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Biomedical subjects

W W Cruikshank

Publications and source records attributed to W W Cruikshank.

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Chemoattractant lymphokines specific for the helper/inducer T-lymphocyte subset.

The cellular content of T-lymphocyte-rich inflammatory sites is dependent in part on the in situ elaboration of chemoattractant factors. We have previously described three T-lymphocyte-specific chemoattractant lymphokines; a chemokinetic factor, lymphocyte chemoattractant factor (LCF, MW 56,000), and two distinct lymphocyte migration inhibitory factors (LyMIF75K, MW 75,000; and LyMIF35K, MW 35,000). These factors are produced by human T cells in response to antigen, concanavalin A, or histamine stimulation. In this communication, we report that LCF and LyMIF35K are produced by OKT8+ (suppressor/cytotoxic) and OKT4+ (helper/inducer) lymphocytes, respectively, and are selectively chemoattractant for the OKT4+ lymphocyte subset. LyMIF75K is produced by OKT4+ cells and inhibits both OKT4+ and OKT8+ lymphocyte migration. Production of LCF and LyMIF35K by infiltrating lymphocyte subsets may be one mechanism whereby unactivated helper/inducer T lymphocytes are selectively recruited to sites of inflammation.

Antibodies, Monoclonal↗

Modulation of lymphocyte migration by human lymphokines. III. Characterization of a lymphocyte migration inhibitory factor (LyMIF35K).

The lymphokine that augments the migration of nonsensitized T lymphocytes (LCF) has been observed to be predominantly a chemokinetic factor, suggesting that separate lymphocyte migration inhibitory lymphokine(s) might exist. Utilizing a modified Boyden chamber assay, lymphocyte migration inhibitory activity was identified in the culture supernatants of human nylon wool-nonadherent blood mononuclear cells stimulated with concanavalin A in vitro for 48 hr. Sephadex G-100 gel filtration chromatography of these culture supernatants was shown to contain two regions of noncytotoxic migration inhibitory activity for nonsensitized human blood lymphocytes and rat splenic lymphocytes. The 30-40,000 dalton inhibitory activity was further characterized and noted to be cationic by ion-exchange chromatography and isoelectric focusing (pI = 8.6). Its biologic activity was sensitive to neuraminidase and to heat treatment but not to trypsin. The migration inhibitory activity of this factor (LyMIF35K) was directly proportional to its ability to increase lymphocyte adherence.

Animals↗

Functional characteristics of histamine receptor-bearing mononuclear cells. II. Identification and characterization of two histamine-induced human lymphokines that inhibit lymphocyte migration.

Although functional histamine receptors have generally been restricted to those human T lymphocytes expressing suppressor cell functions, more recent evidence suggests that histamine receptor-bearing human T lymphocytes are functionally heterogeneous and capable of other immunomodulatory activities. Lymphocyte chemoattractant factor (LCF) is a cationic sialoprotein with an apparent m.w. of 56,000, whose production is limited to histamine-type 2 receptor-bearing human T cells. LCF is selectively chemokinetic for T lymphocytes, and presumably contributes to the recruitment of unsensitized effector lymphocytes at inflammatory sites. In addition to LCF, Sephadex G-100 gel filtration of histamine-induced lymphocyte supernatants revealed two regions of migration inhibitory activity for human blood T and rat splenic lymphocytes. These regions corresponded to m.w. of 70,000 to 80,000 (LyMIF75K) and 30,000 to 40,000 (LyMIF35K). LyMIF75K had a single pI of 7.5 to 8.0, and its biologic activity was sensitive to trypsin but not to neuraminidase or heat (56 degrees C). LyMIF35K had a single pI of 8.5 to 8.8, and its biologic activity was sensitive to neuraminidase and heat but not to trypsin. These LyMIFs therefore appeared to be distinct from one another and physicochemically different from other migration inhibitory lymphokines. All three lymphokine activities appeared within 4 hr of incubation. The minimum concentration of histamine required to stimulate production of the LyMIF was 10(-6) M. Lymphocytes that did not adhere to a histamine affinity matrix were unable to produce either LyMIF upon subsequent stimulation with histamine or concanavalin A (Con A). Lymphocytes incubated with histamine and diphenhydramine produced LCF but neither LyMIF, whereas cells incubated with histamine in the presence of cimetidine produced both LyMIF but not LCF. These data suggest that a subset of lymphocytes defined by the presence of histamine-type 1 receptors are capable of producing two distinct species of lymphocyte migration inhibitory activity. These cells may contribute to the immobilization of effector T lymphocytes chemokinetically attracted to certain inflammatory sites.

