Induction of T-cell-mediated immunity against MethA fibrosarcoma by intratumoral injections of a bacillus Calmette-Guérin nucleic acid fraction

Summary MY-1, which consists of DNA and RNA extracted and purified from bacillus Calmette-Guérin (BCG), has been shown to have strong antitumor activity against various experimental tumors. To examine the role of T cells in the antitumor mechanism of MY-1, the effect of MY-1 injection on the development of tumor-specific immunity against MethA fibrosarcoma was investigated. MY-1 injections inhibited tumor growth less effectively in T-cell-deficient nude mice than in normal BALB/c mice. MethA tumor growth was suppressed after inoculation with L3T4-positive lymphocytes from tumor-bearing mice treated with MY-1. MethA-specific delayed-type hypersensitivity was also detected in tumor-bearing mice treated with MY-1. Immunohistochemical analyses showed that many L3T4-positive and a few Lyt2-positive cells infiltrated the regressing tumors. These results indicate that intratumoral MY-1 injections induce a MethA-specific, L3T4-positive cell-mediated, delayed-type hypersensitivity, which is necessary for the tumor regression.     

Distribution of Lyt antigens on the surface of thymocytes associated with thymic macrophages and dendritic cells

Summary Thymocyte subpopulations that are associated with macrophages and dendritic cells of the thymus in vivo were isolated from the thymuses of C57Bl/6 mice, and their Lyt phenotypes were analyzed. Electron-microscopic examination of immunogold-labeled cells revealed that the thymic complexes formed by macrophages mainly contained Lyt-2-positive thymocytes, while Lyt-1-positive thymocytes were more frequently associated with dendritic cells. The characteristic distributions of Lyt antigens on the surface of thymocytes in regions of reciprocal contact with macrophages (Lyt-2-positive cells) and dendritic cells (Lyt-1-positive cells) suggest that these antigens play a role in specific interactions between thymocytes and stroma cells.Dedicated to Professor Dr. T.H. Schiebler on the occasion of his 65th birthday     

Inducible functions in hybrids of a Lyt-2+ BW5147 transfectant and the 2C CTL line

Cytolytic activity and release of interleukin 2 (IL-2) were induced in Lyt-2-positive T-T cell hybrids by incubation with either concanavalin A or irradiated stimulator cells. Since hybrids of Lyt-2-positive class I-specific cytotoxic T lymphocytes (CTLs) with the fusable mouse thymoma cell line, BW5147, are invariably Lyt-2-negative, a derivative of BW5147 was produced by transfection which constitutively expresses surface Lyt-2.1. This cell line, 3B2, was fused with the H-2L^d-specific long term CTL line, 2C. Such hybrids expressed the transfected Lyt-2 gene but not the endogenous gene of the 2C fusion partner. That Lyt-2 plays a functional role in hybrids of 3b2 with 2C is shown by the observations that: 1) cytolysis by Lyt-2-positive hybrids was inhibited by Lyt-2-specific monoclonal antibody (mAb); 2) Lyt-2-positive but not Lyt-2-negative subclones of one such line develop specific cytotoxicity when incubated with stimulator cells; 3) Less IL-2 was released from Lyt-2-negative subclones incubated with stimulator cells than from Lyt-2-positive subclones; 4) Lyt-2-specific mAb inhibits release of IL-2 from Lyt-2-positive hybrids incubated with stimulator cells. All Lyt-2-positive hybrids expressed functional surface Lyt-3 encoded by the CTL fusion partner, demonstrating that expression of the Lyt-3 gene is not sensitive to the negative regulation which shuts off the endogenous Lyt-2 gene in hybrids of classI-specific CTLs with the 3B2 or BW5147 cell lines. The existence of inducible T-T cell hybrids expressing functional Lyt-2 and Lyt-3 provides a system for evaluation of the role(s) of Lyt-2 and Lyt-3 in the induction of function independent of cell growth. Address correspondence and offprint requests to: Paul D. Gottlieb     

