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The present study is an attempt to produce xenogeneic anti-idiotype antibodies (Id) against mouse anti-H2 antibodies. The purpose is to obtain such anti-Id antibodies with reactivity against both B and T cells in quantities which will allow thorough investigation of the biochemical nature of the T cell receptor for alloantigen. Data are presented from experiments performed with an antiserum 5936 which was obtained after immunization with C57B1/6 anti-CBA antibodies. [ABSTRACT FROM AUTHOR]

The present experiments were carried out in order to answer the question whether the precursor T cells of cytotoxic T lymphocytes (PCTL) are Fc receptor positive (FcR+), Fc receptor negative (FcR-), or both. The data show that cytotoxic T lymphocytes (CTL) can be generated in vitro from both FcR+ and FoR- PCTL. Furthermore, we investigated if the function of FcR+ and FcR- CTL differed in the allograft response in vitro. Qualitatively, FcR PCTL differentiate into FcR- CTL only, whereas FcR+ PCTL differentiate into both FcR+ and FcR- CTL. However, quantitatively. CTL generated from FcR PCTL display a higher T cell mediated cytotoxicity than CTL generated from FcR+ PCTL. Mixing experiments indicate that FcR+ T cells regulate the differentiation of FcR- PCTL into CTL. These conclusions hold true for PCTL in both normal and memory responder cell populations. [ABSTRACT FROM AUTHOR]

The present report deals with our attempts to characterize the potent stimulator cell (s) that induce Fc receptor (FcR)-negative T lymphocytes to differentiate into cytotoxic T lymphocytes in vitro. We found two categories of such cells: [1] resting B cells. FcR+ T cells, and macrophages and [2] T cells either activated in 800-R-irradiated mice against H-2 antigens or M-locus antigens or activated in vitro by concanavalin A. The distinction between potent and weak stimulator cells is discussed in relation to the surface antigenic markers and the immunological function of these cells. [ABSTRACT FROM AUTHOR]

Lethally irradiated mice injected with syngeneic thymocytes and immunized with protein antigens develop specific helper T cells. If injected with semiallogeneic thymocytes, such mice generate H-2 antigen-specific cytotoxic T cells. Most spleen cells from these chimeric mice possess Fc receptors. The present results demonstrate that the development of Fc-receptor-bearing cells in thymocyte-injected irradiation chimeras seemingly is due to the physiological conditions in the mice rather than to the specific immunization. As a corollary, both helper T cells and cytotoxic T cells did not have Fc receptors, at least not in their effector state. Thus, Fc receptors on T cells would seem irrelevant to their immune function. [ABSTRACT FROM AUTHOR]

The antigen-induced proliferative response of lymph node cells (LNC) from mice sensitized to the monofunctional antigen L-tyrosine-p-azobenzenearsonate (ABA-Tyr) was used to monitor genetic control. All strains tested mounted significant responses, but those that were H-2(b) at both the I-A and I-E loci [B10., B6., B10.A(18R), A.BY, and C3H.SW] gave consistently weaker responses than other haplotypes. The F(1) progeny of matings between high and low responder phenotype parents (DBA/2 and B6, respectively) were high responders, establishing the dominance of the responder trait. Proliferative responses of LNC to ABA-Tyr were blocked by the appropriate anti-Ia monoclonal reagents. For example, B10.A(4R) LNCI (I-A(k), I-E(b)) were blocked by anti-I-A(k), whereas B10.A(3R) LNC (I-A(b), I-E(k)) were blocked by anti-I-E(k). Long-term cultures of T cell lines specifically reactive to ABA-Tyr were established from LNC of A/J mice immunized with ABA-Tyr and were cloned by limiting dilution. The proliferative responses to ABA-Tyr of 14 out of 15 clones tested were I-A restricted on the basis of activation by antigen-presenting cells from appropriate recombinant strains and the blocking activity of the monoclonal anti-Ia antibodies. The response of the other clone was I-E restricted. The fine antigen specificity of the clones was studied using structural analogs of the homologous antigen to induce proliferation. The clones could be divided into three types with respect to responsiveness to ABA-histidine (ABA-His). One group responded about equally well to ABA-His and ABA-Tyr. A second set responded less strongly to ABA-His than to ABA-Tyr, while the third showed no response above background to ABA- His. In all instances, the ABA-His-responding clones discriminated exquisitely between the 2-azo and 4-azo histidine isomers, responding only to the 4-azo compound. These T cell clones provide extremely useful tools for studies of T cell specificity, antigen recognition and lymphoid cell interaction systems.

Immune guinea pig lymph node cells were fractionated on Ig anti-Ig or HSA anti-HSA affinity columns or on plastic surface in medium containing carbonyl iron. These techniques selectively removed B lymphocytes, K lymphocytes or adherent cells. The residual cells (Fc receptor-negative T lymphocytes) responded to soluble antigen in vitro in the same way or even better compared with nonfractionated cells. In addition, there was no indication that antigen-antibody complexes were superior to antigen in triggering lymph node cells or purified lymph code T lymphocytes into DNA synthesis. The results obtained suggested that memory T lymphocytes can be stimulated by antigen autonomously.

The survival of peritoneal exudate macrophages after 3 to 10 days in culture was examined by measuring the numbers of phagocytes per culture. This was determined by letting the cultured cells phagocytize Latex particles. The number of Latex particle-containing cells was taken as a measure of the survival of phagocytes. It was found that one tenth of the cells judged by light microscopy as macrophage-like survived the culture period. Thus, the calculated plating factor of 9.3 was used to estimate the actual number of macrophages in suspensions of spleen, lymph node or thymus cells by culturing these cells and subsequently counting Latex particle-containing cells. In addition, the acridine orange technique was used to determine actual numbers of macrophages in freshly prepared cell suspensions of lymphoid organs. Latex studies on spleen and thymus cells gave results correlating well with data obtained by the acridine orange technique. By contrast, many more acridine orange positive cells than phagocytizing cells were found when lymph node cells were cultured.