Adult↗

Functional characteristics of histamine receptor-bearing mononuclear cells. I. Selective production of lymphocyte chemoattractant lymphokines with histamine used as a ligand.

Mitogens and antigens have been the traditional ligands for activating lymphocytes in vitro for the elaboration of lymphokines. Recently, histamine, by interaction with histamine-type 2 receptors on T lymphocytes, has been found to induce the production of one lymphokine, histamine-induced suppressor factor (HSF), that inhibits lymphocyte proliferation and lymphokine production in vitro. Because the biologic effects of HSF appear to be confined to alterations in lymphocyte function, we assessed the ability of soluble products of histamine-stimulated human blood mononuclear cells to affect another lymphocyte function, motility. Utilizing a modified Boyden chamber assay to assess lymphocyte migration, we identified chemoattractant activity for human blood and rat splenic T lymphocytes in histamine-induced mononuclear cell supernatants. No neutrophil or monocyte chemoattractant activity was present. Sephadex G-100 gel filtration of histamine-induced supernatants showed the lymphotactic activity eluted with a 56,000 m.w. This activity was cationic as determined by its elution pattern from a Sephadex QAE anion exchange matrix with a single pl of 9.0 to 9.4 determined by isoelectric focusing in sucrose. Its biologic activity is predominantly chemokinetic in nature, is stable to heating at 56 degrees C for 30 min, but is sensitive to the effects of trypsin and neuraminidase. These physicochemical and functional characteristics establish it as identical to a recently described concanavalin A-induced (Con A) lymphotactic lymphokine (LCF). Mononuclear cells that did not adhere to a histamine affinity matrix were unable to produce LCF when subsequently stimulated with histamine or Con A. Mononuclear cells incubated with histamine and diphenhydramine produced LCF; the addition of cimetidine eliminated LCF production. In fact, supernatants from cells incubated with histamine and cimetidine significantly inhibited lymphocyte migration, a phenomenon explainable by the two regions of lymphocyte migration inhibitory activity that were present in the Sephadex G-100 chromatography of crude histamine-induced supernatants. These data suggest that a subset of lymphocytes defined by the presence of histamine-type 2 receptors is capable of producing LCF while cells that bear histamine-type 1 receptors produce lymphocyte migration inhibitory activity.

Adult↗

Expression and in vitro evaluation of rhesus macaque wild type (wt) and modified CC chemokines.

Several human CC chemokines have been shown to inhibit HIV/ SIV infection in vitro, providing the rationale for their potential use in vivo. However, because of their inherent physiological effect, such chemokines are reasoned to be of limited therapeutic value due to potential side effects. The knowledge that amino terminus modified or deleted human RANTES retains its receptor binding properties but loses its signaling properties has provided a means to use such modified chemokines in vivo for possible therapeutic benefits. In efforts to test the efficacy of such modified chemokines, our laboratory has cloned, sequenced, and prepared recombinant forms of wild-type (wt) and amino-terminus modified rhesus macaque chemokines MIP-1alpha, MIP-1beta, and RANTES. These sets of chemokines were tested for their potential to inhibit SIV infection and induce signaling. The data showed that whereas wt chemokines retained both virus inhibitory and signaling functions, corresponding amino-terminus modified chemokines only showed virus inhibitory effects without detectable signaling effects. Such reagents will be valuable for evaluation of their therapeutic potential in vivo, either alone or as adjuncts to other chemotherapeutic drugs.

Amino Acid Sequence↗

Activation of caspase-3 by interferon alpha causes interleukin-16 secretion but fails to modulate activation induced cell death.

Interferon alpha (IFN-alpha) is the mainstay in the treatment of chronic hepatitis C virus (HCV) infection. Interleukin-16 (IL-16) attracts CD4+ cells to sites of inflammation and plays a role in the interaction of dendritic cells, T cells and B cells. In this study, we show that IFN-alpha itself induces IL-16 secretion by peripheral blood lymphocytes (PBL) and enhances IL-16 secretion by anti-CD3 stimulated PBL. Pro-IL-16 is cleaved into its active form by caspase-3. IFN-alpha increases caspase-3 mRNA levels in activated T cells (ATC), as shown by Northern blot analysis, whereas IL-16 mRNA levels are not affected by IFN-alpha. IL-16 secretion into culture supernatants correlates tightly with intracellular caspase-3 activity in ATC. In our experiments addition of specific caspase inhibitors did not reduce the proportion of ATC undergoing Fas-mediated cell death, but completely blocked IFN-alpha-induced IL-16 secretion into culture supernatants. In conclusion, our results suggest that IFN-alpha activates caspase-3, thereby increasing secretion of IL-16, whereas IFN-alpha-enhanced Fas-mediated cell death in ATC is not caspase-dependent.

Antibodies↗