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K L Holmes

Publications and source records attributed to K L Holmes.

At least 37 records · Page 2Linked to original sources
PubMed1993

Importance of interferons in recovery from mousepox.

Gamma interferon is shown to be critical in recovery of C57BL/6 mice from mousepox. Anti-gamma interferon treatment of mice infected in the footpad with ectromelia virus resulted in enhanced spread to and efficient virus replication in the spleen, lungs, ovaries, and, especially, liver. All treated, infected mice died within a mean of 7 days, 2.5 days earlier than mice with severe combined immunodeficiency that were given a comparable infection. On the other hand, alpha interferon appeared not to have a major role in controlling virus replication in tissues examined, and beta interferon was important for virus clearance in the liver and ovaries but not the spleen. Either anti-alpha, beta interferon or anti-beta interferon antibody therapy resulted in only 25% mortality. Infected control mice survived but showed persistence of ectromelia virus at the site of infection (the footpad) and transient presence of the virus in the spleen, liver, lungs, and ovaries and in the fibroreticular but not lymphoid cells of the draining popliteal lymph node. Depletion of gamma interferon but not alpha and/or beta interferon resulted in a significant reduction in the numbers of splenic T (especially gamma delta-TCR+), B, and Mac-1+ cells, although the proportion of Mac-1+ cells in the spleen increased compared with control values. Depletion of alpha, beta, or gamma interferons did not severely affect the generation of virus-specific cytotoxic T-lymphocyte responses or natural killer cell cytolytic activity. This study, in which a natural virus disease model was used, underscores the crucial importance of gamma interferon in virus clearance at all stages of infection and in all tissues tested except the primary site of infection, where virus clearance appears to be delayed.

Animals↗
PubMed1993

High expression of NK-1.1 antigen is induced by infection with murine AIDS virus.

Spleen cells from mice infected with LP-BM5 MuLV, a causative agent of murine acquired immunodeficiency syndrome (MAIDS), were tested for frequency of NK-1.1+ cells and natural killer (NK) activity. During the first 3 weeks following infection, NK activity was well conserved, but by 9-12 weeks post-infection (p.i.), killer activity was depressed; however, the frequency of NK-1.1+ cells increased within 4 weeks of infection and remained elevated thereafter, even following the decline in functional killing activity. Since the absolute number of NK-1.1+ cells increased after infection, the ability of each NK-1.1+ cell to kill the targets seems drastically impaired. Extraordinary expansion of NK-1.1-positive cells was induced by infection with LP-BM5-defective virus (BM5def), a crucial element for MAIDS induction, but not with a helper non-pathogenic virus. With advance of MAIDS the NK-1.1 antigen (Ag) was preferentially expressed on B220+ and Thy-1+ cells, in contrast to CD4+ and CD8+ cells, and among activated large cells a higher proportion was NK-1.1+ than NK-1.1-. Mice with graft-versus-host disease (GVHD) due to class II major histocompatibility complex (MHC) Ag disparity showed a high frequency of NK-1.1 expression in association with other phenotypic alterations, very similar to those seen in mice with MAIDS. In contrast, B6-lpr/lpr mice developed similar activation of B cells but did not exhibit enhanced expression of the NK-1.1 marker. Thus, enhanced expression of the NK-1.1 Ag might be associated with chronic activation of lymphocytes through a common but not universal pathway.

Animals↗
PubMed1992

Pulmonary histopathology induced by respiratory syncytial virus (RSV) challenge of formalin-inactivated RSV-immunized BALB/c mice is abrogated by depletion of CD4+ T cells.