Acute experimental allergic encephalomyelitis in the mouse: immunopathology of the developing lesion

To investigate the sequence of immunopathologic events during lesion formation in acute experimental allergic encephalomyelitis (EAE), SJL/J mice were inoculated with isogeneic spinal cord in complete Freund's adjuvant (CFA) and with Bordetella pertussis on Days 1 and 3 postinoculation (PI). Mice were sampled at different time points PI and T cells, T-cell subsets. Ia+ cells, Ig+ cells, albumin, and Ig deposits were localized in frozen sections by the avidin-biotin complex (ABC) method and direct fluorescence. Furthermore, samples were stained for Ia antigen, myelin basic protein (MBP), and galactocerebroside (GC) localization on endothelial cells by the ABC technique. Clinical and pathologic observations were correlated with the immunopathologic results. It was found that early in the disease process myelin and Ia-antigens were demonstrable on endothelial cells within the central nervous system (CNS). Simultaneously, damage to the blood-brain barrier was apparent, as indicated by albumin deposits, and small numbers of infiltrating T cells, T-cell subsets, and Ia+ cells were found. With time PI, the density of infiltrating total T cells (Thy-1.2+), helper/inducer (Lyt-1+), and suppressor/cytotoxic (Lyt-2+) T cells increased; Lyt-1+ and Lyt-2+ cells were detectable in meningeal as well as parenchymal infiltrates, while later on, Lyt-1+ cells showed some predilection for the CNS parenchyma and Lyt-2+ cells for meninges. Ia+ cells (B cells, macrophages, activated T cells) were present in small numbers only. Ig+ cells (B cells and macrophages) appeared shortly before onset of signs and persisted in moderate numbers. These results reconfirm the importance of early T-cell involvement for the development of EAE; they might also indicate a secondary role for Ig+ cells and are consistent with the concept that presentation of myelin antigens to T cells might occur locally on Ia-bearing endothelial cells within the CNS.     

In situ characterization of immunologically competent cells during the growth of a transplanted murine sarcoma

To characterize the immunocompetent cell populations which infiltrate a transplantable MCA-induced sarcoma and to study their modifications during tumoral growth, we used fluorescent antibodies to the cell membrane antigens Lyt-1, Lyt-2 and Asialo GM1. Early after tumor graft, an accumulation of cells bearing the Asialo-GM1 antigen was observed; this population corresponds mostly to NK cells. Simultaneously, a macrophage infiltration, identified by a cytochemical method, was seen. After this period, an accumulation of cells bearing the Lyt-1 antigen was observed; Lyt-2 positive cells were detected continuously during experimental period.     

Time course study of in situ expression of antigens following DNA-vaccination against VHS in rainbow trout (Oncorhynchus mykiss Walbaum) fry

The present study was performed as a time course study of fish vaccinated with 20 microg plasmid DNA vaccine encoding either the VHSV G-protein or the VHSV N-protein. Samples of the injection site were collected sequentially over a 7-week period. The study revealed an intense positive staining by immunohistochemistry for the viral G-protein mainly in the membrane of intact myocytes, most prominent by days 10-27, and with concomitant infiltration of inflammatory cells by days 13-38 that subsequently lead to a marked reduction in the number of myocytes expressing the G-protein. By immunofluorescence, infiltrating cells positive for MHC II, IgM, and C3 were demonstrated. By contrast, in fish vaccinated with the VHSV-N construct, fewer, diffusely positive myocytes were found, most prominent by days 13-38, these having a positive reaction for the N-protein mainly in the cytoplasm and variably in the membrane. N-protein positive myocytes did not attract infiltrating cells to the same degree. Positive reaction for the N-protein almost ceased by day 48 post-vaccination.     

