Serological distinction of integral plasma membrane proteins as a class of mycobacterial antigens and their relevance for human T cell activation

Abstract

SUMMARYThis study pertains to classification and antigenic analysis of mycobacterial plasma membrane proteins in relation to human T cell proliferativc responses, using a 'fast grower' Mycobacterium fortuitum as model. Membrane vesicles, prepared hy sonicalion and differential centrifugation, were subjected to biphasic Triton X-114 extraction for isolation of integral (detergent phase) and peripheral (aqueous phase) proteins. Neither protein pool showed any appreciable overlap serologically. SDS-PAGE showed five prominent bands in peripheral and three in ihe integral protein pool, whereas immunohlotling with rahbit antisera identified only two major antigens {60 and 67 kD) in the former and five (24. 34, 42, 51 and 54 kD) in the latter, ELISA with a panel of anli-mycobacterial MoAbs revealed that nine out of 12 previously known antigens were present in the peripheral protein pool. Only two of them (33 and 40 kD) were additionally detected amongst integral proteins. The membrane-associated immunosuppressive moiety lipoarabinomannan was semiquantitatively located in aqueous phase. In bulk T cell proliferation assays, seven out of 10 subjects belonging to a 'respondcr" background (BT-BB leprosy palients and healthy contacts) showed high responses for Myco. fortttitum antigens. Proliterative response with integral proteins was comparable to thai with whole membrane, hut it was significanlly higher (/* < 0 0005) than the response with peripheral proteins. The distinction and relevance of integral membrane proteins as a class of mycobacterial antigens make them worthy of consideration in a subunit vaccine design.

Immunochemical characterisation of styrene maleic acid lipid particles prepared from Mycobacterium tuberculosis plasma membrane

“…The glycosylated constituents of MtM showed abundant binding to Con A, with a binding pattern similar to that reported in an earlier study [53]. Conspicuously, the low molecular mass (< 35 kDa) LAM moieties, which include LM and the membrane anchor PIMs [40,44,45] did not react with Con A suggesting that their mannose residues may be inaccessible to the lectin. Additionally, Con A did not stain any of the major MtM-SMALP proteins.…”

“…The TEM image of MtM showed clusters of vesicles formed spontaneously in the aqueous medium. Formation of such vesicles, typical of a plasma membrane, was also reported by us for a 'fast-grower' mycobacterium-M. fortuitum [45] and by Chiaradia et al [46] for another fast-grower, M. smegmatis. In the latter study, it was also shown that the mycobacterial outer membrane appears as 'unclosed' fragments suggesting that our MtM preparation represented the plasma (or inner) membrane of Mtb.…”

Case Report: Rhizopus arrhizus Rhino-Orbital-Cerebral Mycosis and Lethal Midline Granuloma: Another Fungal Etiological Agent

“…LMG lists among the most malignant ulcers and may occur as a granulomatous response of microbial etiology ( 5 – 8 ). Staphyloccus aureus ( 30 ), Nocardia farcinica ( 31 ), Mycobacterium fortuitum, M. marinum ( 32 ), Leishmania infantum ( 33 ), and EBV ( 9 – 11 , 34 ) are among the suspected causative agents. Mucoralean fungi have been reported to cause infections with highly similar clinical features ( 1 , 24 – 26 ).…”

Rhino-Orbital-Cerebral Mycosis and Extranodal Natural Killer or/and T-Cell Lymphoma, Nasal Type

“…Recently, we reported the inducement of proliferation in ENKTL-NT patients with M. irregularis or R. arrhizus infection ( 16) (Figures 7-9). We retrieved, from the peers, a series of reports about the proliferation of cytotoxic T lymphocytes induced by Staphyloccus aureus (125), Nocardia farcinica (126), Mycobacterium fortuitum, M. marinum (127), and Leishmania infantum (128), all of which were reported to induce ENKTL-NT-like syndrome (129-132). Still, another research reported the recovery of ENKTL-NT following treatment with sulfamethoxazole and levofloxacin when the infections were confirmed in the blood cultures (133).…”