In previous studies, it was observed that children immunized with a formalin-inactivated respiratory syncytial virus vaccine (FI-RSV) developed severe pulmonary disease with greater frequency during subsequent natural RSV infection than did controls. During earlier efforts to develop an animal model of this phenomenon, enhanced pulmonary histopathology was observed after intranasal RSV challenge of FI-RSV-immunized cotton rats. Progress in understanding the immunologic basis for these observations has been hampered by the lack of reagents useful in manipulating the immune response of the cotton rat. This problem prompted us to reinvestigate the characteristics of immunity to RSV in the mouse. In the present studies, extensive pulmonary histopathology was observed in FI-RSV-immunized or RSV-infected BALB/c mice upon RSV challenge, and studies to determine the relative contributions of CD4+ or CD8+ T cells to this process were undertaken. Mice previously immunized with FI-RSV or infected with RSV were depleted of CD4+, CD8+, or both T-cell subsets immediately prior to RSV challenge, and the magnitude of inflammatory cell infiltration around bronchioles and pulmonary blood vessels and into alveolar spaces was quantified. The magnitude of infiltration at each anatomic site in previously FI-RSV-immunized or RSV-infected, nondepleted animals was similar, indicating that this is not a relevant model for enhanced disease. However, the effect of T-cell subset depletion on pulmonary histopathology following RSV challenge was very different between the two groups. Depletion of CD4+ T cells completely abrogated pulmonary histopathology in FI-RSV-immunized mice, whereas it had a much smaller effect on mice previously infected with RSV. FI-RSV-immunized or RSV-infected animals depleted of CD8+ T cells had only a modest reduction of pulmonary histopathology. In addition, RSV infection induced high levels of major histocompatibility complex class I-restricted cytotoxic T-cell activity, whereas FI-RSV immunization induced a low level. These data indicate that immunization with FI-RSV induces a cellular immune response different from that induced by RSV infection, which likely played a role in enhanced disease observed in infants and children.

Animals↗
PubMed1992

Resistance to respiratory syncytial virus (RSV) challenge induced by infection with a vaccinia virus recombinant expressing the RSV M2 protein (Vac-M2) is mediated by CD8+ T cells, while that induced by Vac-F or Vac-G recombinants is mediated by antibodies.

It was previously demonstrated that the vaccinia virus recombinants expressing the respiratory syncytial virus (RSV) F, G, or M2 (also designated as 22K) protein (Vac-F, Vac-G, or Vac-M2, respectively) induced almost complete resistance to RSV challenge in BALB/c mice. In the present study, we sought to identify the humoral and/or cellular mediators of this resistance. Mice were immunized by infection with a single recombinant vaccinia virus and were subsequently given a monoclonal antibody directed against CD4+ or CD8+ T cells or gamma interferon (IFN-gamma) to cause depletion of effector T cells or IFN-gamma, respectively, at the time of RSV challenge (10 days after immunization). Mice immunized with Vac-F or Vac-G were completely or almost completely resistant to RSV challenge after depletion of both CD4+ and CD8+ T cells prior to challenge, indicating that these cells were not required at the time of virus challenge for expression of resistance to RSV infection induced by the recombinants. In contrast, the high level of protection of mice immunized with Vac-M2 was completely abrogated by depletion of CD8+ T cells, whereas depletion of CD4+ T cells or IFN-gamma resulted in intermediate levels of resistance. These results demonstrate that antibodies are sufficient to mediate the resistance to RSV induced by the F and G proteins, whereas the resistance induced by the M2 protein is mediated primarily by CD8+ T cells, with CD4+ T cells and IFN-gamma also contributing to resistance.

Animals↗
PubMed1991

Cytokine secretion by C3H-lpr and -gld T cells. Hypersecretion of IFN-gamma and tumor necrosis factor-alpha by stimulated CD4+ T cells.

