely related fungus Trichosporon beigelii by ELISA but did not recognize any other fungal antigens. The other 3 mabs showed no recognition of T. beigelii or any other fungal pathogens tested.

Preparation of murine monoclonal antibodies against the yeast phase of the dimorphic fungus Sporothrix schenckii

Three murine monoclonal antibodies (Mabs) were raised against a cytoplasmic antigen of the yeast phase of the pathogenic fungus Sporothrix schenckii using a modification of standard hybridoma technology incorporating the immunosuppressive drug cyclophosphamide. When tested for species-specificity within the pathogenic dimorphic fungi one of these Mabs (S5) showed little cross-reactivity by enzyme-linked immunosorbent assay and Western blot, though there was some recognition of Paracoccidioides brasiliensis antigen. This Mab recognized a 70-75 kDa molecule on reduced Western blots of S. schenckii antigen. The other two Mabs (S12 and S15) showed cross-reactivity with all dimorphic fungal antigens tested, though they appeared to recognize a molecule of similar molecular weight. This is the first report of any attempt to raise species-specific Mabs against this important causative agent of dermatological disease.