T cell-mediated immunity to oncornavirus-induced tumors. I. Ly phenotype of precursor and effector cytolytic T lymphocytes

Regression of tumor induced by murine sarcoma virus (MSV) is accompanied by the formation of specific cytolytic T lymphocytes (CTL). Selection of T-cells sets by Ly phenotype determination allows separation of T sets involved in the cytolytic reaction. After MSV inoculation we demonstrate that a) Ly123+ cells contain precursors of CTL, b) direct cytolysis is mainly mediated by Ly23 cells, 3) cytolytic memory is divisible into "early" memory, carried by Ly23 cells, and "late" memory, which reverts to an Ly123 precursor population, and d) Ly1 cells are required to induce anti-MSV antibody formation.

T cell-mediated immunity to oncornavirus-induced tumors. I. Ly phenotype of precursor and effector cytolytic T lymphocytes

Regression of tumor induced by murine sarcoma virus (MSV) is accompanied by the formation of specific cytolytic T lymphocytes (CTL). Selection of T-cells sets by Ly phenotype determination allows separation of T sets involved in the cytolytic reaction. After MSV inoculation we demonstrate that a) Ly123+ cells contain precursors of CTL, b) direct cytolysis is mainly mediated by Ly23 cells, 3) cytolytic memory is divisible into "early" memory, carried by Ly23 cells, and "late" memory, which reverts to an Ly123 precursor population, and d) Ly1 cells are required to induce anti-MSV antibody formation.

T cell-mediated immunity to oncornavirus-induced tumors. II. Ability of different T cell sets to prevent tumor growth in vivo

These studies demonstrate that two different types of protective immunologic reactions are generated in mice after inoculation with M.MSV. Type I protection, mediated by Ly1 cells, prevents MSV-induced sarcomas but has no effect on the growth of MLV+ lymphomas. This anti-MSV protection reflects induction of antivirion antibody and delayed type hypersensitivity reaction. Type II protection is mediated by Ly23 cells and prevents the growth of an MLV+ lymphoma, but has little or no protective effects against MSV-induced sarcomas. This "type II" reaction is directly related to CTL activity. The implications of these two protective reaction are discussed.

T cell-mediated immunity to oncornavirus-induced tumors. II. Ability of different T cell sets to prevent tumor growth in vivo

These studies demonstrate that two different types of protective immunologic reactions are generated in mice after inoculation with M.MSV. Type I protection, mediated by Ly1 cells, prevents MSV-induced sarcomas but has no effect on the growth of MLV+ lymphomas. This anti-MSV protection reflects induction of antivirion antibody and delayed type hypersensitivity reaction. Type II protection is mediated by Ly23 cells and prevents the growth of an MLV+ lymphoma, but has little or no protective effects against MSV-induced sarcomas. This "type II" reaction is directly related to CTL activity. The implications of these two protective reaction are discussed.

Analysis of absorption spectra changes induced by temperature lowering on phycobilisomes, thylakoids and chlorophyll-protein complexes

Using fourth derivative analysis, differences between room and low temperature absorption spectra were studied. The positions of most absorption bands of the water-soluble, accessory pigment complex, the phycobilisome, remained unchanged after cooling. The stability of the wavelength positions of chlorophyll a forms in vivo as a function of temperature (Gulyaev, B.A. and Litvin, F.F. (1967) Biofizika 12, 845--854) was generally confirmed. The wavelength positions of all chlorophyll a forms in the P-700 chlorophyll a protein complex were unchanged when the preparations were cooled to -196 degrees C. Likewise, with other chlorophyll-containing materials: the light-harvesting chlorophyll a/b protein complex and the thylakoids of higher plants, algae, and cyanobacteria, the wavelengths positions of most chlorophyll a forms were stable upon cooling. An exception was a 680 nm chlorophyll a band which was generally split at low temperature into two bands with the materials investigated. An interpretation of the multiplicity of chlorophyll spectral forms and the spectral changes induced by cooling for these forms is given using exciton theory and the energy-coupling variation of chlorophyll a molecules.

Direct evidence that natural killer cells in nonimmune spleen cell populations prevent tumor growth in vivo

Relatively large numbers of nonimmune spleen cells do not protect against the local growth of two lymphomas. However, this heterogeneous population of splenic lymphocytes contains a subset of cells that efficiently protects against in vivo tumor growth. This cell population (cell-surface phenotype Thyl.2(-)Ig(-)Ly5.1(+)) represents less than 5 percent of the spleen cell population and is responsible for in vitro NK-mediated lysis. Although these studies clearly and directly demonstrate that Ly5(+) NK cells selected from a heterogeneous lymphoid population from nonimmune mice can protect syngeneic mice against local in vivo growth of two different types of tumor cells (in contrast to other lymphocyte sets within the spleen), they do not directly bear upon the role of NK cells in immunosurveillance. They do indicate that highly enriched Ig(-)Thyl(-)Ly5(+) cells, which account for virtually all in vitro NK activity, can retard tumor growth in vivo. It is difficult to ascribe all anti-tumor surveillance activity to NK cells, because they probably do not recirculate freely throughout the various organ systems of the body. Perhaps NK ceils may play a role in prevention of neoplastic growth within discrete anatomic compartments where there is rapid differentiation of stem cells to mature progeny (e.g., bone marrow, spleen, and portions of the gastrointestinal tract)and may normally act to regulate the growth and differentiation of non-neoplastic stem cells. Long-term observation of chimeric mice repopulated with bone marrow from congenic or mutant donors expressing very low or very high NK activity may help to answer these questions.

Electrophoretic and spectrophotometric studies of chlorophyll-protein complexes from tobacco chloroplasts. Isolation of a light harvesting pigment protein complex with a molecular weight of 70,000

Abstract— …After a short‐term solubilization with sodium dodecyl sulphate, chloroplast membranes of tobacco were separated by polyacrylamide gel electrophoresis into three chlorophyll‐protein complexes. In addition to the two major complexes termed I and IIc corresponding respectively to P700 chlorophyll a‐protein and light‐harvesting chlorophyll a/b‐protein described by Thornber (1975), a relatively stable complex termed IIa has been observed. This new complex has an apparent molecular weight of 70,000 daltons and possesses Chl a and b.

Complexes I, IIa and IIC have been isolated and precise spectroscopic analyses have been performed. Fourth derivative analyses of low temperature absorption spectra suggest that complex IIa seems more representative than IIC of chlorophyll a forms present in intact thylakoid membranes.

Moreover, the electrophoretic study reveals that CPI and CPII are composed of only one polypeptidic subunit with respective molecular weights of 68,000 and 24,000 daltons.

Immune rejection of tumor cells: in vivo significance of anti-tumor in vitro immune reactions

The mechanism of immune tumor rejection remains poorly understood. The respective roles of antibodies, macrophages, cytolytic T cells (CTL) and that of "K" cells or any other cell which could be involved in antibody dependant cell mediated cytotoxicity are still unknown. It is probable that the CTL play some role in tumor rejection but the "in vivo" relevance of the other, "in vitro" detected phenomena, is less clear. The correlations between "in vivo" tumor rejection and "in vitro" detected reactions are very difficult to establish, specially for the following two reasons: a) the different methods used in vitro do not explore identical phenomena ; b) some of them provide both specific and non-specific reactions.