Redistribution of Lyt-bearing T cells in acute murine experimental allergic encephalomyelitis: selective migration of Lyt-1 cells to the central nervous system is associated with a transient depletion of Lyt-1 cells in peripheral blood

Experimental allergic encephalomyelitis (EAE) was induced in SJL/J mice by using two injections of spinal cord homogenate in incomplete Freund's adjuvant supplemented with mycobacteria. Analysis of circulating Lyt-bearing subsets by indirect immunofluorescence during the course of acute EAE revealed the following: 1) during the pre-clinical phase of EAE (1 to 2 days before the onset of paralysis), there was a decrease in the percentage of Lyt-1- but not of Lyt-2-bearing cells in peripheral blood, and of both Lyt-1- and Lyt-2-bearing cells in spleen; 2) with the onset of clinically evident EAE, there was a decrease in both Lyt-1 and Lyt-2 cells in peripheral blood and an increase in the percentage of Lyt-1-bearing cells in pooled inguinal and axillary lymph node; and 3) after these early changes, there was a rapid reconstitution of the percentages of total Lyt-bearing cells and of both Lyt-1- and Lyt-2-bearing cells in peripheral blood. Immunohistochemical analysis of the central nervous system infiltrate revealed that the earliest lesions consisted predominantly of Lyt-1 T lymphocytes, with few Lyt-2 cells present. These results demonstrate that the influx of cells of the Lyt-1 inducer subset to the central nervous system in acute EAE is accompanied by a transient decrease in Lyt-1 cells in peripheral blood.     

Effects of various fixatives on the reactivity of plant cell tubulin and calmodulin in immunofluorescence microscopy

Summary We have examined the suitability of a variety of fixation regimes for immunofluorescence localization of tubulin and calmodulin in meristematic plant cells. Acrolein and most fixatives that contain glutaraldehyde (GA), while they have been employed by others in immunoenzyme, immunogold or immunofluorescence studies of plant endosperm, animal or plant tissue culture cells, cause unacceptably high background fluorescence of the dense cytoplasm of root meristem cells. Bifunctional imidoester and carbodiimide reagents do not give satisfactory results, either. Fixatives that have produced good results include paraformaldehyde (PFA) with the addition of picric acid or zinc salts or at high pH, a combination of PFA/GA/picric acid, and prefixation in PFA plus a monofunctional imidoester followed by PFA/GA. All of these cross-link the cytoplasm well enough so that cells can withstand isolation procedures, preserve antigenicity, allow antibody penetration and provide good contrast between specific and background fluorescence. The last two fixatives are of particular interest because of the potential they offer for immunoelectron microscopy of densely cytoplasmic, walled cells from tissues.     

Immunopathology of the lesion in chronic relapsing experimental autoimmune encephalomyelitis in the mouse

To analyze immunopathologic events within the central nervous system (CNS) during various stages of actively induced chronic relapsing EAE in SJL/J mice, animals were sampled at various timepoints post inoculation (PI) and T cells, T-cell subsets, Ia+ cells and Ig+ cells, albumin, and Ig deposits were localized in frozen sections by immunocytochemical techniques. Furthermore, sections were stained for the demonstration of Ia antigen, myelin basic protein (MBP), and galactocerebroside (GC) on endothelial cells and astrocytes. During the acute phase of the disease, large numbers of all types of inflammatory cells studied (Lyt-1.2+, L3T4+, Lyt-2+, Ia+, Ig+) were randomly distributed throughout lesions, a finding similar to that described previously for acute EAE. A more distinct distribution pattern of infiltrating T cells was found during active chronic disease in that L3T4+ cells predominated within the CNS parenchyma, while Lyt-2+ cells were more numerous in meningeal and perivascular areas. During all chronic stages, a low-grade diffuse infiltration of the neuraxis by hematogenous cells was present. Ia and myelin antigens were detectable on some endothelial cells and astrocytes. Damage to the blood-brain barrier, as indicated by albumin and Ig deposits, was more extensive during the acute than during chronic stages of the disease. Taken in concert, the results further support the possibility of local antigen presentation on endothelial and astroglial cells and an essential involvement of helper (L3T4+) T cells in CNS lesion formation. These findings correlate well with events reported previously in acute and chronic multiple sclerosis lesions.     