Mice homozygous for lpr and gld develop profound lymphadenopathy characterized by the expansion of two unusual T cell subsets, a predominant Ly-5(B220)+ CD4- CD8- double negative (DN) population and a minor CD4 dull+ Ly-5(B220)+ population. The mechanisms promoting lymphoproliferation are unknown, but one possibility is a abnormality in the production of cytokines that regulate T cell growth. In the present report, unfractionated LN cells and sorted T cell subsets from C3H-lpr, -gld, and -+/+ mice were compared for spontaneous and induced secretion of a spectrum of lymphokines. In addition, CD4+, CD4 dull+ Ly-5(B220)+, and DN T cells were examined for expression of CD3 epsilon, TCR-alpha/beta heterodimers, Ly-6C, and CD44 and for proliferative responses to immobilized anti-TCR mAb and cofactors. These studies revealed that sorted DN T cells did not secrete IL-3, IL-4, IL-5, IL-6, GM-CSF, TNF-alpha, or IFN-gamma spontaneously or after TCR-alpha/beta cross-linking. In contrast, stimulated unfractionated lpr and gld LN cells proliferated strongly and secreted high levels of IFN-gamma and TNF-alpha and low levels of IL-3, IL-4, and IL-6. Despite a 5- to 10-fold deficit in the frequency of CD4+ and CD8+ T cells, cytokine secretion by lpr and gld LN generally exceeded that of +/+ LN. Comparisons of cytokine secretion by stimulated CD4+ T cells revealed that +/+, lpr, and gld CD4+ Ly-5(B220)- T cells proliferated strongly, but only lpr and gld cells produced significant levels of IFN-gamma. The lpr and gld CD4+ T cells also produced higher levels of TNF-alpha and IL-2 than +/+ cells. In contrast to normal CD4+ T cells, lpr and gld CD4+ Ly-5(B220)+ T cells proliferated weakly and did not secrete TNF-alpha, IL-2, or, in most experiments, IFN-gamma after stimulation. Phenotypic studies of T cell subsets revealed that unstimulated lpr and gld CD4+ Ly-5(B220)- T cells express significantly higher levels of CD44 than +/+ CD4+ T cells. In addition, CD4 dull+ Ly-5(B220)+ cells closely resembled DN T cells in size and expression of TCR-alpha/beta, CD3epsilon, CD44, and Ly-6C. Since elevated CD44 expression is generally associated with T cell activation and only previously activated normal CD4+ T cells produce high levels of IFN-gamma in vitro, our data suggest that lpr and gld CD4+ Ly-5(B220)- T cells contain a higher than normal proportion of primed or memory T cells and thus may be polyclonally activated in vivo.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

CD5+ peritoneal B cells express high levels of membrane, but not secretory, C mu mRNA.

We used in situ hybridization to study Ig mRNA levels in murine peritoneal and splenic B cells. Ig mRNA production fell into three distinct groups: low, intermediate, and high. Splenic B cells primarily exhibited low levels characteristic of resting B cells or high Ig mRNA levels characteristic of plasma cells. In contrast, a significant fraction of peritoneal B cells exhibited intermediate Ig mRNA levels. Intermediate Ig mRNA was T cell dependent in that congenic nu/nu mice had far fewer peritoneal cells expressing the intermediate Ig message than their wild type counterparts. CD5+ CD11b+ IgMbright+ peritoneal B cells were found to be mainly responsible for the production of intermediate Ig mRNA levels. The peritoneal CD5- CD11b+ IgMbright+ "sister" B cell subpopulation contained a lower percentage of intermediate Ig mRNA-producing B cells. CD5-CD11b-IgMdull+ "conventional" B cells produced negligible levels of Ig mRNA, comparable to those of unfractionated splenic B cells. Northern analysis showed that the majority of Ig mRNA expressed in the peritoneum is of the membrane rather than the secreted form. Consistent with that result, in short-term culture, peritoneal cells showed markedly less Ig secretion than did spleen cells. These studies describe novel Ig mRNA expression by peritoneal B cells and emphasize that within the peritoneal cavity, B cells do not tend to become antibody-secreting cells.

Animals↗
PubMed1990

Differences in the repertoire expressed by peritoneal and splenic Ly-1 (CD5)+ B cells.

Purified populations of B cells expressing the Ly-1 and/or Mac-1 surface Ag were isolated from normal unmanipulated mice by cell sorting. The number of lymphocytes in each population secreting antibodies reactive with DNA, bromelain-treated mouse RBC, phosphorylcholine and TNP-keyhole limpet hemocyanin was quantitated by ELISA spot assay. The proportion of B cells secreting Ig in vivo and the repertoire of antibodies they produced varied as a function of B cell phenotype and location. Among peritoneal lymphocytes, those that were Ly-1+ or Ly-1- Mac-1+ secreted Ig 10 times more frequently that Mac-1- Ly-1- B cells from the same location. In addition, the former populations expressed repertoires that were significantly skewed toward the production of antibodies reactive with bromelain-treated mouse RBC (p less than 0.001). In contrast, splenic B cells expressing the Ly-1 surface Ag did not differ significantly from splenic Ly-1- B cells in their expressed repertoire or frequency of Ig production. B cells isolated from the spleen and peritoneum tended to differ in antibody specificity from bone marrow and lymph node-derived lymphocytes. For example, B cells from the spleen secreted anti-DNA antibodies two to four times more frequently than B cells from other organs. These results demonstrate that phenotype and microenvironment influence the repertoire of antibodies expressed by B cells in vivo.

