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Biomedical subjects

I Green

Publications and source records attributed to I Green.

At least 163 records · Page 9Linked to original sources
PubMed1972

Histocompatibility-linked immune response gene function in guinea pigs. Specific inhibition of antigen-induced lymphocyte proliferation by alloantisera.

A number of autosomal dominant immune response (IR) genes have been identified in both mice and guinea pigs. These IR genes have been shown to be linked to the major histocompatibility antigens of the species and to be functionally expressed primarily in T lymphocytes. In order to more fully understand the relationship between IR genes, histocompatibility antigens, and immune recognition, the effect of specific alloantisera on lymphocyte stimulation induced by antigens under control of IR genes was examined. Using lymphocytes from strain 2 or strain 13 animals, the in vitro proliferative responses both to antigens which are known to be under genetic control (DNP-GL in strain 2 guinea pigs and GT in strain 13 guinea pigs) and to an antigen which is not known to be under genetic control (PPD) were inhibited to a similar degree and to a much greater extent than the response to phytohemagglutinin. However, when cells from F(1) (2 x 13) animals are used, the alloantisera markedly inhibit only the response which is linked to the histocompatibility antigens against which the serum is directed. Thus, the anti-2 serum inhibited the response to DNP-GL but not to GT; the anti-13 serum inhibited the response to GT but did not affect DNP-GL response. The inhibitory activity of the alloantisera could not be removed by absorption with gamma globulin of the opposite strain. It can be concluded from these observations that immune response genes produce a cell surface-associated product and that this product plays a role in the mechanism of antigen recognition by the T lymphocyte. The mechanisms by which alloantisera block this process of antigenic recognition is not resolved nor is the relationship between the IR gene product and the antigen-binding receptor of the T lymphocyte. The approach described here offers a powerful tool for the resolution of these problems.

Animals↗
PubMed1972

The uropod-bearing lymphocyte of the guinea pig. Evidence for thymic origin.

In this study, the frequency of uropod formation and the type of lymphocyte bearing the uropod was investigated in various guinea pig lymphocyte populations. Without prior in vitro stimulation, almost 40% of peritoneal exudate lymphocytes (PELS) form uropods, while thymocytes and lymph node cells form far fewer. Subsequent stimulation in vitro with purified protein derivative demonstrated that there is an association between antigen reactivity and frequency of uropod formation in these populations. The ultrastructure of these uropods is identical to that described for human lymphocytes stimulated with phytohemagglutinin. In the populations studied, all the lymphocytes forming uropods lack easily detectable surface membrane immunoglobulin and are therefore most likely thymus-derived or T lymphocytes.

Animals↗
PubMed1972

Antibody-dependent lymphoid cell-mediated cytotoxicity: no requirement for thymus-derived lymphocytes.

The capacity of lymphoid cells from nonsensitized mice to lyse antibody-coated target erythrocytes in vitro does not require the presence of thymus-derived or thymus-dependent lymphocytes. Thus, spleen cells from thymus-deprived mice and spleen cell populations from which thymus-dependent lymphocytes had been removed were fully competent to mediate destruction of antibody-coated target cells. However, prior treatment of spleen cell populations with antibody to kappa chains diminished this function, suggesting a role for bone marrow-derived lymphocytes.

Animals↗
PubMed1972

Specific immune response genes of the guinea pig. V. Influence of the GA and GT immune response genes on the specificity of cellular and humoral immune responses to a terpolymer of L-glutamic acid, L-alanine, and L-tyrosine.

The ability of guinea pigs to make immune responses to the random linear copolymer of L-glutamic acid and L-alanine, GA, and to L-glutamic acid and L-tyrosine, GT, is each controlled by a different immune response gene. On the other hand, the random linear terpolymer of L-glutamic acid, L-alanine, and L-tyrosine, GAT, which contains both GA and GT antigenic determinants, is immunogenic in all guinea pigs. After GAT immunization, all animals develop delayed hvpersensitivity and serum antibody specific for GAT. However, only those guinea pigs possessing the GA immune response gene demonstrate cross-reactive delayed hypersensitivity when challenged with GA. In addition, the anti-GAT antisera produced by those animals having the GA gene contain cross-reacting anti-GA antibodies. The sera from guinea pigs lacking the GA gene have no anti-GA antibody activity. Thus, we have demonstrated that a specific immune response gene controlling responsiveness to a "simple" antigen can determine the specificity of both cellular and humoral immune responses to a more complex antigen.

Alanine↗
PubMed1972

Receptors for complement and immunoglobulin on human leukemic cells and human lymphoblastoid cell lines.

The bone marrow-derived (B) lymphocyte can be identified by the presence of easily detectable surface immunoglobulin and a receptor for antigen-antibody-complement complexes (EAC'). Monocytes and macrophages also bear a receptor for EAC' and in addition possess a receptor for red cell-IgG complexes (EA). Thymus-derived (T) lymphocytes bear neither of these receptors. The cells of 15 patients with leukemia and 19 human lymphoblastoid cell lines were examined for the presence of the EAC' and EA receptors. Of the human leukemias studied, only the cells from the patients with chronic lymphatic leukemia (CLL) possess the EAC' receptor. The EA receptor could not be demonstrated on CLL cells; hence, CLL cells bear the lymphocyte EAC' receptor and by this criteria represent B lymphocytes. 12/19 of the cell lines studied could be classified as B lymphocytes by the presence of the EAC' receptor and absence of the EA receptor. 2/19 cell lines possessed both the EAC' and EA receptors and thus resemble the monocyte. 5/19 cell lines had no detectable receptor for EAC' or EA. The approach presented in this study for the classification of leukemias and cell lines as to their B lymphocyte, T lymphocyte, or monocyte origin may have useful diagnostic and therapeutic implications.

Animals↗