T-cell subsets in the thyroids of mice developing autoimmune thyroiditis

To examine the role of T-cell subsets in the development of thyroid lesions, female CBA/J mice were immunized with 60 μg mouse thyroglobulin (MTg) in 0.1 ml complete Freund's adjuvant in both hind footpads. The thyroids were removed 12–21 days later, pooled, and dispersed. The cell suspension was examined by membrane immunofluorescence for the distribution of Thy-1⁺, Lyt-1⁺, Lyt-2⁺, and sIg⁺ lymphocytes. For comparison, peripheral blood leukocytes (PBL) from the same animals were similarly examined. Throughout this 10-day interval, B cells in the thyroid were consistently below 5%, whereas B cells represented 19–24% of PBL. Thy-1⁺ cells in PBL ranged from 45 to 59%, whereas Thy-1⁺ cells in the thyroid were 37–50%. However, only thyroidal T cells showed a consistent decline with time and were replaced gradually by cells without T or B cell markers. In particular, there was a clear shift in the Lyt-1⁺:Lyt-2⁺ ratio from about 7 down to 2 in the thyroid as the early predominance of Lyt-1⁺ cells was followed by a relative increase in Lyt-2⁺ cells. Our results show that there is an accumulation of Lyt-1⁺ and Lyt-2⁺ cells in the infiltrated thyroid. These cells may include MTg-reactive, helper, and cytotoxic T cells which localize (or differentiate) in the thyroid and initiate the lesions.     

Contrasuppressor cells that break oral tolerance are antigen-specific T cells distinct from T helper (L3T4+), T suppressor (Lyt-2+), and B cells

Continuous gastric intubation of mice with the T cell-dependent antigen sheep erythrocytes (SRBC) leads to a state of systemic unresponsiveness to parenteral SRBC challenge, a state termed oral tolerance. The systemic unresponsiveness of mice rendered orally tolerant to SRBC, however, is converted to humoral immune responsiveness by adoptive transfer of effector T contrasuppressor (Tcs) cells. In this study, the authors have isolated and characterized the Tcs cell subset, from the spleens of orally immunized mice, which abrogates oral tolerance. This Tcs cell is a novel cell type, which can be separated from functional T suppressor (Lyt-2+) and T helper (L3T4+) cells, and the effector Tcs cell exhibits a Lyt-1+, 2-, L3T4- phenotype. Furthermore, contrasuppression is not mediated by B cells, including those of the Lyt-1+ phenotype. Adoptive transfer of splenic Lyt-1+, 2-, L3T4- T cells from C3H/HeJ mice given oral SRBC for 21 to 28 days and splenic Lyt-1+, 2-, L3T4- T cells of C3H/HeN mice orally immunized for a shorter interval abrogated oral tolerance. Furthermore, separation of Lyt-1+ T cells into L3T4+ and L3T4- subsets by flow cytometry resulted in Lyt-1+, L3T4+ T cells with helper but not contrasuppressor function, whereas the Lyt-1+, L3T4- T cell fraction abrogated oral tolerance even though it was without helper activity. This Tcs cell subset was also effective when added to cultures of tolerized spleen cells derived from SRBC-fed mice. The effector Tcs cells are antigen-specific, because Tcs cells from SRBC-immunized mice reverse tolerance to SRBC but not to horse erythrocytes (HRBC), and Tcs cells from HRBC-immunized mice reverse tolerance to HRBC but not to SRBC. When splenic T3 (CD3)-positive T cells (Lyt-1+, 2-, and L3T4-) were separated into Vicia villosa-adherent and nonadherent subpopulations, active contrasuppression was associated with the T3-positive and Vicia villosa-adherent T cell fraction. Thus, a distinct Lyt-1+, 2-, L3T4- T cell subset that contains a T3-T cell receptor complex, which can regulate oral tolerance, is present in spleens of orally immunized mice.     