Animals↗
PubMed1990

Fluctuations in subsets of splenocytes and isotypes of Ig in young adult and aged mice resulting from Trypanosoma musculi infections.

A prominent feature of parasitic infections is the marked hyperplasia of lymphoid tissues. The resultant disruption of those tissues may be a major cause of the immunodepression that typifies parasitic infections. Trypanosoma musculi infections in mice evoke lymphoid hyperplasia and depressed immune responses. T. musculi infections are more severe in C3H than in C57BL/6 (B6) mice; and more severe in aged mice of either strain, compared with young adults. This report concerns a flow cytometric analysis of splenic leukocytes, identified by various surface Ag, in young and aged, trypanosome-infected mice of C3H and B6 strains. Companion studies included quantification of serum Ig isotypes at intervals during infection. The results support the following conclusions: a) all major types of splenic leukocytes were activated by trypanosome infection resulting in enlargement of the cells and proliferation ("blastogenic response"); b) in all young-adult mice and in aged B6 mice (but not aged C3H mice) Thy-1+, Ly-1+, and Ly-4+ cells increased moderately during infection whereas the number of Ly-2+ cells remained constant; c) all cells of the B lineage increased during the course of infection (except in aged C3H mice) with disproportionate increases in the most mature stage (IgG+); d) the responses of young adult C3H and B6 mice to infection differed as illustrated by the ability of B6, but not C3H, mice to limit hyperplasia and reverse the effect; e) aging of B6 mice was reflected by relative inability to regulate generation of mature Ig-producing cells; f) aging of C3H mice was severe as reflected by the relative inability of most subsets of leukocytes to react to the infection, possibly because of abnormalities that were intrinsic in aged, normal C3H mice. It is likely that: a) disruption of lymphoid tissue, probably mediated by alterations in the production of and responsiveness to cytokines, is responsible for the depressed ability of the immune system to defend against parasites; and b) such disruptive effects, being more pronounced in aged animals and less easily brought under control, account for the greater vulnerability of aged animals to parasitic infection.

Aging↗
PubMed1990

CD4+ T cells in murine acquired immunodeficiency syndrome: evidence for an intrinsic defect in the proliferative response to soluble antigen.

C57BL/6 mice inoculated with LP-BM5 murine leukemia viruses develop an immunodeficiency syndrome, termed murine acquired immunodeficiency syndrome (MAIDS), characterized by a variety of functional abnormalities of T and B cells. In the present study, we have analyzed the ability of lymph node cells from infected mice to generate secondary in vitro proliferative responses to soluble antigens. Our data demonstrate that the ability of lymph node cells to proliferate in response to soluble antigen or T cell mitogens declines progressively during the course of MAIDS. Impaired proliferative responses were shown to be characteristic of purified CD4+ but not CD8+ cells from infected mice when stimulated in the presence of normal accessory cells. In addition, the impaired responses of unseparated lymph node cells from infected mice could be reconstituted by the addition of purified CD4+ T cells from nodes of primed normal animals. These results strongly suggest that an intrinsic CD4+ T cell defect developing during the course of MAIDS contributes significantly to impaired responses to mitogens and to impaired secondary in vitro proliferative responses to soluble antigen.

Acquired Immunodeficiency Syndrome↗
PubMed1990

A unique subset of normal murine CD4+ T cells lacking Thy-1 is expanded in a murine retrovirus-induced immunodeficiency syndrome, MAIDS.

