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J L Strominger

Publications and source records attributed to J L Strominger.

At least 397 records · Page 22Linked to original sources
PubMed1982

Long-term human cytolytic T-cell lines allospecific for HLA-DR6 antigen are OKT4+.

Human allospecific cytotoxic T lymphocyte lines were established by weekly stimulation of peripheral blood lymphocytes with allogeneic Epstein-Barr virus-transformed lymphoblastoid cell lines in the presence of interleukin 2. The cytotoxic T lymphocyte lines were stimulated by either JY (which expresses HLA-A,B and -DR) or Daudi (which expresses HLA-DR but not -A,B antigens). Specificity of the effector cell lines was determined by antibody blocking and by patterns of cytolysis against a panel of target cell lines. The phenotype of the effector cells was identified by both negative (antibody and complement lysis) and positive (fluorescence-activated cell sorter) selection. The anti-JY lines only recognized targets bearing HLA-A2, B7 antigens and were composed exclusively of OKT4-8+ effector cells. The anti-Daudi lines, on the other hand, specifically recognized targets bearing DR6 and eventually contained only OKT4+8- cells. Thus, stimulation by Daudi cells can result in the generation of OKT4+ CTL lines that are allospecific for DR6 antigen.

Antigens, Surface↗
PubMed1982

Penicillin-binding proteins in Bacillus subtilis mutants.

The penicillin-binding proteins (PBPs) from mutants of Bacillus subtilis were studied and related to morphology. In a previously described cloxacillin-resistant mutant of B. subtilis strain Porton, PBP 2a had an altered mobility by sodium dodecyl sulfate gel electrophoresis and was present in increased amounts. In addition, PBPs 1a and 1b were missing in this mutant. The only morphological change seen was a decrease in size of about 15%. Studies of two Triton-resistant morphological mutants of B. subtilis 168, Tr49 (small diameter) and Tr61 (helical form), revealed no change in the number of PBPs compared with that of the parent strain. However, PBPs 1a and 1b had an altered mobility in the mutant Tr49.

Bacillus subtilis↗
PubMed1982

Penicillin is an active-site inhibitor for four genera of bacteria.

The hypothesis that penicillin acts as an active-site inhibitor cell wall biosynthesis was tested by a method of partial proteolytic mapping of penicillin-binding sites versus substrate-binding sites in cell wall D-alanine carboxypeptidases. This enzyme was obtained from four genera of bacteria, purified, and tested.

Bacillus↗
PubMed1982

The B95-8 isolate of Epstein-Barr virus arose from an isolate with a standard genome.

Blot hybridization studies revealed that the deletion which characterizes the DNA from the B95-8 strain of Epstein-Barr virus was not present in the virus from which the B95-8 strain was derived (883L). The deletion event must have occurred during establishment of the B95-8 cell line or very soon afterward, since the deletion was present in Epstein-Barr virus DNA from a cell line established with B95-8 virus soon after it became available. The presence of the deletion correlates with decreased expression of the gp220 viral envelope glycoprotein.

Cell Line↗
PubMed1982

Characterization of antigen recognized by the monoclonal antibody (4F2): different molecular forms on human T and B lymphoblastoid cell lines.

The monoclonal antibody 4F2 recognizes a disulfide-linked ricin-binding glycoprotein complex (Mr congruent to 125,000) composed of a sialylated heavy subunit (Mr congruent to 85,000 on T cell lines) and an unsialylated light subunit (Mr congruent to 41,000). The antigen (T85,41) recognized by 4F2 on T cell lines is structurally distinct from the antigen (B93, 41) on B cell lines. The heavy subunits, but not the light subunits, from all T cell lines examined were uniformly smaller in size than the heavy subunits from several B cell lines. This reflects differences in carbohydrate rather than protein represent in B93,41 compared with T85,41, because both heavy subunits have a common unglycosylated form (p65) and a common partially glycosylated precursor form (p68). Among non-T, non-B hematopoietic cell lines, the monocytoid line U-937 expressed an antigen that resembles B93,41, whereas the erythroleukemic line K-562 expressed an antigen more similar to T85,41. 4F2 recognizes a protein determinant on the heavy subunit (with or without N-linked glycosylation) and also the unglycosylated heavy subunit retains the ability to associate with light subunit. The light subunit itself contains no detectable N-linked carbohydrate. Unlike the transferrin receptor, synthesis of the antigen recognized by 4F2 on the promyelocytic cell line HL-60 did not diminish upon dimethylsulfoxide-induced differentiation, and thus is not tightly correlated with cell proliferation.

Antibodies, Monoclonal↗
PubMed1982

Delineation of immunologically and biochemically distinct HLA-A2 antigens.