Expression of GM3 microdomains on the surfaces of murine fibroblasts correlates with inhibition of cell proliferation

The expression and surface distribution of monosialoganglioside GM3 on the plasma membranes of NIH3T3 fibroblasts cultured at semiconfluence were analyzed by immunofluorescence as well as by immunogold electron microscopy on thin sections and surface replicas. The GM3 expression was highly variable from cell to cell and the distribution of the ganglioside on the positive cells appeared punctate. Quantitative immunogold electron microscopy showed the existence of well-defined GM3 clusters of different sizes scattered all over the cell surfaces. Double immunofluorescence analysis of 5-bromo-2’-deoxyuridine incorporation to identify proliferating cells and of GM3 expression indicated that most of the GM3-positive cells appear unable to synthesize DNA and demonstrated a growth-dependent expression of GM3. Accepted: 16 November 1999     

Immunohistology of lymphoid and non-lymphoid cells in the thymus in relation to T lymphocyte differentiation

The present paper reports the distribution of lymphoid and non-lymphoid cell types in the thymus of mice. To this purpose, we employed scanning electron microscopy and immunohistology. For immunohistology we used the immunoperoxidase method and incubated frozen sections of the thymus with 1) monoclonal antibodies detecting cell-surface-differentiation antigens on lymphoid cells, such as Thy-1, T-200, Lyt-1, Lyt-2, and MEL-14; 2) monoclonal antibodies detecting the major histocompatibility (MHC) antigens, H-2K, I-A, I-E, and H-2D; and 3) monoclonal antibodies directed against cell-surface antigens associated with cells of the mononuclear phagocyte system, such as Mac-1, Mac-2, and Mac-3. The results of this study indicate that subsets of T lymphocytes are not randomly distributed throughout the thymic parenchyma; rather they are localized in discrete domains. Two major and four minor subpopulations of thymocytes can be detected in frozen sections of the thymus: 1) the majority of cortical thymocytes are strongly Thy-1+ (positive), strongly T-200+, variable in Lyt-1 expression, and strongly Lyt-2+; 2) the majority of medullary thymocytes are weakly Thy-1+, strongly T-200+, strongly Lyt-1+, and Lyt-2- (negative); 3) a minority of medullary cells are weakly Thy-1+, T-200+, strongly Lyt-1+, and strongly Lyt-2+; 4) a small subpopulation of subcapsular lymphoblasts is Thy-1+, T-200+, and negative for the expression of Lyt-1 and Lyt-2 antigens; 5) a small subpopulation of subcapsular lymphoblasts is only Thy-1+ but T-200- and Lyt-; and 6) a small subpopulation of subcapsular lymphoblasts is negative for all antisera tested. Surprisingly, a few individual cells in the thymic cortex, but not in the medulla, react with antibodies directed to MEL-14, a receptor involved in the homing of lymphocytes in peripheral lymphoid organs. MHC antigens (I-A, I-E, H-2K) are mainly expressed on stromal cells in the thymus, as well as on medullary thymocytes. H-2D is also expressed at a low density on cortical thymocytes. In general, anti-MHC antibodies reveal epithelial-reticular cells in the thymic cortex, in a fine dendritic staining pattern. In the medulla, the labeling pattern is more confluent and most probably associated with bone-marrow-derived interdigitating reticular cells and medullary thymocytes. We discuss the distribution of the various lymphoid and non-lymphoid subpopulations within the thymic parenchyma in relation to recently published data on the differentiation of T lymphocytes.     