Some strains of mice inoculated with LP-BM5 murine leukemia virus (MuLV) develop a syndrome, termed mouse acquired immunodeficiency syndrome (MAIDS), characterized by progressive lymphoproliferation and profound immunodeficiency. LP-BM5 MuLV is a virus mixture that contains ecotropic (eco) and mink cell focus-induced MuLV and a defective genome that is the proximal cause of disease. Flow cytometry analyses of spleen and lymph nodes from susceptible C57BL/6 mice infected with this virus mixture revealed the presence in spleen and peripheral lymph nodes of a previously unrecognized subset of CD4+CD3+ T cells that are Thy-1-. The frequency of these cells increased with progression of disease, eventually comprising between 30% and 50% of all CD4+ cells. Infection of A/J mice, a strain which is genetically resistant to development of MAIDS, did not induce an increase of this T cell population, indicating that infection with the virus mixture was insufficient to induce its proliferation. A central role for the defective virus in this process was suggested by the finding that C57BL/6 mice infected with LP-BM5 eco alone did not have increased frequencies of Thy-1-CD4+ cells in spleen. Studies of spleen and peripheral lymph node cells from normal mice demonstrated the presence of Thy-1-CD4+ cells at frequencies of 1%-2%. Studies using two anti-T cell monoclonal antibodies, SM6C10 and SM3G11, that define four CD4+ subsets showed that Thy-1-CD4+ T cells from normal and infected mice were present only in the 6C10- subsets.

Animals↗
PubMed1990

Transformation of murine bone marrow cells with combined v-raf-v-myc oncogenes yields clonally related mature B cells and macrophages.

Murine bone marrow cells infected with replication-defective retroviruses containing v-raf alone or v-myc alone yielded transformed pre-B cell lines, while a retroviral construct containing both v-raf and v-myc oncogenes produced clonally related populations of mature B cells and mature macrophages. The genealogy of these transformants demonstrates that mature myeloid cells were derived from cells with apparent B-lineage commitment and functional immunoglobulin rearrangements. This system should facilitate studies of developmental relationships in hematopoietic differentiation and analysis of lineage determination.

Animals↗
PubMed1989

Functional and phenotypic alterations in T cell subsets during the course of MAIDS, a murine retrovirus-induced immunodeficiency syndrome.

The functional and phenotypic characteristics of Ly-4(CD4)+ and Ly-2(CD8)+ T cells were studied after induction of murine AIDS with LP-BM5 murine leukemia virus. Assays of spleen cells for their ability to generate in vitro CTL responses to TNP-modified autologous cells (self + x CTL) and to alloantigens (allo CTL) showed that self + x CTL responses were greatly impaired at 3 to 4 wk postinfection and were undetectable thereafter. Allo CTL responses were normal at 3 to 4 wk, but were reduced at 8 to 9 wk and absent at 14 wk postinfection. This sequential loss of self + x and allo CTL responses was related to a selective defect in Ly-4(CD4)+ Th cell function associated with impaired production of IL-2 and deficient proliferative responses to Con A or to soluble Ag. Changes in the functional characteristics of Ly-4(CD4)+ T cells were unrelated to changes in their frequency in spleen, but did correlate with marked alterations in their distribution among four subsets defined by mAb SM3C11 and SM6C10. Assays of CTL responses generated by mixtures of spleen cells from normal and infected mice suggested that active suppression of Ly-4(CD4)+ Th function may contribute to this defect. Studies of Ly-2(CD8)+ T cells showed that infection with LP-BM5 murine leukemia virus also induced a major phenotypic shift in subpopulations defined by their reactivity with mAb 6C10. However, this phenotypic change did not appear to correlate with major functional defects.

Animals↗
PubMed1989

Characterization of the immunodeficiency of RIIS/J [corrected] mice. I. Association with the CD5 (LY-1) [corrected] B cell lineage.