Cytotoxic T cell (CTL) recognition of influenza virus in conjunction with HLA-A2 was examined in a population study. Virus-infected target cells from three unrelated A2-positive donors were not lysed by virus-immune CTL from any donor matched only for A2. The A2 antigens of these three donors were indistinguishable from the A2 antigens of other A2-positive donors as assessed by extensive serologic analyses; however, isoelectric focusing (IEF) of A2 molecules from these three donors demonstrated that their A2 heavy polypeptide chains are structurally distinct from those of "normal" A2-positive donors. To date 11% of all A2-positive donors tested exhibited a "variant" A2-associated CTL restriction antigen, and IEF of A2 heavy chains from all "variant" A2-positive cells revealed structural differences in each of these polypeptides. These results suggest there may be considerably greater polymorphism of HLA-A gene products than has been revealed by current serologic techniques.

Chemical Phenomena↗
PubMed1982

Specificity of OKT4+ cytotoxic T lymphocyte clones.

OKT4+, HLA-DR-specific CTL were cloned by limiting dilution, and two clones were evaluated. One clone, B8, specifically recognized DR6 antigens, whereas another cloned, C6, recognized an Ia-like determinant on some DR 3, 5, and 6 target cells. Both clones were OKT3+, OKT4+, and OKT8-, and their cytolysis could be blocked by OKT3 and OKT4, but not OKT8, antibodies. A panel of monoclonal antibodies that recognize DR molecules blocked target cell recognition by these OKT+ CTL. Although cloned B8 recognized a DR6-specific determinant, clone C6 appeared to recognize a supratypic determinant that may be common to some DR molecules (e.g., MT2) or possibly another human Ia-like antigen (e.g., SB). The availability of OKT+ CTL clones should help to dissect the Ia-like antigens recognized by human T cells.

Antibodies, Monoclonal↗
PubMed1982

Generation of long-term human cytolytic cell lines with persistent natural killer activity.

Human cell lines maintained by in vitro stimulation with the HLA-A, B-negative, DR-positive, Epstein Barr virus-transformed, lymphoblastoid cell line Daudi in the presence of conditioned medium demonstrated significant NK activity for over 6 wk in continuous culture. These cells lyse K562 and a broad panel of lymphoblastoid cell lines but do not lyse normal peripheral blood lymphocytes or pokeweed mitogen blasts. They possess the sheep red blood cell receptor but lack other T cell markers (Lyt-3+, OKT3-). Natural killer activity correlated with the presence of a Mac 1-positive subpopulation of cells present in these long-term lines.

Antibodies, Monoclonal↗
PubMed1982

Monoclonal antibodies reacting with immunogenic mycoplasma proteins present in human hematopoietic cell lines.

During studies of human hematopoietic cells, two novel anti-mycoplasma monoclonal antibodies reacting in human cell surface binding assays were generated. These monoclonal antibodies define antigens (called MP71 and MP33) that showed variable positive and negative expression in different cultures of the same human cell lines. Furthermore, negative cell cultures could be converted to positive cultures upon incubation with filtered media from a previously positive cell culture. A DNA staining assay was used to demonstrate the presence of mycoplasma in the cultures positive for MP71. The expression of MP71 on a panel of cell lines always correlated with the expression of MP33, suggesting that the latter antigen is also mycoplasma related. The monoclonal antibodies against both antigens (MP71 and MP33) were each able to block the growth of mycoplasma newly transferred to hematopoietic cell cultures. Biosynthesis of these mycoplasma antigens differed from biosynthesis of host cell surface antigens in that the former showed a relative insensitivity to gamma irradiation. Internal labeling with 35S-methionine or host cell surface labeling with 125I and analysis by immunoprecipitation showed that the antigens MP71 and MP33 had sizes of Mr 71,000 and 33,000, respectively. Also the antigen MP71 was almost completely, although transiently, cleared from the host cell surface by trypsin. Growth inhibition analysis of different mycoplasma species indicated that the monoclonal antibody recognizing MP71 was uniquely reactive with Mycoplasma hyorhinis.

Antibodies, Bacterial↗
PubMed1981

Transglutaminase modifies the carboxy-terminal intracellular region of HLA-A and -B antigens.

The HLA-A and -B antigens, encoded in the major histocompatibility complex, are transmembrane proteins whose carboxy termini project inwards from the cell membrane. The intracellular region of the HLA-B7 antigen is known to include two glutamine residues. We have used guinea pig transglutaminase to show that in vitro the enzyme couples amines specifically to glutamine residues in the carboxy-terminal region of the HLA-B7 and -A2 antigens. The specificity of this reaction has an immediate practical significance, but may also have a wider biological interest.

Cytoplasm↗
PubMed1981

Primary structure of the COOH-terminal membranous segment of a penicillin-sensitive enzyme purified from two Bacilli.