Destruction of pancreatic islet cells by cytotoxic T lymphocytes in nonobese diabetic mice

Proliferation of islet-associated leukocytes occurred when isolated islets from 20-wk-old female nonobese diabetic (NOD) mice were cultured with 10 U/ml rIL-2 for 7 days. Co-culture of these leukocytes with freshly isolated islets from 6- to 8-wk-old NOD donors in the presence of 1 U/ml rIL-2 produced islet structural deformation within 24 h and islet cytolysis within 48 h. Three lines of evidence suggest that these leukocytes were composed mainly of CTL specific for islet cells. First, morphologically, these proliferating cells adhered to NOD islets at 6 h and killed islets within 48 h of culture, but these phenomena could not be observed in the other tissues from NOD mice. These islet-derived cells were cytotoxic to NOD islet cells in a 51Cr-release assay, whereas no appreciable cytotoxicity was observed when NOD Con A-induced splenic blasts or fibroblasts were used as targets. Second, a flow cytometric analysis showed that these cells consisted of 97% Thy-1.2, 69% Lyt-2, 8% L3T4, and 4% asialo-GM1-positive cells, whereas Mac-1-positive cells could not be seen in these assays. After treatment with anti-Thy-1.2 or Lyt-2 mAb and C, these cells lost their activity to lyse NOD islet cells. However, these cells still had a full killing activity after the depletion of L3T4 or asialo GM1-positive cells. Third, islet cells from BALB/c, DBA/2, and B10.GD mice which share the same H-2K Ag with NOD mice were susceptible to cytolytic activity of these cells, whereas islet cells from NON, C57BL/6, C57BL/10, and C3H mice remained intact. Furthermore, anti-Kd antibody was capable of blocking this cytolysis. These results suggest that CTL expressing Thy-1.2 and Lyt-2 phenotypes appear to recognize the islet cell Ag with the restriction of MHC class I Kd, and then destroy NOD islet cells.     

单壁碳纳米管载锦鲤疱疹病毒ORF149核酸疫苗的构建

为了开发新型高效疫苗预防锦鲤疱疹病毒病,以单壁碳纳米管(SWCNT)作为运输载体,构建锦鲤疱疹病毒(KHV)ORF149核酸疫苗。首先构建pcDNA3.1(+)-ORF149重组质粒,通过瞬时转染和免疫印迹分析确定其表达情况,然后通过1,3-偶极环加成反应法将重组质粒与SWCNTs进行偶联,最后通过扫描电镜观察和核酸电泳鉴定其偶联是否成功。结果表明,构建的重组质粒转染细胞后经免疫印迹分析和间接免疫荧光试验均能检测到特异性信号;在核酸琼脂糖凝胶电泳中,构建的重组疫苗电泳条带消失;在场发射扫描电镜观察下,与重组质粒进行偶联的SWCNTs和空白SWCNTs形态差异明显。     

Genetic control of T-Cell subset representation in inbred mice

Lyt-2+ T cells constitute a significantly greater proportion of the total peripheral T-cell population in C57BL mice than in BALB/c and other mouse strains. The inheritance of this differential representation of Lyt-2- vs. Lyt-2+ T cells was studied by two-color immunofluorescence analysis of peripheral T cell subsets in BALB/c, C57BL, F1 and F2 generations, and in CXB recombinant inbred strains. It was shown that the C57BL phenotype (low Lyt-2-/Lyt-2+ ratio) is a dominant Mendelian character. Studies of subpopulations of thymocytes and of early thymus emigrants indicate that the representation of mature Lyt-2- and Lyt-2+ T cells is influenced by mechanisms of selection or differential turnover in the peripheral lymphoid organs, but that thymic and prethymic influences may also play a role.     

Alterations in the genome of wheat seedlings grown under drought stress and the effect of gibberellic acid on these alterations.

The changes in the amount of nuclear, chloroplast and mithocondrial nucleic acids of wheat (Triticum aestivum L.) seedlings in relation with drought stress and the effect of gibberellic acid (GA3) on these changes were investigated by spectrophotometric method. It was found that drought stress caused decrease in the amount of nucleic acids. In the seedlings to which GA3 was applied following drought stress, increase in the amount of nuclear nucleic acids (especially in the amount of labile DNA, which is the active portion) was determined. Similar results were observed in the amount of nucleic acids of mitochondria and chloroplasts. All these results show that drought stress caused quantitative changes in the genetic substrate of wheat seedling cells and GA3 application alleviated this effect by activating the synthesis of nucleic acids.     

