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dc.contributor.authorMukherjee, Jean Margreth
dc.identifier.citationSource: Dissertation Abstracts International, Volume: 53-04, Section: B, page: 1776.;Advisors: Matthew D. Scharff.
dc.description.abstractThe humoral immune responses elicited by T cell-independent (TI) and T cell-dependent (TD) forms of an antigen were studied by examining the B cell immunoglobulin gene rearrangements and proteins which evolved. Therefore the responses elicited by BALB/c mice against the capsular polysaccharide of C. neoformans (CNPS) during Serotype A cryptococcal infection were compared to the TD response elicited by Serotype A glucuronoxylomannan-tetanus toxoid conjugate (GXM-TT) immunization. Although infection rarely resulted in an increase in serum antibody titer, all mice immunized with GXM-TT produced serum IgM, IgG, and IgA. Six IgM and one IgG{dollar}\sb1{dollar} monoclonal antibody (mAb) were isolated from an infected mouse and nine IgM, one IgG{dollar}\sb3,{dollar} eight IgG{dollar}\sb1,{dollar} and four IgA mAbs were isolated from a GXM-TT immunized mouse. At least one common antigenic determinant was recognized during both infection and GXM-TT immunization for the mAbs isolated recognized the four cryptococcal serotypes with the same relative affinities (A {dollar}>{dollar} B {dollar}>{dollar} D {dollar}>{dollar} C) and thus have the same fine specificity profile; bind the GXM but not the GalXM component of CNPS; have a reduced ability to bind de-O-acetylated GXM relative to native GXM; and compete for similar binding sites. Immunoglobulin heavy chain rearrangement patterns and CDR3 nucleotide sequences indicated the hybridomas isolated from each response were derived from 2-3 B cell clones, therefore the responses elicited during infection and GXM-TT immunization were oligoclonal. Consistent with the very similar antigen binding characteristics of mAbs from both responses, analysis of the hybridomas indicates all the mAbs were encoded by the same immunoglobulin gene loci (an unreported V{dollar}\sb{lcub}\rm H{rcub}{dollar}7183 family member, a seven amino acid D, J{dollar}\sb{lcub}\rm H{rcub}{dollar}2/J{dollar}\sb{lcub}\rm H{rcub}{dollar}4, V{dollar}\sb{lcub}\rm k{rcub}{dollar}5.1, and J{dollar}\sb{lcub}\rm k{rcub}{dollar}1). Thus the twenty-nine anti-CNPS mAbs isolated define a highly restricted immune response which arose regardless of the immune system milieu evoked by either TI or TD forms of cryptococcal antigen.;The ability of anti-CNPS mAbs to prolong survival was studied in an in vivo model of lethal murine cryptococcosis. Isotype and epitope specificity, but not moderate changes in affinity determined anti-CNPS mAb efficacy. Clonally related protective IgG{dollar}\sb1{dollar} and IgA mAbs were highly protective, IgM was less so and IgG{dollar}\sb3{dollar} was poorly protective. Efficacy was demonstrated in BALB/c and A/J mice against standard and clinical strains of C. neoformans.
dc.publisherProQuest Dissertations & Theses
dc.subjectCellular biology.
dc.titleCharacterization of hybridomas and monoclonal antibodies elicited by Cryptococcus neoformans

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