D-Alanine carboxypeptidase is a penicillin-sensitive intrinsic membrane enzyme which is composed of a hydrophilic NH2-terminal catalytic domain (Mr congruent to 45,000 to 47,000) and a COOH-terminal membranous segment (approximately 20 to 30 amino acids in length) (Waxman, D. J., and Strominger, J. L. (1979) J. Biol. Chem. 254, 4863-4875; Waxman, D. J., and Strominger, J. L. (1981) J. Biol. Chem. 256, 2059-2066). The primary structures of the COOH-terminal 30 amino acids of two D-alanine carboxypeptidase purified from bacterial membranes were determined (residues numbered from the COOH terminus): Bacillus stearothermophilus: (formula see text) Water-soluble fragments of the B. stearothermophilus D-alanine carboxypeptidase were shown to be formed by cleavage after Phe27 or after Leu25 as indicated by carboxypeptidase A and B analysis and by the release of the four COOH-terminal chymotryptic peptides (Val26-Leu25, Ser24-Phe16, Val15-Trp12, and Thr11-Leu1) upon formation of water-soluble chymotrypsin D-alanine carboxypeptidase. This indicates that the membranous fragment is largely contained within the COOH-terminal 24 residues. Thus, this bacterial membrane protein probably does not contain the significant cytoplasmic domain characteristic of transmembrane proteins such as glycophorin. The absence of an uninterrupted stretch of 20 to 25 uncharged residues suggests that the membrane anchoring of D-alanine carboxypeptidase may differ from that of simple transmembrane proteins. Possible structures for the membranous segment of D-alanine carboxypeptidase are discussed.

Amino Acid Sequence↗
PubMed1981

Human T cell proteins recognized by rabbit heteroantisera and monoclonal antibodies.

Many structural and functional features of the cell surface antigens of human T cells remain to be characterized. In these investigations, heteroantisera have been used to identify potentially interesting antigens not yet recognized by individual monoclonal antibody preparations. These antigens include patterns of bands (Mr 140-240K) on various T cells and T cell lines, at least six other bands on T cell lines and novel antigens on CTL lines. The majority of these antigens are different from the compiled list of antigens recognized by monoclonal antibodies against T cell proteins. The monoclonal OKT9 recognizes an antigen most prevalent on dividing cells, and this antigen is the same as that recognized by another monoclonal antibody, 5E9, and by previously described heteroantisera. The monoclonal antibody 4F2 has a distribution similar to OKT9, but it is structurally distinct, and is also present on monocytes. Three T cell surface proteins, two defined by the monoclonal antibodies OKT6 and OKT10, recognize proteins which resemble HLA antigens physiochemically. OKT6 and NAI/34 both recognize a 49,000 glycoprotein which is associated with a 12,000 subunit which reacts with anti-beta 2-microglobulin antibodies. OKT10 recognizes a 46,000 protein, also found with a 12,000 peptide, while the third protein, a beta 2-microglobulin-associated glycoprotein of 43,000 is not yet defined by a monoclonal Ab. Other monoclonals described here include 3A1 and PVR-11, which are on subsets of peripheral T cell, and B1-192 and B1-499 which are on some activated T cells.

Animals↗
PubMed1981

Dissection of distinct human immunoregulatory T-cell subsets by a monoclonal antibody recognizing a cell surface antigen with wide tissue distribution.

A monoclonal antibody, PVR-11, was obtained after hybridization of X63Ag8.653 murine myeloma cells with spleen cells from a mouse immunized with human lymphocytes. It recognizes a 175,000- to 185,000-dalton surface antigen present on approximately 80% of normal human peripheral T lymphocytes, 50% of non-T non-B cells, and less than 10% of B cells as determined by complement-dependent microcytotoxicity. It is also present on various leukemia T cells, on some but not all T lymphoblastoid cell lines, and on a small fraction of some B lymphoblastoid cell lines. Some B-cell chronic lymphocytic leukemia cells also express the PVR-11 antigen. Functional analysis of normal human T lymphocytes demonstrated that the PVR-11-depleted T-cell subset contains the precursors of both cytotoxic and suppressor cells but lacks helper cells. On the other hand, cytotoxic effector T cells express the PVR-11 antigen. These results demonstrate that antigenic determinants with relatively wide tissue distribution can dissect functionally distinct human immunoregulatory T-cell subsets.

Antibodies↗
PubMed1981

Human T cell surface antigens bearing a structural relationship to HLA antigens.

Three cell surface antigens that are structurally related to the human major histocompatibility antigens (called HLA antigens) have been characterized from the leukemic T cell line MOLT-4. One antigen is a glycoprotein of Mr 49,000 recognized by two monoclonal antibodies. OKT6 and NA1/34, and is associated with a Mr 12,000 subunit that crossreacts serologically with beta 2-microglobulin but can be distinguished from it by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. A second antigen, defined by the monoclonal antibody OKT10, is a Mr 46,000 protein associated with a small subunit distinct from beta 2-microglobulin. The OKT10 antigen is not restricted to T cells and is found on all T and B lymphoblastoid cell lines tested. The third protein is a beta 2-microglobulin-associated glycoprotein of Mr 43,000 that is serologically distinct from the OKT6 (NA1/34), OKT10, and HLA antigens. It is found on some, but not all, T cell lines but is absent from any other hematopoietic cell lines tested.

Antigen-Antibody Complex↗