Heterologous cross-linking of Lyt-2 (CD8) to the alpha beta-T cell receptor is more effective in T cell activation than homologous alpha beta-T cell receptor cross-linking

Ag recognition of Lyt-2 (CD8)-positive T lymphocytes requires the presentation by APC of a suitably processed Ag in association with MHC class I molecules. In previous studies we have obtained evidence that, for optimal activation, both the alpha beta-TCR and Lyt-2 have to participate in this recognition process. In the current study we investigate the functional consequences of limited cross-linking of these cell surface molecules by using soluble, dimeric hetero- and homoconjugates of mAb to Lyt-2 and to the TCR beta-chain (F23.1). Heterologous cross-linking of Lyt-2 to the TCR induced a vigorous, selective Lyt-2+ T cell proliferative response. Functionally active cytotoxic cells were generated, and a high frequency of responding cells was observed in limiting dilution analyses. In contrast, homologous TCR cross-linking initiated a less pronounced proliferation with a relatively low frequency of response, whereas Lyt-2 cross-linking resulted in no cellular proliferation. Significant T cell activation occurred with exposure to anti-Lyt-2: F23.1 mAb dimers at concentrations an order of magnitude lower than those required for stimulation by F23.1:F23.1 mAb dimers. The induction of proliferation by mAb dimers occurred in the absence of Fc components and in rigorously APC depleted, purified T cell preparations. Effective stimulation of resting T cells could be induced also by heterodimers of monovalent Fab fragments. Heterologous cross-linking of Lyt-2 to the TCR was superior to homologous TCR cross-linking primarily with respect to proliferation in IL-2 containing media and to IL-2R expression, whereas proliferation in response to other lymphokines and the production of IL-2 itself were similar under both cross-linking regimens. Thus, when linked to the TCR, Lyt-2 contributed a strong, positive signal toward IL-2-dependent growth of resting T cells. We assume that in the case of Ag-driven T cell activation, the class I MHC molecule acts as the physiologic cross-linking ligand for Lyt-2 and the TCR.     

Effects of environmental temperature on the population of T-cell subsets, the blastogenic responses of lymphocytes in blood and spleen and splenic NK cell activity in mice

The population of T-cell subsets, the blastogenic responses of lymphocytes in blood and spleen and splenic NK cell activity were examined in mice transferred from 22 degrees C to 12 degrees C or 32 degrees C environments. The percentage of Thy-1.2 positive cells and Lyt-1.2 positive cells in the spleen decreased after the transfer. However the percentage of Lyt-2.2 positive cells in the spleen was not affected. Thy-1.2 and Lyt-1.2 positive cells in the blood also decreased. The percentage of Lyt-2.2 positive cells in the blood was not affected in mice exposed to 12 degrees C. However, Lyt-2.2 positive cells in the blood decreased on day 1 but increased on day 3 in mice exposed to 32 degrees C. Blastogenic responses of spleen lymphocytes to concanavalin A (Con A) and pokeweed mitogen (PWM) were suppressed in transferred mice, but responses to lipopolysaccharide (LPS) and phytohemagglutinin-P (PHA-P) were not affected in any group. Blastogenic responses of blood lymphocytes to Con A, PHA-P, and PWM tended to be weaker in transferred mice than in mice kept in the 22 degrees C environment. In particular the response to PWM in mice exposed to 12 degrees C was less than 8% of that in the 22 degrees C mice. Splenic NK cell activity decreased in transferred mice, but was not suppressed as much as in mice administered 5mg of cortisone acetate.(ABSTRACT TRUNCATED AT 250 WORDS)