title: Characterization of tumor-infiltrating T lymphocytes in B-cell lymphomas of mucosa-associated lymphoid tissue.
abstract: B-cell lymphomas of mucosa-associated lymphoid tissue invariably contain large numbers of reactive tumor-infiltrating T cells. In the stomach, these lymphomas develop secondary to Helicobacter pylori infection, and clinical and in vitro studies have shown that their growth depends on help provided by H. pylori-specific T cells. In this study we characterized tumor-infiltrating T cells in low- and high-grade B-cell lymphomas of mucosa-associated lymphoid tissue using immunohistochemistry. In most cases, CD4+ T cells dominated and almost all T cells were CD45RO+ memory cells. In 11 of 13 cases studied, the proliferating T cells were CD4+ and no proliferation was observed in the CD8+ subset. In low-grade lymphomas, between 7 and 24% of T cells expressed CD40L whereas no CD40L expression was observed in the majority of high-grade tumors. Examination of homing receptor profile showed that both alpha 4 beta 7 integrin+ and L-selectin+ T cells were present. Examination of T cell diversity by a panel of antibodies against different T-cell receptor V beta regions and by analysis of T-cell receptor genes using polymerase chain reaction suggested that the T cells in these tumors were polyclonal. These results show that low-grade B-cell lymphomas of mucosa-associated lymphoid tissue contain a significant population of activated helper T cells that may be important in supporting tumor growth.
authors.affiliation: Department of Histopathology, University College London Medical School, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: Koulis
authors.forename: T
authors.initials: T
authors.lastname: Diss
authors.forename: P G
authors.initials: PG
authors.lastname: Isaacson
authors.forename: A
authors.initials: A
authors.lastname: Dogan
mesh_terms: D000368:Aged; D015815:Cell Adhesion Molecules; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D007156:Immunologic Memory / Q000502:physiology; D016023:Integrins / Q000378:metabolism; D019041:L-Selectin / Q000378:metabolism; D016246:Lymphocytes, Tumor-Infiltrating / Q000473:pathology* / Q000502:physiology*; D018442:Lymphoma, B-Cell, Marginal Zone / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009088:Mucoproteins / Q000378:metabolism; D010641:Phenotype; D006377:T-Lymphocytes, Helper-Inducer / Q000473:pathology / Q000502:physiology
chemical_list: D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; D016023:Integrins; C504265:MADCAM1 protein, human; D009088:Mucoproteins; C071777:integrin alpha4beta7; D019041:L-Selectin