Sheldon Dray

Inversion of levels of human T and B cells in early pregnancy

CELL-MEDIATED immunity has been shown to be decreased during pregnancy1,2. Finn et al.3 suggested that the cause may be a decrease in the number of T cells; however, levels of T cells were unchanged in women in the third trimester of pregnancy4. In addition, the normal number of B cells was found in women who had been pregnant for at least 6 months5. Gergely et al.6 also found normal levels of T and B lymphocytes in women between 34 and 36 weeks of gestation. So far no change has been shown in T- and B-cell levels during the latter half of pregnancy.

The development of in vitro and in vivo anti-tumor cytotoxicity in noncytotoxic, mopc-315-tumor-bearer, spleen cells "educated" in vitro with mopc-315 tumor cells.

SummarySpleen cells from mice bearing various sizes of MOPC-315 plasmacytoma tumors were not cytotoxic in the 51Cr release assay or the local adoptive transfer assay. These noncytotoxic spleen cells became cytotoxic, however, upon in vitro cocultivation with MOPC-315 tumor cells. The maximal level of in vitro anti-tumor cytotoxicity (51Cr release) with in vitro “educated” tumor-bearer spleen cells was obtained on the fifth day of the cocultivation and was equal to or lower than the level of cytotoxicity seen with in vitro educated normal spleen cells. On the other hand, the level of in vivo anti-tumor cytotoxicity (Winn assay) achieved with tumor-bearer spleen cells educated in vitro was at least equal to, but usually greater than the level of anti-tumor cytotoxicity obtained with normal spleen cells educated in vitro. Thus, in vitro education can generate anti-tumor cytotoxicity in autochthonous lymphoid cells from tumor-bearing hosts. Such educated histocompatible cells should be useful for immunotherapy regimens that might be applicable to man.

Two Antigenically Different γ-Globulins in Domestic Rabbits Revealed by Isoprecipitins

Isoprecipitins used in an agargel immunochemical analysis of 500 normal sera obtained from several breeds of rabbits show that the individual rabbits contain one or the other or both of two γ-globulin antigenic specificities in their sera but never lack both of them.

Peptide differences of rabbit γG-immunoglobulin light chains controlled by allelic genes

Although antigenic determinants of the rabbit γ G-immunoglobulin molecule (composed of light and heavy polypeptide chains) have been shown to be under the control of at least two genetic loci ( a and b ), the structural basis of the control was not known. In the present work, peptide maps of the light chains derived from rabbits of different genotype have shown that at least part of the amino acid sequence of the light chains is controlled by the b locus. No evidence for such control of light chains by the a locus was detectable. In addition, these light chains were found to be electrophoretically heterogeneous and this heterogeneity was unrelated to the genotype.

Contribution of Allelic Genes Ab4 and Ab5 To Formation of Rabbit 7S γ-Globulins.∗

Summary 1. A method for quantitative analysis of allotypes is presented, based on successive precipitations of specific allotype from I131-labeled 7S γ-globulin with anti-allotype sera. 2. In the homozygotes or heterozygotes, 80–90% of the γ-globulin molecules have Ab4 or Ab5; 10–20% of the γ-globulin molecules have neither Ab4 nor Ab5. 3. An anti-Ab5 serum giving 2 precipitin bands with Ab5 sera was compared with an anti-Ab5 serum giving one precipitin band and was found to precipitate virtually the same quantity of γ-globulin-I131 (82% vs 80%) from the same γ-globulin preparation. This indicates that the 2 precipitin bands represent cross-reacting antigen-antibody systems. 4. In the heterozygote, 64% of the molecules have Ab4, 27% have Ab5. These quantities are independent of the order of precipitation, indicating that Ab4 and Ab5 are not found on the same γ-globuin molecules but only on separate molecules. The limit of overlap is less than 5%. 5. The question as to why allelic genes do not contribute to the same molecule, although both alleles appear to be operating in the synthesis of γ-globulin within the same cell, is discussed. It is suggested that polypeptide chains carrying the allotypic specificity Ab4 form pairs immediately after synthesis; and that the Ab4 pairs do not combine with similarly formed Ab5 pairs.

Identification of five human lymphocyte subpopulations by their differential binding of various strains of bacteria.