RIIIS/J mice produce low antibody responses to several polysaccharide Ag of bacterial origin. They have low levels of serum IgM and IgG3 and high levels of serum IgG2a and IgG2b. Low serum IgM and IgG3 have been attributed to a low frequency of CD5 (Ly-1) B cells, which play an important role in the production of natural antibodies. Indeed, RIIIS/J mice have a low frequency of CD5 (Ly-1)+, IgM bright+, Ly-5 (B220)dull+ (i.e., CD5 (Ly-1) B) cells in their peritoneum. RIIIS/J mice treated with LPS produce a low anti-bromelain-treated mouse RBC splenic plaque-forming cell response and a normal anti-mouse transferrin splenic PFC response. Those data are compatible with the fact that CD5 (Ly-1) B cells contain the precursors of B lymphocytes secreting anti-bromelain-treated mouse RBC antibody. However, they have a higher frequency of IgM bright+, Mac-1+ cells in their peritoneum. These cells represent the CD5 (Ly-1) "sister population" of CD5 (Ly-1) B cells described by others. This suggests that characteristics usually associated with the CD5 (Ly-1) lineage are applicable only to the CD5 (Ly-1)+ Mac-1+ IgM+ population, but not the related CD5 (Ly-1)- Mac-1+ IgM+ population. RIIIS/J mice should thus prove a valuable model to study the CD5 (Ly-1) B cell lineage.

Animals↗
PubMed1989

Biologic and molecular genetic characteristics of a unique MCF virus that is highly leukemogenic in ecotropic virus-negative mice.

California wild mouse-derived ecotropic virus Cas-Br-M induces a spongiform encephalopathy and a wide variety of hematopoietic neoplasms on inoculation of neonatal mice. We isolated a MCF virus [Ns-6(186) MCF] from a thymic T-cell lymphoma developing in a NFS mouse inoculated with Cas-Br-M virus. Biologically cloned NS-6(186) MCF virus, in contrast to previously studied MCF viruses, was found to induce thymic or nonthymic T-cell lymphomas with high efficiency in the absence of ecotropic helper virus. Comparison of the restriction endonuclease maps derived from Cas-Br-M and NS-6(186) MCF revealed differences only in the env region, between 5.8 and 7.8 kb from the 5' end. Two biologically active molecular clones of the NS-6(186) MCF (clone 15 with two LTRs and clone 19 with 1 LTR) were studied. Although both clones exhibited similar in vitro activities, clone 15-derived virus induced only T-cell lymphomas with short latency whereas clone 19-derived virus induced a wide variety of neoplasms with a significantly longer latency. Nucleotide sequence analysis established that the U3 region of each of the two LTRs of clone 15 has a 53-bp duplication which includes "enhancer elements," but that the single LTR of clone 19 has no such duplication.

Amino Acid Sequence↗
PubMed1988

Transcriptional and post-transcriptional regulation of c-myc, c-myb, and p53 during proliferation and differentiation of murine erythroleukemia cells treated with DFMO and DMSO.

The proto-oncogenes myc, myb, and p53 produce nuclear proteins which have been implicated in the regulation of proliferation or differentiation in a number of systems. The expression of these proto-oncogenes was studied in murine erythroleukemia (MEL) cells during (i) normal replication, (ii) DMSO-induced differentiation and (iii), alpha-difluoromethylornithine (DFMO)-restricted cell division and differentiation. The RNA levels of c-myc, c-myb, and p53 were all elevated during normal cellular proliferation; only c-myc expression declined when the cells stopped dividing although the rate of transcription for the gene was unaltered. In contrast, treatment of the cells with DFMO resulted in gradual cessation of cell replication and a decrease in transcription of c-myc, c-myb and p53. When the MEL cells were induced to differentiate with dimethyl sulfoxide (DMSO), a transient reduction in c-myc and c-myb RNA levels occurred immediately prior to the G1 arrest with a concomitant decrease in transcriptional activity, while p53 mRNA production was elevated without an increase in transcription. Similar changes of the proto-oncogene levels were observed when the MEL cells were incubated with DFMO and then later induced with DMSO, a protocol which restricts differentiation of the MEL cells. From these experiments we conclude that (i) c-myc, c-myb, and p53 are regulated independently at both the transcriptional and post-transcriptional levels, (ii) DFMO inhibits MEL cell proliferation and expression of several genes, including c-myc, c-myb and p53, and (iii) DFMO suppresses terminal differentiation but is unable to alter proto-oncogene changes associated with the early stages of differentiation.

Animals↗