Cytotoxic and soluble mediator responses by complement (C3) receptor-bearing lymphocytes from patients with B-cell immunodeficiency diseases

Common variable immunodeficiency and purine nucleotidase and nucleoside phosphorylase deficiency. A case report

The results of immunological and purine enzyme investigations in an adult male patient with common variable immunodeficiency, recurrent lymph node granuloma and splenomegaly are presented. Serum immunoglobulins were present in trace amounts only and a progressive loss of Ig-bearing peripheral lymphocytes were demonstrated. Furthermore, the mitogenic responses to PHA. ConA and PWM were markedly reduced and the ratio of T.m/T.g cells was decreased. Finally, a combined deficiency of lymphocyte purine 5-nucleoside phosphorylase was demonstrated in the patient.

IgG subclasses in human periodontal disease. II. Cytophilic and membrane IgG subclass immunoglobulins

Lymphocyte membrane-associated IgG subclass antibodies in human periodontal disease were studied to ascertain the relative presence of cytophilic IgG antibodies and the membrane Fc receptors which bind them. The experimental approach correlated the effect of incubating gingiva in tissue culture medium to remove cytophilic antibodies with the changes in the number of Fc receptors detectable after washing. The evidence indicated that the majority of lymphocytes in mild gingivitis lesions lacked cytophilic IgG antibodies as well as Fc recetors. In severe gingivitis, the number of IgG subclass bearing lymphocytes increased to about half of the total lymphoid population, while the percentage of Fc receptor bearing cells remained quite low (12.3 % +/- 3.2, S.E.). The majority of IgG subclass bearing lymphocytes had membrane IgG which serve as receptors for antigen; such cells are classically defined as bone marrow (B) derived lymphocytes and serve as the progenitor for plasma cells. Gingival specimens for patients with periodontitis were found to contain the highest percentage of Fc receptor bearing lymphocytes (38.3% +/- 12.6 S.E.) and cytophilic IgG antibodies. The findings indicate that the clinical stages of human periodontal disease are characterized by different populations of infiltrating lymphocytes.

T lymphocyte induction of non-T cell-mediated nonspecific cytotoxicity. I. Introduction mechanisms

Mononuclear cells (MNC) from normal humans consistently failed to give nonspecific cytotoxic responses. However, after removal of T cells by sheep erythrocyte (E) rosetting, the remaining non-RFC (rosette-forming cells) now gave significant nonspecific cytotoxic responses against both autologous and allogeneic target cells. Reconstitution experiments with T cell subpopulations failed to suppress these nonspecific non-E-RFC-mediated cytotoxic responses. There was also no evidence to indicate the involvement of antibody in this nonspecific cytotoxicity. The cytotoxic cells were characterized as non-E-rosetting, non-phagocytic, and glass adherent lymphocytes; no evidence of monocyte-macrophage participation was found. The inductive trigger of non-E-RFC-mediated cytotoxicity was found to be soluble factors released by T cells during E-rosette formation at 4 degrees C. Incubation of MNC with horse, marmoset and human erythrocytes under identical conditions failed to trigger cytotoxicity. The incubation of quiescent MNC with E-rosetting supernatants (ERS) induced nonspecific cytotoxic responses equivalent to those mediated by separated non-E-RFC. ERS-activated MNC destroyed both autologous and allogeneic target cells. The ERS supernatants themselves were not cytolytic. These findings suggested that cell separation procedures, and possibly in vivo events, which activate T cells may also induce non-T cell-mediated nonspecific cytotoxicity.