Abstract The property of various strains of bacteria to bind to lymphocytes is described and used to identify human lymphocyte subpopulations. The following bacterial strains isolated from patients were used: Arizona hinshawii (Ah), three strains of Escherichia coli (Ec 1 , Ec 2 , Ec 3 ), Bacillus globigii (Bg), Brucella melitensis (Bm), two strains of Corynebacterium diphtheriae (Cd 1 , Cd 2 ), Cornyebacterium xerosis (Cx), Sarcina lutea (Sl), two strains of Staphylococcus aureus (Sa 1 , Sa 2 ) and Staphylococcus epidermidis (Se). Purified human lymphocytes were centrifuged together with the bacteria, resuspended, and the percentage of cells with bacteria attached was determined by phase contrast microscopy. Each strain of bacteria was tested for its ability to bind to lymphocytes, to lymphocytes prelabeled with a different bacteria, and to lymphocytes prelabeled with anti-light chain antibody coated E. coli (a nonbinding strain). This procedure allowed the identification of five subpopulations of lymphocytes. B cells (15%) bound all the bacteria tested except Ec 1 , Bg and Se. T 1 cells (15%) bound only Ah, Ec 1 , Ec 2 . Ec 3 , Cd 1 , and Se; T 2 (25%) bound only Ah, Bg, Ec 1 , Ec 2 , Ec 3 , and Cx; T 3 (15%) bound only Cx, S1, and Sa 1 ; T 4 (30%) did not bind any of the bacteria tested. Three of the bacteria, Bm, Cd 2 and Sa 2 exclusively identified B cells.

Identification and genetic control of two rabbit low-density lipoprotein allotypes

Rabbits were immunized with a low-density lipoprotein (LDL) preparation isolated from rabbit serum by ultracentrifugation. This elicited precipitin isoantibodies which distinguished two antigenically different genetic variants, i.e., allotypes of serum LDL. Both allotypes were identified as LDL by the following criteria: (1) the precipitin lines stained intensely with the lipid stain Sudan black B; (2) the antigens were found in the low-density but not the high-density lipoprotein fraction; (3) the antigens migrated electrophoretically on Agarose in the α2to β region. That the inheritance of these two allotypes is controlled by a pair of allelic genes at an autosomal locus is based on allotypes present in 323 progeny from six possible mating combinations. This LDL locus designated Lpqwas shown not to be linked to the light-chain or heavy-chain loci of immunoglobulins.

In vitro conversion of normal mouse lymphocytes by plasmacytoma RNA to express idiotypic specificities on their surface characteristic of the plasmacytoma immunoglobulin

Abstract Using a “blind” experimental protocol, we have reaffirmed that RNA-rich extracts from plasmacytoma can convert normal mouse lymphocytes in vitro so that normal surface immunoglobulins (Ig) are replaced by specific plasmacytoma Ig as judged by an immunocytoadhesion assay that detects cells bearing the idiotypic specificity of the plasmacytoma Ig. No loss of biological activity could be detected when extensive degradation of DNA in the extracts by DNase was explicitly demonstrated or when de novo RNA synthesis by the cells was inhibited by actinomycin D, thus eliminating a role for DNA in the cell conversion. Loss of biological activity also failed to occur after the RNA-rich extracts were treated with pronase or when the amount of contaminating protein was markedly reduced; however, loss of activity did occur when de novo protein synthesis by the cells was inhibited by puromycin or cycloheximide, thus eliminating the possibility that the specific plasmacytoma Ig or a fragment thereof was passively transferred onto the cell surface with the RNA molecule as a carrier. However, mild RNase treatment that causes a relatively small increase in the amount of 4S RNA and yet retaining relatively large amounts of 18S and 28S RNA, as might result from only a few breaks in the intact RNA molecules, effectively destroyed the biological activity of the RNA-rich extracts, reaffirming the requirement for intact RNA. When the RNA-rich extracts were fractionated by sucrose density gradient centrifugation, the activity was limited to the 12S to 23S fractions.

Antibody coated bacteria

Process for identification and enumeration of B and T lymphocytes in an unseparated peripheral body sample comprises contacting the sample with two morphologically distinguishable bacteria, each of which is coated with an antibody specific to an antigen on one of the B or T cells. The presence of a B or a T cell is determined by rosette formation with the corresponding bacteria, as viewed under a microscope in a smear.

Monkey to human transfer of delayed hypersensitivity in vitro with RNA extracts

Abstract Human “nonsensitive” peripheral blood leukocytes were incubated with RNA extracts of lymphoid tissue from rhesus monkeys with skin-test sensitivity to keyhole limpet hemocyanin (KLH), purified protein derivative (PPD) or coccidioidin. In the presence of KLH, PPD, or coccidioidin, these nonsensitive human leukocytes specifically elaborated a material, presumably a migration-inhibitory factor, which inhibited the migration of guinea pig macrophages. Liver RNA extracts from sensitized monkeys, or RNA extracts from lymphoid tissues of nonsensitive monkeys in the presence of antigen, failed to elaborate this material (MIF).