Biomedical subjects

V K Torigian

Publications and source records attributed to V K Torigian.

3 recordsLinked to original sources

PubMed1990

Immunologic responsiveness in American cutaneous leishmaniasis lesions.

American cutaneous leishmaniasis is a disease of skin and mucous membranes in which T lymphocytes reactive to Leishmania (Viannia) braziliensis are thought to contribute to protective immunity. To characterize the nature of the T cell inflammatory infiltrate in American cutaneous leishmaniasis lesions, immunohistochemistry with mAb that define T cell subpopulations and in situ hybridization to detect mRNA coding for IFN-gamma were performed. In both localized cutaneous (LCL) and mucocutaneous (MCL) lesions, we observed a predominance of T memory (CD4+CD45RO+) as compared to T naive cells (CD+CD45RA+). The percentages of cells containing IFN-gamma mRNA were equivalent in both LCL and MCL lesions. T cells were extracted from LCL and MCL lesions and analysis indicated that T cells from both lesions had been stimulated by L. (V.) braziliensis in vivo and gave equivalent proliferative responses in vitro. The present data suggest that T memory cells, which are likely to elaborate IFN-gamma, are components of DTH response to L. (V.) braziliensis and participate in the pathogenesis of both LCL and MCL lesions.

Animals↗

PubMed1989

Characterization of Mycobacterium leprae cell wall-associated proteins with the use of T lymphocyte clones.

Development of a vaccine against leprosy depends on the identification of Ag that stimulate cell-mediated immune responses. We have previously demonstrated that cell wall proteins of Mycobacterium leprae are highly immunogenic. By using human cell wall-specific T cell clones we have begun to characterize soluble proteins that integrate into the cell wall skeleton. T cells from leprosy lesions were expanded with IL-2 in vitro yet retained specificity to Ag of the insoluble cell wall core (CWC) in vitro, indicating that T cells had been activated by CWC Ag in vivo. A cell wall protein-peptidoglycan complex and cell wall protein preparations lacking carbohydrates and lipids from CWC retained T cell reactivity. To identify immunogenic protein component(s) of cell wall protein, T cell lines were established to cell walls and tested against M. leprae proteins separated by SDS-PAGE and transferred to nitrocellulose. Greatest T cell reactivity was observed to proteins of Mr 7 kDa, 16 kDa, and 28 kDa. T cell clones reactive with 7-kDa and 16-kDa Ag from gels failed to respond to proteins of other Mr separated under either reducing or nonreducing conditions, indicating that these molecules are not subunits of larger proteins and may represent monomeric units polymerized into cell walls. The approaches described herein for characterization of immunodominant T cell Ag of M. leprae may be useful for study of T cell Ag in cell walls of bacterial pathogens of man.

Bacterial Proteins↗

PubMed1989

CD2 expression and function in lepromatous leprosy.

Leprosy is a spectral disease in which clinical presentation is thought to be related to the host immune response. Previous investigations have suggested that selective unresponsiveness to Mycobacterium leprae in patients with lepromatous leprosy is due to the presence of M. leprae-specific T-suppressor cells. However, it has recently been suggested that CD2 modulation was the mechanism for the observed impaired immune response in lepromatous patients. Therefore, we studied the expression of CD2 and CD3 on lymphocytes in lepromatous skin lesions and peripheral blood mononuclear cells (PBMC). Using immunohistochemical techniques, we found that virtually all of the CD3+ cells in leprosy skin lesions expressed CD2. In addition, indirect immunofluorescence flow cytometry demonstrated that most CD3+ cells in the peripheral blood possessed the CD2 marker, suggesting that CD2 expression of T-lymphocytes is normal. T-cell activation using paired anti-T11(2) and anti-T11(3) or anti-CD3 monoclonal antibodies demonstrated similar 3H-thymidine incorporation and gamma interferon production in the PBMC of lepromatous patients in comparison with the PBMC of their contacts and tuberculoid patients. However, lepromatous PBMC did not proliferate or produce gamma interferon in response to M. leprae. Our data suggest not only that CD2 expression is normal on T lymphocytes in lepromatous leprosy skin lesions but also that CD2 expression in peripheral blood lymphocytes is functional in T-cell activation. Defective CD2 modulation does not appear to be the mechanism for specific unresponsiveness in lepromatous leprosy.

Antibodies, Monoclonal↗